bims-cagime Biomed News
on Cancer, aging and metabolism
Issue of 2020‒05‒03
fifty-eight papers selected by
Kıvanç Görgülü
Technical University of Munich


  1. Sci Immunol. 2020 May 01. pii: eaaz9631. [Epub ahead of print]5(47):
    Boothby IC, Cohen JN, Rosenblum MD.
      Skin injury is a highly inflammatory process that is carefully regulated to mitigate tissue damage and allow for proper barrier repair. Regulatory T cells (Tregs) are crucial coordinators of the immune response to injury in several organs. Here, we review the emerging role of Tregs in facilitating skin repair after injury. We focus on recently discovered interactions between lymphocytes and nonhematopoietic cells during wound healing and discuss how these interactions are regulated both by "classical" suppressive mechanisms of Tregs and by "nonclassical" reparative Treg functions.
    DOI:  https://doi.org/10.1126/sciimmunol.aaz9631
  2. Nat Commun. 2020 May 01. 11(1): 2141
    Morikawa K, Furuhashi K, de Sena-Tomas C, Garcia-Garcia AL, Bekdash R, Klein AD, Gallerani N, Yamamoto HE, Park SE, Collins GS, Kawano F, Sato M, Lin CS, Targoff KL, Au E, Salling MC, Yazawa M.
      Optogenetic genome engineering tools enable spatiotemporal control of gene expression and provide new insight into biological function. Here, we report the new version of genetically encoded photoactivatable (PA) Cre recombinase, PA-Cre 3.0. To improve PA-Cre technology, we compare light-dimerization tools and optimize for mammalian expression using a CAG promoter, Magnets, and 2A self-cleaving peptide. To prevent background recombination caused by the high sequence similarity in the dimerization domains, we modify the codons for mouse gene targeting and viral production. Overall, these modifications significantly reduce dark leak activity and improve blue-light induction developing our new version, PA-Cre 3.0. As a resource, we have generated and validated AAV-PA-Cre 3.0 as well as two mouse lines that can conditionally express PA-Cre 3.0. Together these new tools will facilitate further biological and biomedical research.
    DOI:  https://doi.org/10.1038/s41467-020-16030-0
  3. Nat Rev Cancer. 2020 Apr 27.
    Castel P, Rauen KA, McCormick F.
      Human oncoproteins promote transformation of cells into tumours by dysregulating the signalling pathways that are involved in cell growth, proliferation and death. Although oncoproteins were discovered many years ago and have been widely studied in the context of cancer, the recent use of high-throughput sequencing techniques has led to the identification of cancer-associated mutations in other conditions, including many congenital disorders. These syndromes offer an opportunity to study oncoprotein signalling and its biology in the absence of additional driver or passenger mutations, as a result of their monogenic nature. Moreover, their expression in multiple tissue lineages provides insight into the biology of the proto-oncoprotein at the physiological level, in both transformed and unaffected tissues. Given the recent paradigm shift in regard to how oncoproteins promote transformation, we review the fundamentals of genetics, signalling and pathogenesis underlying oncoprotein duality.
    DOI:  https://doi.org/10.1038/s41568-020-0256-z
  4. Science. 2020 05 01. 368(6490): 497-505
    Karthaus WR, Hofree M, Choi D, Linton EL, Turkekul M, Bejnood A, Carver B, Gopalan A, Abida W, Laudone V, Biton M, Chaudhary O, Xu T, Masilionis I, Manova K, Mazutis L, Pe'er D, Regev A, Sawyers CL.
      Androgen deprivation is the cornerstone of prostate cancer treatment. It results in involution of the normal gland to ~90% of its original size because of the loss of luminal cells. The prostate regenerates when androgen is restored, a process postulated to involve stem cells. Using single-cell RNA sequencing, we identified a rare luminal population in the mouse prostate that expresses stemlike genes (Sca1 + and Psca +) and a large population of differentiated cells (Nkx3.1 +, Pbsn +). In organoids and in mice, both populations contribute equally to prostate regeneration, partly through androgen-driven expression of growth factors (Nrg2, Rspo3) by mesenchymal cells acting in a paracrine fashion on luminal cells. Analysis of human prostate tissue revealed similar differentiated and stemlike luminal subpopulations that likewise acquire enhanced regenerative potential after androgen ablation. We propose that prostate regeneration is driven by nearly all persisting luminal cells, not just by rare stem cells.
    DOI:  https://doi.org/10.1126/science.aay0267
  5. Mod Pathol. 2020 Apr 29.
    Hayashi A, Yavas A, McIntyre CA, Ho YJ, Erakky A, Wong W, Varghese AM, Melchor JP, Overholtzer M, O'Reilly EM, Klimstra DS, Basturk O, Iacobuzio-Donahue CA.
      Entosis is a type of regulated cell death that promotes cancer cell competition. Though several studies have revealed the molecular mechanisms that govern entosis, the clinical and genetic correlates of entosis in human tumors is less well understood. Here we reviewed entotic cell-in-cell (CIC) patterns in a large single institution sequencing cohort (MSK IMPACT clinical sequencing cohort) of more than 1600 human pancreatic ductal adenocarcinoma (PDAC) samples to identify the genetic and clinical correlates of this cellular feature. After case selection, 516 conventional PDACs and 21 ASCs entered this study and ~45,000 HPFs (median 80 HPFs per sample) were reviewed; 549 entotic-CICs were detected through our cohort. We observed that entotic-CIC occurred more frequently in liver metastasis compared with primary in PDAC. Moreover, poorly differentiated adenocarcinoma or adenosquamous carcinoma had more entotic-CIC than well or moderately differentiated adenocarcinoma. With respect to genetic features TP53 mutations, KRAS amplification, and MYC amplification were significantly associated with entosis in PDAC tissues. From a clinical standpoint entotic CICs were independently associated with a poor prognosis by multivariate Cox regression analysis when considering all cases or primary PDACs specifically. These results provide a contextual basis for understanding entosis in PDAC, a highly aggressive cancer for which molecular insights are needed to improve survival.
    DOI:  https://doi.org/10.1038/s41379-020-0549-5
  6. Cancer Discov. 2020 May 01.
      Beta-cell cholecystokinin expression in obese mice promoted pancreatic ductal adenocarcinoma (PDAC).
    DOI:  https://doi.org/10.1158/2159-8290.CD-RW2020-065
  7. Protein Cell. 2020 Apr 30.
    Zheng Q, Maksimovic I, Upad A, David Y.
      Epigenetic modifications, including those on DNA and histones, have been shown to regulate cellular metabolism by controlling expression of enzymes involved in the corresponding metabolic pathways. In turn, metabolic flux influences epigenetic regulation by affecting the biosynthetic balance of enzyme cofactors or donors for certain chromatin modifications. Recently, non-enzymatic covalent modifications (NECMs) by chemically reactive metabolites have been reported to manipulate chromatin architecture and gene transcription through multiple mechanisms. Here, we summarize these recent advances in the identification and characterization of NECMs on nucleic acids, histones, and transcription factors, providing an additional mechanistic link between metabolism and epigenetics.
    Keywords:  chromatin; epigenetics; human disease; metabolism; non-enzymatic modification
    DOI:  https://doi.org/10.1007/s13238-020-00722-w
  8. Sci Signal. 2020 Apr 28. pii: eaau1453. [Epub ahead of print]13(629):
    Temprine K, Campbell NR, Huang R, Langdon EM, Simon-Vermot T, Mehta K, Clapp A, Chipman M, White RM.
      The DNA polymerase Polκ plays a key role in translesion synthesis, an error-prone replication mechanism. Polκ is overexpressed in various tumor types. Here, we found that melanoma and lung and breast cancer cells experiencing stress from oncogene inhibition up-regulated the expression of Polκ and shifted its localization from the cytoplasm to the nucleus. This effect was phenocopied by inhibition of the kinase mTOR, by induction of ER stress, or by glucose deprivation. In unstressed cells, Polκ is continually transported out of the nucleus by exportin-1. Inhibiting exportin-1 or overexpressing Polκ increased the abundance of nuclear-localized Polκ, particularly in response to the BRAFV600E-targeted inhibitor vemurafenib, which decreased the cytotoxicity of the drug in BRAFV600E melanoma cells. These observations were analogous to how Escherichia coli encountering cell stress and nutrient deprivation can up-regulate and activate DinB/pol IV, the bacterial ortholog of Polκ, to induce mutagenesis that enables stress tolerance or escape. However, we found that the increased expression of Polκ was not excessively mutagenic, indicating that noncatalytic or other functions of Polκ could mediate its role in stress responses in mammalian cells. Repressing the expression or nuclear localization of Polκ might prevent drug resistance in some cancer cells.
    DOI:  https://doi.org/10.1126/scisignal.aau1453
  9. Cancer Discov. 2020 May 01.
      Autophagy-mediated MHC-I degradation facilitated immune evasion in pancreatic ductal adenocarcinoma.
    DOI:  https://doi.org/10.1158/2159-8290.CD-RW2020-063
  10. Cancer Discov. 2020 Apr 27. pii: CD-19-0959. [Epub ahead of print]
    Parker SJ, Amendola CR, Hollinshead KER, Yu Q, Yamamoto K, Encarnacion-Rosado J, Rose RE, LaRue MM, Sohn ASW, Biancur DE, Paulo JA, Gygi SP, Jones DR, Wang H, Philips MR, Bar-Sagi D, Mancias JD, Kimmelman AC.
      Pancreatic ductal adenocarcinoma (PDAC) evolves a complex microenvironment comprised of multiple cell types, including pancreatic stellate cells (PSCs). Previous studies have demonstrated that stromal supply of alanine, lipids, and nucleotides supports the metabolism, growth, and therapeutic resistance of PDAC. Here we demonstrate that alanine crosstalk between PSCs and PDAC is orchestrated by the utilization of specific transporters. PSCs utilize SLC1A4 and other transporter(s) to rapidly exchange and maintain environmental alanine concentrations. Moreover, PDAC cells upregulate SLC38A2 to supply their increased alanine demand. Cells lacking SLC38A2 fail to concentrate intracellular alanine and undergo a profound metabolic crisis resulting in markedly impaired tumor growth. Our results demonstrate that stromal-cancer metabolic niches can form through differential transporter expression, creating unique therapeutic opportunities to target metabolic demands of cancer.
    DOI:  https://doi.org/10.1158/2159-8290.CD-19-0959
  11. Genes Dev. 2020 Apr 30.
    Yamada S, Hinch AG, Kamido H, Zhang Y, Edelmann W, Keeney S.
      Exonucleolytic resection, critical to repair double-strand breaks (DSBs) by recombination, is not well understood, particularly in mammalian meiosis. Here, we define structures of resected DSBs in mouse spermatocytes genome-wide at nucleotide resolution. Resection tracts averaged 1100 nt, but with substantial fine-scale heterogeneity at individual hot spots. Surprisingly, EXO1 is not the major 5' → 3' exonuclease, but the DSB-responsive kinase ATM proved a key regulator of both initiation and extension of resection. In wild type, apparent intermolecular recombination intermediates clustered near to but offset from DSB positions, consistent with joint molecules with incompletely invaded 3' ends. Finally, we provide evidence for PRDM9-dependent chromatin remodeling leading to increased accessibility at recombination sites. Our findings give insight into the mechanisms of DSB processing and repair in meiotic chromatin.
    Keywords:  ATM; DNA double-strand breaks; EXO1; PRDM9; chromatin; meiosis; recombination; resection
    DOI:  https://doi.org/10.1101/gad.336032.119
  12. Front Physiol. 2020 ;11 326
    Bertholet AM, Kirichok Y.
      Mitochondria convert the chemical energy of metabolic substrates into adenosine triphosphate (ATP) and heat. Although ATP production has become a focal point of research in bioenergetics, mitochondrial thermogenesis is also crucial for energy metabolism. Mitochondria generate heat due to H+ leak across the inner mitochondrial membrane (IMM) which is mediated by mitochondrial uncoupling proteins. The mitochondrial H+ leak was first identified, and studied for many decades, using mitochondrial respiration technique. Unfortunately, this method measures H+ leak indirectly, and its precision is insufficient for the rigorous insight into the mitochondrial function at the molecular level. Direct patch-clamp recording of H+ leak would have a significantly higher amplitude and time resolution, but application of the patch-clamp technique to a small subcellular organelle such as mitochondria has been challenging. We developed a method that facilitates patch-clamp recording from the whole IMM, enabling the direct measurement of small H+ leak currents via uncoupling proteins and thus, providing a rigorous understanding of the molecular mechanisms involved. In this paper we cover the methodology of measuring the H+ leak in mitochondria of specialized thermogenic tissues brown and beige fat.
    Keywords:  H+ leak pathway; beige fat; brown fat; fatty acid; mitochondria; patch-clamp technique; thermogenesis; uncoupling
    DOI:  https://doi.org/10.3389/fphys.2020.00326
  13. Nat Commun. 2020 Apr 29. 11(1): 2082
    Vinckier NK, Patel NA, Geusz RJ, Wang A, Wang J, Matta I, Harrington AR, Wortham M, Wetton N, Wang J, Jhala US, Rosenfeld MG, Benner CW, Shih HP, Sander M.
      Developmental progression depends on temporally defined changes in gene expression mediated by transient exposure of lineage intermediates to signals in the progenitor niche. To determine whether cell-intrinsic epigenetic mechanisms contribute to signal-induced transcriptional responses, here we manipulate the signalling environment and activity of the histone demethylase LSD1 during differentiation of hESC-gut tube intermediates into pancreatic endocrine cells. We identify a transient requirement for LSD1 in endocrine cell differentiation spanning a short time-window early in pancreas development, a phenotype we reproduced in mice. Examination of enhancer and transcriptome landscapes revealed that LSD1 silences transiently active retinoic acid (RA)-induced enhancers and their target genes. Furthermore, prolonged RA exposure phenocopies LSD1 inhibition, suggesting that LSD1 regulates endocrine cell differentiation by limiting the duration of RA signalling. Our findings identify LSD1-mediated enhancer silencing as a cell-intrinsic epigenetic feedback mechanism by which the duration of the transcriptional response to a developmental signal is limited.
    DOI:  https://doi.org/10.1038/s41467-020-16017-x
  14. Cells. 2020 Apr 24. pii: E1063. [Epub ahead of print]9(4):
    Görgülü K, Diakopoulos KN, Kaya-Aksoy E, Ciecielski KJ, Ai J, Lesina M, Algül H.
      Pancreatic cancer is one of the deadliest cancer types urgently requiring effective therapeutic strategies. Autophagy occurs in several compartments of pancreatic cancer tissue including cancer cells, cancer associated fibroblasts, and immune cells where it can be subjected to a multitude of stimulatory and inhibitory signals fine-tuning its activity. Therefore, the effects of autophagy on pancreatic carcinogenesis and progression differ in a stage and context dependent manner. In the initiation stage autophagy hinders development of preneoplastic lesions; in the progression stage however, autophagy promotes tumor growth. This double-edged action of autophagy makes it a hard therapeutic target. Indeed, autophagy inhibitors have not yet shown survival improvements in clinical trials, indicating a need for better evaluation of existing results and smarter targeting techniques. Clearly, the role of autophagy in pancreatic cancer is complex and many aspects have to be considered when moving from the bench to the bedside.
    Keywords:  autophagy; pancreatic cancer; therapy; tumor microenvironment
    DOI:  https://doi.org/10.3390/cells9041063
  15. Cancer Discov. 2020 Apr 27. pii: CD-19-0597. [Epub ahead of print]
    Hou P, Kapoor A, Zhang Q, Li J, Wu CJ, Li J, Lan Z, Tang M, Ma X, Ackroyd JJ, Kalluri R, Zhang J, Jiang S, Spring DJ, Wang YA, DePinho RA.
      Oncogenic KRAS (KRAS*) is a key tumor maintenance gene in pancreatic ductal adenocarcinoma (PDAC), motivating pharmacological targeting of KRAS* and its effectors. Here, we explored mechanisms involving the tumor microenvironment (TME) as a potential basis for resistance to targeting KRAS*. Using the inducible KrasG12D p53 null (iKPC) PDAC mouse model, gain-of-function screens of epigenetic regulators identified HDAC5 as the top hit enabling KRAS* independent tumor growth. HDAC5-driven escaper tumors showed a prominent neutrophil-to-macrophage switch relative to KRAS*-driven tumors. Mechanistically, HDAC5 represses Socs3, a negative regulator of chemokine CCL2, resulting in increased CCL2 which recruits CCR2+ macrophages. Correspondingly, enforced Ccl2 promotes macrophage recruitment into the TME and enables tumor recurrence following KRAS* extinction. These tumor-associated macrophages (TAMs) in turn provide cancer cell with trophic support including TGFB to enable KRAS* bypass in a Smad4-dependent manner. Our work uncovers a KRAS* resistance mechanism involving immune cell remodeling of the PDAC TME.
    DOI:  https://doi.org/10.1158/2159-8290.CD-19-0597
  16. Nat Cell Biol. 2020 Apr 27.
    Htet ZM, Gillies JP, Baker RW, Leschziner AE, DeSantis ME, Reck-Peterson SL.
      Cytoplasmic dynein-1 is a molecular motor that drives nearly all minus-end-directed microtubule-based transport in human cells, performing functions that range from retrograde axonal transport to mitotic spindle assembly1,2. Activated dynein complexes consist of one or two dynein dimers, the dynactin complex and an 'activating adaptor', and they show faster velocity when two dynein dimers are present3-6. Little is known about the assembly process of this massive ~4 MDa complex. Here, using purified recombinant human proteins, we uncover a role for the dynein-binding protein LIS1 in promoting the formation of activated dynein-dynactin complexes that contain two dynein dimers. Complexes activated by proteins representing three families of activating adaptors-BicD2, Hook3 and Ninl-all show enhanced motile properties in the presence of LIS1. Activated dynein complexes do not require sustained LIS1 binding for fast velocity. Using cryo-electron microscopy, we show that human LIS1 binds to dynein at two sites on the motor domain of dynein. Our research suggests that LIS1 binding at these sites functions in multiple stages of assembling the motile dynein-dynactin-activating adaptor complex.
    DOI:  https://doi.org/10.1038/s41556-020-0506-z
  17. J Immunol. 2020 Apr 29. pii: ji1901133. [Epub ahead of print]
    Devlin JC, Zwack EE, Tang MS, Li Z, Fenyo D, Torres VJ, Ruggles KV, Loke P.
      Myeloid cells are a vital component of innate immunity and comprise monocytes, macrophages, dendritic cells, and granulocytes. How myeloid cell lineage affects activation states in response to cytokines remains poorly understood. The cytokine environment and cellular infiltrate during an inflammatory response may contain prognostic features that predict disease outcome. In this study, we analyzed the transcriptional responses of human monocytes, macrophages, dendritic cells, and neutrophils in response to stimulation by IFN-γ, IFN-β, IFN-λ, IL-4, IL-13, and IL-10 cytokines to better understand the heterogeneity of activation states in inflammatory conditions. This generated a myeloid cell-cytokine-specific response matrix that can infer representation of myeloid cells and the cytokine environment they encounter during infection, in tumors and in whole blood. Neutrophils were highly responsive to type 1 and type 2 cytokine stimulation but did not respond to IL-10. We identified transcripts specific to IFN-β stimulation, whereas other IFN signature genes were upregulated by both IFN-γ and IFN-β. When we used our matrix to deconvolute blood profiles from tuberculosis patients, the IFN-β-specific neutrophil signature was reduced in tuberculosis patients with active disease, whereas the shared response to IFN-γ and IFN-β in neutrophils was increased. When applied to glioma patients, transcripts of neutrophils exposed to IL-4/IL-13 and monocyte responses to IFN-γ or IFN-β emerged as opposing predictors of patient survival. Hence, by dissecting how different myeloid cells respond to cytokine activation, we can delineate biological roles for myeloid cells in different cytokine environments during disease processes, especially during infection and tumor progression.
    DOI:  https://doi.org/10.4049/jimmunol.1901133
  18. Mech Ageing Dev. 2020 Apr 25. pii: S0047-6374(20)30050-6. [Epub ahead of print] 111254
    Wei-Chieh M, Ohkubo R, Widjaja A, Chen D.
      Stem cell aging contributes to aging-associated tissue degeneration and dysfunction. Recent studies reveal a mitochondrial metabolic checkpoint that regulates stem cell quiescence and maintenance, and dysregulation of the checkpoint leads to functional deterioration of aged stem cells. Here, we present the evidence supporting the mitochondrial metabolic checkpoint regulating stem cell aging and demonstrating the feasibility to target this checkpoint to reverse stem cell aging. We discuss the mechanisms by which mitochondrial stress leads to stem cell deterioration. We speculate the therapeutic potential of targeting the mitochondrial metabolic checkpoint for rejuvenating aged stem cells and improving aging tissue functions.
    Keywords:  NLRP3; SIRT2; SIRT3; SIRT7; stem cell aging
    DOI:  https://doi.org/10.1016/j.mad.2020.111254
  19. Am J Pathol. 2020 Apr 24. pii: S0002-9440(20)30200-5. [Epub ahead of print]
    Ruggeri JM, Franco-Barraza J, Sohail A, Zhang Y, Long D, Pasca di Magliano M, Cukierman E, Fridman R, Crawford HC.
      Pancreatic ductal adenocarcinoma (PDA) and chronic pancreatitis (CP) are characterized by a dense collagen-rich desmoplastic reaction. Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase activated by collagens that can regulate cell proliferation, migration, adhesion, and remodeling of the extracellular matrix (ECM). To address the role of DDR1 in PDA, we crossed DDR1-null (DDR1-/-) mice into the KrasG12D/+; Trp53R172H/+; Ptf1aCre/+(KPC) model of metastatic PDA. We found that DDR1-/-; KPC mice progress to differentiated PDA, but resist progression to poorly-differentiated cancer, compared to KPC control mice. Strikingly, severe pancreatic atrophy accompanied tumor progression in DDR1-/-; KPC mice. To further explore the effects of DDR1 ablation, we crossed the DDR1-/- mice into the KrasG12D/+; Ptf1aCre/+(KC) neoplasia model and also subjected them to cerulein-induced experimental pancreatitis. Similar to KPC mice, tissue atrophy was a hallmark of both neoplasia and pancreatitis models in the absence of DDR1. Compared to controls, DDR1-/- models showed increased acinar cell drop-out and reduced proliferation with no difference in apoptotic cell death between control and DDR1-/- animals. In most models, organ atrophy was accompanied by increased fibrillar collagen deposition, suggesting a compensatory response in the absence of this collagen receptor. Overall, our data suggest that DDR1 regulates tissue homeostasis in the neoplastic and injured pancreas.
    DOI:  https://doi.org/10.1016/j.ajpath.2020.03.020
  20. J Natl Cancer Inst. 2020 Apr 29. pii: djaa060. [Epub ahead of print]
    Guida JL, Agurs-Collins T, Ahles TA, Campisi J, Dale W, Demark-Wahnefried W, Dietrich J, Fuldner R, Gallicchio L, Green PA, Hurria A, Janelsins MC, Jhappan C, Kirkland JL, Kohanski R, Longo V, Meydani S, Mohile S, Niedernhofer LJ, Nelson C, Perna F, Schadler K, Scott JM, Schrack JA, Tracy RP, van Deursen J, Ness KK.
      Up to 85% of adult cancer survivors and 99% of adult survivors of childhood cancer live with an accumulation of chronic conditions, frailty, and/or cognitive impairments resulting from cancer and its treatment. Thus, survivors often show an accelerated development of multiple geriatric syndromes and need therapeutic interventions. To advance progress in this area, the National Cancer Institute convened the second of two think tanks under the auspices of the Cancer and Accelerated Aging: Advancing Research for Healthy Survivors initiative. Experts assembled to share evidence of promising strategies to prevent, slow, or reverse the aging consequences of cancer and its treatment. The meeting identified research and resource needs, including geroscience-guided clinical trials; comprehensive assessments of functional, cognitive, and psychosocial vulnerabilities to assess and predict age-related outcomes; preclinical and clinical research to determine the optimal dosing for behavioral (e.g., diet, exercise) and pharmacologic (e.g., senolytic) therapies; healthcare delivery research to evaluate the efficacy of integrated cancer care delivery models; optimization of intervention implementation, delivery, and uptake; and patient/provider education on cancer and treatment-related late and long-term adverse effects. Addressing these needs will expand knowledge of aging-related consequences of cancer and cancer treatment and inform strategies to promote healthy aging of cancer survivors.
    DOI:  https://doi.org/10.1093/jnci/djaa060
  21. Proc Natl Acad Sci U S A. 2020 May 01. pii: 201922388. [Epub ahead of print]
    Li Y, Shan Y, Desai RV, Cox KH, Weinberger LS, Takahashi JS.
      Nongenetic cellular heterogeneity is associated with aging and disease. However, the origins of cell-to-cell variability are complex and the individual contributions of different factors to total phenotypic variance are still unclear. Here, we took advantage of clear phenotypic heterogeneity of circadian oscillations in clonal cell populations to investigate the underlying mechanisms of cell-to-cell variability. Using a fully automated tracking and analysis pipeline, we examined circadian period length in thousands of single cells and hundreds of clonal cell lines and found that longer circadian period is associated with increased intercellular heterogeneity. Based on our experimental results, we then estimated the contributions of heritable and nonheritable factors to this variation in circadian period length using a variance partitioning model. We found that nonheritable noise predominantly drives intercellular circadian period variation in clonal cell lines, thereby revealing a previously unrecognized link between circadian oscillations and intercellular heterogeneity. Moreover, administration of a noise-enhancing drug reversibly increased both period length and variance. These findings suggest that circadian period may be used as an indicator of cellular noise and drug screening for noise control.
    Keywords:  circadian oscillation; heterogeneity/variance; period; single-cell imaging; transcriptional noise
    DOI:  https://doi.org/10.1073/pnas.1922388117
  22. Cell Rep. 2020 Apr 28. pii: S2211-1247(20)30523-4. [Epub ahead of print]31(4): 107574
    Zhou Y, Shao N, Bessa de Castro R, Zhang P, Ma Y, Liu X, Huang F, Wang RF, Qin L.
      Comprehensive evaluation of single T cell functions such as cytokine secretion and cytolysis of target cells is greatly needed in adoptive cell therapy (ACT) but has never been fully fulfilled by current approaches. Herein, we develop a hierarchical loading microwell chip (HL-Chip) that aligns multiple cells and functionalized beads in a high-throughput microwell array with single-cell/bead precision based on size differences. We demonstrate the potential of the HL-Chip in evaluating single T cell functions by three applications: high-throughput longitudinal secretory profiling of single T cells, large-scale evaluation of cytolytic activity of single T cells, and integrated T cell-tumor cell interactions. The HL-Chip is a simple and robust technology that constructs arrays of defined cell/object combinations for multiple measurements and material retrieval.
    Keywords:  T cell function; adoptive cell therapy; cell-bead pairing; cell-cell interaction; cytokine detection; cytotoxicity; microfluidics; single cell
    DOI:  https://doi.org/10.1016/j.celrep.2020.107574
  23. Nat Rev Immunol. 2020 Apr 28.
    Petroni G, Formenti SC, Chen-Kiang S, Galluzzi L.
      Cell cycle proteins that are often dysregulated in malignant cells, such as cyclin-dependent kinase 4 (CDK4) and CDK6, have attracted considerable interest as potential targets for cancer therapy. In this context, multiple inhibitors of CDK4 and CDK6 have been developed, including three small molecules (palbociclib, abemaciclib and ribociclib) that are currently approved for the treatment of patients with breast cancer and are being extensively tested in individuals with other solid and haematological malignancies. Accumulating preclinical and clinical evidence indicates that the anticancer activity of CDK4/CDK6 inhibitors results not only from their ability to block the cell cycle in malignant cells but also from a range of immunostimulatory effects. In this Review, we discuss the ability of anticancer cell cycle inhibitors to modulate various immune functions in support of effective antitumour immunity.
    DOI:  https://doi.org/10.1038/s41577-020-0300-y
  24. Int Rev Cell Mol Biol. 2020 ;pii: S1937-6448(20)30047-2. [Epub ahead of print]352 xi-xv
    Spetz J, Galluzzi L.
      
    Keywords:  Apoptosis; Autophagy; Immunogenic cell death; Mitochondrial outer membrane permeabilization; Mitochondrial permeability transition; Necroptosis; Parthanatos; Pyroptosis
    DOI:  https://doi.org/10.1016/S1937-6448(20)30047-2
  25. Nat Cell Biol. 2020 Apr 27.
    Elshenawy MM, Kusakci E, Volz S, Baumbach J, Bullock SL, Yildiz A.
      Lissencephaly-1 (Lis1) is a key cofactor for dynein-mediated intracellular transport towards the minus-ends of microtubules. It remains unclear whether Lis1 serves as an inhibitor or an activator of mammalian dynein motility. Here we use single-molecule imaging and optical trapping to show that Lis1 does not directly alter the stepping and force production of individual dynein motors assembled with dynactin and a cargo adaptor. Instead, Lis1 promotes the formation of an active complex with dynactin. Lis1 also favours the recruitment of two dyneins to dynactin, resulting in increased velocity, higher force production and more effective competition against kinesin in a tug-of-war. Lis1 dissociates from motile complexes, indicating that its primary role is to orchestrate the assembly of the transport machinery. We propose that Lis1 binding releases dynein from its autoinhibited state, which provides a mechanistic explanation for why Lis1 is required for efficient transport of many dynein-associated cargos in cells.
    DOI:  https://doi.org/10.1038/s41556-020-0501-4
  26. iScience. 2020 Apr 11. pii: S2589-0042(20)30232-7. [Epub ahead of print]23(5): 101047
    Tian XJ, Zhou D, Fu H, Zhang R, Wang X, Huang S, Liu Y, Xing J.
      Tissue fibrosis compromises organ function and occurs as a potential long-term outcome in response to acute tissue injuries. Currently, lack of mechanistic understanding prevents effective prevention and treatment of the progression from acute injury to fibrosis. Here, we combined quantitative experimental studies with a mouse kidney injury model and a computational approach to determine how the physiological consequences are determined by the severity of ischemia injury and to identify how to manipulate Wnt signaling to accelerate repair of ischemic tissue damage while minimizing fibrosis. The study reveals that memory of prior injury contributes to fibrosis progression and ischemic preconditioning reduces the risk of death but increases the risk of fibrosis. Furthermore, we validated the prediction that sequential combination therapy of initial treatment with a Wnt agonist followed by treatment with a Wnt antagonist can reduce both the risk of death and fibrosis in response to acute injuries.
    Keywords:  Cellular Physiology; Mathematical Biosciences; Molecular Physiology; Pathophysiology; Physiology
    DOI:  https://doi.org/10.1016/j.isci.2020.101047
  27. Cell Metab. 2020 Apr 23. pii: S1550-4131(20)30183-2. [Epub ahead of print]
    Kulkarni AS, Gubbi S, Barzilai N.
      Biological aging involves an interplay of conserved and targetable molecular mechanisms, summarized as the hallmarks of aging. Metformin, a biguanide that combats age-related disorders and improves health span, is the first drug to be tested for its age-targeting effects in the large clinical trial-TAME (targeting aging by metformin). This review focuses on metformin's mechanisms in attenuating hallmarks of aging and their interconnectivity, by improving nutrient sensing, enhancing autophagy and intercellular communication, protecting against macromolecular damage, delaying stem cell aging, modulating mitochondrial function, regulating transcription, and lowering telomere attrition and senescence. These characteristics make metformin an attractive gerotherapeutic to translate to human trials.
    Keywords:  TAME; aging; aging hallmarks; health span; longevity; metabolism; metformin
    DOI:  https://doi.org/10.1016/j.cmet.2020.04.001
  28. Mod Pathol. 2020 May 01.
    Prall OWJ, Nastevski V, Xu H, McEvoy CRE, Vissers JHA, Byrne DJ, Takano E, Yerneni S, Ellis S, Green T, Mitchell CA, Murray WK, Scott CL, Grimmond SM, Hofmann O, Papenfuss A, Kee D, Fellowes A, Brown IS, Miller G, Kumarasinghe MP, Perren A, Nahm CB, Mittal A, Samra J, Ahadi M, Fox SB, Chou A, Gill AJ.
      There is now evidence that gene fusions activating the MAPK pathway are relatively common in pancreatic acinar cell carcinoma with potentially actionable BRAF or RET fusions being found in ~30%. We sought to investigate the incidence of RAF1 fusions in pancreatic malignancies with acinar cell differentiation. FISH testing for RAF1 was undertaken on 30 tumors comprising 25 'pure' acinar cell carcinomas, 2 mixed pancreatic acinar-neuroendocrine carcinomas, 1 mixed acinar cell-low grade neuroendocrine tumor and 2 pancreatoblastomas. RAF1 rearrangements were identified in 5 cases and confirmed by DNA and RNA sequencing to represent oncogenic fusions (GATM-RAF1, GOLGA4-RAF1, PDZRN3-RAF1, HERPUD1-RAF1 and TRIM33-RAF1) and to be mutually exclusive with BRAF and RET fusions, as well as KRAS mutations. Large genome-wide copy number changes were common and included 1q gain and/or 1p loss in all five RAF1 FISH-positive acinar cell carcinomas. RAF1 expression by immunohistochemistry was found in 3 of 5 (60%) of fusion-positive cases and no FISH-negative cases. Phospho-ERK1/2 expression was found in 4 of 5 RAF1-fusion-positive cases. Expression of both RAF1 and phospho-ERK1/2 was heterogeneous and often only detected at the tumor-stroma interface, thus limiting their clinical utility. We conclude that RAF1 gene rearrangements are relatively common in pancreatic acinar cell carcinomas (14.3% to 18.5% of cases) and can be effectively identified by FISH with follow up molecular testing. The combined results of several studies now indicate that BRAF, RET or RAF1 fusions occur in between one third and one-half of these tumors but are extremely rare in other pancreatic malignancies. As these fusions are potentially actionable with currently available therapies, a strong argument can be made to perform FISH or molecular testing on all pancreatic acinar cell carcinomas.
    DOI:  https://doi.org/10.1038/s41379-020-0545-9
  29. Proc Natl Acad Sci U S A. 2020 Apr 27. pii: 201919250. [Epub ahead of print]
    Nilsson A, Haanstra JR, Engqvist M, Gerding A, Bakker BM, Klingmüller U, Teusink B, Nielsen J.
      Many cancer cells consume glutamine at high rates; counterintuitively, they simultaneously excrete glutamate, the first intermediate in glutamine metabolism. Glutamine consumption has been linked to replenishment of tricarboxylic acid cycle (TCA) intermediates and synthesis of adenosine triphosphate (ATP), but the reason for glutamate excretion is unclear. Here, we dynamically profile the uptake and excretion fluxes of a liver cancer cell line (HepG2) and use genome-scale metabolic modeling for in-depth analysis. We find that up to 30% of the glutamine is metabolized in the cytosol, primarily for nucleotide synthesis, producing cytosolic glutamate. We hypothesize that excreting glutamate helps the cell to increase the nucleotide synthesis rate to sustain growth. Indeed, we show experimentally that partial inhibition of glutamate excretion reduces cell growth. Our integrative approach thus links glutamine addiction to glutamate excretion in cancer and points toward potential drug targets.
    Keywords:  flux-balance analysis; genome-scale modeling; metabolic engineering; systems biology
    DOI:  https://doi.org/10.1073/pnas.1919250117
  30. Methods Protoc. 2020 Apr 27. pii: E32. [Epub ahead of print]3(2):
    Sim JJ, Jeong KY.
      In this protocol, we introduced a method of measuring mitochondrial dysfunction to confirm the epithelial-mesenchymal transition (EMT) in pancreatic cancer cells under a hypoxic environment. There are many expertized and complicated methods to verify EMT. However, our methods have indicated that EMT can be identified by examining changes in reactive oxygen species (ROS) generation and membrane potential in mitochondria. To demonstrate whether the changes in the indicators of mitochondrial dysfunction are correlative to EMT, cell morphology, and expression of E-cadherin and N-cadherin were additionally observed. The results verified that a decrease in membrane potential and an increase in ROS in mitochondria were associated with EMT of pancreatic cancer cells. This protocol would be useful as a basis for providing an additional indicator for changes in the tumor microenvironment of pancreatic cancer cells relating to EMT under a hypoxic environment.
    Keywords:  ROS; epithelial–mesenchymal transition; hypoxia; membrane potential; mitochondria; pancreatic cancer cell
    DOI:  https://doi.org/10.3390/mps3020032
  31. Cancer Lett. 2020 Apr 25. pii: S0304-3835(20)30204-4. [Epub ahead of print]
    Shukla SK, Markov SD, Attri KS, Vernucci E, King RJ, Dasgupta A, Grandgenett PM, Hollingsworth MA, Singh PK, Yu F, Mehla K.
      Incidence of cachexia is highly prevalent in pancreatic ductal adenocarcinoma (PDAC); advanced disease stage directly correlates with decreased muscle and fat mass in PDAC patients. The pancreatic tumor microenvironment is central to the release of systemic factors that govern lipolysis, proteolysis, and muscle and fat degeneration leading to the cachectic phenotype in cancer patients. The current study explores the role of macrophages, a key immunosuppressive player in the pancreatic tumor microenvironment, in regulating cancer cachexia. We observed a negative correlation between CD163-positive macrophage infiltration and muscle-fiber cross sectional area in human PDAC patients. To investigate the role of macrophages in myodegeneration, we utilized conditioned media transplant assays and orthotopic models of PDAC-induced cachexia in immune-competent mice with and without macrophage depletion. We observed that macrophage-derived conditioned medium, in combination with tumor cell-conditioned medium, synergistically promoted muscle atrophy through STAT3 signaling. Furthermore, macrophage depletion attenuated systemic inflammation and muscle wasting in pancreatic tumor-bearing mice. Targeting macrophage-mediated STAT3 activation or macrophage-derived interleukin-1 alpha or interleukin-6 diminished myofiber atrophy. Taken together, the current study identified the critical association between macrophages and cachexia phenotype in pancreatic cancer.
    Keywords:  Cancer cachexia; IL-6; Macrophages; Pancreatic cancer; STAT3
    DOI:  https://doi.org/10.1016/j.canlet.2020.04.017
  32. Proc Natl Acad Sci U S A. 2020 Apr 28. pii: 202003620. [Epub ahead of print]
    Bag N, Ramezani M, Holowka DA, Baird BA.
      
    DOI:  https://doi.org/10.1073/pnas.2003620117
  33. Cells. 2020 Apr 25. pii: E1069. [Epub ahead of print]9(5):
    Frye K, Renda F, Fomicheva M, Zhu X, Gong L, Khodjakov A, Kaverina I.
      Here, we characterize spatial distribution of the Golgi complex in human cells. In contrast to the prevailing view that the Golgi compactly surrounds the centrosome throughout interphase, we observe characteristic differences in the morphology of Golgi ribbons and their association with the centrosome during various periods of the cell cycle. The compact Golgi complex is typical in G1; during S-phase, Golgi ribbons lose their association with the centrosome and extend along the nuclear envelope to largely encircle the nucleus in G2. Interestingly, pre-mitotic separation of duplicated centrosomes always occurs after dissociation from the Golgi. Shortly before the nuclear envelope breakdown, scattered Golgi ribbons reassociate with the separated centrosomes restoring two compact Golgi complexes. Transitions between the compact and distributed Golgi morphologies are microtubule-dependent. However, they occur even in the absence of centrosomes, which implies that Golgi reorganization is not driven by the centrosomal microtubule asters. Cells with different Golgi morphology exhibit distinct differences in the directional persistence and velocity of migration. These data suggest that changes in the radial distribution of the Golgi around the nucleus define the extent of cell polarization and regulate cell motility in a cell cycle-dependent manner.
    Keywords:  Golgi complex; cell motility; centrinone; centrosome separation; interphase; microtubules; prophase
    DOI:  https://doi.org/10.3390/cells9051069
  34. Nat Commun. 2020 Apr 29. 11(1): 2084
    Cang Z, Nie Q.
      Single-cell RNA sequencing (scRNA-seq) provides details for individual cells; however, crucial spatial information is often lost. We present SpaOTsc, a method relying on structured optimal transport to recover spatial properties of scRNA-seq data by utilizing spatial measurements of a relatively small number of genes. A spatial metric for individual cells in scRNA-seq data is first established based on a map connecting it with the spatial measurements. The cell-cell communications are then obtained by "optimally transporting" signal senders to target signal receivers in space. Using partial information decomposition, we next compute the intercellular gene-gene information flow to estimate the spatial regulations between genes across cells. Four datasets are employed for cross-validation of spatial gene expression prediction and comparison to known cell-cell communications. SpaOTsc has broader applications, both in integrating non-spatial single-cell measurements with spatial data, and directly in spatial single-cell transcriptomics data to reconstruct spatial cellular dynamics in tissues.
    DOI:  https://doi.org/10.1038/s41467-020-15968-5
  35. Nat Biomed Eng. 2020 Apr 27.
    von Erlach T, Saxton S, Shi Y, Minahan D, Reker D, Javid F, Lee YL, Schoellhammer C, Esfandiary T, Cleveland C, Booth L, Lin J, Levy H, Blackburn S, Hayward A, Langer R, Traverso G.
      Monolayers of cancer-derived cell lines are widely used in the modelling of the gastrointestinal (GI) absorption of drugs and in oral drug development. However, they do not generally predict drug absorption in vivo. Here, we report a robotically handled system that uses large porcine GI tissue explants that are functionally maintained for an extended period in culture for the high-throughput interrogation (several thousand samples per day) of whole segments of the GI tract. The automated culture system provided higher predictability of drug absorption in the human GI tract than a Caco-2 Transwell system (Spearman's correlation coefficients of 0.906 and 0.302, respectively). By using the culture system to analyse the intestinal absorption of 2,930 formulations of the peptide drug oxytocin, we discovered an absorption enhancer that resulted in a 11.3-fold increase in the oral bioavailability of oxytocin in pigs in the absence of cellular disruption of the intestinal tissue. The robotically handled whole-tissue culture system should help advance the development of oral drug formulations and might also be useful for drug screening applications.
    DOI:  https://doi.org/10.1038/s41551-020-0545-6
  36. Nat Cancer. 2020 Apr 21. 1-4
    Desai A, Warner J, Kuderer N, Thompson M, Painter C, Lyman G, Lopes G.
      Crowdsourcing efforts are currently underway to collect and analyze data from patients with cancer who are affected by the COVID-19 pandemic. These community-led initiatives will fill key knowledge gaps to tackle crucial clinical questions on the complexities of infection with the causative coronavirus SARS-Cov-2 in the large, heterogeneous group of vulnerable patients with cancer.
    Keywords:  Cancer; SARS-CoV-2; Scientific community
    DOI:  https://doi.org/10.1038/s43018-020-0065-z
  37. Mol Oncol. 2020 Apr 26.
    Yuan X, Tang Z, Du R, Yao Z, Cheung SH, Zhang X, Wei J, Zhao Y, Du Y, Liu Y, Hu X, Gong W, Liu Y, Gao Y, Huang Z, Cao Z, Wei M, Zhou C, Wang L, Rosen N, Smith PD, Luo L.
      The mutation of K-RAS represents one of the most frequent genetic alterations in cancer. Targeting of downstream effectors of RAS, including of MEK and ERK, has limited clinical success in cancer patients with K-RAS-mutations. The reduced sensitivity of K-RAS-mutated cells to certain MEK inhibitors is associated with the feedback phosphorylation of MEK by CRAF and with the reactivation of mitogen-activated protein kinase (MAPK) signaling. Here, we report that the RAF dimer inhibitors, lifirafenib (BGB-283) and Compound C, show a strong synergistic effect with MEK inhibitors (MEKi), including mirdametinib (PD-0325901) and selumetinib, in suppressing the proliferation of K-RAS-mutated non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) cell lines. This synergistic effect was not observed with the B-RAFV600E selective inhibitor, vemurafenib. Our mechanistic analysis revealed that RAF dimer inhibition suppresses RAF-dependent MEK reactivation and leads to the sustained inhibition of MAPK signaling in K-RAS-mutated cells. This synergistic effect was also observed in several K-RAS mutant mouse xenograft models. A pharmacodynamic analysis supported a role for the synergistic phospho-ERK blockade in enhancing the antitumor activity observed in the K-RAS mutant models. These findings support a vertical inhibition strategy in which RAF dimer and MEK inhibitors are combined to target K-RAS-mutated cancers, and has led to a Phase 1b/2 combination therapy study of lifirafenib and mirdametinib in solid tumor patients with K-RAS mutations and other MAPK pathway aberrations.
    Keywords:  MEK inhibitor; RAF dimer inhibitor; RAS mutated cancer; combination therapy; synergy
    DOI:  https://doi.org/10.1002/1878-0261.12698
  38. Int J Mol Sci. 2020 Apr 28. pii: E3100. [Epub ahead of print]21(9):
    Ghoneum A, Abdulfattah AY, Warren BO, Shu J, Said N.
      Reactive Oxygen Species or "ROS" encompass several molecules derived from oxygen that can oxidize other molecules and subsequently transition rapidly between species. The key roles of ROS in biological processes are cell signaling, biosynthetic processes, and host defense. In cancer cells, increased ROS production and oxidative stress are instigated by carcinogens, oncogenic mutations, and importantly, metabolic reprograming of the rapidly proliferating cancer cells. Increased ROS production activates myriad downstream survival pathways that further cancer progression and metastasis. In this review, we highlight the relation between ROS, the metabolic programing of cancer, and stromal and immune cells with emphasis on and the transcription machinery involved in redox homeostasis, metabolic programing and malignant phenotype. We also shed light on the therapeutic targeting of metabolic pathways generating ROS as we investigate: Orlistat, Biguandes, AICAR, 2 Deoxyglucose, CPI-613, and Etomoxir.
    Keywords:  HIF-1α; Nrf2; PGC-1α; ROS; metabolic targeting; metabolism; oxidative stress; redox systems
    DOI:  https://doi.org/10.3390/ijms21093100
  39. Cell Death Discov. 2020 ;6 29
    Lindenboim L, Zohar H, Worman HJ, Stein R.
      Apoptosis is characterized by the destruction of essential cell organelles, including the cell nucleus. The nuclear envelope (NE) separates the nuclear interior from the cytosol. During apoptosis, the apoptotic machinery, in particular caspases, increases NE permeability by cleaving its proteins, such as those of the nuclear pore complex (NPC) and the nuclear lamina. This in turns leads to passive diffusion of cytosolic apoptogenic proteins, such as caspases and nucleases, through NPCs into the nucleus and the subsequent breakdown of the NE and destruction of the nucleus. However, NE leakiness at early stages of the apoptotic process can also occur in a caspase-independent manner, where Bax, by a non-canonical action, promotes transient and repetitive localized generation and subsequent rupture of nuclear protein-filled nuclear bubbles. This NE rupture leads to discharge of apoptogenic nuclear proteins from the nucleus to the cytosol, a process that can contribute to the death process. Therefore, the NE may play a role as mediator of cell death at early stages of apoptosis. The NE can also serve as a platform for assembly of complexes that regulate the death process. Thus, the NE should be viewed as both a mediator of the cell death process and a target.
    Keywords:  Apoptosis; Proteases
    DOI:  https://doi.org/10.1038/s41420-020-0256-5
  40. Gut. 2020 Apr 29. pii: gutjnl-2020-320726. [Epub ahead of print]
    Luchini C, Brosens LAA, Wood LD, Chatterjee D, Shin JI, Sciammarella C, Fiadone G, Malleo G, Salvia R, Kryklyva V, Piredda ML, Cheng L, Lawlor RT, Adsay V, Scarpa A.
      OBJECTIVE: Recently, tumours with microsatellite instability (MSI)/defective DNA mismatch repair (dMMR) have gained considerable interest due to the success of immunotherapy in this molecular setting. Here, we aim to clarify clinical-pathological and/or molecular features of this tumour subgroup through a systematic review coupled with a comparative analysis with existing databases, also providing indications for a correct approach to the clinical identification of MSI/dMMR pancreatic ductal adenocarcinoma (PDAC).DESIGN: PubMed, SCOPUS and Embase were searched for studies reporting data on MSI/dMMR in PDAC up to 30 November 2019. Histological and molecular data of MSI/dMMR PDAC were compared with non-MSI/dMMR PDAC and with PDAC reference cohorts (including SEER database and The Cancer Genome Atlas Research Network - TCGA project).
    RESULTS: Overall, 34 studies with 8323 patients with PDAC were included in the systematic review. MSI/dMMR demonstrated a very low prevalence in PDAC (around 1%-2%). Compared with conventional PDAC, MSI/dMMR PDAC resulted strongly associated with medullary and mucinous/colloid histology (p<0.01) and with a KRAS/TP53 wild-type molecular background (p<0.01), with more common JAK genes mutations. Data on survival are still unclear.
    CONCLUSION: PDAC showing typical medullary or mucinous/colloid histology should be routinely examined for MSI/dMMR status using specific tests (immunohistochemistry, followed by MSI-PCR in cases with doubtful results). Next-generation sequencing (NGS) should be adopted either where there is limited tissue or as part of NGS tumour profiling in the context of precision oncology, acknowledging that conventional histology of PDAC may rarely harbour MSI/dMMR.
    Keywords:  immunotherapy; microsatellite instability; pancreatic cancer
    DOI:  https://doi.org/10.1136/gutjnl-2020-320726
  41. Nat Commun. 2020 May 01. 11(1): 2176
    Baumann D, Hägele T, Mochayedi J, Drebant J, Vent C, Blobner S, Noll JH, Nickel I, Schumacher C, Boos SL, Daniel AS, Wendler S, Volkmar M, Strobel O, Offringa R.
      Cancer types with lower mutational load and a non-permissive tumor microenvironment are intrinsically resistant to immune checkpoint blockade. While the combination of cytostatic drugs and immunostimulatory antibodies constitutes an attractive concept for overcoming this refractoriness, suppression of immune cell function by cytostatic drugs may limit therapeutic efficacy. Here we show that targeted inhibition of mitogen-activated protein kinase (MAPK) kinase (MEK) does not impair dendritic cell-mediated T cell priming and activation. Accordingly, combining MEK inhibitors (MEKi) with agonist antibodies (Abs) targeting the immunostimulatory CD40 receptor results in potent synergistic antitumor efficacy. Detailed analysis of the mechanism of action of MEKi shows that this drug exerts multiple pro-immunogenic effects, including the suppression of M2-type macrophages, myeloid derived suppressor cells and T-regulatory cells. The combination of MEK inhibition with agonist anti-CD40 Ab is therefore a promising therapeutic concept, especially for the treatment of mutant Kras-driven tumors such as pancreatic ductal adenocarcinoma.
    DOI:  https://doi.org/10.1038/s41467-020-15979-2
  42. Mol Oncol. 2020 Apr 26.
    Hedegger K, Algül H, Lesina M, Blutke A, Schmid RM, Schneider MR, Dahlhoff M.
      Pancreatic ductal adenocarcinoma (PDAC) will soon belong to the top three cancer killers. The only approved specific PDAC therapy targets the epidermal growth factor receptor (EGFR). Although EGFR is a crucial player in PDAC development, EGFR-based therapy is disappointing. In this study, we evaluated the role of the EGFR ligand betacellulin (BTC) in PDAC. The expression of BTC was investigated in human pancreatic cancer specimen. Then, we generated a BTC knockout mouse model by CRISPR/Cas9 technology and a BTC overexpression model. Both models were crossed with the Ptf1aCre/+ ;KRASG12D/+ (KC) mouse model (B-/- KC or BKC, respectively). In addition, EGFR, ERBB2, and ERBB4 were investigated by the pancreas-specific deletion of each receptor using the Cre-loxP system. Tumor initiation and progression were analyzed in all mouse lines and the underlying molecular biology of PDAC was investigated at different time points. BTC is expressed in human and murine PDAC. B-/- KC mice showed a decelerated PDAC progression, associated with decreased EGFR activation. BKC mice developed severe PDAC with a poor survival rate. The dramatically increased BTC-mediated tumor burden was EGFR-dependent, but also ERBB4 and ERBB2 were involved in PDAC development or progression, as depletion of EGFR, ERBB2 or ERBB4 significantly improved the survival rate of BTC-mediated PDAC. BTC increases PDAC tumor burden dramatically by enhanced RAS activation. EGFR-, ERBB2-, and ERBB4-signaling are involved in accelerated PDAC development mediated by BTC indicating that targeting the whole ERBB family, instead of a single receptor, is a promising strategy for the development of future PDAC therapies.
    Keywords:  BTC; EGFR; ERBB2; ERBB4; PDAC; mouse model
    DOI:  https://doi.org/10.1002/1878-0261.12699
  43. Pancreatology. 2020 Apr 20. pii: S1424-3903(20)30133-2. [Epub ahead of print]
    Ben Q, Sun Y, Liu J, Wang W, Zou D, Yuan Y.
      BACKGROUND: Nicotine, the major component of cigarette smoke, has been reported to promote pancreatic ductal adenocarcinoma (PDAC) growth and invasion. Deregulation of microRNA (miRNA) expression is found in many cancers, including PDAC. The effects of nicotine on miRNAs change in PDAC progression remain unknown.METHODS: The effects of cigarette smoking/nicotine exposure on PDAC cell lines and tissues were evaluated. Quantitative real-time PCR and in situ hybridization assays were used to determine miR-155-5p expression in human PDAC tissue and cell lines upon cigarette smoking/nicotine exposure. Bioinformatics, loss-of-function experiments, luciferase reporter assay were performed to validate Nedd4 family interacting protein 1 (NDFIP1) as a direct target of miR-155-5p. The potentials of systemic miR-155-5p inhibitor-based therapy in overcoming nicotine exposure were evaluated in tumor xenograft model.
    RESULTS: Nicotine promoted PDAC cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in a dose-response manner. MiR-155-5p was found to be highly expressed in PDAC cell lines and tissues upon cigarette smoking/nicotine exposure. Functional studies showed that miR-155-5p knockdown could override the enhancement of oncogenic activity due to nicotine exposure in vitro and in vivo by directly interacting with the 3' untranslated regions (UTRs) of NDFIP1.
    CONCLUSIONS: These data demonstrate that nicotine-regulated miR-155-5p/NDFIP1 promotes tumor progression and EMT of PDAC.
    Keywords:  NDFIP1; Nicotine; Pancreatic ductal adenocarcinoma; miR-155-5p
    DOI:  https://doi.org/10.1016/j.pan.2020.04.004
  44. Proc Natl Acad Sci U S A. 2020 May 01. pii: 202001387. [Epub ahead of print]
    Jedrychowski MP, Lu GZ, Szpyt J, Mariotti M, Garrity R, Paulo JA, Schweppe DK, Laznik-Bogoslavski D, Kazak L, Murphy MP, Gladyshev VN, Gygi SP, Chouchani ET, Spiegelman BM.
      Oxidation of cysteine thiols by physiological reactive oxygen species (ROS) initiates thermogenesis in brown and beige adipose tissues. Cellular selenocysteines, where sulfur is replaced with selenium, exhibit enhanced reactivity with ROS. Despite their critical roles in physiology, methods for broad and direct detection of proteogenic selenocysteines are limited. Here we developed a mass spectrometric method to interrogate incorporation of selenium into proteins. Unexpectedly, this approach revealed facultative incorporation of selenium as selenocysteine or selenomethionine into proteins that lack canonical encoding for selenocysteine. Selenium was selectively incorporated into regulatory sites on key metabolic proteins, including as selenocysteine-replacing cysteine at position 253 in uncoupling protein 1 (UCP1). This facultative utilization of selenium was initiated by increasing cellular levels of organic, but not inorganic, forms of selenium. Remarkably, dietary selenium supplementation elevated facultative incorporation into UCP1, elevated energy expenditure through thermogenic adipose tissue, and protected against obesity. Together, these findings reveal the existence of facultative protein selenation, which correlates with impacts on thermogenic adipocyte function and presumably other biological processes as well.
    Keywords:  ROS; brown adipose tissue; cysteine; selenocysteine
    DOI:  https://doi.org/10.1073/pnas.2001387117
  45. In Vivo. 2020 May-Jun;34(3):34(3): 1469-1474
    Tamagawa H, Aoyama T, Yamamoto N, Kamiya M, Murakawa M, Atsumi Y, Numata M, Kazama K, Hara K, Yukawa N, Rino Y, Masuda M, Morinaga S.
      BACKGROUND: Pancreatic cancer is a fatal disease with a poor prognosis. Pancreatic cancer is often unresectable at the time of diagnosis, so the analysis of risk factors in patients with indications for surgery is important. We investigated the impact of intraoperative blood loss (IBL) on survival and recurrence in patients with stage II/III pancreatic cancer after curative surgery.PATIENTS AND METHODS: This study included 76 patients who underwent curative surgery for stage II/III pancreatic cancer between 2007 and 2012. The risk factors for overall (OS) and recurrence-free (RFS) survival were identified.
    RESULTS: IBL of 1,000 ml was considered to be the optimal cut-off value for classification based on a receiver operating characteristic (ROC) curve analysis. The OS rates at 5 years after surgery in the groups with low and high IBL were 36.6% and 11.4%, respectively, which was a statistically significant difference (p=0.003). The RFS rates at 1 year after surgery were 49.8% and 24.6%, respectively, which was a significant difference (p=0.045). A multivariate analysis demonstrated that IBL was a significant independent risk factor for OS.
    CONCLUSION: IBL is an independent prognostic factor after curative resection of stage II/III pancreatic cancer. The reduction of bleeding during surgery is necessary to improve the results of pancreatic cancer surgery.
    Keywords:  Intraoperative blood loss; Pancreatic cancer; recurrence; survival
    DOI:  https://doi.org/10.21873/invivo.11931
  46. Nat Rev Mol Cell Biol. 2020 Apr 29.
    Levental I.
      
    DOI:  https://doi.org/10.1038/s41580-020-0252-x
  47. Cancers (Basel). 2020 Apr 24. pii: E1056. [Epub ahead of print]12(4):
    Sonoda Y, Sasaki Y, Gunji A, Shirai H, Araki T, Imamichi S, Onodera T, Rydén AM, Watanabe M, Itami J, Honda T, Ashizawa K, Nakao K, Masutani M.
      PolyADP-ribosylation is a post-translational modification of proteins, and poly(ADP-ribose) (PAR) polymerase (PARP) family proteins synthesize PAR using NAD as a substrate. Poly(ADP-ribose) glycohydrolase (PARG) functions as the main enzyme for the degradation of PAR. In this study, we investigated the effects of Parg deficiency on tumorigenesis and therapeutic efficacy of DNA damaging agents, using mouse ES cell-derived tumor models. To examine the effects of Parg deficiency on tumorigenesis, Parg+/+ and Parg-/- ES cells were subcutaneously injected into nude mice. The results showed that Parg deficiency delays early onset of tumorigenesis from ES cells. All the tumors were phenotypically similar to teratocarcinoma and microscopic findings indicated that differentiation spectrum was similar between the Parg genotypes. The augmented anti-tumor therapeutic effects of X-irradiation were observed under Parg deficiency. These results suggest that Parg deficiency suppresses early stages of tumorigenesis and that Parg inhibition, in combination with DNA damaging agents, may efficiently control tumor growth in particular types of germ cell tumors.
    Keywords:  ES cells; cancer; poly (ADP-ribose) glycohydrolase; poly (ADP-ribose) polymerase; radiosensitization
    DOI:  https://doi.org/10.3390/cancers12041056
  48. Cancer Discov. 2020 May 01.
      In recent years, genomic-based blood testing has been heralded as a promising tool for early detection in a wide range of cancers. At the American Association for Cancer Research Virtual Annual Meeting I, two research teams independently developing such blood tests reported compelling data on the specificity and sensitivity of their tests.
    DOI:  https://doi.org/10.1158/2159-8290.CD-NB2020-041
  49. J Biol Chem. 2020 May 01. pii: jbc.RA119.011748. [Epub ahead of print]
    Khan MA, Srivastava SK, Zubair H, Patel GK, Arora S, Khushman M, Carter JE, Gorman GS, Singh S, Singh AP.
      Pancreatic cancer (PC) remains a therapeutic challenge because of its intrinsic and extrinsic chemoresistance mechanisms. Here, we report that C-X-C motif chemokine receptor 4 (CXCR4) and hedgehog pathways cooperate in PC chemoresistance via bi-directional tumor-stromal crosstalk. We show that when PC cells are co-cultured with pancreatic stellate cells (PSCs) they are significantly more resistant to gemcitabine toxicity than those grown in monoculture. We also demonstrate that this co-culture-induced chemoresistance is abrogated by inhibition of the CXCR4 and hedgehog pathways. Similarly, the co-culture-induced altered expression of genes in PC cells associated with gemcitabine metabolism, antioxidant defense, and cancer stemness is also reversed upon CXCR4 and hedgehog inhibition. We have confirmed the functional impact of these genetic alterations by measuring gemcitabine metabolites, reactive oxygen species production, and sphere formation in vehicle- or gemcitabine-treated mono- and co-cultured PC cells. Treatment of orthotopic pancreatic tumor-bearing mice with gemcitabine alone or in combination with a CXCR4 antagonist (AMD3100) or hedgehog inhibitor (GDC-0449) display reduced tumor growth. Notably, we show that the triple combination treatment is the most effective resulting in nearly complete suppression of tumor growth. Immuno-histochemical analysis of Ki67 and cleaved caspase-3 confirm these findings from in vivo imaging and tumor measurements. Our findings provide preclinical and mechanistic evidence that a combination of gemcitabine treatment with targeted inhibition of both the CXCR4 and hedgehog pathways improves outcomes in a PC mouse model.
    Keywords:  C-X-C chemokine receptor type 4 (CXCR-4); cancer stemness; chemoresistance; chemotherapy; pancreatic cancer; pancreatic stellate cell (PSC); paracrine signaling; sonic hedgehog (SHH); stromal cell
    DOI:  https://doi.org/10.1074/jbc.RA119.011748
  50. Sci Rep. 2020 Apr 30. 10(1): 7315
    Yu S, Wu Y, Li C, Qu Z, Lou G, Guo X, Ji J, Li N, Guo M, Zhang M, Lei L, Tai S.
      SLC16A family members play crucial roles in tumorigenesis and tumor progression. However, the exact role of distinct members in the SLC16A family in human pancreatic cancer remains unclear. Integrated bioinformatics analysis for the identification of therapeutic targets for certain cancers based on transcriptomics, proteomics and high-throughput sequencing could help us obtain novel information and understand potential underlying molecular mechanisms. In the present study, we investigated SLC16A family members in pancreatic cancer through accumulated data from GEO (Gene Expression Omnibus), TCGA (The Cancer Genome Atlas) and other available databases. The expression profile, clinical application significance and prognostic value of the SLC16A family for patients with pancreatic cancer were explored. SLC16A1, SLC16A3 and SLC16A13 exhibited biomarker potential for prognosis, and we further identified their related genes and regulatory networks, revealing core molecular pathways that require further investigation for pancreatic cancer.
    DOI:  https://doi.org/10.1038/s41598-020-64356-y