bims-cagime Biomed News
on Cancer, aging and metabolism
Issue of 2021‒12‒19
forty-one papers selected by
Kıvanç Görgülü
Technical University of Munich

  1. Cancer Res. 2021 Dec 13. pii: canres.3209.2020. [Epub ahead of print]
      The mortality of patients with pancreatic ductal adenocarcinoma (PDAC) is strongly associated with metastasis, a multi-step process that is incompletely understood in this disease. Although genetic drivers of PDAC metastasis have not been defined, transcriptional and epigenetic rewiring can contribute to the metastatic process. The epigenetic eraser histone deacetylase 2 (HDAC2) has been connected to less differentiated PDAC, but the function of HDAC2 in PDAC has not been comprehensively evaluated. Using genetically defined models, we show that HDAC2 is a cellular fitness factor that controls cell cycle in vitro and metastasis in vivo, particularly in undifferentiated, mesenchymal PDAC cells. Unbiased expression profiling detected a core set of HDAC2-regulated genes. HDAC2 controlled expression of several pro-survival receptor tyrosine kinases connected to mesenchymal PDAC, including PDGFRα, PDGFRβ, and EGFR. The HDAC2-maintained program disabled the tumor-suppressive arm of the TGFβ-pathway, explaining impaired metastasis formation of HDAC2-deficient PDAC. This data identifies HDAC2 as a tractable player in the PDAC metastatic cascade. The complexity of the function of epigenetic regulators like HDAC2 implicates that an increased understanding of these proteins is needed for implementation of effective epigenetic therapies.
  2. J Cell Biol. 2022 Jan 03. pii: e202112049. [Epub ahead of print]221(1):
      Rushika M. Perera studies how pancreatic cancer cells use autophagy and the lysosome to adapt to stress.
  3. JPEN J Parenter Enteral Nutr. 2021 Nov;45(S2): 16-25
      Cancer cachexia, or progressive weight loss, often despite adequate nutrition contributes greatly to cancer morbidity and mortality. Cachexia is metabolically distinct from starvation or protein malnutrition, although many patients with cancer and cachexia exhibit lowered appetite and food consumption. Tumors affect neural mechanisms that regulate appetite and energy expenditure, while promoting wasting of peripheral tissues via catabolism of cardiac and skeletal muscle, adipose, and bone. These multimodal actions of tumors on the host suggest a need for multimodal interventions. However, multiple recent consensus guidelines for management of cancer cachexia differ in treatment recommendations, highlighting the lack of effective, available therapies. Challenges to defining appropriate nutrition or other interventions for cancer cachexia include lack of consensus on definitions, low strength of evidence from clinical trials, and a scarcity of robust, rigorous, and mechanistic studies. However, efforts to diagnose, stage, and monitor cachexia are increasing along with clinical trial activity. Furthermore, preclinical models for cancer cachexia are growing more sophisticated, encompassing a greater number of tumor types in organ-appropriate contexts and for metastatic disease to model the clinical condition more accurately. It is expected that continued growth, investment, and coordination of research in this topic will ultimately yield robust biomarkers, clinically useful classification and staging algorithms, targetable pathways, pivotal clinical trials, and ultimately, cures. Here, we provide an overview of the clinical and scientific knowledge and its limitations around cancer cachexia.
    Keywords:  animal models; anorexia; appetite; cachexia; cancer; malnutrition; nutrition
  4. Nat Commun. 2021 Dec 17. 12(1): 7336
      Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy with a complex microenvironment. Dichotomous tumour-promoting and -restrictive roles have been ascribed to the tumour microenvironment, however the effects of individual stromal subsets remain incompletely characterised. Here, we describe how heterocellular Oncostatin M (OSM) - Oncostatin M Receptor (OSMR) signalling reprograms fibroblasts, regulates tumour growth and metastasis. Macrophage-secreted OSM stimulates inflammatory gene expression in cancer-associated fibroblasts (CAFs), which in turn induce a pro-tumourigenic environment and engage tumour cell survival and migratory signalling pathways. Tumour cells implanted in Osm-deficient (Osm-/-) mice display an epithelial-dominated morphology, reduced tumour growth and do not metastasise. Moreover, the tumour microenvironment of Osm-/- animals exhibit increased abundance of α smooth muscle actin positive myofibroblasts and a shift in myeloid and T cell phenotypes, consistent with a more immunogenic environment. Taken together, these data demonstrate how OSM-OSMR signalling coordinates heterocellular interactions to drive a pro-tumourigenic environment in PDA.
  5. Biochim Biophys Acta Rev Cancer. 2021 Dec 13. pii: S0304-419X(21)00167-0. [Epub ahead of print] 188669
      Pancreatic cancer (PC) is the deadliest of the neoplastic epithelial malignancies and is projected to be the second leading cause of cancer-related mortality by 2024. Five years overall survival being ~10%, mortality and incidence rates are disturbing. Acinar to ductal cell metaplasia (ADM) encompasses cellular reprogramming and phenotypic switch-over, making it a cardinal event in tumor initiation. Differential cues and varied regulatory factors drive synchronous functions of metaplastic cell populations leading to multiple cell fates and physiological outcomes. ADM is a precursor for developing early pre-neoplastic lesions further progressing into PC due to oncogenic signaling. Hence delineating molecular events guiding tumor initiation may provide regenerative medicine and precision onco-medicine. Therefore, understanding PC pathogenesis and early diagnosis are crucial. We hereby provide a timely overview of the current progress in this direction and future perspectives we foresee unfolding in the best interest of patient well-being and better clinical management of PC.
    Keywords:  Acinar-ductal metaplasia; PDAC; Pancreatic cancer initiation; Preneoplastic pancreatic lesions; Trans-differentiation
  6. Proc Natl Acad Sci U S A. 2021 Dec 21. pii: e2114126118. [Epub ahead of print]118(51):
      KRAS is mutated in 90% of human pancreatic ductal adenocarcinomas (PDACs). To function, KRAS must localize to the plasma membrane (PM) via a C-terminal membrane anchor that specifically engages phosphatidylserine (PtdSer). This anchor-binding specificity renders KRAS-PM localization and signaling capacity critically dependent on PM PtdSer content. We now show that the PtdSer lipid transport proteins, ORP5 and ORP8, which are essential for maintaining PM PtdSer levels and hence KRAS PM localization, are required for KRAS oncogenesis. Knockdown of either protein, separately or simultaneously, abrogated growth of KRAS-mutant but not KRAS-wild-type pancreatic cancer cell xenografts. ORP5 or ORP8 knockout also abrogated tumor growth in an immune-competent orthotopic pancreatic cancer mouse model. Analysis of human datasets revealed that all components of this PtdSer transport mechanism, including the PM-localized EFR3A-PI4KIIIα complex that generates phosphatidylinositol-4-phosphate (PI4P), and endoplasmic reticulum (ER)-localized SAC1 phosphatase that hydrolyzes counter transported PI4P, are significantly up-regulated in pancreatic tumors compared to normal tissue. Taken together, these results support targeting PI4KIIIα in KRAS-mutant cancers to deplete the PM-to-ER PI4P gradient, reducing PM PtdSer content. We therefore repurposed the US Food and Drug Administration-approved hepatitis C antiviral agent, simeprevir, as a PI4KIIIα inhibitor In a PDAC setting. Simeprevir potently mislocalized KRAS from the PM, reduced the clonogenic potential of pancreatic cancer cell lines in vitro, and abrogated the growth of KRAS-dependent tumors in vivo with enhanced efficacy when combined with MAPK and PI3K inhibitors. We conclude that the cellular ER-to-PM PtdSer transport mechanism is essential for KRAS PM localization and oncogenesis and is accessible to therapeutic intervention.
    Keywords:  KRAS; ORP5; ORP8; PI4KA; phosphatidylserine
  7. Nat Aging. 2021 Aug;1(8): 634-650
      Autophagy is a fundamental cellular process that eliminates molecules and subcellular elements, including nucleic acids, proteins, lipids and organelles, via lysosome-mediated degradation to promote homeostasis, differentiation, development and survival. While autophagy is intimately linked to health, the intricate relationship among autophagy, aging and disease remains unclear. This Review examines several emerging features of autophagy and postulates how they may be linked to aging as well as to the development and progression of disease. In addition, we discuss current preclinical evidence arguing for the use of autophagy modulators as suppressors of age-related pathologies such as neurodegenerative diseases. Finally, we highlight key questions and propose novel research avenues that will likely reveal new links between autophagy and the hallmarks of aging. Understanding the precise interplay between autophagy and the risk of age-related pathologies across organisms will eventually facilitate the development of clinical applications that promote long-term health.
  8. Nature. 2021 Dec 15.
      The state and behaviour of a cell can be influenced by both genetic and environmental factors. In particular, tumour progression is determined by underlying genetic aberrations1-4 as well as the makeup of the tumour microenvironment5,6. Quantifying the contributions of these factors requires new technologies that can accurately measure the spatial location of genomic sequence together with phenotypic readouts. Here we developed slide-DNA-seq, a method for capturing spatially resolved DNA sequences from intact tissue sections. We demonstrate that this method accurately preserves local tumour architecture and enables the de novo discovery of distinct tumour clones and their copy number alterations. We then apply slide-DNA-seq to a mouse model of metastasis and a primary human cancer, revealing that clonal populations are confined to distinct spatial regions. Moreover, through integration with spatial transcriptomics, we uncover distinct sets of genes that are associated with clone-specific genetic aberrations, the local tumour microenvironment, or both. Together, this multi-modal spatial genomics approach provides a versatile platform for quantifying how cell-intrinsic and cell-extrinsic factors contribute to gene expression, protein abundance and other cellular phenotypes.
  9. Cell Rep. 2021 Dec 14. pii: S2211-1247(21)01631-4. [Epub ahead of print]37(11): 110135
      Two studies by Lodestijn et al. in Cell Stem Cell and Cell Reports reveal a lack of stem cell hierarchies in acinar cell-derived tissue renewal and host instructed clonogenic growth of pancreatic cancer, thereby elucidating determinants of pancreas regeneration and cancer.
  10. Clin Cancer Res. 2021 Dec 14. pii: clincanres.1798.2021. [Epub ahead of print]
      PURPOSE: Advances in our understanding of the contribution of aberrant glycosylation to the pro-oncogenic signaling and metastasis of tumor cells has reinvigorated the development of mucin-targeted therapies. Here, we validate the tumor-targeting ability of a novel monoclonal antibody, AR9.6, that binds MUC16 and abrogates downstream oncogenic signaling to confer a therapeutic response.EXPERIMENTAL DESIGN: The in vitro and ex vivo validation of the binding of AR9.6 to MUC16 was achieved via flow cytometry, radioligand binding assay (RBA), and immunohistochemistry (IHC). The in vivo MUC16-targeting of AR9.6 was validated by creating an 89Zr-labeled radioimmunoconjugate of the mAb and utilizing immunoPET and ex vivo biodistribution studies in xenograft models of human ovarian and pancreatic cancer.
    RESULTS: Flow cytometry, RBA, and IHC revealed that AR9.6 binds to ovarian and pancreatic cancer cells in a MUC16-dependent manner. The in vivo radiopharmacologic profile of [89Zr]Zr-DFO-muAR9.6 in mice bearing ovarian and pancreatic cancer xenografts confirmed the MUC16-dependent tumor targeting by the radioimmunoconjugate. Radioactivity uptake was also observed in the distant lymph nodes (LN) of mice bearing xenografts with high levels of MUC16 expression. IHC analyses of these PET-positive LNs highlighted the presence of shed antigen as well as necrotic, phagocytized, and actively infiltrating neoplastic cells. The humanization of AR9.6 did not compromise its ability to target MUC16-expressing tumors.
    CONCLUSION: The unique therapeutic mechanism of AR9.6 combined with its excellent in vivo tumor targeting make it a highly promising theranostic agent. huAR9.6 is poised for clinical translation to impact the management of metastatic ovarian and pancreatic cancers.
  11. Cancer Res. 2021 Dec 17. pii: canres.1443.2021. [Epub ahead of print]
      The aggressive nature of pancreatic ductal adenocarcinoma (PDAC) mandates the development of improved therapies. Since KRAS mutations are found in 95% of PDAC and are critical for tumor maintenance, one promising strategy involves exploiting KRAS-dependent metabolic perturbations. The macrometabolic process of autophagy is upregulated in KRAS-mutant PDAC, and PDAC growth is reliant on autophagy. However, inhibition of autophagy as monotherapy using the lysosomal inhibitor hydroxychloroquine (HCQ) has shown limited clinical efficacy. To identify strategies that can improve PDAC sensitivity to HCQ, we applied a CRISPR-Cas9 loss-of-function screen and found that a top sensitizer was the receptor tyrosine kinase (RTK) insulin-like growth factor 1 receptor (IGF1R). Additionally, RPPA pathway activation mapping profiled the signaling pathways altered by CQ treatment. Activating phosphorylation of RTKs, including IGF1R, were common compensatory increases in response to CQ. Inhibition of IGF1R increased autophagic flux and sensitivity to CQ-mediated growth suppression both in vitro and in vivo. Co-targeting both IGF1R and pathways that antagonize autophagy, such as ERK-MAPK axis, was strongly synergistic. IGF1R and ERK inhibition converged on suppression of glycolysis, leading to enhanced dependence on autophagy. Accordingly, concurrent inhibition of IGF1R, ERK, and autophagy induced cytotoxicity in PDAC cell lines, and decreased viability in human PDAC organoids. In conclusion, targeting IGF1R together with ERK enhances the effectiveness of autophagy inhibitors in PDAC.
  12. J Appl Physiol (1985). 2021 Dec 16.
      Growth differentiating factor-15 (GDF15) is expressed, and secreted, from a wide range of tissues and serves as a marker of cellular stress. A key transcriptional regulator of this hormone is the endoplasmic reticulum stress protein, CHOP (C/EBP Homologous Protein). Exercise increases GDF15 levels but the underlying mechanisms of this are not known. To test whether CHOP regulates GDF15 during exercise we used various models of altered ER stress. We examined the effects of acute exercise on circulating GDF15 and GDF15 mRNA expression in liver, triceps skeletal muscle, and epididymal white adipose tissue and examined the GDF15 response to acute exercise in lean and high-fat diet-induced obese mice, sedentary and exercise trained mice, and CHOP deficient mice. We found that obesity augments exercise-induced circulating GDF15 although ER stress markers were similar in lean and obese mice. Exercise-induced GDF15 was increased in trained and sedentary mice that ran at the same relative exercise intensity, despite trained mice being protected against increased markers of ER stress. Finally, exercise-induced increases in GDF15 at the tissue and whole-body level were intact in CHOP deficient mice. Together, these results provide evidence that exercise-induced GDF15 expression and secretion occurs independent of ER stress/CHOP.
    Keywords:  CHOP; ER Stress; Exercise; GDF15; Obesity
  13. J Cell Sci. 2021 Dec 15. pii: jcs258944. [Epub ahead of print]134(24):
      The dynamic nature of mitochondria, which can fuse, divide and move throughout the cell, allows these critical organelles to adapt their function in response to cellular demands, and is also important for regulating mitochondrial DNA (mtDNA). While it is established that impairments in mitochondrial fusion and fission impact the mitochondrial genome and can lead to mtDNA depletion, abnormal nucleoid organization or accumulation of deletions, it is not entirely clear how or why remodeling mitochondrial network morphology affects mtDNA. Here, we focus on recent advances in our understanding of how mitochondrial dynamics contribute to the regulation of mtDNA and discuss links to human disease.
    Keywords:  Fission; Fusion; Mitochondria; Mitochondrial dynamics; Mitophagy; mtDNA
  14. Elife. 2021 Dec 13. pii: e69729. [Epub ahead of print]10
      Increased protein synthesis supports the rapid cell proliferation associated with cancer. The Rpl24Bst mutant mouse reduces the expression of the ribosomal protein RPL24 and has been used to suppress translation and limit tumorigenesis in multiple mouse models of cancer. Here, we show that Rpl24Bst also suppresses tumorigenesis and proliferation in a model of colorectal cancer (CRC) with two common patient mutations, Apc and Kras. In contrast to previous reports, Rpl24Bst mutation has no effect on ribosomal subunit abundance but suppresses translation elongation through phosphorylation of eEF2, reducing protein synthesis by 40% in tumour cells. Ablating eEF2 phosphorylation in Rpl24Bst mutant mice by inactivating its kinase, eEF2K, completely restores the rates of elongation and protein synthesis. Furthermore, eEF2K activity is required for the Rpl24Bst mutant to suppress tumorigenesis. This work demonstrates that elevation of eEF2 phosphorylation is an effective means to suppress colorectal tumorigenesis with two driver mutations. This positions translation elongation as a therapeutic target in CRC, as well as in other cancers where the Rpl24Bst mutation has a tumour suppressive effect in mouse models.
    Keywords:  RPL24; cancer biology; cell biology; eEF2K; in vivo models; intestinal cancer; mouse; protein sythesis; translation
  15. JCI Insight. 2021 Dec 16. pii: e150330. [Epub ahead of print]
      Pancreatic ductal adenocarcinoma (PDA) is an extremely metastatic and lethal disease. Here in both murine and human PDA we demonstrate that extracellular matrix architecture regulates cell extrusion and subsequent invasion from intact ductal structures through Tumor-Associated Collagen Signatures (TACS). This results in early dissemination from histologically pre-malignant lesions and continual invasion from well-differentiated disease, and suggests TACS as a biomarker to aid in the pathologic assessment of early disease. Furthermore, we show that pancreatitis results in invasion-conducive architectures, thus priming the stroma prior to malignant disease. Analysis in novel microfluidics-derived microtissues and in vivo demonstrates decreased extrusion and invasion following focal adhesion kinase (FAK) inhibition, consistent with decreased metastasis. Thus, data suggest that targeting FAK or strategies to re-engineer and normalize tumor microenvironments, may have a role not only in also in very early disease but also for limiting continued dissemination from unresectable disease. Likewise, it may be beneficial to employ stroma targeting strategies to resolve precursor diseases such as pancreatitis in order to remove stromal architectures that increase risk for early dissemination.
    Keywords:  Cancer; Cell Biology; Cell migration/adhesion; Diagnostic imaging; Oncology
  16. FEBS J. 2021 May 02.
      Autophagy is an essential intracellular process for cellular quality control. It enables cell homeostasis through the selective degradation of harmful protein aggregates and damaged organelles. Autophagy is essential for recycling nutrients, generating energy to maintain cell viability in most tissues and during adverse conditions such as hypoxia/ischaemia. The progressive understanding of the mechanisms modulating autophagy in the vasculature has recently led numerous studies to link intact autophagic responses with endothelial cell (EC) homeostasis and function. Preserved autophagic flux within the ECs has an essential role in maintaining their physiological characteristics, whereas defective autophagy can promote endothelial pro-inflammatory and atherogenic phenotype. However, we still lack a good knowledge of the complete molecular repertoire controlling various aspects of endothelial autophagy and how this is associated with vascular diseases. Here, we provide an overview of the current state of the art of autophagy in ECs. We review the discoveries that have so far defined autophagy as an essential mechanism in vascular biology and analyse how autophagy influences ECs behaviour in vascular disease. Finally, we emphasise opportunities for compounds to regulate autophagy in ECs and discuss the challenges of exploiting them to resolve vascular disease.
    Keywords:  autophagy; endothelial cells; inflammation; senescence; therapeutic modulation; vascular disease
  17. Oncogene. 2021 Dec 14.
      The tumor suppressive transcription factor p53 is frequently inactivated in cancer cells by missense mutations that cluster in the DNA binding domain. 30% hit mutational hotspot residues, resulting in a complete loss of transcriptional activity and mutant p53-driven chemotherapy resistance. Of the remaining 70% of non-hotspot mutants, many are partial loss-of-function (partial-LOF) mutants with residual transcriptional activity. The therapeutic consequences of a partial-LOF have remained largely elusive. Using a p53 mutation engineered to reduce DNA binding, we demonstrate that partial-LOF is sufficient to enhance oncogene-driven tumorigenesis in mouse models of lung and pancreatic ductal adenocarcinoma and acute myeloid leukemia. Interestingly, mouse and human tumors with partial-LOF mutations showed mutant p53 protein accumulation similar as known for hotspot mutants. Different from the chemotherapy resistance caused by p53-loss, the partial-LOF mutant sensitized to an apoptotic chemotherapy response and led to a survival benefit. Mechanistically, the pro-apoptotic transcriptional activity of mouse and human partial-LOF mutants was rescued at high mutant protein levels, suggesting that accumulation of partial-LOF mutants enables the observed apoptotic chemotherapy response. p53 non-hotspot mutants with partial-LOF, therefore, represent tumorigenic p53 mutations that need to be distinguished from other mutations because of their beneficial impact on survival in a therapy context.
  18. Trends Cell Biol. 2021 Dec 09. pii: S0962-8924(21)00230-0. [Epub ahead of print]
      Creatine is a nitrogen-containing organic acid naturally existing in mammals. It can be converted into phosphocreatine to provide energy for muscle and nerve tissues. Creatine and its analog, cyclocreatine, have been considered cancer suppressive metabolites due to their effects on suppression of subcutaneous cancer growth. Recently, emerging studies have demonstrated the promoting effect of creatine on cancer metastasis. Orthotopic mouse models revealed that creatine promoted invasion and metastasis of pancreatic cancer, colorectal cancer, and breast cancer. Thus, creatine possesses considerably complicated roles in cancer progression. In this review, we systematically summarized the role of creatine in tumor progression, which will call to caution when considering creatine supplementation to clinically treat cancer patients.
    Keywords:  cancer; creatine; creatine kinase; metastasis; phosphocreatine
  19. Nat Commun. 2021 Dec 15. 12(1): 7300
      Cancer stem cells (CSCs) play an important role during metastasis, but the dynamic behavior and induction mechanisms of CSCs are not well understood. Here, we employ high-resolution intravital microscopy using a CSC biosensor to directly observe CSCs in live mice with mammary tumors. CSCs display the slow-migratory, invadopod-rich phenotype that is the hallmark of disseminating tumor cells. CSCs are enriched near macrophages, particularly near macrophage-containing intravasation sites called Tumor Microenvironment of Metastasis (TMEM) doorways. Substantial enrichment of CSCs occurs on association with TMEM doorways, contributing to the finding that CSCs represent >60% of circulating tumor cells. Mechanistically, stemness is induced in non-stem cancer cells upon their direct contact with macrophages via Notch-Jagged signaling. In breast cancers from patients, the density of TMEM doorways correlates with the proportion of cancer cells expressing stem cell markers, indicating that in human breast cancer TMEM doorways are not only cancer cell intravasation portals but also CSC programming sites.
  20. Elife. 2021 Dec 17. pii: e70151. [Epub ahead of print]10
      Metastasis is responsible for approximately 90% of cancer-associated mortality but few models exist that allow for rapid and effective screening of anti-metastasis drugs. Current mouse models of metastasis are too expensive and time consuming to use for rapid and high-throughput screening. Therefore, we created a unique screening concept utilizing conserved mechanisms between zebrafish gastrulation and cancer metastasis for identification of potential anti-metastatic drugs. We hypothesized that small chemicals that interrupt zebrafish gastrulation might also suppress metastatic progression of cancer cells and developed a phenotype-based chemical screen to test the hypothesis. The screen used epiboly, the first morphogenetic movement in gastrulation, as a marker and enabled 100 chemicals to be tested in five hours. The screen tested 1280 FDA-approved drugs and identified Pizotifen, an antagonist for serotonin receptor 2C (HTR2C) as an epiboly-interrupting drug. Pharmacologic and genetic inhibition of HTR2C suppressed metastatic progression in a mouse model. Blocking HTR2C with Pizotifen restored epithelial properties to metastatic cells through inhibition of Wnt-signaling. In contrast, HTR2C induced epithelial to mesenchymal transition (EMT) through activation of Wnt-signaling and promoted metastatic dissemination of human cancer cells in a zebrafish xenotransplantation model. Taken together, our concept offers a novel platform for discovery of anti-metastasis drugs.
    Keywords:  developmental biology; zebrafish
  21. Front Cell Dev Biol. 2021 ;9 787485
      Pancreatic ductal adenocarcinoma (PDAC) has one of the worst outcomes among cancers with a 5-years survival rate of below 10%. This is a result of late diagnosis and the lack of effective treatments. The tumor is characterized by a highly fibrotic stroma containing distinct cellular components, embedded within an extracellular matrix (ECM). This ECM-abundant tumor microenvironment (TME) in PDAC plays a pivotal role in tumor progression and resistance to treatment. Cancer-associated fibroblasts (CAFs), being a dominant cell type of the stroma, are in fact functionally heterogeneous populations of cells within the TME. Certain subtypes of CAFs are the main producer of the ECM components of the stroma, with the most abundant one being the collagen family of proteins. Collagens are large macromolecules that upon deposition into the ECM form supramolecular fibrillar structures which provide a mechanical framework to the TME. They not only bring structure to the tissue by being the main structural proteins but also contain binding domains that interact with surface receptors on the cancer cells. These interactions can induce various responses in the cancer cells and activate signaling pathways leading to epithelial-to-mesenchymal transition (EMT) and ultimately metastasis. In addition, collagens are one of the main contributors to building up mechanical forces in the tumor. These forces influence the signaling pathways that are involved in cell motility and tumor progression and affect tumor microstructure and tissue stiffness by exerting solid stress and interstitial fluid pressure on the cells. Taken together, the TME is subjected to various types of mechanical forces and interactions that affect tumor progression, metastasis, and drug response. In this review article, we aim to summarize and contextualize the recent knowledge of components of the PDAC stroma, especially the role of different collagens and mechanical traits on tumor progression. We furthermore discuss different experimental models available for studying tumor-stromal interactions and finally discuss potential therapeutic targets within the stroma.
    Keywords:  PDAC—pancreatic ductal adenocarcinoma; collagen; extracellular matrix; mechanical traits; pancreatic cancer; stroma
  22. Gut. 2021 Dec 17. pii: gutjnl-2021-325180. [Epub ahead of print]
      OBJECTIVE: Stromal barriers, such as the abundant desmoplastic stroma that is characteristic of pancreatic ductal adenocarcinoma (PDAC), can block the delivery and decrease the tumour-penetrating ability of therapeutics such as tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), which can selectively induce cancer cell apoptosis. This study aimed to develop a TRAIL-based nanotherapy that not only eliminated the extracellular matrix barrier to increase TRAIL delivery into tumours but also blocked antiapoptotic mechanisms to overcome TRAIL resistance in PDAC.DESIGN: Nitric oxide (NO) plays a role in preventing tissue desmoplasia and could thus be delivered to disrupt the stromal barrier and improve TRAIL delivery in PDAC. We applied an in vitro-in vivo combinatorial phage display technique to identify novel peptide ligands to target the desmoplastic stroma in both murine and human orthotopic PDAC. We then constructed a stroma-targeted nanogel modified with phage display-identified tumour stroma-targeting peptides to co-deliver NO and TRAIL to PDAC and examined the anticancer effect in three-dimensional spheroid cultures in vitro and in orthotopic PDAC models in vivo.
    RESULTS: The delivery of NO to the PDAC tumour stroma resulted in reprogramming of activated pancreatic stellate cells, alleviation of tumour desmoplasia and downregulation of antiapoptotic BCL-2 protein expression, thereby facilitating tumour penetration by TRAIL and substantially enhancing the antitumour efficacy of TRAIL therapy.
    CONCLUSION: The co-delivery of TRAIL and NO by a stroma-targeted nanogel that remodels the fibrotic tumour microenvironment and suppresses tumour growth has the potential to be translated into a safe and promising treatment for PDAC.
    Keywords:  drug resistance; fibrosis; pancreatic cancer
  23. EMBO J. 2021 Dec 17. e109221
      Within a tumor, cancer cells exist in different states that are associated with distinct tumor functions, including proliferation, differentiation, invasion, metastasis, and resistance to anti-cancer therapy. The identification of the gene regulatory networks underpinning each state is essential for better understanding functional tumor heterogeneity and revealing tumor vulnerabilities. Here, we review the different studies identifying tumor states by single-cell sequencing approaches and the mechanisms that promote and sustain these functional states and regulate their transitions. We also describe how different tumor states are spatially distributed and interact with the specific stromal cells that compose the tumor microenvironment. Finally, we discuss how the understanding of tumor plasticity and transition states can be used to develop new strategies to improve cancer therapy.
    Keywords:  EMT; cancer therapy; metastasis; single-cell; tumor heterogeneity
  24. Cell Calcium. 2021 Dec 10. pii: S0143-4160(21)00171-8. [Epub ahead of print]101 102517
      OPA1 and MICU1 are both involved in the regulation of mitochondrial Ca2+ uptake and the stabilization of the cristae junction, which separates the inner mitochondrial membrane into the interboundary membrane and the cristae membrane. In this mini-review, we focus on the synergetic control of OPA1 and MICU1 on the cristae junction that serves as a fundamental regulator of multiple mitochondrial functions. In particular, we point to the critical role of an adaptive cristae junction permeability in mitochondrial Ca2+ signaling, spatial H+ gradients and mitochondrial membrane potential, metabolic activity, and apoptosis. These characteristics bear on a distinct localization of the oxidative phosphorylation machinery, the FoF1-ATPase, and mitochondrial Ca2+uniporter (MCU) within sections of the inner mitochondrial membrane isolated by the cristae junction and regulated by proteins like OPA1 and MICU1. We specifically focus on the impact of MICU1-regulated cristae junction on the activity and distribution of MCU within the complex ultrastructure of mitochondria.
  25. Cell Metab. 2021 Dec 09. pii: S1550-4131(21)00541-6. [Epub ahead of print]
      Increased hepatic glucose production (HGP) contributes to hyperglycemia in type 2 diabetes. Hormonal regulation of this process is primarily, but not exclusively, mediated by the AKT-FoxO1 pathway. Here, we show that cAMP and dexamethasone regulate the high-mobility group superfamily member TOX4 to mediate HGP, independent of the insulin receptor/FoxO1 pathway. TOX4 inhibition decreases glucose production in primary hepatocytes and liver and increases glucose tolerance. Combined genetic ablation of TOX4 and FoxO1 in liver has additive effects on glucose tolerance and gluconeogenesis. Moreover, TOX4 ablation fails to reverse the metabolic derangement brought by insulin receptor knockout. TOX4 expression is increased in livers of patients with steatosis and diabetes and in diet-induced obese and db/db mice. In the latter two murine models, knockdown Tox4 decreases glycemia and improves glucose tolerance. We conclude that TOX4 is an insulin receptor-independent regulator of HGP and a candidate contributor to the pathophysiology of diabetes.
    Keywords:  TOX2, transcription regulation, HGP, type 2 diabetes
  26. Nat Commun. 2021 Dec 15. 12(1): 7311
      Copper serves as a co-factor for a host of metalloenzymes that contribute to malignant progression. The orally bioavailable copper chelating agent tetrathiomolybdate (TM) has been associated with a significant survival benefit in high-risk triple negative breast cancer (TNBC) patients. Despite these promising data, the mechanisms by which copper depletion impacts metastasis are poorly understood and this remains a major barrier to advancing TM to a randomized phase II trial. Here, using two independent TNBC models, we report a discrete subpopulation of highly metastatic SOX2/OCT4+ cells within primary tumors that exhibit elevated intracellular copper levels and a marked sensitivity to TM. Global proteomic and metabolomic profiling identifies TM-mediated inactivation of Complex IV as the primary metabolic defect in the SOX2/OCT4+ cell population. We also identify AMPK/mTORC1 energy sensor as an important downstream pathway and show that AMPK inhibition rescues TM-mediated loss of invasion. Furthermore, loss of the mitochondria-specific copper chaperone, COX17, restricts copper deficiency to mitochondria and phenocopies TM-mediated alterations. These findings identify a copper-metabolism-metastasis axis with potential to enrich patient populations in next-generation therapeutic trials.
  27. J Biol Chem. 2021 Dec 14. pii: S0021-9258(21)01304-1. [Epub ahead of print] 101494
      Changing physiological conditions can increase the need for protein degradative capacity in eukaryotic cells. Both the ubiquitin-proteasome system and autophagy contribute to protein degradation. However, these processes can be differently regulated depending on the physiological conditions. Strikingly, proteasomes themselves can be a substrate for autophagy. The signals and molecular mechanisms that govern proteasome autophagy (proteaphagy) are only partly understood. Here, we used immunoblots, native gel analyses, and fluorescent microscopy to understand the regulation of proteaphagy in response to genetic and small molecule-induced perturbations. Our data indicate that chemical inhibition of the master nutrient sensor TORC1 (inhibition of which induces general autophagy) with rapamycin induces a bi-phasic response where proteasome levels are upregulated followed by an autophagy-dependent reduction. Surprisingly, several conditions that result in inhibited TORC1, such as caffeinine treatment or nitrogen starvation, only induced proteaphagy (i.e. without any proteasome upregulation), suggesting a convergence of signals upstream of proteaphagy under different physiological conditions. Indeed, we found that several conditions that activated general autophagy did not induce proteaphagy, further distinguishing proteaphagy from general autophagy. Consistent with this, we show that Atg11, a selective autophagy receptor, as well as the MAP kinases Mpk1, Mkk1, and Mkk2 all play a role in autophagy of proteasomes, while they are dispensable for general autophagy. Taken together, our data provide new insights into the molecular regulation of proteaphagy by demonstrating that degradation of proteasome complexes is specifically regulated under different autophagy-inducing conditions.
    Keywords:  autophagy; proteaphagy; proteasome; proteasome inhibitor; protein degradation; starvation; target of rapamycin (TOR); vacuole; yeast
  28. J Exp Med. 2022 Feb 07. pii: e20210564. [Epub ahead of print]219(2):
      Tumor-associated macrophages (TAMs) are correlated with the progression of prostatic adenocarcinoma (PCa). The mechanistic basis of this correlation and therapeutic strategies to target TAMs in PCa remain poorly defined. Here, single-cell RNA sequencing was used to profile the transcriptional landscape of TAMs in human PCa, leading to identification of a subset of macrophages characterized by dysregulation in transcriptional pathways associated with lipid metabolism. This subset of TAMs correlates positively with PCa progression and shorter disease-free survival and is characterized by an accumulation of lipids that is dependent on Marco. Mechanistically, cancer cell-derived IL-1β enhances Marco expression on macrophages, and reciprocally, cancer cell migration is promoted by CCL6 released by lipid-loaded TAMs. Moreover, administration of a high-fat diet to tumor-bearing mice raises the abundance of lipid-loaded TAMs. Finally, targeting lipid accumulation by Marco blockade hinders tumor growth and invasiveness and improves the efficacy of chemotherapy in models of PCa, pointing to combinatorial strategies that may influence patient outcomes.
  29. iScience. 2021 Dec 17. 24(12): 103415
      A major challenge for treating patients with pancreatic ductal adenocarcinoma (PDAC) is the unpredictability of their prognoses due to high heterogeneity. We present Multi-Omics DEep Learning for Prognosis-correlated subtyping (MODEL-P) to identify PDAC subtypes and to predict prognoses of new patients. MODEL-P was trained on autoencoder integrated multi-omics of 146 patients with PDAC together with their survival outcome. Using MODEL-P, we identified two PDAC subtypes with distinct survival outcomes (median survival 10.1 and 22.7 months, respectively, log rank p = 1 × 10-6), which correspond to DNA damage repair and immune response. We rigorously validated MODEL-P by stratifying patients in five independent datasets into these two survival groups and achieved significant survival difference, which is superior to current practice and other subtyping schemas. We believe the subtype-specific signatures would facilitate PDAC pathogenesis discovery, and MODEL-P can provide clinicians the prognoses information in the treatment decision-making to better gauge the benefits versus the risks.
    Keywords:  Biocomputational method; Cancer; Cancer systems biology
  30. Cell. 2021 Dec 08. pii: S0092-8674(21)01381-7. [Epub ahead of print]
      Colorectal cancers (CRCs) arise from precursor polyps whose cellular origins, molecular heterogeneity, and immunogenic potential may reveal diagnostic and therapeutic insights when analyzed at high resolution. We present a single-cell transcriptomic and imaging atlas of the two most common human colorectal polyps, conventional adenomas and serrated polyps, and their resulting CRC counterparts. Integrative analysis of 128 datasets from 62 participants reveals adenomas arise from WNT-driven expansion of stem cells, while serrated polyps derive from differentiated cells through gastric metaplasia. Metaplasia-associated damage is coupled to a cytotoxic immune microenvironment preceding hypermutation, driven partly by antigen-presentation differences associated with tumor cell-differentiation status. Microsatellite unstable CRCs contain distinct non-metaplastic regions where tumor cells acquire stem cell properties and cytotoxic immune cells are depleted. Our multi-omic atlas provides insights into malignant progression of colorectal polyps and their microenvironment, serving as a framework for precision surveillance and prevention of CRC.
    Keywords:  adenoma; colorectal cancer; cytotoxic; differentiation; metaplasia; multiplex; polyp; serrated; single-cell RNA-seq; stem cells
  31. Front Pharmacol. 2021 ;12 751568
      Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease characterized by early metastasis, late detection, and poor prognosis. Progress towards effective therapy has been slow despite significant efforts. Novel treatment approaches are desperately needed and autophagy, an evolutionary conserved process through which proteins and organelles are recycled for use as alternative energy sources, may represent one such target. Although incompletely understood, there is growing evidence suggesting that autophagy may play a role in PDAC carcinogenesis, metastasis, and survival. Early clinical trials involving autophagy inhibiting agents, either alone or in combination with chemotherapy, have been disappointing. Recently, evidence has demonstrated synergy between the MAPK pathway and autophagy inhibitors in PDAC, suggesting a promising therapeutic intervention. In addition, novel agents, such as ONC212, have preclinical activity in pancreatic cancer, in part through autophagy inhibition. We discuss autophagy in PDAC tumorigenesis, metabolism, modulation of the immune response, and preclinical and clinical data with selected autophagy modulators as therapeutics.
    Keywords:  Atg5; LC3; MEK inhibitors; ONC212; autophagy; beclin 1; chloroquine; pancreatic cancer
  32. STAR Protoc. 2021 Dec 17. 2(4): 100997
      Cell competition is a mechanism of interaction that dictates cell selection based on differences in cellular fitness. We designed a protocol to generate mixed murine organoids and enteroid monolayers used to study such complex cellular interactions in a mammalian system. This protocol is dedicated to follow the behavior of different cell populations over time, using (time-lapse) microscopy or transcriptome/proteome analysis. For complete details on the use and execution of this protocol, please refer to Krotenberg Garcia et al. (2021).
    Keywords:  Cancer; Cell Biology; Cell culture; Microscopy; Organoids
  33. FEBS J. 2021 Dec 15.
      Dietary choices have a profound impact on the aging process. In addition to the total amount of energy intake, macronutrient composition influences both health and lifespan. However, the exact mechanisms by which dietary macronutrients influence onset and progression of age-associated features remain poorly understood. Cellular senescence is a state of stable growth arrest characterized by the secretion of numerous bioactive molecules with pro-inflammatory properties. Accumulation of senescent cells is considered one of the basic mechanisms of aging and an important contributor to chronic inflammation and tissue degeneration. Whether dietary macronutrients affect the accumulation and the phenotype of senescent cells with age is still unknown. Here, we show that feeding on diets with varying ratios of dietary macronutrients for 3 months has a significant effect on different senescence-associated markers in the mouse liver. High protein intake is associated with higher expression levels of the two classical senescence-associated growth arrest genes, p21 and p16. Furthermore, the expression of many pro-inflammatory secretory markers was increased in diets enriched in protein and further enhanced by increases in fat content. These results provide preliminary evidence that dietary macronutrients have a significant influence on senescence markers and merit further investigation.
    Keywords:  SASP; Senescence; inflammation; macronutrients composition
  34. Clin Exp Metastasis. 2021 Dec 18.
      Metastasis is the primary cause of cancer related deaths due to the limited number of efficient druggable targets. Signatures of dysregulated cancer metabolism could serve as a roadmap for the determination of new treatment strategies. However, the metabolic signatures of metastatic cells remain vastly elusive. Our aim was to determine metabolic dysregulations associated with high metastatic potential in breast cancer cell lines. We have selected 5 triple negative breast cancer (TNBC) cell lines including three with high metastatic potential (HMP) (MDA-MB-231, MDA-MB-436, MDA-MB-468) and two with low metastatic potential (LMP) (BT549, HCC1143). The normal epithelial breast cell line (hTERT-HME1) was also investigated. The untargeted metabolic profiling of cells and growth media was conducted and total of 479 metabolites were quantified. First we characterized metabolic features differentiating TNBC cell lines from normal cells as well as identified cell line specific metabolic fingerprints. Next, we determined 92 metabolites in cells and 22 in growth medium that display significant differences between LMP and HMP. The HMP cell lines had elevated level of molecules involved in glycolysis, TCA cycle and lipid metabolism. We identified metabolic advantages of cell lines with HMP beyond enhanced glycolysis by pinpointing the role of branched chain amino acids (BCAA) catabolism as well as molecules supporting coagulation and platelet activation as important contributors to the metastatic cascade. The landscape of metabolic dysregulations, characterized in our study, could serve as a roadmap for the identification of treatment strategies targeting cancer cells with enhanced metastatic potential.
    Keywords:  Branch chain amino acid metabolism; Metabolic profiling; Metastasis; Metastatic potential; TCA cycle; Triple negative breast cancer
  35. Nat Commun. 2021 Dec 14. 12(1): 7256
      Several members of the FGF family have been identified as potential regulators of glucose homeostasis. We previously reported that a low threshold of FGF-induced FGF receptor 1c (FGFR1c) dimerization and activity is sufficient to evoke a glucose lowering activity. We therefore reasoned that ligand identity may not matter, and that besides paracrine FGF1 and endocrine FGF21, other cognate paracrine FGFs of FGFR1c might possess such activity. Indeed, via a side-by-side testing of multiple cognate FGFs of FGFR1c in diabetic mice we identified the paracrine FGF4 as a potent anti-hyperglycemic FGF. Importantly, we found that like FGF1, the paracrine FGF4 is also more efficacious than endocrine FGF21 in lowering blood glucose. We show that paracrine FGF4 and FGF1 exert their superior glycemic control by targeting skeletal muscle, which expresses copious FGFR1c but lacks β-klotho (KLB), an obligatory FGF21 co-receptor. Mechanistically, both FGF4 and FGF1 upregulate GLUT4 cell surface abundance in skeletal muscle in an AMPKα-dependent but insulin-independent manner. Chronic treatment with rFGF4 improves insulin resistance and suppresses adipose macrophage infiltration and inflammation. Notably, unlike FGF1 (a pan-FGFR ligand), FGF4, which has more restricted FGFR1c binding specificity, has no apparent effect on food intake. The potent anti-hyperglycemic and anti-inflammatory properties of FGF4 testify to its promising potential for use in the treatment of T2D and related metabolic disorders.
  36. Exp Cell Res. 2021 Dec 11. pii: S0014-4827(21)00522-X. [Epub ahead of print] 112966
      Endogenous skeletal muscle development, regeneration, and pathology are extremely complex processes, influenced by local and systemic factors. Unpinning how these mechanisms function is crucial for fundamental biology and to develop therapeutic interventions for genetic disorders, but also conditions like sarcopenia and volumetric muscle loss. Ex vivo skeletal models range from two- and three-dimensional primary cultures of satellite stem cell-derived myoblasts grown alone or in co-culture, to single muscle myofibers, myobundles, and whole tissues. Together, these systems provide the opportunity to gain mechanistic insights of stem cell behavior, cell-cell interactions, and mature muscle function in simplified systems, without confounding variables. Here, we highlight recent advances (published in the last 5 years) using in vitro primary cells and ex vivo skeletal muscle models, and summarize the new insights, tools, datasets, and screening methods they have provided. Finally, we highlight the opportunity for exponential advance of skeletal muscle knowledge, with spatiotemporal resolution, that is offered by guiding the study of muscle biology and physiology with in silico modelling and implementing high-content cell biology systems and ex vivo physiology platforms.
    Keywords:  Explants; In vitro; Myofiber; Physiology; Satellite cell; Skeletal muscle
  37. Biochemistry (Mosc). 2021 Oct;86(10): 1288-1300
      One of the main factors associated with worse prognosis in oncology is metastasis, which is based on the ability of tumor cells to migrate from the primary source and to form secondary tumors. The search for new strategies to control migration of metastatic cells is one of the urgent issues in biomedicine. One of the strategies to stop spread of cancer cells could be regulation of the nuclear elasticity. Nucleus, as the biggest and stiffest cellular compartment, determines mechanical properties of the cell as a whole, and, hence, could prevent cell migration through the three-dimensional extracellular matrix. Nuclear rigidity is maintained by the nuclear lamina, two-dimensional network of intermediate filaments in the inner nuclear membrane (INM). Here we present the most significant factors defining nucleus rigidity, discuss the role of nuclear envelope composition in the cell migration, as well consider possible approaches to control lamina composition in order to change plasticity of the cell nucleus and ability of the tumor cells to metastasize.
    Keywords:  ZMPSTE24; aging; cell migration; chromatin; lamin A; laminopathies; metastasis; nuclear lamina
  38. Biochim Biophys Acta Mol Cell Res. 2021 Dec 10. pii: S0167-4889(21)00240-8. [Epub ahead of print] 119186
      Cationic amphiphilic drugs (CADs) are known from lysosomotropism, drug-induced phospholipidosis (DIPL), activation of autophagy, and decreased cell viability, but the relationship between these events is not clear and little is known about DIPL in the endothelium. In this work, the effects of fluoxetine, amiodarone, clozapine, and risperidone on human microvascular endothelial cells (HMEC-1) were studied using a combined methodology of label-free Raman imaging and fluorescence staining. Raman spectroscopy was applied to characterize biochemical changes in lipid profile and their distribution in the cellular compartments, while fluorescence staining (LysoTracker, LipidTOX, LC3B, and JC-1) was used to analyze lysosome volume expansion, activation of autophagy, lipid accumulation, and mitochondrial membrane depolarization. We demonstrated that fluoxetine, amiodarone, and clozapine, but not risperidone, at non-toxic concentrations induced lipid accumulations in the perinuclear and cytoplasmic regions of endothelial cells. Spectroscopic markers of DIPL included a robust increase in the ratio (lipid/(protein + lipid)), an increased choline-containing lipid, fatty acids, and the presence of cholesterol esters, while starvation-induced activated autophagy revealed a spectroscopic signature associated with only subtle changes in the lipid profile. Interestingly, lysosomal volume expansion, occurrence of DIPL, and activation of autophagy induced by selected CADs all depended on drug-accumulation in acidic pH of lysosome cellular compartments whereas reduced endothelial viability did not, and was attributed to mitochondrial mechanisms as evidenced by a decreased mitochondrial transmembrane potential. In conclusion, drug-induced phospholipidosis in the endothelium did not reduce endothelial viability per se and can be efficiently assayed by Raman imaging.
    Keywords:  CADs; Cationic amphiphilic drugs; Endothelium; LC3 lipidation; Lysosomotropism; Raman microscopy
  39. Trends Biochem Sci. 2021 Dec 09. pii: S0968-0004(21)00245-0. [Epub ahead of print]
      The simultaneous incorporation of distinct noncanonical amino acids into different proteins within eukaryotic cells remains challenging. This new study by Reinkemeier and Lemke demonstrates how 2D phase separation can be used to engineer spatially separated organelles. These film-like organelles translate proteins independently from each other and the canonical genetic code.
    Keywords:  2D phase separation; enzyme engineering; genetic code expansion; noncanonical amino acid; synthetic biology; synthetic organelle
  40. Aging (Albany NY). 2021 Dec 13. undefined(undefined):
    Keywords:  Raman microspectroscopy; aging; cellular senescence; chemical imaging; correlated multimodal imaging
  41. Sci Signal. 2021 Dec 14. 14(713): eabn6544
      [Figure: see text].