bims-cagime Biomed News
on Cancer, aging and metabolism
Issue of 2022‒05‒01
38 papers selected by
Kıvanç Görgülü
Technical University of Munich

  1. Cancer Lett. 2022 Apr 23. pii: S0304-3835(22)00176-8. [Epub ahead of print]538 215693
      Owing to the lack of early diagnosis, pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal tumours. Because acinar-to-ductal metaplasia (ADM) is a critical process to pancreatic regeneration and PDAC initiation, we applied GSE65146, a dataset composed of transcripts at different time points in wild-type and KrasG12D mutant mice upon pancreatitis induction, to obtain regeneration- and tumour initiation-related genes. By overlapping with genes differentially expressed in human PDAC, we defined the initiation- and progression-related genes, and the most prognostic gene, SULF2, was selected for further verification. By using multiple PDAC genetically engineered murine models (GEMMs), we further verified that the expression of SULF2 was increased at the ADM and PDAC stages. Functionally, SULF2 was able to promote the dedifferentiation of acinar cells as well as the metastatic ability of PDAC. Additionally, our study revealed that SULF2 could enhance TGFβ-SMAD signalling via GDF15. More importantly, serum SULF2 was elevated in patients with PDAC, and in combination with CA19-9, it provided a better method for PDAC diagnosis. Herein, our study screened out key genes for the initiation and progression of PDAC, providing potential indicators for the diagnosis of the disease.
    Keywords:  Early diagnosis; Pancreatic ductal adenocarcinoma (PDAC); SULF2; Tumor initiation; Tumor progression
  2. Science. 2022 Apr 29. 376(6592): 476-483
      Genotoxic therapy such as radiation serves as a frontline cancer treatment, yet acquired resistance that leads to tumor reoccurrence is frequent. We found that cancer cells maintain viability during irradiation by reversibly increasing genome-wide DNA breaks, thereby limiting premature mitotic progression. We identify caspase-activated DNase (CAD) as the nuclease inflicting these de novo DNA lesions at defined loci, which are in proximity to chromatin-modifying CCCTC-binding factor (CTCF) sites. CAD nuclease activity is governed through phosphorylation by DNA damage response kinases, independent of caspase activity. In turn, loss of CAD activity impairs cell fate decisions, rendering cancer cells vulnerable to radiation-induced DNA double-strand breaks. Our observations highlight a cancer-selective survival adaptation, whereby tumor cells deploy regulated DNA breaks to delimit the detrimental effects of therapy-evoked DNA damage.
  3. Cancer Cell. 2022 Apr 21. pii: S1535-6108(22)00164-7. [Epub ahead of print]
      The translational challenges in the field of precision oncology are in part related to the biological complexity and diversity of this disease. Technological advances in genomics have facilitated large sequencing efforts and discoveries that have further supported this notion. In this review, we reflect on the impact of these discoveries on our understanding of several concepts: cancer initiation, cancer prevention, early detection, adjuvant therapy and minimal residual disease monitoring, cancer drug resistance, and cancer evolution in metastasis. We discuss key areas of focus for improving cancer outcomes, from biological insights to clinical application, and suggest where the development of these technologies will lead us. Finally, we discuss practical challenges to the wider adoption of molecular profiling in the clinic and the need for robust translational infrastructure.
    Keywords:  cancer evolution; cancer genomics; drug resistance
  4. Nat Chem Biol. 2022 May;18(5): 441-450
      Metabolic reprogramming is observed across all cancer types. Indeed, the success of many classic chemotherapies stems from their targeting of cancer metabolism. Contemporary research in this area has refined our understanding of tumor-specific metabolic mechanisms and has revealed strategies for exploiting these vulnerabilities selectively. Based on this growing understanding, new small-molecule tools and drugs have been developed to study and target tumor metabolism. Here, we highlight allosteric modulation of metabolic enzymes as an attractive mechanism of action for small molecules that target metabolic enzymes. We then discuss the mechanistic insights garnered from their application in cancer studies and highlight the achievements of this approach in targeting cancer metabolism. Finally, we discuss technological advances in drug discovery for allosteric modulators of enzyme activity.
  5. Trends Cell Biol. 2022 Apr 25. pii: S0962-8924(22)00079-4. [Epub ahead of print]
      Most solid cancer-related deaths result from metastasis, a multistep process in which cancer cells exit the primary site, intravasate into the bloodstream, extravasate, and colonize distant organs. Colonization is facilitated by clonal selection and the high phenotypic plasticity of cancer cells that creates reversible switching of cellular states. Cancer cell plasticity leads to intratumor heterogeneity and fitness, yielding cells with molecular and cellular programs that facilitate survival and colonization. While cancer cell plasticity is sometimes limited to the process of epithelial-to-mesenchymal transition (EMT), recent studies have broadened its definition. Plasticity arises from both cell-intrinsic and cell-extrinsic factors and is a major obstacle to efficacious anti-cancer therapies. Here, we discuss the multifaceted notion of cancer cell plasticity associated with metastatic colonization.
    Keywords:  EMT; colonization; dormancy; metastasis; microenvironment; plasticity
  6. Cell Rep Methods. 2021 Jun 21. 1(2): 100016
      Quantitative information about the levels and dynamics of post-translational modifications (PTMs) is critical for an understanding of cellular functions. Protein arginine methylation (ArgMet) is an important subclass of PTMs and is involved in a plethora of (patho)physiological processes. However, because of the lack of methods for global analysis of ArgMet, the link between ArgMet levels, dynamics, and (patho)physiology remains largely unknown. We utilized the high sensitivity and robustness of nuclear magnetic resonance (NMR) spectroscopy to develop a general method for the quantification of global protein ArgMet. Our NMR-based approach enables the detection of protein ArgMet in purified proteins, cells, organoids, and mouse tissues. We demonstrate that the process of ArgMet is a highly prevalent PTM and can be modulated by small-molecule inhibitors and metabolites and changes in cancer and during aging. Thus, our approach enables us to address a wide range of biological questions related to ArgMet in health and disease.
    Keywords:  NMR spectroscopy; aging; arginine methylation; cancer; cell differentiation; mouse models; one carbon metabolism; organoids; protein arginine methyltransferases; yeast
  7. Elife. 2022 Apr 25. pii: e75143. [Epub ahead of print]11
      How environmental cues influence peroxisome proliferation, particularly through organelles, remains largely unknown. Yeast peroxisomes metabolize fatty acids (FA), and methylotrophic yeasts also metabolize methanol. NADH and acetyl-CoA, produced by these pathways enter mitochondria for ATP production and for anabolic reactions. During the metabolism of FA and/or methanol, the mitochondrial oxidative phosphorylation (OXPHOS) pathway accepts NADH for ATP production and maintains cellular redox balance. Remarkably, peroxisome proliferation in Pichia pastoris was abolished in NADH shuttling- and OXPHOS mutants affecting complex I or III, or by the mitochondrial uncoupler, 2,4-dinitrophenol (DNP), indicating ATP depletion causes the phenotype. We show that mitochondrial OXPHOS deficiency inhibits expression of several peroxisomal proteins implicated in FA and methanol metabolism, as well as in peroxisome division and proliferation. These genes are regulated by the Snf1 complex (SNF1), a pathway generally activated by a high AMP/ATP ratio. In OXPHOS mutants, Snf1 is activated by phosphorylation, but Gal83, its interacting subunit, fails to translocate to the nucleus. Phenotypic defects in peroxisome proliferation observed in the OXPHOS mutants, and phenocopied by the Dgal83 mutant, were rescued by deletion of three transcriptional repressor genes (MIG1, MIG2 and NRG1) controlled by SNF1 signaling. Our results are interpreted in terms of a mechanism by which peroxisomal and mitochondrial proteins and/or metabolites influence redox and energy metabolism, while also influencing peroxisome biogenesis and proliferation, thereby exemplifying interorganellar communication and interplay involving peroxisomes, mitochondria, cytosol and the nucleus. We discuss the physiological relevance of this work in the context of human OXPHOS deficiencies.
    Keywords:  cell biology
  8. Gastroenterology. 2022 Apr 14. pii: S0016-5085(22)00369-9. [Epub ahead of print]
    North American Pancreatitis Study 2 (NAPS2) consortium
      BACKGROUND & AIMS: Mitochondrial dysfunction disrupts the synthesis and secretion of digestive enzymes in pancreatic acinar cells and plays a primary role in the etiology of exocrine pancreas disorders. However, the transcriptional mechanisms that regulate mitochondrial function to support acinar cell physiology are poorly understood. Here, we aim to elucidate the function of estrogen-related receptor γ (ERRγ) in pancreatic acinar cell mitochondrial homeostasis and energy production.METHODS: Two models of ERRγ inhibition, GSK5182-treated wild-type mice and ERRγ conditional knock-out (cKO) mice, were established to investigate ERRγ function in the exocrine pancreas. To identify the functional role of ERRγ in pancreatic acinar cells, we performed histological and transcriptome analysis with the pancreas isolated from ERRγ cKO mice. To determine the relevance of these findings for human disease, we analyzed transcriptome data from multiple independent human cohorts and conducted genetic association studies for ESRRG variants in two distinct human pancreatitis cohorts.
    RESULTS: Blocking ERRγ function in mice by genetic deletion or inverse agonist treatment results in striking pancreatitis-like phenotypes accompanied by inflammation, fibrosis, and cell death. Mechanistically, loss-of-ERRγ in primary acini abrogates mRNA expression and protein levels of mitochondrial oxidative phosphorylation (OXPHOS) complex genes, resulting in defective acinar cell energetics. Mitochondrial dysfunction due to ERRγ deletion further triggers autophagy dysfunction, ER stress, and production of reactive oxygen species, ultimately leading to cell death. Interestingly, ERRγ-deficient acinar cells that escape cell death acquire ductal cell characteristics indicating a role for ERRγ in acinar-to-ductal metaplasia. Consistent with our findings in ERRγ cKO mice, ERRγ expression was significantly reduced in patients with chronic pancreatitis compared to normal subjects. Furthermore, candidate locus region genetic association studies revealed multiple single nucleotide variants (SNVs) for ERRγ that associated with chronic pancreatitis.
    CONCLUSIONS: Collectively, our findings highlight an essential role for ERRγ in maintaining the transcriptional program that supports acinar cell mitochondrial function and organellar homeostasis and provide a novel molecular link between ERRγ and exocrine pancreas disorders.
    Keywords:  Acinar-to-ductal metaplasia; ERRγ; Mitochondrial oxidative phosphorylation; Pancreatic acinar cells; Reactive oxygen species
  9. Dev Cell. 2022 Apr 18. pii: S1534-5807(22)00245-3. [Epub ahead of print]
      Senescence is a cellular state which involves cell cycle arrest and a proinflammatory phenotype, and it has traditionally been associated with cellular and organismal aging. However, increasing evidence suggests key roles in tissue growth and regrowth, especially during development and regeneration. Conversely, cellular plasticity-the capacity of cells to undergo identity change, including differentiation and dedifferentiation-is associated with development and regeneration but is now being investigated in the context of age-related diseases such as Alzheimer disease. Here, we discuss the paradox of the role for cellular senescence in cellular plasticity: senescence can act as a cell-autonomous barrier and a paracrine driver of plasticity. We provide a conceptual framework for integrating recent data and use the interplay between cellular senescence and plasticity to provide insight into age-related diseases. Finally, we argue that age-related diseases can be better deciphered when senescence is recognized as a core mechanism of regeneration and development.
    Keywords:  aging; cell plasticity; cellular senescence; differentiation; regeneration; wound healing
  10. Proc Natl Acad Sci U S A. 2022 May 03. 119(18): e2114672119
      Altered tissue mechanics and metabolism have gained significant attention as drivers of tumorigenesis, and mechanoresponsive metabolism has been implicated in migration and metastasis. However, heterogeneity in cell populations makes it difficult to link changes in behavior with metabolism, as individual cell behaviors are not necessarily reflected in population-based measurements. As such, the impact of increased collagen deposition, a tumor-associated collagen signature, on metabolism remains ambiguous. Here, we utilize a wide range of collagen densities to alter migration ability and study the bioenergetics of individual cells over time. Sorting cells based on their level of motility revealed energetics are a function of collagen density only for highly motile cells, not the entire population or cells with low motility. Changes in migration with increasing collagen density were correlated with cellular energetics, where matrix conditions most permissive to migration required less energy usage during movement and migrated more efficiently. These findings reveal a link between matrix mechanics, migratory phenotype, and bioenergetics and suggest that energetic costs are determined by the extracellular matrix and influence cell motility.
    Keywords:  cell migration; extracellular matrix; heterogeneity; mechanobiology; metabolism
  11. J Immunol Res. 2022 ;2022 5665964
      Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, and the patients are generally diagnosed with distant metastasis. Liver is one of the preferred organs of distant metastasis, and liver metastasis is the leading cause of death in PDAC. Diet-induced obesity (DIO) is a risk factor for PDAC, and it remains unclear whether and how DIO contributes to liver metastasis of PDAC. In our study, we found that DIO significantly promoted PDAC liver metastasis compared with normal diet (ND) in intrasplenic injection mouse model. RNA-seq analysis for liver metastasis nodules showed that the various chemokines and several chemokine receptors were altered between ND and DIO samples. The expression levels of CX3CL1 and CX3CR1 were significantly upregulated in DIO-induced liver metastasis of PDAC compared to ND. Increased CX3CL1 promoted the recruitment of CX3CR1-expressing pancreatic tumor cells. Taken together, our data demonstrated that DIO promoted PDAC liver metastasis via CX3CL1/CX3CR1 axis.
  12. Proc Natl Acad Sci U S A. 2022 May 03. 119(18): e2200143119
      SignificancePancreatic cancer is a leading cause of cancer-related death, in part due to incomplete responses to standard-of-care chemotherapy. In this study, using a combination of single-cell RNA sequencing and high-throughput proteomics, we identified the calcium-responsive protein calmodulin as a key mediator of resistance to the first-line chemotherapy agent gemcitabine. Inhibition of calmodulin led to the loss of gemcitabine resistance in vitro, which was recapitulated using a calcium chelator or Food and Drug Administration-approved calcium channel blockers (CCBs), including amlodipine. In animal studies, amlodipine markedly enhanced therapeutic responses to gemcitabine chemotherapy, reducing the incidence of distant metastases and extending survival. Hence, incorporating CCBs may provide a safe and effective means of improving responses to gemcitabine-based chemotherapy in pancreatic cancer patients.
    Keywords:  chemotherapy; drug resistance; gemcitabine; pancreatic cancer
  13. Sci Adv. 2022 Apr 29. 8(17): eabm7012
      The immune checkpoint B7-H3 (CD276) is a member of the B7 family that has been studied in the tumor microenvironment and immunotherapy, but its potential role in metabolism remains largely unknown. Here, we show that B7-H3 is highly expressed in mouse and human adipose tissue at steady state, with the highest levels in adipocyte progenitor cells. B7-H3 is rapidly down-regulated upon the initiation of adipocyte differentiation. Combined RNA sequencing and metabolic studies reveal that B7-H3 stimulates glycolytic and mitochondrial activity of adipocyte progenitors. Loss of B7-H3 in progenitors results in impaired oxidative metabolism program and increased lipid accumulation in derived adipocytes. Consistent with these observations, mice knocked out for B7-H3 develop spontaneous obesity, metabolic dysfunction, and adipose tissue inflammation. Our results reveal an unexpected metabolic role for B7-H3 in adipose tissue and open potential new avenues for the treatment of metabolic diseases by targeting the B7-H3 pathway.
  14. In Vivo. 2022 May-Jun;36(3):36(3): 1114-1119
      BACKGROUND/AIM: Pancreatic cancer (PC) is one of the leading causes of cancer-related death. The purpose of the present study was to establish a patient-derived orthotopic xenograft model (PDOX) for pancreatic ductal adenocarcinoma (PDAC), thus providing a tumor microenvironment resembling that of the human pancreas to identify novel potential biomarkers and treatment regimens.MATERIALS AND METHODS: PDAC tissue samples were received from 35 patients, following informed consent, and three mouse strains were implemented.
    RESULTS: Successful PDOX engraftment was performed in nonobese diabetic/severe combined immunodeficient (NOD/SCID) and NOD/SCID gamma (NSG) mice. Nonetheless, we found a higher rate of successful engraftment and tumor growth in NSG compared to NOD/SCID mice, possibly owning to the different level of immunosuppression and more specifically of the natural killer cells presence.
    CONCLUSION: Our suggested PDOX model represents a preclinical cancer research model with a high affinity for the patient's tumor microenvironment, thus enabling the acceleration of PDAC research.
    Keywords:  PDAC; PDOX; PDX; Pancreatic cancer; pancreatic ductal adenocarcinoma; patient-derived xenografts
  15. Cell Rep Methods. 2021 Nov 22. 1(7): 100104
      Deciphering the spatial composition of cells in tissues is essential for detailed understanding of biological processes in health and disease. Recent technological advances enabled the assessment of the enormous complexity of tissue-derived parameters by highly multiplexed tissue imaging (HMTI), but elaborate machinery and data analyses are required. This severely limits broad applicability of HMTI. Here we demonstrate for the first time the application of ChipCytometry technology, which has unique features for widespread use, on formalin-fixed paraffin-embedded samples, the most commonly used storage technique of clinically relevant patient specimens worldwide. The excellent staining quality permits workflows for automated quantification of signal intensities, which we further optimized to compensate signal spillover from neighboring cells. In combination with the high number of validated markers, the reported platform can be used from unbiased analyses of tissue composition to detection of phenotypically complex rare cells, and can be easily implemented in both routine research and clinical pathology.
    Keywords:  automated quantification of signal intensities; cell-type segmentation; formalin-fixed paraffin-embedded samples; highly multiplexed tissue imaging; spatial spillover correction
  16. Aging (Albany NY). 2022 Apr 25. 14(undefined):
      BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly fatal malignancy and lacks effective therapeutic targets. Trametinib is considered to be a promising potential indirectly targeted KRAS inhibitor in PDAC. However, the clinical outcomes were poor. JQ1 displayed a significant synergistic effect when combined with chemotherapy or potential targeted therapy in pancreatic cancer. The impact of Trametinib and JQ1 combination treatment in PDAC remains to be fully elucidated.METHODS: The efficacy of trametinib and JQ1 on cell proliferation and cytotoxicity was assayed in 7 KRAS mutant pancreatic cancer cell lines. The cytotoxic effects of drugs either alone or in combination were evaluated using a luminescent cell viability assay. Immunoblot analysis was carried out to investigate changes in p62 and autophagy.
    RESULTS: We found that either trametinib or JQ1 alone inhibited the proliferation of some pancreatic cancer cell lines with KRAS alterations, irrespective of the mutational loci of KRAS and the aberrant status of the other driver genes. The synergistic effects of combination treatment of trametinib and JQ1 were observed in both trametinib-resistant and trametinib-sensitive cells. In trametinib-sensitive PDAC cells, the combined treatment definitely inhibited p62 expression compared with trametinib alone, while LC3 expression at high levels changed little. In trametinib-resistant PDAC cells, the combination of MEK/BET inhibitor dramatically decreased p62 expression compared with single agent, while p62 expression increased after anti-autophagic therapy was added.
    CONCLUSIONS: Blocking RAS downstream signaling and epigenetic pathway synergistically increases the antiproliferative activity in KRAS mutant PDAC cells. Combination therapeutic synergism may induce different cell death modes in different pancreatic cancer subtypes.
    Keywords:  BET inhibitor; MEK inhibitor; autophagy; pancreatic ductal adenocarcinoma; synergistic effect
  17. Aging (Albany NY). 2022 Apr 27. 14(undefined):
      TP53 is a master regulator of many signaling and apoptotic pathways involved in: aging, cell cycle progression, gene regulation, growth, apoptosis, cellular senescence, DNA repair, drug resistance, malignant transformation, metastasis, and metabolism. Most pancreatic cancers are classified as pancreatic ductal adenocarcinomas (PDAC). The tumor suppressor gene TP53 is mutated frequently (50-75%) in PDAC. Different types of TP53 mutations have been observed including gain of function (GOF) point mutations and various deletions of the TP53 gene resulting in lack of the protein expression. Most PDACs have point mutations at the KRAS gene which result in constitutive activation of KRas and multiple downstream signaling pathways. It has been difficult to develop specific KRas inhibitors and/or methods that result in recovery of functional TP53 activity. To further elucidate the roles of TP53 in drug-resistance of pancreatic cancer cells, we introduced wild-type (WT) TP53 or a control vector into two different PDAC cell lines. Introduction of WT-TP53 increased the sensitivity of the cells to multiple chemotherapeutic drugs, signal transduction inhibitors, drugs and nutraceuticals and influenced key metabolic properties of the cells. Therefore, TP53 is a key molecule which is critical in drug sensitivity and metabolism of PDAC.
    Keywords:  PDAC; TP53; chemotherapeutic drugs; metabolic properties; targeted therapy
  18. Science. 2022 Apr 29. 376(6592): eabi8175
      Establishing causal relationships between genetic alterations of human cancers and specific phenotypes of malignancy remains a challenge. We sequentially introduced mutations into healthy human melanocytes in up to five genes spanning six commonly disrupted melanoma pathways, forming nine genetically distinct cellular models of melanoma. We connected mutant melanocyte genotypes to malignant cell expression programs in vitro and in vivo, replicative immortality, malignancy, rapid tumor growth, pigmentation, metastasis, and histopathology. Mutations in malignant cells also affected tumor microenvironment composition and cell states. Our melanoma models shared genotype-associated expression programs with patient melanomas, and a deep learning model showed that these models partially recapitulated genotype-associated histopathological features as well. Thus, a progressive series of genome-edited human cancer models can causally connect genotypes carrying multiple mutations to phenotype.
  19. Am J Epidemiol. 2022 Apr 26. pii: kwac082. [Epub ahead of print]
      Few prospective studies have examined associations between diet quality and pancreatic ductal adenocarcinoma (PDAC), or comprehensively compared diet quality indices. We conducted a prospective analysis of adherence to the Healthy Eating Index (HEI)-2015, alternative HEI-2010 (AHEI-2010), alternate Mediterranean diet (aMED), and two Dietary Approaches to Stop Hypertension (DASH, Fung and Mellen) indices and PDAC within the National Institutes of Health (NIH)-AARP Diet and Health Study (United States, 1995-2011). The dietary quality indices were calculated using responses from a 124-item food frequency questionnaire completed by 535,824 (315,780 men and 220,044 women) participants. We used Cox proportional hazard regression models to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each diet quality index and PDAC. During follow-up through 2011 (15.5-year median), 3,137 incident PDAC cases were identified. Compared to those with the lowest adherence quintiles (Q1), participants with the highest adherence (Q5) [HRs (95% CIs)] to the HEI-2015 [0.84 (0.75, 0.94)], aMED [0.82 (0.73, 0.93)], DASH-Fung [0.85 (0.77, 0.95)], and DASH-Mellen [0.86 (0.77, 0.96)] had a statistically significant lower PDAC risk but not the AHEI-2010 [0.93 (0.83, 1.04)]. This prospective observational study supports the hypothesis that greater adherence to the HEI-2015, aMED, and DASH dietary recommendations may reduce PDAC.
    Keywords:  AHEI-2010; DASH; Diet; HEI-2015; aMED; pancreatic cancer
  20. Cancer Res. 2022 Apr 26. OF1-OF9
      Cancer is an evolutionary process that is characterized by the emergence of multiple genetically distinct populations or clones within the primary tumor. Intratumor heterogeneity provides a substrate for the selection of adaptive clones, such as those that lead to metastasis. Comparative molecular studies of primary tumors and metastases have identified distinct genomic features associated with the development of metastases. In this review, we discuss how these insights could inform clinical decision-making and uncover rational antimetastasis treatment strategies.
  21. Nature. 2022 Apr 27.
      Colorectal cancer (CRC) is among the most frequent forms of cancer, and new strategies for its prevention and therapy are urgently needed1. Here we identify a metabolite signalling pathway that provides actionable insights towards this goal. We perform a dietary screen in autochthonous animal models of CRC and find that ketogenic diets exhibit a strong tumour-inhibitory effect. These properties of ketogenic diets are recapitulated by the ketone body β-hydroxybutyrate (BHB), which reduces the proliferation of colonic crypt cells and potently suppresses intestinal tumour growth. We find that BHB acts through the surface receptor Hcar2 and induces the transcriptional regulator Hopx, thereby altering gene expression and inhibiting cell proliferation. Cancer organoid assays and single-cell RNA sequencing of biopsies from patients with CRC provide evidence that elevated BHB levels and active HOPX are associated with reduced intestinal epithelial proliferation in humans. This study thus identifies a BHB-triggered pathway regulating intestinal tumorigenesis and indicates that oral or systemic interventions with a single metabolite may complement current prevention and treatment strategies for CRC.
  22. Trends Cell Biol. 2022 Apr 25. pii: S0962-8924(22)00077-0. [Epub ahead of print]
      Biomolecular condensates are membraneless organelles (MLOs) that are enriched in specific proteins and nucleic acids, compartmentalized to perform biochemical functions. Such condensates are formed by phase separation (PS) enabled by protein domains that allow multivalent interactions. Chromosomal translocation-derived in-frame gene fusions often generate proteins with non-native domain combinations that rewire protein-protein interaction networks. Several recent studies have shown that, for a subset of these fusion proteins, pathogenesis can be driven by the ability of the fusion protein to undergo phase transitions at non-physiological cellular locations to form ectopic condensates. We highlight how such ectopic phase transitions can alter biological processes and posit that dysfunction via protein PS at non-physiological locations represents a generic route to oncogenic transformation.
    Keywords:  biomolecular condensates; liquid–liquid phase separation; oncofusion; oncogenesis; prion-like domain
  23. Curr Protoc. 2022 Apr;2(4): e422
      Pancreatitis occurs in two forms defined by its chronicity. Acute pancreatitis (AP) occurs suddenly and only lasts for several days. Consequently, most patients with AP recover without permanent damage to the pancreas, and about 20% of patients with AP have severe disease. In contrast, chronic pancreatitis (CP) is a long-lasting inflammation that causes permanent damage to pancreatic tissue; consequently, this form is marked by the emergence of persistent endocrine and exocrine pancreatic insufficiency. Despite these differences, AP and CP share central mechanisms of disease: in both forms, inflammation is initiated and/or sustained by the intrapancreatic activation of pancreatic digestive enzymes followed by the autodigestion of pancreatic tissues. In addition, in both forms enzymatic damage is accompanied by changes in intestinal permeability and entry of commensal organisms into the pancreas where they elicit innate immune responses that ultimately dominate and define pancreatic inflammation. In the murine models of AP and CP described here, both of these elements of pancreatitis pathogenesis are taken into account. Thus, in one approach mice are administered high doses of cerulein, a cholecystokinin analog with the ability at this dose to induce excessive activation of the cholecystokinin receptor expressed in pancreatic acinar cells and the release of active trypsin that causes both direct and indirect acinar damages due to entry of commensal organisms and stimulation of innate immune responses. In a second approach mice are administered low doses of cerulein, which causes little or no damage to the pancreas unless given along with nucleotide-binding oligomerization domain 1 (NOD1) ligand, which in the presence of low-dose cerulein administration induces a pathologic innate immune response mediated by NOD1. These approaches are adopted to produce AP when cerulein or cerulein plus NOD1 ligand is applied only once or to produce CP when a similar regimen is applied multiple times. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Cerulein-induced acute pancreatitis Alternate Protocol 1: Acute pancreatitis induced by cerulein and NOD1 ligand Basic Protocol 2: Cerulein-induced chronic pancreatitis Alternate Protocol 2: Chronic pancreatitis induced by cerulein and NOD1 ligand Support Protocol: Isolation of pancreatic mononuclear cells.
    Keywords:  NOD1; acute pancreatitis; cholecystokinin; chronic pancreatitis
  24. Cell. 2022 Apr 28. pii: S0092-8674(22)00398-1. [Epub ahead of print]185(9): 1455-1470
      Diet as a whole, encompassing food composition, calorie intake, and the length and frequency of fasting periods, affects the time span in which health and functional capacity are maintained. Here, we analyze aging and nutrition studies in simple organisms, rodents, monkeys, and humans to link longevity to conserved growth and metabolic pathways and outline their role in aging and age-related disease. We focus on feasible nutritional strategies shown to delay aging and/or prevent diseases through epidemiological, model organism, clinical, and centenarian studies and underline the need to avoid malnourishment and frailty. These findings are integrated to define a longevity diet based on a multi-pillar approach adjusted for age and health status to optimize lifespan and healthspan in humans.
  25. J Surg Oncol. 2022 Apr 27.
      BACKGROUND: Few studies have evaluated outcomes of total neoadjuvant therapy (TNT) compared with single modality neoadjuvant therapy (SMNT) or surgery first (SF) for pancreatic ductal adenocarcinoma (PDAC).METHODS: A single-institution retrospective review of PDAC patients who underwent pancreatectomy was conducted (1993-2019). Overall survival (OS) estimates from diagnosis and from surgery were determined using Kaplan-Meier methods; Cox proportional hazards models adjusted for covariates.
    RESULTS: Surgery was performed upfront (SF) in 168 (46.9%), while 111 (31.0%) had chemotherapy or chemoradiation before resection (SMNT), and 79 (22.1%) underwent TNT (chemotherapy and chemoradiation). Resection margins were more frequently R0 in the TNT group (86.1%) compared with SMNT (64.0%) and SF (72%) (p < 0.001). Complete pathologic response was more common in the TNT group (10.1%) compared with SMNT (3.6%) or SF (0.6%) (p = 0.001), resulting in prolonged survival (median OS = 100.2 months). TNT patients demonstrated longer median OS from surgery (33.6 months) compared with SF (19.1 months) and SMNT (17.4 months) (p = 0.010), which persisted after controlling for covariates.
    CONCLUSIONS: TNT is associated with more frequent complete pathologic response, a higher rate of margin negative resection, and prolonged OS as compared with SF or SMNT. Additional studies to identify subgroups that derive the greatest benefit are warranted.
    Keywords:  cancer; neoadjuvant; outcomes; pancreas; survival
  26. Mol Metab. 2022 Apr 22. pii: S2212-8778(22)00057-6. [Epub ahead of print] 101488
      OBJECTIVE: IL-6 is an important contributor to glucose and energy homeostasis through changes in whole-body glucose disposal, insulin sensitivity, food intake and energy expenditure. However, the relative contributions of peripheral versus central IL-6 signaling to these metabolic actions are presently unclear. A conditional mouse model with reduced brain IL-6Ra expression was used to explore how blunted central IL-6 signaling alters metabolic status in lean and obese mice.METHODS: Transgenic mice with reduced levels of central IL-6 receptor alpha (IL-6Ra) levels (IL-6Ra KD mice) and Nestin Cre controls (Cre+/- mice) were fed standard chow or high-fat diet for 20 weeks. Obese and lean mouse cohorts underwent metabolic phenotyping with various measures of energy and glucose homeostasis determined. Glucose-stimulated insulin secretion was assessed in vivo and ex vivo in both mouse groups.
    RESULTS: IL-6Ra KD mice exhibited altered body fat mass, liver steatosis, plasma insulin, IL-6 and NEFA levels versus Cre+/- mice in a diet-dependent manner. IL-6Ra KD mice had increased food intake, higher RER, decreased energy expenditure with diminished cold tolerance compared to Cre+/- controls. Standard chow-fed IL-6Ra KD mice displayed reduced plasma insulin and glucose-stimulated insulin secretion with impaired glucose disposal and unchanged insulin sensitivity. Isolated pancreatic islets from standard chow-fed IL-6Ra KD mice showed comparable morphology and glucose-stimulated insulin secretion to Cre+/- controls. The diminished in vivo insulin secretion exhibited by IL-6Ra KD mice was recovered by blockade of autonomic ganglia.
    CONCLUSIONS: This study shows that central IL-6Ra signaling contributes to glucose and energy control mechanisms by regulating food intake, energy expenditure, fuel flexibility and insulin secretion. A plausible mechanism linking central IL-6Ra signaling and pancreatic insulin secretion is through the modulation of autonomic output activity. Thus, brain IL-6 signaling may contribute to the central adaptive mechanisms engaged in response to metabolic stress.
    Keywords:  Autonomic output; Energy expenditure; Food intake; Insulin secretion; Interleukin-6
  27. J Gastrointest Cancer. 2022 Apr 26.
      PURPOSE: Pancreatic cancer is characterized by its high mortality, usually attributed to its diagnosis in already advanced stages. This article aims at presenting an overview of the economic burden of pancreatic cancer in Europe.METHODS: A systematic literature review was conducted. It made use of the search engines EconLit, Google Scholar, PubMed and Web of Science, and retrieved articles published after December 31st, 1992, and before April 1st, 2020. Study characteristics and cost information were extracted. Cost per patient and cost per patient per month (PPM) were calculated, and drivers of estimate heterogeneity was analysed. Results were converted into 2019 Euros.
    RESULTS: The literature review yielded 26 studies on the economic burden attributable to pancreatic cancer in Europe. Cost per patient was on average 40,357 euros (median 15,991), while figures PPM were on average 3,656 euros (median 1,536). Indirect costs were found to be on average 154,257 euros per patient or 14,568 euros PPM, while direct costs 20,108 euros per patient and 2,004 euros PPM. Nevertheless, variation on cost estimations was large and driven by study methodology, patient sample characteristics, such as type of tumour and cancer stage and cost components included in analyses, such as type of procedure.
    CONCLUSION: Pancreatic cancer direct costs PPM are in the upper bound relative to other cancer types; however, direct per patient costs are likely to be lower because of shorter survival. Indirect costs are substantial, mainly attributed to high mortality.
    Keywords:  Cancer; Economic Burden; Europe; Pancreas; Review
  28. Nat Rev Clin Oncol. 2022 Apr 28.
      Numerous agents targeting various phosphatidylinositol 3-kinase (PI3K) pathway components, including PI3K, AKT and mTOR, have been tested in oncology clinical trials, resulting in regulatory approvals for the treatment of selected patients with breast cancer, certain other solid tumours or particular haematological malignancies. However, given the prominence of PI3K signalling in cancer and the crucial role of this pathway in linking cancer growth with metabolism, these clinical results could arguably be improved upon. In this Review, we discuss past and present efforts to overcome the somewhat limited clinical efficacy of PI3Kα pathway inhibitors, including optimization of inhibitor specificity, patient selection and biomarkers across cancer types, with a focus on breast cancer, as well as identification and abrogation of signalling-related and metabolic mechanisms of resistance, and interventions to improve management of prohibitive adverse events. We highlight the advantages and limitations of laboratory-based model systems used to study the PI3K pathway, and propose technologies and experimental inquiries to guide the future clinical deployment of PI3K pathway inhibitors in the treatment of cancer.
  29. Cell Res. 2022 Apr 27.
      Biomolecular condensation driven by liquid-liquid phase separation (LLPS) is key to assembly of membraneless organelles in numerous crucial pathways. It is largely unknown how cellular structures or components spatiotemporally regulate LLPS and condensate formation. Here we reveal that cytoskeletal dynamics can control the condensation of p62 bodies comprising the autophagic adaptor p62/SQSTM1 and poly-ubiquitinated cargos. Branched actin networks are associated with p62 bodies and are required for their condensation. Myosin 1D, a branched actin-associated motor protein, drives coalescence of small nanoscale p62 bodies into large micron-scale condensates along the branched actin network. Impairment of actin cytoskeletal networks compromises the condensation of p62 bodies and retards substrate degradation by autophagy in both cellular models and Myosin 1D knockout mice. Coupling of LLPS scaffold to cytoskeleton systems may represent a general mechanism by which cells exert spatiotemporal control over phase condensation processes.
  30. Mol Metab. 2022 Apr 22. pii: S2212-8778(22)00073-4. [Epub ahead of print] 101504
      OBJECTIVE: Exercise is a critical component of a healthy lifestyle and a key strategy for the prevention and management of metabolic disease. Identifying molecular mechanisms underlying adaptation in response to chronic physical activity is of critical interest in metabolic physiology. Circadian rhythms broadly modulate metabolism, including muscle substrate utilization and exercise capacity. Here, we define the molecular and physiological changes induced across the daily cycle by voluntary low intensity daily exercise.METHODS: Wildtype C57BL6/J male and female mice were housed with or without access to a running wheel for six weeks. Maximum running speed was measured at four different zeitgeber times (ZTs, hours after lights on) using either electrical or manual stimulation to motivate continued running on a motorized treadmill. RNA isolated from plantaris muscles at six ZTs was sequenced to establish the impact of daily activity on genome-wide transcription. Patterns of gene expression were analyzed using Gene Set Enrichment Analysis (GSEA) and Detection of Differential Rhythmicity (DODR). Blood glucose, lactate, and ketones, and muscle and liver glycogen were measured before and after exercise.
    RESULTS: We demonstrate that the use of mild electrical shocks to motivate running negatively impacts maximum running speed in mice, and describe a manual method to motivate running in rodent exercise studies. Using this method, we show that time of day influences the increase in exercise capacity afforded by six weeks of voluntary wheel running: when maximum running speed is measured at the beginning of the nighttime active period in mice, there is no measurable benefit from a history of daily voluntary running, while maximum increase in performance occurs at the end of the night. We show that daily voluntary exercise dramatically remodels the murine muscle circadian transcriptome. Finally, we describe daily rhythms in carbohydrate metabolism associated with the time-dependent response to moderate daily exercise in mice.
    CONCLUSIONS: Collectively, these data indicate that chronic nighttime physical activity dramatically remodels daily rhythms of murine muscle gene expression, which in turn support daily fluctuations in exercise performance.
    Keywords:  Circadian Clock; Exercise; Glycogen; Metabolism; Muscle
  31. Cell Rep Methods. 2021 Aug 23. 1(4): 100052
      Engineered synthetic biomolecular devices that integrate elaborate information processing and precisely regulate living cell behavior have potential in various applications. Although devices that directly regulate key biomolecules constituting inherent biological systems exist, no devices have been developed to control intracellular membrane architecture, contributing to the spatiotemporal functions of these biomolecules. This study developed a synthetic biomolecular device, termed inducible counter mitochondrial morphology (iCMM), to manipulate mitochondrial morphology, an emerging informative property for understanding physiopathological cellular behaviors, on a minute timescale by using a chemically inducible dimerization system. Using iCMM, we determined cellular changes by altering mitochondrial morphology in an unprecedented manner. This approach serves as a platform for developing more sophisticated synthetic biomolecular devices to regulate biological systems by extending manipulation targets from conventional biomolecules to mitochondria. Furthermore, iCMM might serve as a tool for uncovering the biological significance of mitochondrial morphology in various physiopathological cellular processes.
    Keywords:  Boolean logic gate; mitochondria; mitochondrial morphology; synthetic biocomputing device; synthetic biology
  32. Int J Cancer. 2022 Apr 25.
      Adjuvant chemotherapy has become standard of care for pancreatic ductal adenocarcinoma (PDAC) as it improves patient outcome. However, its clinical meaning in early-stage, UICC I tumors remains uncertain. We examined the effect of adjuvant therapy on disease-free survival (DFS) and overall survival (OS) of UICC stage I PDAC patients treated at an academic tertiary care center between 2000 and 2016. Among 124 patients (69 male, 55 female; median age 68 years, range 41 - 84 years) with UICC stage I disease, adjuvant therapy improved both DFS (19.8 vs 12.8 months, HR 0.59, 95%CI 0.37 - 0.94, P=.03) and OS (40.9 vs 20.3 months, HR 0.54, 95%CI 0.35 - 0.84, P=.005). Multivariate analyses and propensity score matching confirmed the prognostic impact of adjuvant therapy independent of localization, differentiation and R-status. Thus, every patient with UICC I PDAC should receive adjuvant chemotherapy as it may improve outcome significantly. Our findings support the concept of PDAC as systemic disease from early stages on.
    Keywords:  adjuvant therapy; early-stage pancreatic cancer; outcome
  33. BMC Cancer. 2022 Apr 27. 22(1): 463
      BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is an often fatal malignancy with an extremely low survival rate. Liver metastasis, which causes high mortality, is the most common recurring metastasis for PDAC. However, the mechanisms underlying this liver metastasis and associated candidate biomarkers are unknown.METHODS: We performed mRNA profiling comparisons in 8 primary tumors (T) and 12 liver metastases (M) samples using the Gene Expression Omnibus (GEO) database. After determining differentially expressed genes (DEG), gene ontology (GO), pathway enrichment and protein-protein interaction (PPI) network analyses were performed to determine DEG functions. Then, Cytoscape was used to screen out significant hub genes, after which their clinical relevance was investigated using The Cancer Genome Atlas (TCGA) resources. Furthermore, prognosis-associated gene expression was validated using Oncomine and TCGA database. Lastly, associations between prognosis-associated genes, immune cells and immunological checkpoint genes were evaluated using the Tumor Immune Estimation Resource (TIMER).
    RESULTS: In total, 102 genes were related to liver metastasis and predominantly involved in cell migration, motility, and adhesion. Using Cytoscape, this number was narrowed down to 16 hub genes. Elevated mRNA expression levels for two of these genes, SPARC (P = 0.019) and TPM1 (P = 0.037) were significantly correlated with poor disease prognosis. For the remaining 14, expression was not related to overall patient survival. SPARC had higher expression in patients with metastatic PDAC than those with non-metastatic PDAC in TCGA dataset. SPARC and TPM1 levels were also positively correlated with the immune infiltration of specific cell types. Additionally, both genes exhibited strong co-expression associations with immune checkpoint genes.
    CONCLUSIONS: Combined, we suggest SPARC has high potential as biomarker to predict liver metastasis during PDAC. Additionally, both SPARC and TPM1 appeared to recruit and regulate immune-infiltrating cells during these pathophysiological processes.
    Keywords:  Bioinformatics analysis; Biomarker; Liver metastasis; Pancreatic ductal adenocarcinoma; SPARC; TPM1
  34. Geroscience. 2022 Apr 26.
      Obesity and aging have both seen dramatic increases in prevalence throughout society. This review seeks to highlight common pathologies that present with obesity, along with the underlying risk factors, that have remarkable similarity to what is observed in the aged. These include skeletal muscle dysfunction (loss of quantity and quality), significant increases in adiposity, systemic alterations to autonomic dysfunction, reduction in nitric oxide bioavailability, increases in oxidant stress and inflammation, dysregulation of glucose homeostasis, and mitochondrial dysfunction. This review is organized by the aforementioned indices and succinctly highlights literature that demonstrates similarities between the aged and obese phenotypes in both human and animal models. As aging is an inevitability and obesity prevalence is unlikely to significantly decrease in the near future, these two phenotypes will ultimately combine as a multidimensional syndrome (a pathology termed sarcopenic obesity). Whether the pre-mature aging indices accompanying obesity are additive or synergistic upon entering aging is not yet well defined, but the goal of this review is to illustrate the potential consequences of a double aged phenotype in sarcopenic obesity. Clinically, the modifiable risk factors could be targeted specifically in obesity to allow for increased health span in the aged and sarcopenic obese populations.
    Keywords:  Aging; Diabetes; Inflammation; Nitric oxide; Obesity; Oxidant stress; Sarcopenic obesity; Skeletal muscle
  35. Nat Commun. 2022 Apr 29. 13(1): 2339
      Recent technological advancements have enabled spatially resolved transcriptomic profiling but at multi-cellular pixel resolution, thereby hindering the identification of cell-type-specific spatial patterns and gene expression variation. To address this challenge, we develop STdeconvolve as a reference-free approach to deconvolve underlying cell types comprising such multi-cellular pixel resolution spatial transcriptomics (ST) datasets. Using simulated as well as real ST datasets from diverse spatial transcriptomics technologies comprising a variety of spatial resolutions such as Spatial Transcriptomics, 10X Visium, DBiT-seq, and Slide-seq, we show that STdeconvolve can effectively recover cell-type transcriptional profiles and their proportional representation within pixels without reliance on external single-cell transcriptomics references. STdeconvolve provides comparable performance to existing reference-based methods when suitable single-cell references are available, as well as potentially superior performance when suitable single-cell references are not available. STdeconvolve is available as an open-source R software package with the source code available at .
  36. Cell Rep. 2022 Apr 26. pii: S2211-1247(22)00491-0. [Epub ahead of print]39(4): 110730
      Mammals have limited regenerative capacity, whereas some vertebrates, like fish and salamanders, are able to regenerate their organs efficiently. The regeneration in these species depends on cell dedifferentiation followed by proliferation. We generate a mouse model that enables the inducible expression of the four Yamanaka factors (Oct-3/4, Sox2, Klf4, and c-Myc, or 4F) specifically in hepatocytes. Transient in vivo 4F expression induces partial reprogramming of adult hepatocytes to a progenitor state and concomitantly increases cell proliferation. This is indicated by reduced expression of differentiated hepatic-lineage markers, an increase in markers of proliferation and chromatin modifiers, global changes in DNA accessibility, and an acquisition of liver stem and progenitor cell markers. Functionally, short-term expression of 4F enhances liver regenerative capacity through topoisomerase2-mediated partial reprogramming. Our results reveal that liver-specific 4F expression in vivo induces cellular plasticity and counteracts liver failure, suggesting that partial reprogramming may represent an avenue for enhancing tissue regeneration.
    Keywords:  CP: Stem cell research; dedifferentiation; liver; regeneration; reprogramming
  37. Proc Natl Acad Sci U S A. 2022 May 03. 119(18): e2120512119
      SignificanceKRASG12C inhibitors have demonstrated promising efficacy in non-small-cell lung cancer patients harboring the KRASG12C mutation. However, the mechanism of resistance remains to be fully understood. To understand the consequences of single amino acid changes within KRASG12C, we conducted a saturation mutagenesis screen of the KRASG12C protein and assessed the mutational impact on drug sensitivity. Not only did our screen reveal resistant hits that were identified from patients' samples (V8L, C12F, R68S, H95D, H95R, and Y96C), but we also discovered variants that sensitize the inhibition. Furthermore, we examined the human genetics databases and identified germline or somatic KRAS mutations that appear among the strong resistance hits. Our study positions future drug discovery targeting KRASG12C toward focusing on inhibitors preserving potency against resistance mutations at key residues.
    Keywords:  KRASG12C; adagrasib; drug resistance; mutagenesis screen; sotorasib