bims-cagime 2022-07-10 papers

bims-cagime

Biomed News

on Cancer, aging and metabolism

Issue of 2022–07–10
thirty-six papers selected by
Kıvanç Görgülü, Technical University of Munich

Autophagy Loss Impedes Cancer-Associated Fibroblast Activation via Downregulating Proline Biosynthesis.
Mechanisms of mitochondrial respiratory adaptation.
STAT3 in tumor fibroblasts promotes an immunosuppressive microenvironment in pancreatic cancer.
Emerging Role of CREB in Epithelial to Mesenchymal Plasticity of Pancreatic Cancer.
Modulating mitofusins to control mitochondrial function and signaling.
CHAPERONE-MEDIATED AUTOPHAGY PROTECTS AGAINST ATHEROSCLEROSIS.
Secretory autophagy during lysosome inhibition (SALI).
CEND-1: a game changer for pancreatic cancer chemotherapy?
Cell competition and the regulative nature of early mammalian development.
Cytokine-Mediated STAT3 Transcription Supports ATGL/CGI-58-Dependent Adipocyte Lipolysis in Cancer Cachexia.
PRMT5 activates AKT via methylation to promote tumor metastasis.
Targeting telomeres: advances in telomere maintenance mechanism-specific cancer therapies.
Efficient correction of oncogenic KRAS and TP53 mutations through CRISPR base editing.
CRISPR screening uncovers a central requirement for HHEX in pancreatic lineage commitment and plasticity restriction.
Dual αV-integrin and neuropilin-1 targeting peptide CEND-1 plus nab-paclitaxel and gemcitabine for the treatment of metastatic pancreatic ductal adenocarcinoma: a first-in-human, open-label, multicentre, phase 1 study.
Senescence: An Identity Crisis Originating from Deep Within the Nucleus.
Heterogeneity of metabolic adaptive capacity affects the prognosis among pancreatic ductal adenocarcinomas.
SQSTM1, lipid droplets and current state of their lipophagy affairs.
Oncogenic gain of function due to p53 amyloids by aberrant alteration of cell cycle and proliferation.
Genetically controlled mtDNA deletions prevent ROS damage by arresting oxidative phosphorylation.
Aging clocks & mortality timers, methylation, glycomic, telomeric and more. A window to measuring biological age.
Ribosomopathies and cancer: pharmacological implications.
Malondialdehyde-acetaldehyde extracellular matrix protein adducts attenuate unfolded protein response during alcohol and smoking-induced pancreatitis.
Inhibition of lysosomal acid β-glucosidase and induces cell apoptosis via impairing mitochondrial clearance in pancreatic cancer.
Ferroptosis turns 10: Emerging mechanisms, physiological functions, and therapeutic applications.
Dissecting the treatment-naive ecosystem of human melanoma brain metastasis.
Weight Cycling Impairs Pancreatic Insulin Secretion but Does Not Perturb Whole-Body Insulin Action in Diet-Induced Obese Mice.
Systemic approaches using single cell transcriptome reveal that C/EBPγ regulates autophagy under amino acid starved condition.
Liquid-liquid phase separation in tumor biology.
Endosomal LC3C-pathway selectively targets plasma membrane cargo for autophagic degradation.
Plant-Based and Ketogenic Diets As Diverging Paths to Address Cancer: A Review.
Metabolic Labeling-Based Chemoproteomics Establishes Choline Metabolites as Protein Function Modulators.
The Differential Clinical Impacts of Cachexia and Sarcopenia on the Prognosis of Advanced Pancreatic Cancer.
A multiplex implantable microdevice assay identifies synergistic combinations of cancer immunotherapies and conventional drugs.
Expanding the view of the molecular mechanisms of autophagy pathway.
Local and systemic immune profiles of human pancreatic ductal adenocarcinoma revealed by single-cell mass cytometry.

Autophagy. 2022 Jul 04.

Autophagy Loss Impedes Cancer-Associated Fibroblast Activation via Downregulating Proline Biosynthesis.

Jingru Bai, Tong Liu, Bo Tu, Meng Yuan, Zhaoqi Shu, Minghe Fan, Sihan Huo, Yuyao Guo, Lina Wang, Hua Wang, Ying Zhao.

  Cancer-associated fibroblasts (CAFs) are considered one of the most critical stromal cells that interact with pancreatic ductal adenocarcinoma (PDAC) and promote tumor growth, metastasis, and treatment resistance. Previous studies illustrated macroautophagy/autophagy contributes to CAF activation during tumor progression. Here in our study, we found that autophagy deficiency in CAFs impedes CAF activation by inhibiting proline biosynthesis and collagen production. Furthermore, we uncovered that autophagy promotes proline biosynthesis through mitophagy-mediated regulation of NADK2 (NAD kinase 2, mitochondrial), an enzyme responsible for production of mitochondrial NADP(H). Using an orthotopic mouse model of PDAC, we found that inhibiting mitophagy by targeting PRKN (parkin RBR E3 ubiquitin protein ligase) in the stroma reduced tumor weight. Thus, inhibition of CAFs mitophagy might be an attractive strategy for stroma-focused anti-cancer intervention.

Keywords:  NADK2; autophagy; cancer-associated fibroblasts (CAFs); mitophagy; proline biosynthesis

DOI:  https://doi.org/10.1080/15548627.2022.2093026
Nat Rev Mol Cell Biol. 2022 Jul 08.

Mechanisms of mitochondrial respiratory adaptation.

Christopher F Bennett, Pedro Latorre-Muro, Pere Puigserver.

Mitochondrial energetic adaptations encompass a plethora of conserved processes that maintain cell and organismal fitness and survival in the changing environment by adjusting the respiratory capacity of mitochondria. These mitochondrial responses are governed by general principles of regulatory biology exemplified by changes in gene expression, protein translation, protein complex formation, transmembrane transport, enzymatic activities and metabolite levels. These changes can promote mitochondrial biogenesis and membrane dynamics that in turn support mitochondrial respiration. The main regulatory components of mitochondrial energetic adaptation include: the transcription coactivator peroxisome proliferator-activated receptor-γ (PPARγ) coactivator 1α (PGC1α) and associated transcription factors; mTOR and endoplasmic reticulum stress signalling; TOM70-dependent mitochondrial protein import; the cristae remodelling factors, including mitochondrial contact site and cristae organizing system (MICOS) and OPA1; lipid remodelling; and the assembly and metabolite-dependent regulation of respiratory complexes. These adaptive molecular and structural mechanisms increase respiration to maintain basic processes specific to cell types and tissues. Failure to execute these regulatory responses causes cell damage and inflammation or senescence, compromising cell survival and the ability to adapt to energetically demanding conditions. Thus, mitochondrial adaptive cellular processes are important for physiological responses, including to nutrient availability, temperature and physical activity, and their failure leads to diseases associated with mitochondrial dysfunction such as metabolic and age-associated diseases and cancer.

DOI: https://doi.org/10.1038/s41580-022-00506-6
Life Sci Alliance. 2022 Nov;pii: e202201460. [Epub ahead of print]5(11):

STAT3 in tumor fibroblasts promotes an immunosuppressive microenvironment in pancreatic cancer.

Julia E Lefler, Catherine B MarElia-Bennett, Katie A Thies, Blake E Hildreth, Sudarshana M Sharma, Jason R Pitarresi, Lu Han, Caroline Everett, Christopher Koivisto, Maria C Cuitino, Cynthia D Timmers, Elizabeth O'Quinn, Melodie Parrish, Martin J Romeo, Amanda J Linke, G Aaron Hobbs, Gustavo Leone, Denis C Guttridge, Teresa A Zimmers, Gregory B Lesinski, Michael C Ostrowski.

Pancreatic ductal adenocarcinoma (PDAC) is associated with an incredibly dense stroma, which contributes to its recalcitrance to therapy. Cancer-associated fibroblasts (CAFs) are one of the most abundant cell types within the PDAC stroma and have context-dependent regulation of tumor progression in the tumor microenvironment (TME). Therefore, understanding tumor-promoting pathways in CAFs is essential for developing better stromal targeting therapies. Here, we show that disruption of the STAT3 signaling axis via genetic ablation of Stat3 in stromal fibroblasts in a Kras G12D PDAC mouse model not only slows tumor progression and increases survival, but re-shapes the characteristic immune-suppressive TME by decreasing M2 macrophages (F480+CD206+) and increasing CD8+ T cells. Mechanistically, we show that loss of the tumor suppressor PTEN in pancreatic CAFs leads to an increase in STAT3 phosphorylation. In addition, increased STAT3 phosphorylation in pancreatic CAFs promotes secretion of CXCL1. Inhibition of CXCL1 signaling inhibits M2 polarization in vitro. The results provide a potential mechanism by which CAFs promote an immune-suppressive TME and promote tumor progression in a spontaneous model of PDAC.

DOI: https://doi.org/10.26508/lsa.202201460
Front Oncol. 2022 ;12 925687

Emerging Role of CREB in Epithelial to Mesenchymal Plasticity of Pancreatic Cancer.

Siddharth Mehra, Samara Singh, Nagaraj Nagathihalli.

  Pancreatic ductal adenocarcinoma (PDAC) is an aggressive solid malignancy with a high rate of metastasis and therapeutic resistance as its major hallmarks. Although a defining mutational event in pancreatic cancer initiation is the presence of oncogenic KRAS, more advanced PDAC lesions accumulate additional genomic alterations, including loss of tumor suppressor gene TP53. Co-occurrence of mutant KRAS and TP53 in PDAC promotes hyperactivation of cancer cell signaling pathways driving epithelial to mesenchymal plasticity (EMP). The cellular process of EMP influences the biological behavior of cancer cells by increasing their migratory and invasive properties, thus promoting metastasis. Our previous work has demonstrated that oncogenic KRAS-mediated activation of cyclic AMP response element-binding protein 1 (CREB) is one of the critical drivers of PDAC aggressiveness. The therapeutic approach of targeting this key transcription factor attenuates tumor burden in genetically engineered mouse models (GEMMs) of this disease. Herein, we discuss the significant role of CREB in perpetuating disease aggressiveness and therapeutic resistance through the EMP process. Furthermore, this review updates the therapeutic implications of targeting CREB, highlighting the challenges and emerging approaches in PDAC.

Keywords:  CREB; MicroRNAs; RAS; epithelial to mesenchymal plasticity; metastasis; pancreatic cancer; therapeutic resistance

DOI:  https://doi.org/10.3389/fonc.2022.925687
Nat Commun. 2022 Jul 07. 13(1): 3775

Modulating mitofusins to control mitochondrial function and signaling.

Emmanouil Zacharioudakis, Bogos Agianian, Vasantha Kumar Mv, Nikolaos Biris, Thomas P Garner, Inna Rabinovich-Nikitin, Amanda T Ouchida, Victoria Margulets, Lars Ulrik Nordstrøm, Joel S Riley, Igor Dolgalev, Yun Chen, Andre J H Wittig, Ryan Pekson, Chris Mathew, Peter Wei, Aristotelis Tsirigos, Stephen W G Tait, Lorrie A Kirshenbaum, Richard N Kitsis, Evripidis Gavathiotis.

Mitofusins reside on the outer mitochondrial membrane and regulate mitochondrial fusion, a physiological process that impacts diverse cellular processes. Mitofusins are activated by conformational changes and subsequently oligomerize to enable mitochondrial fusion. Here, we identify small molecules that directly increase or inhibit mitofusins activity by modulating mitofusin conformations and oligomerization. We use these small molecules to better understand the role of mitofusins activity in mitochondrial fusion, function, and signaling. We find that mitofusin activation increases, whereas mitofusin inhibition decreases mitochondrial fusion and functionality. Remarkably, mitofusin inhibition also induces minority mitochondrial outer membrane permeabilization followed by sub-lethal caspase-3/7 activation, which in turn induces DNA damage and upregulates DNA damage response genes. In this context, apoptotic death induced by a second mitochondria-derived activator of caspases (SMAC) mimetic is potentiated by mitofusin inhibition. These data provide mechanistic insights into the function and regulation of mitofusins as well as small molecules to pharmacologically target mitofusins.

DOI: https://doi.org/10.1038/s41467-022-31324-1
Autophagy. 2022 Jul 05.

CHAPERONE-MEDIATED AUTOPHAGY PROTECTS AGAINST ATHEROSCLEROSIS.

Julio Madrigal-Matute, Ana Maria Cuervo, Judith C Sluimer.

  Atherosclerosis, the leading cause of cardiovascular death, is driven by hyperlipidemia, inflammation and aggravated by aging. As chaperone-mediated autophagy (CMA), a selective type of lysosomal degradation for intracellular proteins, diminishes with age and is inhibited by lipid excess, we studied if the decline in CMA could contribute to atherosclerosis pathogenesis. We found that CMA declines in human and murine vasculature with disease progression. Inhibition and reactivation of CMA using transgenic mouse models establishes a protective effect of CMA against atherogenesis. CMA upregulation ameliorates both systemic metabolic parameters, and vascular cell function. Our work suggests CMA reactivation could be a viable therapeutic strategy to prevent and reduce cardiovascular disease.

Keywords:  Cardiovascular disease; cholesterol; inflammation; insulin; lysosomes; macrophages; smooth muscle cells

DOI:  https://doi.org/10.1080/15548627.2022.2096397
Autophagy. 2022 Jul 04.

Secretory autophagy during lysosome inhibition (SALI).

Jayanta Debnath, Andrew M Leidal.

  Both macroautophagy/autophagy and extracellular vesicle (EV) secretion pathways converge upon the endolysosome system. Although lysosome impairment leads to defects in autophagic degradation, the impact of such dysfunction on EV secretion remains poorly understood. Recently, we uncovered a novel secretory autophagy pathway that employs EVs and nanoparticles (EVPs) for the secretion of autophagy cargo receptors outside the cell when either autophagosome maturation or lysosomal function is blocked. We term this process secretory autophagy during lysosome inhibition (SALI). SALI functionally requires multiple steps in classical autophagosome formation and the small GTPase RAB27A. Because the intracellular accumulation of autophagy cargo receptors perturbs cell signaling and quality control pathways, we propose that SALI functions as a failsafe mechanism to preserve protein and cellular homeostasis when autophagic or lysosomal degradation is impaired.

Keywords:  Autophagy cargo receptors; extracellular vesicles; lysosome; proteostasis; secretory autophagy; vesicular trafficking

DOI:  https://doi.org/10.1080/15548627.2022.2095788
Lancet Gastroenterol Hepatol. 2022 Jul 05. pii: S2468-1253(22)00197-2. [Epub ahead of print]

CEND-1: a game changer for pancreatic cancer chemotherapy?

Christoph Springfeld, John P Neoptolemos.

DOI: https://doi.org/10.1016/S2468-1253(22)00197-2
Cell Stem Cell. 2022 Jul 07. pii: S1934-5909(22)00252-1. [Epub ahead of print]29(7): 1018-1030

Cell competition and the regulative nature of early mammalian development.

Jennifer Nichols, Ana Lima, Tristan A Rodríguez.

The mammalian embryo exhibits a remarkable plasticity that allows it to correct for the presence of aberrant cells, adjust its growth so that its size is in accordance with its developmental stage, or integrate cells of another species to form fully functional organs. Here, we will discuss the contribution that cell competition, a quality control that eliminates viable cells that are less fit than their neighbors, makes to this plasticity. We will do this by reviewing the roles that cell competition plays in the early mammalian embryo and how they contribute to ensure normal development of the embryo.

DOI: https://doi.org/10.1016/j.stem.2022.06.003
Front Oncol. 2022 ;12 841758

Cytokine-Mediated STAT3 Transcription Supports ATGL/CGI-58-Dependent Adipocyte Lipolysis in Cancer Cachexia.

Aakash Y Gandhi, Jinhai Yu, Arun Gupta, Tong Guo, Puneeth Iyengar, Rodney E Infante.

  Adipose tissue inflammation is observed in multiple metabolically-altered states including cancer-associated cachexia and obesity. Although cachexia is a syndrome of adipose loss and obesity is a disease of adipose excess, both pathologies demonstrate increases in circulating levels of IL-6 family cytokines, β-adrenergic signaling, and adipocyte lipolysis. While β-adrenergic-stimulated adipocyte lipolysis is well described, there is limited mechanistic insight into how cancer cachexia-associated inflammatory cytokines contribute to adipocyte lipolysis under pathologic conditions. Here, we set out to compare adipocyte lipolysis signaling by cancer cachexia-associated IL-6 family cytokines (IL-6 and LIF) to that of the β-adrenergic agonist isoproterenol. Unlike isoproterenol, the IL-6 family of cytokines required JAK/STAT3-dependent transcriptional changes to induce adipocyte lipolysis. Furthermore, cachexia-associated cytokines that used STAT3 to induce lipolysis were primarily dependent on the lipase ATGL and its cofactor CGI-58 rather than lipases HSL and MAGL. Finally, administration of JAK but not β-adrenergic inhibitors suppressed adipose STAT3 phosphorylation and associated adipose wasting in a murine model of cancer cachexia characterized by increased systemic IL-6 family cytokine levels. Combined, our results demonstrate how the IL-6 family of cytokines diverge from β-adrenergic signals by employing JAK/STAT3-driven transcriptional changes to promote adipocyte ATGL/CGI-58-dependent lipolysis contributing to adipose wasting in cancer cachexia.

Keywords:  adipocyte lipolysis; adipose triglyceride lipase (ATGL); adipose wasting (malnutrition); cancer cachexia; interleukin-6 (IL-6); leukemia inhibitor factor; signal transducer and activator of transcription 3 (STAT3); β-adrenergic signaling

DOI:  https://doi.org/10.3389/fonc.2022.841758
Nat Commun. 2022 Jul 08. 13(1): 3955

PRMT5 activates AKT via methylation to promote tumor metastasis.

Lei Huang, Xiao-Ou Zhang, Esteban J Rozen, Xiaomei Sun, Benjamin Sallis, Odette Verdejo-Torres, Kim Wigglesworth, Daniel Moon, Tingting Huang, John P Cavaretta, Gang Wang, Lei Zhang, Jason M Shohet, Mary M Lee, Qiong Wu.

Protein arginine methyltransferase 5 (PRMT5) is the primary methyltransferase generating symmetric-dimethyl-arginine marks on histone and non-histone proteins. PRMT5 dysregulation is implicated in multiple oncogenic processes. Here, we report that PRMT5-mediated methylation of protein kinase B (AKT) is required for its subsequent phosphorylation at Thr308 and Ser473. Moreover, pharmacologic or genetic inhibition of PRMT5 abolishes AKT1 arginine 15 methylation, thereby preventing AKT1 translocation to the plasma membrane and subsequent recruitment of its upstream activating kinases PDK1 and mTOR2. We show that PRMT5/AKT signaling controls the expression of the epithelial-mesenchymal-transition transcription factors ZEB1, SNAIL, and TWIST1. PRMT5 inhibition significantly attenuates primary tumor growth and broadly blocks metastasis in multiple organs in xenograft tumor models of high-risk neuroblastoma. Collectively, our results suggest that PRMT5 inhibition augments anti-AKT or other downstream targeted therapeutics in high-risk metastatic cancers.

DOI: https://doi.org/10.1038/s41467-022-31645-1
Nat Rev Cancer. 2022 Jul 05.

Targeting telomeres: advances in telomere maintenance mechanism-specific cancer therapies.

Jixuan Gao, Hilda A Pickett.

Cancer cells establish replicative immortality by activating a telomere-maintenance mechanism (TMM), be it telomerase or the alternative lengthening of telomeres (ALT) pathway. Targeting telomere maintenance represents an intriguing opportunity to treat the vast majority of all cancer types. Whilst telomerase inhibitors have historically been heralded as promising anticancer agents, the reality has been more challenging, and there are currently no therapeutic options for cancer types that use ALT despite their aggressive nature and poor prognosis. In this Review, we discuss the mechanistic differences between telomere maintenance by telomerase and ALT, the current methods used to detect each mechanism, the utility of these tests for clinical diagnosis, and recent developments in the therapeutic strategies being employed to target both telomerase and ALT. We present notable developments in repurposing established therapeutic agents and new avenues that are emerging to target cancer types according to which TMM they employ. These opportunities extend beyond inhibition of telomere maintenance, by finding and exploiting inherent weaknesses in the telomeres themselves to trigger rapid cellular effects that lead to cell death.

DOI: https://doi.org/10.1038/s41568-022-00490-1
Cancer Res. 2022 Jul 08. pii: can.21.2519. [Epub ahead of print]

Efficient correction of oncogenic KRAS and TP53 mutations through CRISPR base editing.

Shady Sayed, Olga Alexandra Sidorova, Alexander Hennig, Martina Augsburg, Catherine P Cortes Vesga, Moustafa Abohawya, Lukas Theo Schmitt, Duran S R N, Daniel E Stange, Jovan Mircetic, Frank Buchholz.

KRAS is the most frequently mutated oncogene in human cancer, and its activating mutations represent long-sought therapeutic targets. Programmable nucleases, particularly the CRISPR-Cas9 system, provide an attractive tool for genetically targeting KRAS mutations in cancer cells. Here, we show that cleavage of a panel of KRAS driver mutations suppresses growth in various human cancer cell lines, revealing their dependence on mutant KRAS. However, analysis of the remaining cell population after long-term Cas9 expression unmasked the occurence of oncogenic KRAS escape variants that were resistant to Cas9-cleavage. In contrast, the use of an adenine base editor (ABE) to correct oncogenic KRAS mutations progressively depleted the targeted cells without the appearance of escape variants and allowed efficient and simultaneous correction of a cancer-associated TP53 mutation. Oncogenic KRAS and TP53 base editing was possible in patient-derived cancer organoids, suggesting that base editor approaches to correct oncogenic mutations could be developed for functional interrogation of vulnerabilities in a personalized manner for future precision oncology applications.

DOI: https://doi.org/10.1158/0008-5472.CAN-21-2519
Nat Cell Biol. 2022 Jul 04.

CRISPR screening uncovers a central requirement for HHEX in pancreatic lineage commitment and plasticity restriction.

Dapeng Yang, Hyunwoo Cho, Zakieh Tayyebi, Abhijit Shukla, Renhe Luo, Gary Dixon, Valeria Ursu, Stephanie Stransky, Daniel M Tremmel, Sara D Sackett, Richard Koche, Samuel J Kaplan, Qing V Li, Jiwoon Park, Zengrong Zhu, Bess P Rosen, Julian Pulecio, Zhong-Dong Shi, Yaron Bram, Robert E Schwartz, Jon S Odorico, Simone Sidoli, Christopher V Wright, Christina S Leslie, Danwei Huangfu.

The pancreas and liver arise from a common pool of progenitors. However, the underlying mechanisms that drive their lineage diversification from the foregut endoderm are not fully understood. To tackle this question, we undertook a multifactorial approach that integrated human pluripotent-stem-cell-guided differentiation, genome-scale CRISPR-Cas9 screening, single-cell analysis, genomics and proteomics. We discovered that HHEX, a transcription factor (TF) widely recognized as a key regulator of liver development, acts as a gatekeeper of pancreatic lineage specification. HHEX deletion impaired pancreatic commitment and unleashed an unexpected degree of cellular plasticity towards the liver and duodenum fates. Mechanistically, HHEX cooperates with the pioneer TFs FOXA1, FOXA2 and GATA4, shared by both pancreas and liver differentiation programmes, to promote pancreas commitment, and this cooperation restrains the shared TFs from activating alternative lineages. These findings provide a generalizable model for how gatekeeper TFs like HHEX orchestrate lineage commitment and plasticity restriction in broad developmental contexts.

DOI: https://doi.org/10.1038/s41556-022-00946-4
Lancet Gastroenterol Hepatol. 2022 Jul 05. pii: S2468-1253(22)00167-4. [Epub ahead of print]

Dual αV-integrin and neuropilin-1 targeting peptide CEND-1 plus nab-paclitaxel and gemcitabine for the treatment of metastatic pancreatic ductal adenocarcinoma: a first-in-human, open-label, multicentre, phase 1 study.

Andrew Dean, Sanjeev Gill, Mark McGregor, Vy Broadbridge, Harri A Järveläinen, Timothy Price.

BACKGROUND: CEND-1 is a novel cyclic peptide that targets αV integrins and neuropilin-1 and enhances tumour delivery of co-administered anticancer drugs. We investigated the safety, tolerability, and biological activity of CEND-1 in patients with metastatic pancreatic ductal adenocarcinoma in combination with nab-paclitaxel and gemcitabine.
METHODS: This open-label, multicentre, phase 1 study, conducted at three hospitals in Australia, enrolled participants aged 18 years or older with histologically confirmed metastatic pancreatic ductal adenocarcinoma who had one or more lesions measurable on MRI or CT, an Eastern Cooperative Oncology Group performance status score of 0 or 1, and a life expectancy of at least 3 months. Exclusion criteria included previous chemotherapy and brain metastases or other malignancy (unless receiving curative intent). There was no randomisation or masking. CEND-1 monotherapy was given as an intravenous fluid bolus on day 1 of a run-in phase of 7 days (0·2-3·2 mg/kg) followed by CEND-1 plus intravenous gemcitabine (1000 mg/m2) and nab-paclitaxel (125 mg/m2) on days 1, 8, and 15 of 28-day treatment cycles until disease progression. The primary safety endpoints were incidence, severity, and duration of treatment-emergent and treatment-related adverse events; overall survival; and clinical laboratory results, which were all assessed in the safety population. This study is registered with ClinicalTrials.gov, NCT03517176, and the Australian New Zealand Clinical Trials Registry, ACTRN12618000804280.
FINDINGS: Between Aug 13, 2018, and Nov 30, 2019, 31 patients were enrolled (eight in the dose-escalation phase [cohort 1a] and 23 in the expansion phase [cohort 1b]). Two patients were excluded from the efficacy population. No CEND-1 dose-limiting toxicities were observed in the safety population (n=31). The most common grade 3 or 4 events were neutropenia (17 [55%] patients), anaemia (eight [26%]), leukopenia (five [16%]), and pulmonary embolism (four [13%]). Serious adverse events occurred in 22 (71%) patients, mostly related to disease progression. Ten deaths occurred during the study due to progression of metastatic pancreatic cancer (n=9) and a left middle cerebral artery stroke (n=1). In the efficacy population (n=29), 17 (59%) patients had an objective response, including one complete response and 16 partial responses. After a median follow-up of 26 months (IQR 24-30), median overall survival was 13·2 months (95% CI 9·7-22·5).
INTERPRETATION: CEND-1 with nab-paclitaxel and gemcitabine has an acceptable safety profile, with no dose-limiting toxicities and encouraging activity. Adverse events were generally consistent with those seen with nab-paclitaxel and gemcitabine. Further randomised trials to determine the efficacy of CEND-1 are warranted.
FUNDING: DrugCendR Australia Pty.

DOI: https://doi.org/10.1016/S2468-1253(22)00167-4
Annu Rev Cell Dev Biol. 2022 Jul 08.

Senescence: An Identity Crisis Originating from Deep Within the Nucleus.

Ioana Olan, Masashi Narita.

Cellular senescence is implicated in a wide range of physiological and pathological conditions throughout an organism's entire lifetime. In particular, it has become evident that senescence plays a causative role in aging and age-associated disorders. This is not due simply to the loss of function of senescent cells. Instead, the substantial alterations of the cellular activities of senescent cells, especially the array of secretory factors, impacts the surrounding tissues or even entire organisms. Such non-cell-autonomous functionality is largely coordinated by tissue-specific genes, constituting a cell fate-determining state. Senescence can be viewed as a gain-of-function phenotype or a process of cell identity shift. Cellular functionality or lineage-specific gene expression is tightly linked to the cell type-specific epigenetic landscape, reinforcing the heterogeneity of senescence across cell types. Here, we aim to define the senescence cellular functionality and epigenetic features that may contribute to the gain-of-function phenotype. Expected final online publication date for the Annual Review of Cell and Developmental Biology Volume 38 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

DOI: https://doi.org/10.1146/annurev-cellbio-120420-013537
J Gastroenterol. 2022 Jul 03.

Heterogeneity of metabolic adaptive capacity affects the prognosis among pancreatic ductal adenocarcinomas.

Taishu Kanda, Taiichi Wakiya, Keinosuke Ishido, Norihisa Kimura, Hiroaki Fujita, Tadashi Yoshizawa, Shintaro Goto, Yota Tatara, Hiroshi Kijima, Kenichi Hakamada.

   BACKGROUND: Evolutionary cancer has a supply mechanism to satisfy higher energy demands even in poor-nutrient conditions. Metabolic reprogramming is essential to supply sufficient energy. The relationship between metabolic reprogramming and the clinical course of pancreatic ductal adenocarcinoma (PDAC) remains unclear. We aimed to clarify the differences in metabolic status among PDAC patients.
METHODS: We collected clinical data from 128 cases of resectable PDAC patients undergoing surgery. Sixty-three resected tissues, 15 tissues from the low carbohydrate antigen 19-9 (CA19-9), 38-100 U/mL, and high CA19-9, > 500 U/mL groups, and 33 non-tumor control parts, were subjected to tandem mass spectrometry workflow to systematically explore metabolic status. Clinical and proteomic data were compared on the most used PDAC biomarker, preoperative CA19-9 value.
RESULTS: Higher CA19-9 levels were clearly associated with higher early recurrence (p < 0.001), decreased RFS (p < 0.001), and decreased DSS (p = 0.025). From proteomic analysis, we discovered that cancer evolution-related as well as various metabolism-related pathways were more notable in the high group. Using resected tissue immunohistochemical staining, we learned that high CA19-9 PDAC demonstrated aerobic glycolysis enhancement, yet no decrease in protein synthesis. We found a heterogeneity of various metabolic processes, including carbohydrates, proteins, amino acids, lipids, and nucleic acids, between the low and the high groups, suggesting differences in metabolic adaptive capacity.
CONCLUSIONS: Our study found metabolic adaptation differences among PDAC cases, pertaining to both cancer evolution and the prognosis. CA19-9 can help estimate the metabolic adaptive capacity of energy supply for PDAC evolution.

Keywords:  Biological evolution; CA19-9; Heterogeneity; Metabolic reprogramming; Pancreatic cancer

DOI:  https://doi.org/10.1007/s00535-022-01898-0
Autophagy. 2022 Jul 07. 1-4

SQSTM1, lipid droplets and current state of their lipophagy affairs.

Ankit Shroff, Taras Y Nazarko.

  SQSTM1/p62 (sequestosome 1) is a well-established indicator of macroautophagic/autophagic flux. It was initially characterized as the ubiquitin-binding autophagic receptor in aggrephagy, the selective autophagy of ubiquitinated protein aggregates. Recently, several studies correlated its levels with the abundance of intracellular lipid droplets (LDs). In the absence of a bona fide receptor for the selective autophagy of LDs (lipophagy), a few studies demonstrated the role of SQSTM1 in lipophagy. Our analysis of these studies shows that SQSTM1 colocalizes with LDs, bridges them with phagophores, is co-degraded with them in the lysosomes, and affects LD abundance in a variety of cells and under diverse experimental conditions. Although only one study reported all these functions together, the overwhelming and complementary evidence from other studies suggests that the role of SQSTM1 in lipophagy via tagging, movement, aggregation/clustering and sequestration of LDs is rather a common phenomenon in mammalian cells. As ubiquitination of the LD-associated proteins under stress conditions is increasingly recognized as another common phenomenon, some other ubiquitin-binding autophagic receptors, such as NBR1 and OPTN, might soon join SQSTM1 on a list of the non-exclusive lipophagy receptors.Abbreviations: LD: lipid droplet; LIR: LC3-interacting region; PAT: Perilipin, ADRP and TIP47 domain; SAR: selective autophagy receptor.

Keywords:  Lipid droplet; SAR; SQSTM1; lipophagy; lipophagy receptor; p62; phagophore; selective autophagy; selective autophagy receptor; ubiquitin

DOI:  https://doi.org/10.1080/15548627.2022.2094606
J Cell Sci. 2022 Jul 07. pii: jcs.259500. [Epub ahead of print]

Oncogenic gain of function due to p53 amyloids by aberrant alteration of cell cycle and proliferation.

Ambuja Navalkar, Ajoy Paul, Arunima Sakunthala, Satyaprakash Pandey, Amit Kumar Dey, Sandhini Saha, Sarthak Sahoo, Mohit K Jolly, Tushar K Maiti, Samir K Maji.

  Transcription factor p53 has been shown to aggregate into cytoplasmic/nuclear inclusions, compromising its native tumor suppressive functions. Recently, p53 is shown to form amyloids, which play a role in conferring cancerous properties to cells leading to tumorigenesis. However, the exact pathways involved in p53 amyloid-mediated cellular transformations are unknown. Here, using an in cellulo model of full-length p53 amyloid formation, we demonstrate the mechanism of loss of p53 tumor-suppressive function with concomitant oncogenic gain-of functions. Global gene expression profiling of cells suggests that p53 amyloid formation dysregulates the genes associated with cell cycle, proliferation, apoptosis, senescence along with major signaling pathways. This is further supported by the proteome analysis, showing a significant alteration in levels of p53 target proteins and enhanced metabolism, which enables the survival of cells. Our data indicate that specifically targeting the key molecules in pathways affected by p53 amyloid formation such as cyclin-dependent kinase-1, leads to loss of oncogenic phenotype and induces apoptosis of cells. Overall, our work establishes the mechanism of the transformation of cells due to p53 amyloids leading to cancer pathogenesis.

Keywords:  Cancer; Oncogenic gain-of-function; Tumor suppression; p53 amyloids

DOI:  https://doi.org/10.1242/jcs.259500
Elife. 2022 Jul 08. pii: e76095. [Epub ahead of print]11

Genetically controlled mtDNA deletions prevent ROS damage by arresting oxidative phosphorylation.

Simon Stenberg, Jing Li, Arne B Gjuvsland, Karl Persson, Erik Demitz-Helin, Carles González Peña, Jia-Xing Yue, Ciaran Gilchrist, Timmy Ärengård, Payam Ghiaci, Lisa Larsson-Berghund, Martin Zackrisson, Silvana Smits, Johan Hallin, Johanna L Höög, Mikael Molin, Gianni Liti, Stig W Omholt, Jonas Warringer.

  Deletion of mitochondrial DNA in eukaryotes is currently attributed to rare accidental events associated with mitochondrial replication or repair of double-strand breaks. We report the discovery that yeast cells arrest harmful intramitochondrial superoxide production by shutting down respiration through genetically controlled deletion of mitochondrial oxidative phosphorylation genes. We show that this process critically involves the antioxidant enzyme superoxide dismutase 2 and two-way mitochondrial-nuclear communication through Rtg2 and Rtg3. While mitochondrial DNA homeostasis is rapidly restored after cessation of a short-term superoxide stress, long-term stress causes maladaptive persistence of the deletion process, leading to complete annihilation of the cellular pool of intact mitochondrial genomes and irrevocable loss of respiratory ability. This shows that oxidative stress-induced mitochondrial impairment may be under strict regulatory control. If the results extend to human cells, the results may prove to be of etiological as well as therapeutic importance with regard to age-related mitochondrial impairment and disease.

Keywords:  S. cerevisiae; cell biology; genetics; genomics

DOI:  https://doi.org/10.7554/eLife.76095
Aging Med (Milton). 2022 Jun;5(2): 120-125

Aging clocks & mortality timers, methylation, glycomic, telomeric and more. A window to measuring biological age.

Raymond D Palmer.

  As humans age multiple forms of biological decay ensue, and many aspects of human biology can be measured to determine how far biological machinery has drifted from homeostasis. Research has led to aging clocks being developed that claim to predict biological age as opposed to chronological age. Aging could be regarded as a measured loss of homeostatic biological equilibrium that augments biological decay in fully developed tissues. Measuring aspects of how far various elements of biology have drifted from a youthful state may allow us to make determinations on a subject's health but also make informed predictions on their biological age. As we see across human physiology, many facets that maintain human health taper off such as nicotinamide adenine dinucleotide, glutathione, catalase, super oxide dismutase, and more. Extracellular vesicle density also tapers off during age combined with epigenetic drift, telomere attrition, and stem cell exhaustion, whilst genomic instability and biological insults from environment and lifestyle factors increase. Measuring these types of biomarkers with aging clocks may allow subjects to understand their own health more accurately and enable subjects to better focus on their efforts in the pursuit of longevity and, in addition, allow healthcare practitioners to deliver better health advice.

Keywords:  aging clocks; epigenetic clock; telomeres

DOI:  https://doi.org/10.1002/agm2.12197
Expert Rev Clin Pharmacol. 2022 Jul 05.

Ribosomopathies and cancer: pharmacological implications.

Gazmend Temaj, Sarmistha Saha, Shpend Dragusha, Valon Ejupi, Brigitta Buttari, Elisabetta Profumo, Lule Beqa, Luciano Saso.

   INTRODUCTION: The ribosome is a ribonucleoprotein organelle responsible for protein synthesis, and its biogenesis is a highly coordinated process that involves many macromolecular components. Any acquired or inherited impairment in ribosome biogenesis or ribosomopathies is associated with the development of different cancers and rare genetic diseases. Interference with multiple steps of protein synthesis has been shown to promote tumor cell death.
AREAS COVERED: We discuss the current insights about impaired ribosome biogenesis and their secondary consequences on protein synthesis, transcriptional and translational responses, proteotoxic stress, and other metabolic pathways associated with cancer and rare diseases. Studies investigating the modulation of different therapeutic chemical entities targeting cancer in in vitro and in vivo models have also been detailed.
EXPERT OPINION: Despite the association between inherited mutations affecting ribosome biogenesis and cancer biology, the development of therapeutics targeting the essential cellular machinery has only started to emerge. New chemical entities should be designed to modulate different checkpoints (translating oncoproteins, dysregulation of specific ribosome-assembly machinery, ribosomal stress, and rewiring ribosomal functions). Although safe and effective therapies are lacking, consideration should also be given to using existing drugs alone or in combination for long-term safety, with known risks for feasibility in clinical trials and synergistic effects.

Keywords:  cancer diseases; p53 activation; ribosome biogenesis; ribosomopathies; therapy

DOI:  https://doi.org/10.1080/17512433.2022.2098110
Gastroenterology. 2022 Jul 01. pii: S0016-5085(22)00733-8. [Epub ahead of print]

Malondialdehyde-acetaldehyde extracellular matrix protein adducts attenuate unfolded protein response during alcohol and smoking-induced pancreatitis.

Rakesh Bhatia, Christopher M Thompson, Emalie J Clement, Koelina Ganguly, Jesse L Cox, Sanchita Rauth, Jawed Akhtar Siddiqui, Simran S Mashiana, Maneesh Jain, Todd A Wyatt, Harmeet S Mashiana, Shailender Singh, Nicholas T Woods, Kusum K Kharbanda, Surinder K Batra, Sushil Kumar.

   BACKGROUND AND AIMS: Epidemiological studies have established alcohol and smoking as independent risk factors for recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP). However, the molecular players responsible for the progressive loss of pancreatic parenchyma and fibroinflammatory response are poorly characterized.
METHODS: Tandem mass tag-based proteomic and bioinformatics analyses were performed on the pancreata of mice exposed to alcohol, smoke, or combination. Biochemical, IHC, and transcriptome analyses were performed on the pancreatic tissues and primary acinar cells treated with cerulein in combination with ethanol (50mmol/L) and cigarette smoke extract (40μg/ml)] for the mechanistic studies.
RESULTS: A unique alteration in the pancreatic proteome was observed in mice exposed chronically to the combination of alcohol and cigarette smoke (56.5%) compared to smoke (21%) or alcohol (17%) alone. The formation of toxic metabolites (p<0.001) and attenuated unfolded protein response (p<0.04) were the significantly altered pathways upon combined exposure. The extracellular matrix (ECM) proteins showed stable malondialdehyde-acetaldehyde (MAA) adducts in the pancreata of the combination group and CP patients with a history of smoking and alcohol consumption. Interestingly, MAA-ECM adducts significantly suppressed the expression of XBP1, leading to acinar cell death in the presence of alcohol and smoking. The stable MAA-ECM adducts persist even after alcohol and smoking cessation and significantly delay pancreatic regeneration by abrogating the expression of cyclin-dependent kinases (CDK7, CDK5) and regeneration markers.
CONCLUSIONS: The combined alcohol and smoking generate stable MAA-ECM adducts that increase ER stress and acinar cell death due to attenuated UPR and suppress the expression of cell cycle regulators. Targeting aldehyde-adducts might provide a novel therapeutic strategy for the management of RAP and CP.

Keywords:  Alcohol; Aldehyde adducts; Chronic pancreatitis; Extracellular matrix proteins; Smoking

DOI:  https://doi.org/10.1053/j.gastro.2022.06.071
Carcinogenesis. 2022 Jul 04. pii: bgac060. [Epub ahead of print]

Inhibition of lysosomal acid β-glucosidase and induces cell apoptosis via impairing mitochondrial clearance in pancreatic cancer.

Mitsuru Yanagaki, Yoshihiro Shirai, Yohta Shimada, Ryoga Hamura, Tomohiko Taniai, Takashi Horiuchi, Naoki Takada, Koichiro Haruki, Kenei Furukawa, Tadashi Uwagawa, Hiroshi Kobayashi, Toru Ikegami.

Sphingolipid metabolism plays an important role in the formation of cellular membranes and is associated with malignant potential and chemosensitivity of cancer cells. Sphingolipid degradation depends on multiple lysosomal glucosidases. We focused on acid β-glucosidase (GBA), a lysosomal enzyme the deficiency of which is related to mitochondrial dysfunction. We analyzed the function of GBA in pancreatic ductal adenocarcinoma (PDAC). Human PDAC cell lines (PANC-1, BxPC-3, and AsPC-1) were examined under conditions of GBA knockdown via the short interfering RNA (siRNA) method. We assessed the morphological changes, GBA enzyme activity, GBA protein expression, cell viability, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), and mitophagy flux of PDAC cells. The GBA protein level and enzyme activity differed among cell lines. GBA knockdown suppressed cell proliferation and induced apoptosis, especially in PANC-1 and BxPC-3 cells, with low GBA enzyme activity. GBA knockdown also decreased the MMP and impaired mitochondrial clearance. This impaired mitochondrial clearance further induced dysfunctional mitochondria accumulation and ROS generation in PDAC cells, inducing apoptosis. The antiproliferative effects of the combination of GBA suppression and gemcitabine were higher than those of gemcitabine alone. These results showed that GBA suppression exerts a significant antitumor effect and may have therapeutic potential in the clinical treatment of PDAC.

DOI: https://doi.org/10.1093/carcin/bgac060
Cell. 2022 Jul 07. pii: S0092-8674(22)00708-5. [Epub ahead of print]185(14): 2401-2421

Ferroptosis turns 10: Emerging mechanisms, physiological functions, and therapeutic applications.

Brent R Stockwell.

Ferroptosis, a form of cell death driven by iron-dependent lipid peroxidation, was identified as a distinct phenomenon and named a decade ago. Ferroptosis has been implicated in a broad set of biological contexts, from development to aging, immunity, and cancer. This review describes key regulators of this form of cell death within a framework of metabolism, ROS biology, and iron biology. Key concepts and major unanswered questions in the ferroptosis field are highlighted. The next decade promises to yield further breakthroughs in the mechanisms governing ferroptosis and additional ways of harnessing ferroptosis for therapeutic benefit.

DOI: https://doi.org/10.1016/j.cell.2022.06.003
Cell. 2022 Jul 07. pii: S0092-8674(22)00712-7. [Epub ahead of print]185(14): 2591-2608.e30

Dissecting the treatment-naive ecosystem of human melanoma brain metastasis.

Jana Biermann, Johannes C Melms, Amit Dipak Amin, Yiping Wang, Lindsay A Caprio, Alcida Karz, Somnath Tagore, Irving Barrera, Miguel A Ibarra-Arellano, Massimo Andreatta, Benjamin T Fullerton, Kristjan H Gretarsson, Varun Sahu, Vaibhav S Mangipudy, Trang T T Nguyen, Ajay Nair, Meri Rogava, Patricia Ho, Peter D Koch, Matei Banu, Nelson Humala, Aayushi Mahajan, Zachary H Walsh, Shivem B Shah, Daniel H Vaccaro, Blake Caldwell, Michael Mu, Florian Wünnemann, Margot Chazotte, Simon Berhe, Adrienne M Luoma, Joseph Driver, Matthew Ingham, Shaheer A Khan, Suthee Rapisuwon, Craig L Slingluff, Thomas Eigentler, Martin Röcken, Richard Carvajal, Michael B Atkins, Michael A Davies, Albert Agustinus, Samuel F Bakhoum, Elham Azizi, Markus Siegelin, Chao Lu, Santiago J Carmona, Hanina Hibshoosh, Antoni Ribas, Peter Canoll, Jeffrey N Bruce, Wenya Linda Bi, Praveen Agrawal, Denis Schapiro, Eva Hernando, Evan Z Macosko, Fei Chen, Gary K Schwartz, Benjamin Izar.

  Melanoma brain metastasis (MBM) frequently occurs in patients with advanced melanoma; yet, our understanding of the underlying salient biology is rudimentary. Here, we performed single-cell/nucleus RNA-seq in 22 treatment-naive MBMs and 10 extracranial melanoma metastases (ECMs) and matched spatial single-cell transcriptomics and T cell receptor (TCR)-seq. Cancer cells from MBM were more chromosomally unstable, adopted a neuronal-like cell state, and enriched for spatially variably expressed metabolic pathways. Key observations were validated in independent patient cohorts, patient-derived MBM/ECM xenograft models, RNA/ATAC-seq, proteomics, and multiplexed imaging. Integrated spatial analyses revealed distinct geography of putative cancer immune evasion and evidence for more abundant intra-tumoral B to plasma cell differentiation in lymphoid aggregates in MBM. MBM harbored larger fractions of monocyte-derived macrophages and dysfunctional TOX+CD8+ T cells with distinct expression of immune checkpoints. This work provides comprehensive insights into MBM biology and serves as a foundational resource for further discovery and therapeutic exploration.

Keywords:  brain metastasis; chromosomal instability; melanoma; neuronal-like cell state; single-cell genomics; spatial transcriptomics; tumor-microenvironment

DOI:  https://doi.org/10.1016/j.cell.2022.06.007
Diabetes. 2022 Jul 08. pii: db220161. [Epub ahead of print]

Weight Cycling Impairs Pancreatic Insulin Secretion but Does Not Perturb Whole-Body Insulin Action in Diet-Induced Obese Mice.

Nathan C Winn, Matthew A Cottam, Monica Bhanot, Heather L Caslin, Jamie N Garcia, Rafael Arrojo E Drigo, Alyssa H Hasty.

In the setting of obesity and insulin resistance, glycemia is controlled in part by beta cell compensation and subsequent hyperinsulinemia. Weight loss improves glycemia and decreases hyperinsulinemia, whereas weight cycling worsens glycemic control. The mechanisms responsible for weight cycling-induced deterioration in glucose homeostasis are poorly understood. Thus, we aimed to pinpoint the main regulatory junctions at which weight cycling alters glucose homeostasis in mice. Using in vivo and ex vivo procedures we show that despite having worsened glucose tolerance, weight-cycled mice do not manifest impaired whole-body insulin action. Instead, weight cycling reduces insulin secretory capacity in vivo during clamped hyperglycemia and ex vivo in perifused islets. Islets from weight-cycled mice have reduced expression of factors essential for β-cell function (Mafa, Pdx1, Nkx6.1, Ucn3) and lower islet insulin content, compared to those from obese mice, suggesting inadequate transcriptional and posttranscriptional response to repeated nutrient overload. Collectively, these data support a model in which pancreatic plasticity is challenged in the face of large fluctuations in body weight resulting in a mismatch between glycemia and insulin secretion in mice.

DOI: https://doi.org/10.2337/db22-0161
Nucleic Acids Res. 2022 Jul 08. pii: gkac593. [Epub ahead of print]

Systemic approaches using single cell transcriptome reveal that C/EBPγ regulates autophagy under amino acid starved condition.

Dongha Kim, Junil Kim, Young Suk Yu, Yong Ryoul Kim, Sung Hee Baek, Kyoung-Jae Won.

Autophagy, a catabolic process to remove unnecessary or dysfunctional organelles, is triggered by various signals including nutrient starvation. Depending on the types of the nutrient deficiency, diverse sensing mechanisms and signaling pathways orchestrate for transcriptional and epigenetic regulation of autophagy. However, our knowledge about nutrient type-specific transcriptional regulation during autophagy is limited. To understand nutrient type-dependent transcriptional mechanisms during autophagy, we performed single cell RNA sequencing (scRNAseq) in the mouse embryonic fibroblasts (MEFs) with or without glucose starvation (GS) as well as amino acid starvation (AAS). Trajectory analysis using scRNAseq identified sequential induction of potential transcriptional regulators for each condition. Gene regulatory rules inferred using TENET newly identified CCAAT/enhancer binding protein γ (C/EBPγ) as a regulator of autophagy in AAS, but not GS, condition, and knockdown experiment confirmed the TENET result. Cell biological and biochemical studies validated that activating transcription factor 4 (ATF4) is responsible for conferring specificity to C/EBPγ for the activation of autophagy genes under AAS, but not under GS condition. Together, our data identified C/EBPγ as a previously unidentified key regulator under AAS-induced autophagy.

DOI: https://doi.org/10.1093/nar/gkac593
Signal Transduct Target Ther. 2022 Jul 08. 7(1): 221

Liquid-liquid phase separation in tumor biology.

Xuhui Tong, Rong Tang, Jin Xu, Wei Wang, Yingjun Zhao, Xianjun Yu, Si Shi.

Liquid-liquid phase separation (LLPS) is a novel principle for explaining the precise spatial and temporal regulation in living cells. LLPS compartmentalizes proteins and nucleic acids into micron-scale, liquid-like, membraneless bodies with specific functions, which were recently termed biomolecular condensates. Biomolecular condensates are executors underlying the intracellular spatiotemporal coordination of various biological activities, including chromatin organization, genomic stability, DNA damage response and repair, transcription, and signal transduction. Dysregulation of these cellular processes is a key event in the initiation and/or evolution of cancer, and emerging evidence has linked the formation and regulation of LLPS to malignant transformations in tumor biology. In this review, we comprehensively summarize the detailed mechanisms of biomolecular condensate formation and biophysical function and review the recent major advances toward elucidating the multiple mechanisms involved in cancer cell pathology driven by aberrant LLPS. In addition, we discuss the therapeutic perspectives of LLPS in cancer research and the most recently developed drug candidates targeting LLPS modulation that can be used to combat tumorigenesis.

DOI: https://doi.org/10.1038/s41392-022-01076-x
Nat Commun. 2022 Jul 02. 13(1): 3812

Endosomal LC3C-pathway selectively targets plasma membrane cargo for autophagic degradation.

Paula P Coelho, Geoffrey G Hesketh, Annika Pedersen, Elena Kuzmin, Anne-Marie N Fortier, Emily S Bell, Colin D H Ratcliffe, Anne-Claude Gingras, Morag Park.

Autophagy selectively targets cargo for degradation, yet mechanistic understanding remains incomplete. The ATG8-family plays key roles in autophagic cargo recruitment. Here by mapping the proximal interactome of ATG8-paralogs, LC3B and LC3C, we uncover a LC3C-Endocytic-Associated-Pathway (LEAP) that selectively recruits plasma-membrane (PM) cargo to autophagosomes. We show that LC3C localizes to peripheral endosomes and engages proteins that traffic between PM, endosomes and autophagosomes, including the SNARE-VAMP3 and ATG9, a transmembrane protein essential for autophagy. We establish that endocytic LC3C binds cargo internalized from the PM, including the Met receptor tyrosine kinase and transferrin receptor, and is necessary for their recruitment into ATG9 vesicles targeted to sites of autophagosome initiation. Structure-function analysis identified that LC3C-endocytic localization and engagement with PM-cargo requires the extended carboxy-tail unique to LC3C, the TBK1 kinase, and TBK1-phosphosites on LC3C. These findings identify LEAP as an unexpected LC3C-dependent pathway, providing new understanding of selective coupling of PM signalling with autophagic degradation.

DOI: https://doi.org/10.1038/s41467-022-31465-3
JAMA Oncol. 2022 Jul 07.

Plant-Based and Ketogenic Diets As Diverging Paths to Address Cancer: A Review.

Urvi A Shah, Neil M Iyengar.

Importance: As the incidence of cancer and metabolic disorders, such as obesity, concurrently rise, there has been increasing awareness of the pervasive effect of nutrition. The whole foods plant-based diet (WFPBD) and ketogenic diet (KD) have gained popularity in oncology, and this topic is increasingly permeating clinical dialogue.
Observations: Dietary intake is associated with multiple pathways involved in carcinogenesis and tumor progression. Consumption of a plant-enriched diet is associated with reduced cancer incidence and is recommended by dietary guidelines for cancer prevention. Despite a starkly different nutrient composition, a WFPBD and KD can be associated with weight loss, decreased inflammation, and decreased insulin levels. In addition, a WFPBD is associated with increased fiber, phytochemicals, and butyrate levels and decreased insulin-like growth factor 1 levels, whereas a KD exerts potential anticancer effects by increasing β hydroxybutyrate levels. A KD may be of interest in select, less common settings, such as tumors treated with phosphatidylinositol 3-kinase inhibitors, which induce hyperinsulinemia and hyperglycemia. Completed interventional trials have focused on increasing fruit and vegetable intake or reducing fat intake but have not specifically tested WFPBD or KD for cancer prevention or treatment. Currently available data support plant-based diets as opposed to KD as part of a lifestyle associated with reduced cancer risk. In the postdiagnosis setting, there are currently no rigorously tested approaches that support the recommendation of any diet to treat cancer.
Conclusions and Relevance: The results of this review suggest that the collective evidence supports plant-enriched diets vs KD for the reduction of cancer risk and the improvement of metabolic disorders in survivors. Additional prospective randomized clinical trials are needed to encourage use of dietary modification across the cancer continuum. Rigorous trial designs that adapt classical oncologic end points may identify populations that are likely to benefit from starkly contrasting diets. Current data support prioritization of plant-based diets, and future data could further personalize dietary recommendations in cancer populations.

DOI: https://doi.org/10.1001/jamaoncol.2022.1769
ACS Chem Biol. 2022 Jul 08.

Metabolic Labeling-Based Chemoproteomics Establishes Choline Metabolites as Protein Function Modulators.

Aditi Dixit, Gregor P Jose, Chitra Shanbhag, Nitin Tagad, Jeet Kalia.

Choline is an essential nutrient for mammalian cells. Our understanding of the cellular functions of choline and its metabolites, independent of their roles as choline lipid metabolism intermediates, remains limited. In addition to fundamental cellular physiology, this knowledge has implications for cancer biology because elevated choline metabolite levels are a hallmark of cancer. Here, we establish a mammalian choline metabolite-interacting proteome by utilizing a photocrosslinkable choline probe. To design this probe, we performed metabolic labeling experiments with structurally diverse choline analogues that resulted in the serendipitous discovery of a choline lipid headgroup remodeling mechanism involving sequential dealkylation and methylation steps. We demonstrate that phosphocholine inhibits the binding of one of the proteins identified, the attractive anticancer target p32, to its endogenous ligands and to the promising p32-targeting anticancer agent, Lyp-1. Our results reveal that choline metabolites play vital roles in cellular physiology by serving as modulators of protein function.

DOI: https://doi.org/10.1021/acschembio.2c00400
Cancers (Basel). 2022 Jun 26. pii: 3137. [Epub ahead of print]14(13):

The Differential Clinical Impacts of Cachexia and Sarcopenia on the Prognosis of Advanced Pancreatic Cancer.

Ya-Chin Hou, Chien-Yu Chen, Chien-Jui Huang, Chih-Jung Wang, Ying-Jui Chao, Nai-Jung Chiang, Hao-Chen Wang, Hui-Ling Tung, Hsiao-Chun Liu, Yan-Shen Shan.

  Pancreatic cancer (PC) has the highest frequency of developing cancer cachexia (CC)-sarcopenia (SC) syndrome, which negatively influences patients' outcome, quality of life, and tolerance/response to treatments. However, the clinical impacts of CC, SC, and their associated factors on outcomes for advanced PC has yet to be fully investigated. A total of 232 patients were enrolled in this study for the retrospective review of their clinical information and the measurement of skeletal muscle areas at the third lumber vertebra by computed tomography scan to identify CC or SC. The association and concurrent occurrence of clinicopathological features in each patient, prevalence rates, and prognosis with the CC or SC were calculated. CC and SC were observed in 83.6% (n = 194) and 49.1% (n = 114) of PC patients, respectively. Low hemoglobin levels more often occurred in CC patients than in non-CC patients (p = 0.014). Older age (p = 0.000), female gender (p = 0.024), low body mass index (BMI) values (p = 0.004), low hemoglobin levels (p = 0.036), and low albumin levels (p = 0.001) were more often found in SC patients than in non-SC patients. Univariate and multivariate analyses showed that CC was an independent poor prognostic factor of overall survival (OS) and progression-free survival for all patients, the chemotherapy (C/T) subgroup, and the high BMI subgroup. Meanwhile, SC was an independent predictor of poor OS for the subgroups of C/T or high BMI but not for all patients. These findings reveal the clinical differences for CC and SC and provide useful information for predicting the prognosis of advanced PC patients and conducting personalized medicine.

Keywords:  advanced stage; age; albumin; body mass index; cancer cachexia; hemoglobin; pancreatic cancer; sarcopenia

DOI:  https://doi.org/10.3390/cancers14133137
Nat Biotechnol. 2022 Jul 04.

A multiplex implantable microdevice assay identifies synergistic combinations of cancer immunotherapies and conventional drugs.

Zuzana Tatarova, Dylan C Blumberg, James E Korkola, Laura M Heiser, John L Muschler, Pepper J Schedin, Sebastian W Ahn, Gordon B Mills, Lisa M Coussens, Oliver Jonas, Joe W Gray.

Systematically identifying synergistic combinations of targeted agents and immunotherapies for cancer treatments remains difficult. In this study, we integrated high-throughput and high-content techniques-an implantable microdevice to administer multiple drugs into different sites in tumors at nanodoses and multiplexed imaging of tumor microenvironmental states-to investigate the tumor cell and immunological response signatures to different treatment regimens. Using a mouse model of breast cancer, we identified effective combinations from among numerous agents within days. In vivo studies in three immunocompetent mammary carcinoma models demonstrated that the predicted combinations synergistically increased therapeutic efficacy. We identified at least five promising treatment strategies, of which the panobinostat, venetoclax and anti-CD40 triple therapy was the most effective in inducing complete tumor remission across models. Successful drug combinations increased spatial association of cancer stem cells with dendritic cells during immunogenic cell death, suggesting this as an important mechanism of action in long-term breast cancer control.

DOI: https://doi.org/10.1038/s41587-022-01379-y
J Cell Physiol. 2022 Jul 05.

Expanding the view of the molecular mechanisms of autophagy pathway.

Sheikh Tahir Majeed, Rabiya Majeed, Khurshid I Andrabi.

  Autophagy is an evolutionarily conserved multistep degradation mechanism in eukaryotes, that maintains cellular homoeostasis by replenishing cells with nutrients through catabolic lysis of the cytoplasmic components. This critically coordinated pathway involves sequential processing events that begin with initiation, nucleation, and elongation of phagophores, followed by the formation of double-membrane vesicles known as autophagosomes. Finally, autophagosomes migrate towards and fuse with lysosomes in mammals and vacuoles in yeast and plants, for the eventual degradation of the intravesicular cargo. Here, we review the recent advances in our understanding of the molecular events that define the process of autophagy.

Keywords:  ATG proteins; ULK1 complex; autophagosome; autophagy; lysosomes; phagophore

DOI:  https://doi.org/10.1002/jcp.30819
J Immunother Cancer. 2022 Jul;pii: e004638. [Epub ahead of print]10(7):

Local and systemic immune profiles of human pancreatic ductal adenocarcinoma revealed by single-cell mass cytometry.

Thomas P Brouwer, Natasja L de Vries, Tamim Abdelaal, Ricki T Krog, Zheng Li, Dina Ruano, Arantza Fariña, Boudewijn P F Lelieveldt, Hans Morreau, Bert A Bonsing, Alexander L Vahrmeijer, Frits Koning, Noel F C C de Miranda.

   BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy in need of effective (immuno)therapeutic treatment strategies. For the optimal application and development of cancer immunotherapies, a comprehensive understanding of local and systemic immune profiles in patients with PDAC is required. Here, our goal was to decipher the interplay between local and systemic immune profiles in treatment-naïve patients with PDAC.
METHODS: The immune composition of PDAC, matched non-malignant pancreatic tissue, regional lymph nodes, spleen, portal vein blood, and peripheral blood samples (collected before and after surgery) from 11 patients with PDAC was assessed by measuring 41 immune cell markers by single-cell mass cytometry. Furthermore, the activation potential of tumor-infiltrating lymphocytes as determined by their ability to produce cytokines was investigated by flow cytometry. In addition, the spatial localization of tumor-infiltrating innate lymphocytes in the tumor microenvironment was confirmed by multispectral immunofluorescence.
RESULTS: We found that CD103+CD8+ T cells with cytotoxic potential are infrequent in the PDAC immune microenvironment and lack the expression of activation markers and checkpoint blockade molecule programmed cell death protein-1 (PD-1). In contrast, PDAC tissues showed a remarkable increased relative frequency of B cells and regulatory T cells as compared with non-malignant pancreatic tissues. Besides, a previously unappreciated innate lymphocyte cell (ILC) population (CD127-CD103+CD39+CD45RO+ ILC1-like) was discovered in PDAC tissues. Strikingly, the increased relative frequency of B cells and regulatory T cells in pancreatic cancer samples was reflected in matched portal vein blood samples but not in peripheral blood, suggesting a regional enrichment of immune cells that infiltrate the PDAC microenvironment. After surgery, decreased frequencies of myeloid dendritic cells were found in peripheral blood.
CONCLUSIONS: Our work demonstrates an immunosuppressive landscape in PDAC tissues, generally deprived of cytotoxic T cells and enriched in regulatory T cells and B cells. The antitumor potential of ILC1-like cells in PDAC may be exploited in a therapeutic setting. Importantly, immune profiles detected in blood isolated from the portal vein reflected the immune cell composition of the PDAC microenvironment, suggesting that this anatomical location could be a source of tumor-associated immune cell subsets.

Keywords:  gastrointestinal neoplasms; lymphocytes, tumor-infiltrating; tumor microenvironment

DOI:  https://doi.org/10.1136/jitc-2022-004638