bims-cagime 2024-08-04 papers

bims-cagime

Biomed News

on Cancer, aging and metabolism

Issue of 2024–08–04
twenty-six papers selected by
Kıvanç Görgülü, Technical University of Munich

Organelle-Targeted Laurdans Measure Heterogeneity in Subcellular Membranes and Their Responses to Saturated Lipid Stress.
ZDHHC7-mediated S-palmitoylation of ATG16L1 facilitates LC3 lipidation and autophagosome formation.
Insights into the mechanisms driven by H3K4 KMTs in pancreatic cancer.
Epigenetic regulation of the tumor microenvironment: A leading force driving pancreatic cancer.
The Warburg Effect Revisited through Blood and Electron Flow.
The mortality burden of cachexia or weight loss in patients with colorectal or pancreatic cancer: A systematic literature review.
Context-dependent roles for autophagy in myeloid cells in tumor progression.
HaloTag as a substrate-based macroautophagy reporter.
Copper and iron orchestrate cell-state transitions in cancer and immunity.
The Significance of Circulating Tumor Cells in Pancreatic Cancer.
Localized in vivo gene editing of murine cancer-associated fibroblasts.
A selective S-acyltransferase inhibitor suppresses tumor growth.
Protocol for evaluating S-acylated protein membrane affinity using protein-lipid conjugates.
Chromosomal instability as a driver of cancer progression.
Emerging mechanisms and promising approaches in pancreatic cancer metabolism.
LPCAT2-mediated lipid droplet production supports pancreatic cancer chemoresistance and cell motility.
Pan-cancer evaluation of tumor-infiltrating lymphocytes and programmed cell death protein ligand-1 in metastatic biopsies and matched primary tumors.
Development of a functional beige fat cell line uncovers independent subclasses of cells expressing UCP1 and the futile creatine cycle.
ASCT2 is a major contributor to serine uptake in cancer cells.
The V-ATPase/ATG16L1 axis is controlled by the V1H subunit.
Mechanism insights and therapeutic intervention of tumor metastasis: latest developments and perspectives.
Iron Chelation Therapy Elicits Innate Immune Control of Metastatic Ovarian Cancer.
What are the causes of acute pancreatitis?
CGPA: multi-context insights from the cancer gene prognosis atlas.
High-motility pro-tumorigenic monocytes drive macrophage enrichment in the tumor microenvironment.
Drug resistant pancreatic cancer cells exhibit altered biophysical interactions with stromal fibroblasts in imaging studies of 3D co-culture models.

ACS Chem Biol. 2024 Jul 28.

Organelle-Targeted Laurdans Measure Heterogeneity in Subcellular Membranes and Their Responses to Saturated Lipid Stress.

Adrian M Wong, Itay Budin.

Organelles feature characteristic lipid compositions that lead to differences in membrane properties. In cells, membrane ordering and fluidity are commonly measured using the solvatochromic dye Laurdan, whose fluorescence is sensitive to lipid packing. As a general lipophilic dye, Laurdan stains all hydrophobic environments in cells; therefore, it is challenging to characterize membrane properties in specific organelles or assess their responses to pharmacological treatments in intact cells. Here, we describe the synthesis and application of Laurdan-derived probes that read out the membrane packing of individual cellular organelles. The set of organelle-targeted Laurdans (OTL) localizes to the ER, mitochondria, lysosomes, and Golgi compartments with high specificity while retaining the spectral resolution needed to detect biological changes in membrane ordering. We show that ratiometric imaging with OTLs can resolve membrane heterogeneity within organelles as well as changes in lipid packing resulting from inhibition of trafficking or bioenergetic processes. We apply these probes to characterize organelle-specific responses to saturated lipid stress. While the ER and lysosomal membrane fluidity is sensitive to exogenous saturated fatty acids, that of mitochondrial membranes is protected. We then use differences in ER membrane fluidity to sort populations of cells based on their fatty acid diet, highlighting the ability of organelle-localized solvatochromic probes to distinguish between cells based on their metabolic state. These results expand the repertoire of targeted membrane probes and demonstrate their application in interrogating lipid dysregulation.

DOI: https://doi.org/10.1021/acschembio.4c00249
Autophagy. 2024 Aug 01.

ZDHHC7-mediated S-palmitoylation of ATG16L1 facilitates LC3 lipidation and autophagosome formation.

Fujing Wei, Yu Wang, Jia Yao, Ligang Mei, Xue Huang, Hesheng Kong, Jing Chen, Xiaorong Chen, Lu Liu, Zhuolin Wang, Jiaxin Wang, Jiong Song, Eryan Kong, Aimin Yang.

  Macroautophagy/autophagy is a fundamental cellular catabolic process that delivers cytoplasmic components into double-membrane vesicles called autophagosomes, which then fuse with lysosomes and their contents are degraded. Autophagy recycles cytoplasmic components, including misfolded proteins, dysfunctional organelles and even microbial invaders, thereby playing an essential role in development, immunity and cell death. Autophagosome formation is the main step in autophagy, which is governed by a set of ATG (autophagy related) proteins. ATG16L1 interacts with ATG12-ATG5 conjugate to form an ATG12-ATG5-ATG16L1 complex. The complex acts as a ubiquitin-like E3 ligase that catalyzes the lipidation of MAP1LC3/LC3 (microtubule associated protein 1 light chain 3), which is crucial for autophagosome formation. In the present study, we found that ATG16L1 was subject to S-palmitoylation on cysteine 153, which was catalyzed by ZDHHC7 (zinc finger DHHC-type palmitoyltransferase 7). We observed that re-expressing ATG16L1 but not the S-palmitoylation-deficient mutant ATG16L1C153S rescued a defect in the lipidation of LC3 and the formation of autophagosomes in ATG16L1-KO (knockout) HeLa cells. Furthermore, increasing ATG16L1 S-palmitoylation by ZDHHC7 expression promoted the production of LC3-II, whereas reducing ATG16L1 S-palmitoylation by ZDHHC7 deletion inhibited the LC3 lipidation process and autophagosome formation. Mechanistically, the addition of a hydrophobic 16-carbon palmitoyl group on Cys153 residue of ATG16L1 enhances the formation of ATG16L1-WIPI2B complex and ATG16L1-RAB33B complex on phagophore, thereby facilitating the LC3 lipidation process and autophagosome formation. In conclusion, S-palmitoylation of ATG16L1 is essential for the lipidation process of LC3 and the formation of autophagosomes. Our research uncovers a new regulatory mechanism of ATG16L1 function in autophagy.

Keywords:  ATG16L1; LC3-II; ZDHHC7; autophagosome; autophagy; s-palmitoylation

DOI:  https://doi.org/10.1080/15548627.2024.2386915
Biochem J. 2024 Aug 07. 481(15): 983-997

Insights into the mechanisms driven by H3K4 KMTs in pancreatic cancer.

Kayla C LaRue-Nolan, Glancis Luzeena Raja Arul, Ashley N Sigafoos, Jiaqi Shi, Martin E Fernandez-Zapico.

  Pancreatic cancer is a malignancy arising from the endocrine or exocrine compartment of this organ. Tumors from exocrine origin comprise over 90% of all pancreatic cancers diagnosed. Of these, pancreatic ductal adenocarcinoma (PDAC) is the most common histological subtype. The five-year survival rate for PDAC ranged between 5 and 9% for over four decades, and only recently saw a modest increase to ∼12-13%, making this a severe and lethal disease. Like other cancers, PDAC initiation stems from genetic changes. However, therapeutic targeting of PDAC genetic drivers has remained relatively unsuccessful, thus the focus in recent years has expanded to the non-genetic factors underlying the disease pathogenesis. Specifically, it has been proposed that dynamic changes in the epigenetic landscape promote tumor growth and metastasis. Emphasis has been given to the re-organization of enhancers, essential regulatory elements controlling oncogenic gene expression, commonly marked my histone 3 lysine 4 monomethylation (H3K4me1). H3K4me1 is typically deposited by histone lysine methyltransferases (KMTs). While well characterized as oncogenes in other cancer types, recent work has expanded the role of KMTs as tumor suppressor in pancreatic cancer. Here, we review the role and translational significance for PDAC development and therapeutics of KMTs.

Keywords:  H3K4me1; KMTs; enhancer; pancreatic cancer

DOI:  https://doi.org/10.1042/BCJ20230374
Pancreatology. 2024 Jul 15. pii: S1424-3903(24)00685-9. [Epub ahead of print]

Epigenetic regulation of the tumor microenvironment: A leading force driving pancreatic cancer.

Renzo Vera, María Julia Lamberti, Alina L Gonzalez, Martín E Fernandez-Zapico.

  Dysregulation of the epigenomic landscape of tumor cells has been implicated in the pathogenesis of pancreatic cancer. However, these alterations are not only restricted to neoplastic cells. The behavior of other cell populations in the tumor stroma such as cancer-associated fibroblasts, immune cells, and others are mostly regulated by epigenetic pathways. Here, we present an overview of the main cellular and acellular components of the pancreatic cancer tumor microenvironment and discuss how the epigenetic mechanisms operate at different levels in the stroma to establish a differential gene expression to regulate distinct cellular phenotypes contributing to pancreatic tumorigenesis.

Keywords:  Epigenetics; Gene expression; Pancreatic cancer; Stroma; Tumor microenvironment

DOI:  https://doi.org/10.1016/j.pan.2024.07.005
Cancer Res. 2024 Jul 02. 84(13): 2046-2048

The Warburg Effect Revisited through Blood and Electron Flow.

Yahui Wang, Chi V Dang.

The Warburg effect describes the propensity of many cancers to consume glucose avidly and convert it to lactate in the presence of oxygen. The benefit of the Warburg effect on cancer cells remains enigmatic, particularly because extracellular disposal of incompletely oxidized lactate is wasteful. However, lactate is not discarded from the body, but rather recycled as pyruvate for metabolism through the tricarboxylic acid cycle in oxidative tissues and cells. Hence, tissue and interorgan metabolism play important roles in tumor metabolism. The production of tumor lactate to be recycled elsewhere parallels the Cori cycle, in which lactate produced by muscle activity is shuttled to the liver, where it is converted to pyruvate and subsequently stored as glucose moieties in glycogen. This perspective will consider this organismal contextwhile discussing how glucose is used in tumors. We highlight several key articles published decades ago in Cancer Research that are foundational to our current understanding of cancer biology and metabolism.

DOI: https://doi.org/10.1158/0008-5472.CAN-24-0474
J Cachexia Sarcopenia Muscle. 2024 Aug 02.

The mortality burden of cachexia or weight loss in patients with colorectal or pancreatic cancer: A systematic literature review.

Richard F Dunne, Jeffrey Crawford, Karen E Smoyer, Thomas D McRae, Michelle I Rossulek, James H Revkin, Lisa C Tarasenko, Philip D Bonomi.

  Cancer-associated cachexia is a multifactorial wasting disorder characterized by anorexia, unintentional weight loss (skeletal muscle mass with or without loss of fat mass), progressive functional impairment, and poor prognosis. This systematic literature review (SLR) examined the relationship between cachexia and survival in patients with colorectal or pancreatic cancer in recent literature. The SLR was conducted following PRISMA guidelines. Embase® and PubMed were searched to identify articles published in English between 1 January 2016 and 10 October 2021 reporting survival in adults with cancer and cachexia or at risk of cachexia, defined by international consensus (IC) diagnostic criteria or a broader definition of any weight loss. Included publications were studies in ≥100 patients with colorectal or pancreatic cancer. Thirteen publications in patients with colorectal cancer and 13 with pancreatic cancer met eligibility criteria. Included studies were observational and primarily from Europe and the United States. Eleven studies (42%) reported cachexia using IC criteria and 15 (58%) reported any weight loss. An association between survival and cachexia or weight loss was assessed across studies using multivariate (n = 23) or univariate (n = 3) analyses and within each study across multiple weight loss categories. Cachexia/weight loss was associated with a statistically significantly poorer survival in at least one weight loss category in 16 of 23 studies that used multivariate analyses and in 1 of 3 studies (33%) that used univariate analyses. Of the 17 studies demonstrating a significant association, 9 were in patients with colorectal cancer and 8 were in patients with pancreatic cancer. Cachexia or weight loss was associated with significantly poorer survival in patients with colorectal or pancreatic cancer in nearly two-thirds of the studies. The classification of weight loss varied across and within studies (multiple categories were evaluated) and may have contributed to variability. Nonetheless, awareness of cachexia and routine assessment of weight change in clinical practice in patients with colorectal or pancreatic cancer could help inform prognosis and influence early disease management strategies.

Keywords:  Cachexia; Colorectal cancer; Muscle wasting; Pancreatic cancer; Systematic literature review; Weight loss

DOI:  https://doi.org/10.1002/jcsm.13510
bioRxiv. 2024 Jul 16. pii: 2024.07.12.603292. [Epub ahead of print]

Context-dependent roles for autophagy in myeloid cells in tumor progression.

Jayoung Choi, Gayoung Park, Steve Seung-Young Lee, Erin Dominici, Lev Becker, Kay F Macleod, Stephen J Kron, Seungmin Hwang.

  Autophagy is known to suppress tumor initiation by removing genotoxic stresses in normal cells. Conversely, autophagy is also known to support tumor progression by alleviating metabolic stresses in neoplastic cells. Centered on this pro-tumor role of autophagy, there have been many clinical trials to treat cancers through systemic blocking of autophagy. Such systemic inhibition affects both tumor cells and non-tumor cells, and the consequence of blocked autophagy in non-tumor cells in the context of tumor microenvironment is relatively understudied. Here, we examined the effect of autophagy-deficient myeloid cells on the progression of autophagy-competent tumors. We found that blocking autophagy only in myeloid cells modulated tumor progression markedly but such effects were context dependent. In a tumor implantation model, the growth of implanted tumor cells was substantially reduced in mice with autophagy-deficient myeloid cells; T cells infiltrated deeper into the tumors and were responsible for the reduced growth of the implanted tumor cells. In an oncogene-driven tumor induction model, however, tumors grew faster and metastasized more in mice with autophagy-deficient myeloid cells. These data demonstrate that the autophagy status of myeloid cells plays a critical role in tumor progression, promoting or suppressing tumor growth depending on the context of tumor-myeloid cell interactions. This study indicates that systemic use of autophagy inhibitors in cancer therapy may have differential effects on rates of tumor progression in patients due to effects on myeloid cells and that this warrants more targeted use of selective autophagy inhibitors in a cancer therapy in a clinical setting.

Keywords:  Autophagy; macrophage; microenvironment; myeloid cell; tumor

DOI:  https://doi.org/10.1101/2024.07.12.603292
Proc Natl Acad Sci U S A. 2024 Aug 06. 121(32): e2322500121

HaloTag as a substrate-based macroautophagy reporter.

Qiang Xiao, Gabrielle Cruz, Rachel Botham, Susan G Fox, Anan Yu, Seth Allen, Richard I Morimoto, Jeffery W Kelly.

  Macroautophagy is a conserved cellular degradation pathway that, upon upregulation, confers resilience toward various stress conditions, including protection against proteotoxicity associated with neurodegenerative diseases, leading to cell survival. Monitoring autophagy regulation in living cells is important to understand its role in physiology and pathology, which remains challenging. Here, we report that when HaloTag is expressed within a cell of interest and reacts with tetramethylrhodamine (TMR; its ligand attached to a fluorophore), the rate of fluorescent TMR-HaloTag conjugate accumulation in autophagosomes and lysosomes, observed by fluorescence microscopy, reflects the rate of autophagy. Notably, we found that TMR-HaloTag conjugates were mainly degraded by the proteasome (~95%) under basal conditions, while lysosomal degradation (~10% upon pharmacological autophagy activation) was slow and incomplete, forming a degraded product that remained fluorescent within a SDS-PAGE gel, in agreement with previous reports that HaloTag is resistant to lysosomal degradation when fused to proteins of interest. Autophagy activation is distinguished from autophagy inhibition by the increased production of the degraded TMR-HaloTag band relative to the full-length TMR-HaloTag band as assessed by SDS-PAGE and by a faster rate of TMR-HaloTag conjugate lysosomal puncta accumulation as observed by fluorescence microscopy. Pharmacological proteasome inhibition leads to accumulation of TMR-HaloTag in lysosomes, indicating possible cross talk between autophagy and proteasomal degradation.

Keywords:  HaloTag; autophagy; lysosome; macroautophagy; reporter

DOI:  https://doi.org/10.1073/pnas.2322500121
Trends Cell Biol. 2024 Jul 29. pii: S0962-8924(24)00143-0. [Epub ahead of print]

Copper and iron orchestrate cell-state transitions in cancer and immunity.

Sebastian Müller, Tatiana Cañeque, Stéphanie Solier, Raphaël Rodriguez.

  Whereas genetic mutations can alter cell properties, nongenetic mechanisms can drive rapid and reversible adaptations to changes in their physical environment, a phenomenon termed 'cell-state transition'. Metals, in particular copper and iron, have been shown to be rate-limiting catalysts of cell-state transitions controlling key chemical reactions in mitochondria and the cell nucleus, which govern metabolic and epigenetic changes underlying the acquisition of distinct cell phenotypes. Acquisition of a distinct cell identity, independently of genetic alterations, is an underlying phenomenon of various biological processes, including development, inflammation, erythropoiesis, aging, and cancer. Here, mechanisms that have been uncovered related to the role of these metals in the regulation of cell plasticity are described, illustrating how copper and iron can be exploited for therapeutic intervention.

Keywords:  cancer; cell-state transition; copper; epigenetics; inflammation; iron; metabolism

DOI:  https://doi.org/10.1016/j.tcb.2024.07.005
Adv Surg. 2024 Sep;pii: S0065-3411(24)00018-6. [Epub ahead of print]58(1): 135-142

The Significance of Circulating Tumor Cells in Pancreatic Cancer.

Joseph R Habib, Ammar A Javed, Christopher L Wolfgang.

  The notion that technically resectable pancreatic ductal adenocarcinoma presents as localized disease is now known to be inaccurate. Evidence supports that most patients have subclinical systemic dissemination at the time of diagnosis. It is now widely accepted that both a local and systemic component of disease coexist, each requiring treatment of improved survival and potential cure. The advent of multiagent chemotherapy regimens has resulted in a modest improvement in survival. Consequently, this article will emphasize the expanding potential and significance of circulating tumor cells in the prognostication and management of patients with pancreatic cancer.

Keywords:  Biomarkers; Circulating tumor cells; Liquid biopsy; Pancreatic cancer

DOI:  https://doi.org/10.1016/j.yasu.2024.05.001
bioRxiv. 2024 Jul 16. pii: 2024.07.11.603114. [Epub ahead of print]

Localized in vivo gene editing of murine cancer-associated fibroblasts.

Nicholas F Kuhn, Itzia Zaleta-Linares, William A Nyberg, Justin Eyquem, Matthew F Krummel.

Discovering the role of fibroblasts residing in the tumor microenvironment (TME) requires controlled, localized perturbations because fibroblasts play critical roles in regulating immunity and tumor biology at multiple sites. Systemic perturbations can lead to unintended, confounding secondary effects, and methods to locally genetically engineer fibroblasts are lacking. To specifically investigate murine stromal cell perturbations restricted to the TME, we developed an adeno-associated virus (AAV)-based method to target any gene-of-interest in fibroblasts at high efficiency (>80%). As proof of concept, we generated single (sKO) and double gene KOs (dKO) of Osmr , Tgfbr2 , and Il1r1 in cancer-associated fibroblasts (CAFs) and investigated how their cell states and those of other cells of the TME subsequently change in mouse models of melanoma and pancreatic ductal adenocarcinoma (PDAC). Furthermore, we developed an in vivo knockin-knockout (KIKO) strategy to achieve long-term tracking of CAFs with target gene KO via knocked-in reporter gene expression. This validated in vivo gene editing toolbox is fast, affordable, and modular, and thus holds great potential for further exploration of gene function in stromal cells residing in tumors and beyond.

DOI: https://doi.org/10.1101/2024.07.11.603114
bioRxiv. 2024 Jul 22. pii: 2024.07.18.604152. [Epub ahead of print]

A selective S-acyltransferase inhibitor suppresses tumor growth.

Jia-Ying Lee, Sebastian Dilones, Timothe Maujean, Mohammad Asad, Altaf Mohd, Noam Auslander, Donita C Brady, George M Burslem, Eric S Witze.

S-acyltransferases play integral roles in essential physiological processes including regulation of oncogenic signaling pathways. While discovered over 40 years ago the field still lacks specific S-acylation inhibitors thus the potential benefit of pharmacologically targeting S-acyltransferases for human disease is still unknown. Here we report the identification of an orally bioavailable acyltransferase inhibitor SD-066-4 that inhibits the acyltransferase ZDHHC20. We identified a specific alanine residue that accommodates the methyl group of SD-066-4, thus providing isoform selectivity. SD-066-4 stably reduces EGFR S-acylation in Kras mutant cells and blocks the growth of Kras mutant lung tumors extending overall survival. We find that lung cancer patients harboring deletions in ZDHHC20 or ZDHHC14 concurrent with Kras alterations have a significant survival benefit, underscoring the translational importance of these enzymes.

DOI: https://doi.org/10.1101/2024.07.18.604152
STAR Protoc. 2024 Aug 01. pii: S2666-1667(24)00347-2. [Epub ahead of print]5(3): 103182

Protocol for evaluating S-acylated protein membrane affinity using protein-lipid conjugates.

Chunyang Xie, Dong Luo, Lu Liu, Xue Huang, Shao-Lin Zhang, Aimin Yang.

  S-acylation of proteins allows their association with membranes. Here, we present a protocol for establishing a platform for membrane affinity evaluation of S-acylated proteins in vitro. We describe steps for preparing lipid-maleimide compounds, mCherry-p62 recombinant proteins, and total cellular membranes. We then detail procedures for synthesizing protein-lipid conjugates using lipid-maleimide compounds and recombinant proteins and evaluating the membrane affinity of protein-lipid conjugates. For complete details on the use and execution of this protocol, please refer to Huang Xue et al.1.

Keywords:  Cell Membrane; Chemistry; Protein expression and purification

DOI:  https://doi.org/10.1016/j.xpro.2024.103182
Nat Rev Genet. 2024 Jul 29.

Chromosomal instability as a driver of cancer progression.

Xuelan Chen, Albert S Agustinus, Jun Li, Melody DiBona, Samuel F Bakhoum.

Chromosomal instability (CIN) refers to an increased propensity of cells to acquire structural and numerical chromosomal abnormalities during cell division, which contributes to tumour genetic heterogeneity. CIN has long been recognized as a hallmark of cancer, and evidence over the past decade has strongly linked CIN to tumour evolution, metastasis, immune evasion and treatment resistance. Until recently, the mechanisms by which CIN propels cancer progression have remained elusive. Beyond the generation of genomic copy number heterogeneity, recent work has unveiled additional tumour-promoting consequences of abnormal chromosome segregation. These mechanisms include complex chromosomal rearrangements, epigenetic reprogramming and the induction of cancer cell-intrinsic inflammation, emphasizing the multifaceted role of CIN in cancer.

DOI: https://doi.org/10.1038/s41576-024-00761-7
Cell Death Dis. 2024 Aug 01. 15(8): 553

Emerging mechanisms and promising approaches in pancreatic cancer metabolism.

Hao Wu, Mengdi Fu, Mengwei Wu, Zhen Cao, Qiyao Zhang, Ziwen Liu.

Pancreatic cancer is an aggressive cancer with a poor prognosis. Metabolic abnormalities are one of the hallmarks of pancreatic cancer, and pancreatic cancer cells can adapt to biosynthesis, energy intake, and redox needs through metabolic reprogramming to tolerate nutrient deficiency and hypoxic microenvironments. Pancreatic cancer cells can use glucose, amino acids, and lipids as energy to maintain malignant growth. Moreover, they also metabolically interact with cells in the tumour microenvironment to change cell fate, promote tumour progression, and even affect immune responses. Importantly, metabolic changes at the body level deserve more attention. Basic research and clinical trials based on targeted metabolic therapy or in combination with other treatments are in full swing. A more comprehensive and in-depth understanding of the metabolic regulation of pancreatic cancer cells will not only enrich the understanding of the mechanisms of disease progression but also provide inspiration for new diagnostic and therapeutic approaches.

DOI: https://doi.org/10.1038/s41419-024-06930-0
Int Immunopharmacol. 2024 Jul 27. pii: S1567-5769(24)01202-5. [Epub ahead of print]139 112681

LPCAT2-mediated lipid droplet production supports pancreatic cancer chemoresistance and cell motility.

Yuhe Lin, Xin Zhang, Yihui Wang, Wei Yao.

  Lipid droplet (LD) accumulation is one of the features in various tumors, whereas the significance of LD accumulation in pancreatic cancer progression remains unclear under chemotherapeutic condition. Since chemoresistance towards gemcitabine (GEM) is an obstacle for clinical therapy of pancreatic cancer, we sought to investigate the contribution of LD accumulation to GEM resistance. Herein, triacsin C (an inhibitor of LD production) dampened the proliferation, migration, and invasion of pancreatic cancer cells. The inhibition of LD accumulation induced by triacsin C or silencing of perilipin 2 (a marker of LD) sensitized cells to GEM treatment. Next, 75 paraffin-embedded samples and 5 pairs of frozen samples from pancreatic cancer patients were obtained for the detection of lysophosphatidylcholine acyltransferase 2 (LPCAT2; a LD-located enzyme contributing phosphatidylcholine synthesis) expression. The results revealed that LPCAT2 was upregulated in pancreatic cancer tissues, and its expression was correlated with clinical parameters and the basal LD content of cancer cell lines. Loss of LPCAT2 repressed the LD accumulation, GEM resistance, and cell motility. The enhancement of chemotherapy sensitivity was further confirmed in a xenograft model of mice in vivo. The carcinogenesis role of LPCAT2 was at least partly mediated by the LD accumulation. Then, signal transducer and activator of transcription 5B (STAT5B) activated the transcription of LPCAT2. Both LPCAT2 downregulation and triacsin C reversed the STAT5B-induced potentiation of malignant phenotypes in pancreatic cancer cells. In conclusion, LPCAT2-mediated lipid droplet production supported pancreatic cancer chemoresistance and cell motility, which was triggered by STAT5B.

Keywords:  Gemcitabine; Lipid droplet; Lysophosphatidylcholine acyltransferase 2; Pancreatic cancer; Signal transducer and activator of transcription 5B

DOI:  https://doi.org/10.1016/j.intimp.2024.112681
J Pathol. 2024 Jul 29.

Pan-cancer evaluation of tumor-infiltrating lymphocytes and programmed cell death protein ligand-1 in metastatic biopsies and matched primary tumors.

Zakhia El Beaino, Célia Dupain, Grégoire Marret, Xavier Paoletti, Laëtitia Fuhrmann, Charlotte Martinat, Yves Allory, Maral Halladjian, Ivan Bièche, Christophe Le Tourneau, Maud Kamal, Anne Vincent-Salomon.

  Tumor immunological characterization includes evaluation of tumor-infiltrating lymphocytes (TILs) and programmed cell death protein ligand-1 (PD-L1) expression. This study investigated TIL distribution, its prognostic value, and PD-L1 expression in metastatic and matched primary tumors (PTs). Specimens from 550 pan-cancer patients of the SHIVA01 trial (NCT01771458) with available metastatic biopsy and 111 matched PTs were evaluated for TILs and PD-L1. Combined positive score (CPS), tumor proportion score (TPS), and immune cell (IC) score were determined. TILs and PD-L1 were assessed according to PT organ of origin, histological subtype, and metastatic biopsy site. We found that TIL distribution in metastases did not vary according to PT organ of origin, histological subtype, or metastatic biopsy site, with a median of 10% (range: 0-70). TILs were decreased in metastases compared to PT (20% [5-60] versus 10% [0-40], p < 0.0001). CPS varied according to histological subtype (p = 0.02) and biopsy site (p < 0.02). TPS varied according to PT organ of origin (p = 0.003), histological subtype (p = 0.0004), and metastatic biopsy site (p = 0.00004). TPS was higher in metastases than in PT (p < 0.0001). TILs in metastases did not correlate with overall survival. In conclusion, metastases harbored fewer TILs than matched PT, regardless of PT organ of origin, histological subtype, and metastatic biopsy site. PD-L1 expression increased with disease progression. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Keywords:  CPS; PD‐L1; SHIVA01; TPS; metastatic biopsies; primary tumors; tumor‐infiltrating lymphocytes

DOI:  https://doi.org/10.1002/path.6334
Cell Metab. 2024 Jul 24. pii: S1550-4131(24)00273-0. [Epub ahead of print]

Development of a functional beige fat cell line uncovers independent subclasses of cells expressing UCP1 and the futile creatine cycle.

Ariana Vargas-Castillo, Yizhi Sun, Amanda L Smythers, Louisa Grauvogel, Phillip A Dumesic, Margo P Emont, Linus T Tsai, Evan D Rosen, Nathan W Zammit, Sydney M Shaffer, Martha Ordonez, Edward T Chouchani, Steven P Gygi, Tongtong Wang, Anand K Sharma, Miroslav Balaz, Christian Wolfrum, Bruce M Spiegelman.

  Although uncoupling protein 1 (UCP1) is established as a major contributor to adipose thermogenesis, recent data have illustrated an important role for alternative pathways, particularly the futile creatine cycle (FCC). How these pathways co-exist in cells and tissues has not been explored. Beige cell adipogenesis occurs in vivo but has been difficult to model in vitro; here, we describe the development of a murine beige cell line that executes a robust respiratory response, including uncoupled respiration and the FCC. The key FCC enzyme, tissue-nonspecific alkaline phosphatase (TNAP), is localized almost exclusively to mitochondria in these cells. Surprisingly, single-cell cloning from this cell line shows that cells with the highest levels of UCP1 express little TNAP, and cells with the highest expression of TNAP express little UCP1. Immunofluorescence analysis of subcutaneous fat from cold-exposed mice confirms that the highest levels of these critical thermogenic components are expressed in distinct fat cell populations.

Keywords:  Alpl gene; SV40 large T antigen; TNAP; UCP1; aP2-Prdm16 transgenic mice; functional beige cell line; futile creatine cycle; immortalized beige adipocytes; thermogenesis

DOI:  https://doi.org/10.1016/j.cmet.2024.07.002
Cell Rep. 2024 Jul 26. pii: S2211-1247(24)00881-7. [Epub ahead of print]43(8): 114552

ASCT2 is a major contributor to serine uptake in cancer cells.

Kelly O Conger, Christopher Chidley, Mete Emir Ozgurses, Huiping Zhao, Yumi Kim, Svetlana E Semina, Philippa Burns, Vipin Rawat, Lina Lietuvninkas, Ryan Sheldon, Issam Ben-Sahra, Jonna Frasor, Peter K Sorger, Gina M DeNicola, Jonathan L Coloff.

  The non-essential amino acid serine is a critical nutrient for cancer cells due to its diverse biosynthetic functions. While some tumors can synthesize serine de novo, others are auxotrophic and therefore reliant on serine uptake. Importantly, despite several transporters being known to be capable of transporting serine, the transporters that mediate serine uptake in cancer cells are not known. Here, we characterize the amino acid transporter ASCT2 (SLC1A5) as a major contributor to serine uptake in cancer cells. ASCT2 is well known as a glutamine transporter in cancer, and our work demonstrates that serine and glutamine compete for uptake through ASCT2. We further show that ASCT2-mediated serine uptake is essential for purine nucleotide biosynthesis and that estrogen receptor α (ERα) promotes serine uptake by directly activating SLC1A5 transcription. Collectively, our work defines an additional important role for ASCT2 as a serine transporter in cancer and evaluates ASCT2 as a potential therapeutic target.

Keywords:  ASCT2; CP: Cancer; ERα; SLC1A5; amino acid uptake; breast cancer; cancer metabolism; diet; purine biosynthesis; serine starvation; serine transporter

DOI:  https://doi.org/10.1016/j.celrep.2024.114552
Mol Cell. 2024 Jul 24. pii: S1097-2765(24)00579-3. [Epub ahead of print]

The V-ATPase/ATG16L1 axis is controlled by the V1H subunit.

Lewis Timimi, Antoni G Wrobel, George N Chiduza, Sarah L Maslen, Antonio Torres-Méndez, Beatriz Montaner, Colin Davis, Taylor Minckley, Katriona L Hole, Andrea Serio, Michael J Devine, J Mark Skehel, John L Rubinstein, Anne Schreiber, Rupert Beale.

  Defects in organellar acidification indicate compromised or infected compartments. Recruitment of the autophagy-related ATG16L1 complex to pathologically neutralized organelles targets ubiquitin-like ATG8 molecules to perturbed membranes. How this process is coupled to proton gradient disruption is unclear. Here, we reveal that the V1H subunit of the vacuolar ATPase (V-ATPase) proton pump binds directly to ATG16L1. The V1H/ATG16L1 interaction only occurs within fully assembled V-ATPases, allowing ATG16L1 recruitment to be coupled to increased V-ATPase assembly following organelle neutralization. Cells lacking V1H fail to target ATG8s during influenza infection or after activation of the immune receptor stimulator of interferon genes (STING). We identify a loop within V1H that mediates ATG16L1 binding. A neuronal V1H isoform lacks this loop and is associated with attenuated ATG8 targeting in response to ionophores in primary murine and human iPSC-derived neurons. Thus, V1H controls ATG16L1 recruitment following proton gradient dissipation, suggesting that the V-ATPase acts as a cell-intrinsic damage sensor.

Keywords:  ATG16L1; ATP6V1H; CASM; STING; V-ATPase; VAIL; autophagy; influenza; non-canonical autophagy; vacuolar ATPase

DOI:  https://doi.org/10.1016/j.molcel.2024.07.003
Signal Transduct Target Ther. 2024 Aug 02. 9(1): 192

Mechanism insights and therapeutic intervention of tumor metastasis: latest developments and perspectives.

Xiaoli Shi, Xinyi Wang, Wentao Yao, Dongmin Shi, Xihuan Shao, Zhengqing Lu, Yue Chai, Jinhua Song, Weiwei Tang, Xuehao Wang.

Metastasis remains a pivotal characteristic of cancer and is the primary contributor to cancer-associated mortality. Despite its significance, the mechanisms governing metastasis are not fully elucidated. Contemporary findings in the domain of cancer biology have shed light on the molecular aspects of this intricate process. Tumor cells undergoing invasion engage with other cellular entities and proteins en route to their destination. Insights into these engagements have enhanced our comprehension of the principles directing the movement and adaptability of metastatic cells. The tumor microenvironment plays a pivotal role in facilitating the invasion and proliferation of cancer cells by enabling tumor cells to navigate through stromal barriers. Such attributes are influenced by genetic and epigenetic changes occurring in the tumor cells and their surrounding milieu. A profound understanding of the metastatic process's biological mechanisms is indispensable for devising efficacious therapeutic strategies. This review delves into recent developments concerning metastasis-associated genes, important signaling pathways, tumor microenvironment, metabolic processes, peripheral immunity, and mechanical forces and cancer metastasis. In addition, we combine recent advances with a particular emphasis on the prospect of developing effective interventions including the most popular cancer immunotherapies and nanotechnology to combat metastasis. We have also identified the limitations of current research on tumor metastasis, encompassing drug resistance, restricted animal models, inadequate biomarkers and early detection methods, as well as heterogeneity among others. It is anticipated that this comprehensive review will significantly contribute to the advancement of cancer metastasis research.

DOI: https://doi.org/10.1038/s41392-024-01885-2
Cancer Discov. 2024 Jul 29.

Iron Chelation Therapy Elicits Innate Immune Control of Metastatic Ovarian Cancer.

Tito A Sandoval, Camilla Salvagno, Chang-Suk Chae, Deepika Awasthi, Paolo Giovanelli, Matias Marin Falco, Sung-Min Hwang, Eli Teran-Cabanillas, Lasse Suominen, Takahiro Yamazaki, Hui-Hsuan Kuo, Jenna E Moyer, M Laura Martin, Jyothi Manohar, Kihwan Kim, Maria A Sierra, Yusibeska Ramos, Chen Tan, Alexander Emmanuelli, Minkyung Song, Diana K Morales, Dmitriy Zamarin, Melissa K Frey, Evelyn Cantillo, Eloise Chapman-Davis, Kevin Holcomb, Christopher E Mason, Lorenzo Galluzzi, Zhen Ni Zhou, Anna Vaharautio, Suzanne M Cloonan, Juan R Cubillos-Ruiz.

Iron accumulation in tumors contributes to disease progression and chemoresistance. While targeting this process can influence various hallmarks of cancer, the immunomodulatory effects of iron chelation in the tumor microenvironment are unknown. Here, we report that treatment with deferiprone, an FDA-approved iron chelator, unleashes innate immune responses that restrain ovarian cancer. Deferiprone reprogrammed ovarian cancer cells towards an immunostimulatory state characterized by production of type I interferon (IFN) and overexpression of molecules that activate natural killer (NK) cells. Mechanistically, these effects were driven by innate sensing of mitochondrial DNA in the cytosol and concomitant activation of nuclear DNA damage responses triggered upon iron chelation. Deferiprone synergized with chemotherapy and prolonged the survival of mice with ovarian cancer by bolstering type I IFN responses that drove NK cell-dependent control of metastatic disease. Hence, iron chelation may represent an alternative immunotherapeutic strategy for malignancies that are refractory to current T cell-centric modalities.

DOI: https://doi.org/10.1158/2159-8290.CD-23-1451
Gastroenterology. 2024 Jul 30. pii: S0016-5085(24)05289-2. [Epub ahead of print]

What are the causes of acute pancreatitis?

Kiyoaki Ochi, Tsuneyoshi Ogawa, Toru Ueki.



Keywords:  acute pancreatitis; light chain amyloidosis; pancreatic amyloidoma

DOI:  https://doi.org/10.1053/j.gastro.2024.07.030
bioRxiv. 2024 Jul 23. pii: 2024.07.19.604345. [Epub ahead of print]

CGPA: multi-context insights from the cancer gene prognosis atlas.

Biwei Cao, Xiaoqing Yu, Gullermo Gonzalez, Amith R Murthy, Tingyi Li, Yuanyuan Shen, Sijie Yao, Jose R Conejo-Garcia, Peng Jiang, Xuefeng Wang.

Cancer transcriptomic data are used extensively to interrogate the prognostic value of targeted genes, yet basic scientists and clinicians have predominantly relied on univariable survival analysis for this purpose. This method often fails to capture the full prognostic potential and contextual relevance of the genes under study, inadvertently omitting a group of genes we term univariable missed-opportunity prognostic (UMOP) genes. Recognizing the complexity of revealing multifaceted prognostic implications, especially when extending the analysis to include various covariates and thresholds, we present the Cancer Gene Prognosis Atlas (CGPA). This platform greatly enhances gene-centric biomarker research across cancer types by offering an interactive and user-friendly interface for highly customized, in-depth prognostic analysis. CGPA notably supports data-driven exploration of gene pairs and gene-hallmark relationships, elucidating key composite biological mechanisms like synthetic lethality and immunosuppression. It further expands its capabilities to assess multi-gene panels using both public and user-provided data, facilitating a seamless mechanism-to-machine analysis. Additionally, CGPA features a designated portal for discovering prognostic gene modules using curated cancer immunotherapy data. Ultimately, CGPA's comprehensive, accessible tools allow cancer researchers, including those without statistical expertise, to precisely investigate the prognostic landscape of genes, customizing the model to fit specific research hypotheses and enhancing biomarker discovery and validation through a synergy of mechanistic and data-driven strategies.
Significance: CGPA is a streamlined, interactive platform for multi-context gene-centric prognostic analysis, simplifying biomarker discovery and validation in oncology for clinicians and basic scientists, and bridging a critical gap in translational cancer research.

DOI: https://doi.org/10.1101/2024.07.19.604345
bioRxiv. 2024 Jul 18. pii: 2024.07.16.603739. [Epub ahead of print]

High-motility pro-tumorigenic monocytes drive macrophage enrichment in the tumor microenvironment.

Wenxuan Du, Bryan Zhou, André Forjaz, Sarah M Shin, Fan Wu, Ashleigh J Crawford, Praful R Nair, Adrian C Johnston, Hoku West-Foyle, Ashley Tang, Dongjoo Kim, Rong Fan, Ashley L Kiemen, Pei-Hsun Wu, Jude M Phillip, Won Jin Ho, David E Sanin, Denis Wirtz.

Enrichment of tumor-associated macrophages (TAMΦs) in the tumor microenvironment correlates with worse clinical outcomes in triple-negative breast cancer (TNBC) patients, prompting the development of therapies to inhibit TAMΦ infiltration. However, the lackluster efficacy of CCL2-based chemotaxis blockade in clinical trials suggests that a new understanding of monocyte/macrophage infiltration may be necessary. Here we demonstrate that random migration, and not only chemotaxis, drives macrophage tumor infiltration. We identified tumor- associated monocytes (TAMos) that display a dramatically enhanced migration capability, induced rapidly by the tumor microenvironment, that drives effective tumor infiltration, in contrast to low-motility differentiated macrophages. TAMo, not TAMΦ, promotes cancer cell proliferation through activation of the MAPK pathway. IL-6 secreted both by cancer cells and TAMo themselves enhances TAMo migration by increasing dendritic protrusion dynamics and myosin- based contractility via the JAK2/STAT3 signaling pathway. Independent from CCL2 mediated chemotaxis, IL-6 driven enhanced migration and pro-proliferative effect of TAMo were validated in a syngeneic TNBC mouse model. Depletion of IL-6 in cancer cells significantly attenuated monocyte infiltration and reversed TAMo-induced cancer cell proliferation. This work reveals the critical role random migration plays in monocyte driven TAMΦ enrichment in a tumor and pinpoints IL-6 as a potential therapeutic target in combination with CCL2 to ameliorate current strategies against TAMΦ infiltration.

DOI: https://doi.org/10.1101/2024.07.16.603739
bioRxiv. 2024 Jul 17. pii: 2024.07.14.602133. [Epub ahead of print]

Drug resistant pancreatic cancer cells exhibit altered biophysical interactions with stromal fibroblasts in imaging studies of 3D co-culture models.

Eric Struth, Maryam Labaf, Vida Karimnia, Yiran Liu, Gwendolyn Cramer, Joanna B Dahl, Frank J Slack, Kourosh Zarringhalam, Jonathan P Celli.

Interactions between tumor and stromal cells are well known to play a prominent roles in progression of pancreatic ductal adenocarcinoma (PDAC). As knowledge of stromal crosstalk in PDAC has evolved, it has become clear that cancer associated fibroblasts can play both tumor promoting and tumor suppressive roles through a combination of paracrine crosstalk and juxtacrine interactions involving direct physical contact. Another major contributor to dismal survival statistics for PDAC is development of resistance to chemotherapy drugs. Though less is known about how the acquisition of chemoresistance impacts upon tumor-stromal crosstalk. Here, we use 3D co-culture geometries to recapitulate juxtacrine interactions between epithelial and stromal cells. In particular, extracellular matrix (ECM) overlay cultures in which stromal cells (pancreatic stellate cells, or normal human fibroblasts) are placed adjacent to PDAC cells (PANC1), result in direct heterotypic cell adhesions accompanied by dramatic fibroblast contractility which leads to highly condensed macroscopic multicellular aggregates as detected using particle image velocimetry (PIV) analysis to quantify cell velocities over the course of time lapse movie sequences. To investigate how drug resistance impacts these juxtacrine interactions we contrast cultures in which PANC1 are substituted with a drug resistant subline (PANC1-OR) previously established in our lab. We find that heterotypic cell-cell interactions are highly suppressed in drug-resistant cells relative to the parental PANC1 cells. To investigate further we conduct RNA-seq and bioinformatics analysis to identify differential gene expression in PANC1 and PANC1-OR, which shows that negative regulation of cell adhesion molecules, consistent with increased epithelial mesenchymal transition (EMT), is also consistent with loss of hetrotypic cell-cell contact necessary for the contractile behavior observed in drug naïve cultures. Overall these findings elucidate the role of drug-resistance in inhibiting an avenue of stromal crosstalk which is associated with tumor suppression and also help to establish cell culture conditions useful for further mechanistic investigation.

DOI: https://doi.org/10.1101/2024.07.14.602133