bims-cagime 2023-03-26 papers

bims-cagime

Biomed News

on Cancer, aging and metabolism

Issue of 2023–03–26
24 papers selected by
Kıvanç Görgülü, Technical University of Munich

Reprogramming of tissue metabolism during cancer metastasis.
Single-cell profiling to explore pancreatic cancer heterogeneity, plasticity and response to therapy.
Cell-autonomous Cxcl1 sustains tolerogenic circuitries and stromal inflammation via neutrophil-derived TNF in pancreatic cancer.
RBFOX2 modulates a metastatic signature of alternative splicing in pancreatic cancer.
A quantitative fluorescence-based approach to study mitochondrial protein import.
Purinergic GPCR-integrin interactions drive pancreatic cancer cell invasion.
Monitoring autophagic flux in vivo revealed its physiological response and significance of heterogeneity in pancreatic beta cells.
signifinder enables the identification of tumor cell states and cancer expression signatures in bulk, single-cell and spatial transcriptomic data.
Molecular principles of tissue invasion and metastasis.
Integrated Physiology of the Exocrine and Endocrine Compartments in Pancreatic Diseases: Workshop Proceedings.
Principles of phosphoproteomics and applications in cancer research.
Immunometabolism at the crossroads of obesity and cancer-a Keystone Symposia report.
Venous Thromboembolism in Metastatic Pancreatic Cancer.
EXT418, a novel long-acting ghrelin, mitigates Lewis lung carcinoma induced cachexia in mice.
Antigen-presenting type-I conventional dendritic cells facilitate curative checkpoint blockade immunotherapy in pancreatic cancer.
Stromal and therapy-induced macrophage proliferation promotes PDAC progression and susceptibility to innate immunotherapy.
Crawling, waving, inch worming, dilating, and pivoting mechanics of migrating cells: Lessons from Ken Jacobson.
Dynamic modeling of the cellular senescence gene regulatory network.
Small-molecule correctors and stabilizers to target p53.
RAS Degraders: The New Frontier for RAS Driven Cancers.
RHOJ controls EMT-associated resistance to chemotherapy.
Pancreatic adenocarcinoma with brain metastases.
Metabolic and histomorphological changes of adipose tissue in cachexia.
The Road to Quantitative Lipid Biochemistry in Living Cells.

Trends Cancer. 2023 Mar 17. pii: S2405-8033(23)00028-6. [Epub ahead of print]

Reprogramming of tissue metabolism during cancer metastasis.

Koelina Ganguly, Alec C Kimmelman.

  Cancer is a systemic disease that involves malignant cell-intrinsic and -extrinsic metabolic adaptations. Most studies have tended to focus on elucidating the metabolic vulnerabilities in the primary tumor microenvironment, leaving the metastatic microenvironment less explored. In this opinion article, we discuss the current understanding of the metabolic crosstalk between the cancer cells and the tumor microenvironment, both at local and systemic levels. We explore the possible influence of the primary tumor secretome to metabolically and epigenetically rewire the nonmalignant distant organs during prometastatic niche formation and successful metastatic colonization by the cancer cells. In an attempt to understand the process of prometastatic niche formation, we have speculated how cancer may hijack the inherent regenerative propensity of tissue parenchyma during metastatic colonization.

Keywords:  metabolism; metastasis; prometastatic niche; stroma; tissue regeneration; wound response

DOI:  https://doi.org/10.1016/j.trecan.2023.02.005
Nat Cancer. 2023 Mar 23.

Single-cell profiling to explore pancreatic cancer heterogeneity, plasticity and response to therapy.

Stefanie Bärthel, Chiara Falcomatà, Roland Rad, Fabian J Theis, Dieter Saur.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer entity characterized by a heterogeneous genetic landscape and an immunosuppressive tumor microenvironment. Recent advances in high-resolution single-cell sequencing and spatial transcriptomics technologies have enabled an in-depth characterization of both malignant and host cell types and increased our understanding of the heterogeneity and plasticity of PDAC in the steady state and under therapeutic perturbation. In this Review we outline single-cell analyses in PDAC, discuss their implications on our understanding of the disease and present future perspectives of multimodal approaches to elucidate its biology and response to therapy at the single-cell level.

DOI: https://doi.org/10.1038/s43018-023-00526-x
Cancer Discov. 2023 Mar 22. pii: CD-22-1046. [Epub ahead of print]

Cell-autonomous Cxcl1 sustains tolerogenic circuitries and stromal inflammation via neutrophil-derived TNF in pancreatic cancer.

Anna Bianchi, Iago De Castro Silva, Nilesh U Deshpande, Samara Singh, Siddharth Mehra, Vanessa T Garrido, Xinyu Guo, Luis A Nivelo, Despina S Kolonias, Shannon J Saigh, Eric Wieder, Christine I Rafie, Austin R Dosch, Zhiqun Zhou, Oliver Umland, Haleh Amirian, Ifeanyichukwu C Ogobuiro, Jian Zhang, Yuguang Ban, Carina Shiau, Nagaraj S Nagathihalli, Elizabeth A Montgomery, William L Hwang, Roberta Brambilla, Krishna Komanduri, Alejandro V Villarino, Eneda Toska, Ben Z Stanger, Dmitry I Gabrilovich, Nipun B Merchant, Jashodeep Datta.

We have shown that KRAS-TP53 genomic co-alteration is associated with immune-excluded microenvironments, chemoresistance, and poor survival in pancreatic ductal adenocarcinoma (PDAC) patients. By treating KRAS-TP53 cooperativity as a model for high-risk biology, we now identify cell-autonomous Cxcl1 as a key mediator of spatial T-cell restriction via interactions with CXCR2+ neutrophilic myeloid-derived suppressor cells in human PDAC using imaging mass cytometry. Silencing of cell-intrinsic Cxcl1 in LSL-K-rasG12D/+;Trp53R172H/+;Pdx-1Cre/+(KPC) cells reprograms trafficking and functional dynamics of neutrophils to overcome T-cell exclusion, and controls tumor growth in a T-cell-dependent manner. Mechanistically, neutrophil-derived TNF is a central regulator of this immunologic rewiring, instigating feed-forward Cxcl1 overproduction from tumor-cells and cancer-associated fibroblasts (CAF), T-cell dysfunction, and inflammatory CAF polarization via transmembraneTNF-TNFR2 interactions. TNFR2 inhibition disrupts this circuitry and improves sensitivity to chemotherapy in vivo. Our results uncover cancer cell-neutrophil crosstalk in which context-dependent TNF signaling amplifies stromal inflammation and immune tolerance to promote therapeutic resistance in PDAC.

DOI: https://doi.org/10.1158/2159-8290.CD-22-1046
Nature. 2023 Mar 22.

RBFOX2 modulates a metastatic signature of alternative splicing in pancreatic cancer.

Amina Jbara, Kuan-Ting Lin, Chani Stossel, Zahava Siegfried, Haya Shqerat, Adi Amar-Schwartz, Ela Elyada, Maxim Mogilevsky, Maria Raitses-Gurevich, Jared L Johnson, Tomer M Yaron, Ofek Ovadia, Gun Ho Jang, Miri Danan-Gotthold, Lewis C Cantley, Erez Y Levanon, Steven Gallinger, Adrian R Krainer, Talia Golan, Rotem Karni.

Pancreatic ductal adenocarcinoma (PDA) is characterized by aggressive local invasion and metastatic spread, leading to high lethality. Although driver gene mutations during PDA progression are conserved, no specific mutation is correlated with the dissemination of metastases1-3. Here we analysed RNA splicing data of a large cohort of primary and metastatic PDA tumours to identify differentially spliced events that correlate with PDA progression. De novo motif analysis of these events detected enrichment of motifs with high similarity to the RBFOX2 motif. Overexpression of RBFOX2 in a patient-derived xenograft (PDX) metastatic PDA cell line drastically reduced the metastatic potential of these cells in vitro and in vivo, whereas depletion of RBFOX2 in primary pancreatic tumour cell lines increased the metastatic potential of these cells. These findings support the role of RBFOX2 as a potent metastatic suppressor in PDA. RNA-sequencing and splicing analysis of RBFOX2 target genes revealed enrichment of genes in the RHO GTPase pathways, suggesting a role of RBFOX2 splicing activity in cytoskeletal organization and focal adhesion formation. Modulation of RBFOX2-regulated splicing events, such as via myosin phosphatase RHO-interacting protein (MPRIP), is associated with PDA metastases, altered cytoskeletal organization and the induction of focal adhesion formation. Our results implicate the splicing-regulatory function of RBFOX2 as a tumour suppressor in PDA and suggest a therapeutic approach for metastatic PDA.

DOI: https://doi.org/10.1038/s41586-023-05820-3
EMBO Rep. 2023 Mar 20. e55760

A quantitative fluorescence-based approach to study mitochondrial protein import.

Naintara Jain, Ridhima Gomkale, Olaf Bernhard, Peter Rehling, Luis Daniel Cruz-Zaragoza.

  Mitochondria play central roles in cellular energy production and metabolism. Most proteins required to carry out these functions are synthesized in the cytosol and imported into mitochondria. A growing number of metabolic disorders arising from mitochondrial dysfunction can be traced to errors in mitochondrial protein import. The mechanisms underlying the import of precursor proteins are commonly studied using radioactively labeled precursor proteins imported into purified mitochondria. Here, we establish a fluorescence-based import assay to analyze protein import into mitochondria. We show that fluorescently labeled precursors enable import analysis with similar sensitivity to those using radioactive precursors, yet they provide the advantage of quantifying import with picomole resolution. We adapted the import assay to a 96-well plate format allowing for fast analysis in a screening-compatible format. Moreover, we show that fluorescently labeled precursors can be used to monitor the assembly of the F1 F0 ATP synthase in purified mitochondria. Thus, we provide a sensitive fluorescence-based import assay that enables quantitative and fast import analysis.

Keywords:  fluorescent precursor; in vitro import; mitochondria; presequence pathway; protein import

DOI:  https://doi.org/10.15252/embr.202255760
Elife. 2023 Mar 21. pii: e86971. [Epub ahead of print]12

Purinergic GPCR-integrin interactions drive pancreatic cancer cell invasion.

Elena Tomas Bort, Megan Daisy Joseph, Qiaoying Wang, Edward Philip Carter, Nicolas Jaime Roth, Jessica Gibson, Ariana Samadi, Hemant M Kocher, Sabrina Simoncelli, Peter J McCormick, Richard Philip Grose.

  Pancreatic ductal adenocarcinoma (PDAC) continues to show no improvement in survival rates. One aspect of PDAC is elevated ATP levels, pointing to the purinergic axis as a potential attractive therapeutic target. Mediated in part by highly druggable extracellular proteins, this axis plays essential roles in fibrosis, inflammation response and immune function. Analysing the main members of the PDAC extracellular purinome using publicly available databases discerned which members may impact patient survival. P2RY2 presents as the purinergic gene with the strongest association with hypoxia, the highest cancer cell-specific expression and the strongest impact on overall survival. Invasion assays using a 3D spheroid model revealed P2Y2 to be critical in facilitating invasion driven by extracellular ATP. Using genetic modification and pharmacological strategies we demonstrate mechanistically that this ATP-driven invasion requires direct protein-protein interactions between P2Y2 and αV integrins. DNA-PAINT super-resolution fluorescence microscopy reveals that P2Y2 regulates the amount and distribution of integrin αV in the plasma membrane. Moreover, receptor-integrin interactions were required for effective downstream signalling, leading to cancer cell invasion. This work elucidates a novel GPCR-integrin interaction in cancer invasion, highlighting its potential for therapeutic targeting.

Keywords:  cancer biology; cell biology; human

DOI:  https://doi.org/10.7554/eLife.86971
Cell Chem Biol. 2023 Mar 16. pii: S2451-9456(23)00060-0. [Epub ahead of print]

Monitoring autophagic flux in vivo revealed its physiological response and significance of heterogeneity in pancreatic beta cells.

Shuhei Aoyama, Yuya Nishida, Hirotsugu Uzawa, Miwa Himuro, Akiko Kanai, Kyosei Ueki, Minami Ito, Hitoshi Iida, Isei Tanida, Takeshi Miyatsuka, Yoshio Fujitani, Masaki Matsumoto, Hirotaka Watada.

  Autophagy plays an essential role in preserving cellular homeostasis in pancreatic beta cells. However, the extent of autophagic flux in pancreatic islets induced in various physiological settings remains unclear. In this study, we generate transgenic mice expressing pHluorin-LC3-mCherry reporter for monitoring systemic autophagic flux by measuring the pHluorin/mCherry ratio, validating them in the starvation and insulin-deficient model. Our findings reveal that autophagic flux in pancreatic islets enhances after starvation, and suppression of the flux after short-term refeeding needs more prolonged re-starvation in islets than in the other insulin-targeted organs. Furthermore, heterogeneity of autophagic flux in pancreatic beta cells manifests under insulin resistance, and intracellular calcium influx by glucose stimulation increases more in high- than low-autophagic flux beta cells, with differential gene expression, including lipoprotein lipase. Our pHluorin-LC3-mCherry mice enable us to reveal biological insight into heterogeneity in autophagic flux in pancreatic beta cells.

Keywords:  autophagy; diabetes mellitus; heterogeneity; insulin resistance; insulin secretion; pHluorin; pancreatic beta cells

DOI:  https://doi.org/10.1016/j.chembiol.2023.03.001
bioRxiv. 2023 Mar 10. pii: 2023.03.07.530940. [Epub ahead of print]

signifinder enables the identification of tumor cell states and cancer expression signatures in bulk, single-cell and spatial transcriptomic data.

Stefania Pirrotta, Laura Masatti, Anna Corr, Fabiola Pedrini, Giovanni Esposito, Paolo Martini, Davide Risso, Chiara Romualdi, Enrica Calura.

Over the last decade, many studies and some clinical trials have proposed gene expression signatures as a valuable tool for understanding cancer mechanisms, defining subtypes, monitoring patient prognosis, and therapy efficacy. However, technical and biological concerns about reproducibility have been raised. Technical reproducibility is a major concern: we currently lack a computational implementation of the proposed signatures, which would provide detailed signature definition and assure reproducibility, dissemination, and usability of the classifier. Another concern regards intratumor heterogeneity, which has never been addressed when studying these types of biomarkers using bulk transcriptomics. With the aim of providing a tool able to improve the reproducibility and usability of gene expression signatures, we propose signifinder , an R package that provides the infrastructure to collect, implement, and compare expression-based signatures from cancer literature. The included signatures cover a wide range of biological processes from metabolism and programmed cell death, to morphological changes, such as quantification of epithelial or mesenchymal-like status. Collected signatures can score tumor cell characteristics, such as the predicted response to therapy or the survival association, and can quantify microenvironmental information, including hypoxia and immune response activity. signifinder has been used to characterize tumor samples and to investigate intra-tumor heterogeneity, extending its application to single-cell and spatial transcriptomic data. Through these higher-resolution technologies, it has become increasingly apparent that the single-sample score assessment obtained by transcriptional signatures is conditioned by the phenotypic and genetic intratumor heterogeneity of tumor masses. Since the characteristics of the most abundant cell type or clone might not necessarily predict the properties of mixed populations, signature prediction efficacy is lowered, thus impeding effective clinical diagnostics. Through signifinder , we offer general principles for interpreting and comparing transcriptional signatures, as well as suggestions for additional signatures that would allow for more complete and robust data inferences. We consider signifinder a useful tool to pave the way for reproducibility and comparison of transcriptional signatures in oncology.

DOI: https://doi.org/10.1101/2023.03.07.530940
Am J Physiol Cell Physiol. 2023 Mar 20.

Molecular principles of tissue invasion and metastasis.

Dhanisha Sulekha Suresh, Chandrasekharan Guruvayoorappan.

  Cancer associated metastasis is the primary cause of morbidity and mortality. Yet, its underlying biological mechanism remains poorly understood. Efforts to prevent or delay metastasis require a deep understanding of the underlying molecular mechanisms. However, continues advancement in cancer biology research has improved the comprehensive understanding of some of the molecular keystones of dissemination process. However, the emergence of new paradigms in the study of metastasis intuitively recognizes the involvement of genetics, epigenetics, extrinsic traits and tumor microenvironment in metastatic initiation, progression and colonization. On its way to the target site, the disseminated tumor cells interact with multiplex of proteins and cells. Identification of mechanisms underlying metastatic program is crucial for developing effective and efficient therapeutic interventions. In this review, we discuss details about recent advancements in the field of metastasis and organotropism, also highlights the role of genetics, epigenetics, exosomes, circadian rhythm, microbiome, integrins and other adhesion molecules, and chemokines in the regulation of metastatic events.

Keywords:  CTCs; EMT; Metastasis;; dormancy; metabolic profile of cancer ;

DOI:  https://doi.org/10.1152/ajpcell.00348.2022
Diabetes. 2023 04 01. 72(4): 433-448

Integrated Physiology of the Exocrine and Endocrine Compartments in Pancreatic Diseases: Workshop Proceedings.

Teresa L Mastracci, Minoti Apte, Laufey T Amundadottir, Alexandra Alvarsson, Steven Artandi, Melena D Bellin, Ernesto Bernal-Mizrachi, Alejandro Caicedo, Martha Campbell-Thompson, Zobeida Cruz-Monserrate, Abdelfattah El Ouaamari, Kyle J Gaulton, Andrea Geisz, Mark O Goodarzi, Manami Hara, Rebecca L Hull-Meichle, Alexander Kleger, Alison P Klein, Janel L Kopp, Rohit N Kulkarni, Mandar D Muzumdar, Anjaparavanda P Naren, Scott A Oakes, Søren S Olesen, Edward A Phelps, Alvin C Powers, Cherie L Stabler, Temel Tirkes, David C Whitcomb, Dhiraj Yadav, Jing Yong, Norann A Zaghloul, Stephen J Pandol, Maike Sander.

The Integrated Physiology of the Exocrine and Endocrine Compartments in Pancreatic Diseases workshop was a 1.5-day scientific conference at the National Institutes of Health (Bethesda, MD) that engaged clinical and basic science investigators interested in diseases of the pancreas. This report provides a summary of the proceedings from the workshop. The goals of the workshop were to forge connections and identify gaps in knowledge that could guide future research directions. Presentations were segregated into six major theme areas, including 1) pancreas anatomy and physiology, 2) diabetes in the setting of exocrine disease, 3) metabolic influences on the exocrine pancreas, 4) genetic drivers of pancreatic diseases, 5) tools for integrated pancreatic analysis, and 6) implications of exocrine-endocrine cross talk. For each theme, multiple presentations were followed by panel discussions on specific topics relevant to each area of research; these are summarized here. Significantly, the discussions resulted in the identification of research gaps and opportunities for the field to address. In general, it was concluded that as a pancreas research community, we must more thoughtfully integrate our current knowledge of normal physiology as well as the disease mechanisms that underlie endocrine and exocrine disorders so that there is a better understanding of the interplay between these compartments.

DOI: https://doi.org/10.2337/db22-0942
Biochem J. 2023 Mar 31. 480(6): 403-420

Principles of phosphoproteomics and applications in cancer research.

Luke Higgins, Henry Gerdes, Pedro R Cutillas.

  Phosphorylation constitutes the most common and best-studied regulatory post-translational modification in biological systems and archetypal signalling pathways driven by protein and lipid kinases are disrupted in essentially all cancer types. Thus, the study of the phosphoproteome stands to provide unique biological information on signalling pathway activity and on kinase network circuitry that is not captured by genetic or transcriptomic technologies. Here, we discuss the methods and tools used in phosphoproteomics and highlight how this technique has been used, and can be used in the future, for cancer research. Challenges still exist in mass spectrometry phosphoproteomics and in the software required to provide biological information from these datasets. Nevertheless, improvements in mass spectrometers with enhanced scan rates, separation capabilities and sensitivity, in biochemical methods for sample preparation and in computational pipelines are enabling an increasingly deep analysis of the phosphoproteome, where previous bottlenecks in data acquisition, processing and interpretation are being relieved. These powerful hardware and algorithmic innovations are not only providing exciting new mechanistic insights into tumour biology, from where new drug targets may be derived, but are also leading to the discovery of phosphoproteins as mediators of drug sensitivity and resistance and as classifiers of disease subtypes. These studies are, therefore, uncovering phosphoproteins as a new generation of disruptive biomarkers to improve personalised anti-cancer therapies.

Keywords:  kinase biology; mass spectrometry; proteomics

DOI:  https://doi.org/10.1042/BCJ20220220
Ann N Y Acad Sci. 2023 Mar 24.

Immunometabolism at the crossroads of obesity and cancer-a Keystone Symposia report.

Jennifer Cable, Jeffrey C Rathmell, Erika L Pearce, Ping-Chih Ho, Marcia C Haigis, Murad R Mamedov, Meng-Ju Wu, Susan M Kaech, Lydia Lynch, Mark A Febbraio, Sagar P Bapat, Hanna S Hong, Weiping Zou, Yasmine Belkaid, Zuri A Sullivan, Andrea Keller, Stefanie K Wculek, Douglas R Green, Catherine Postic, Ido Amit, Salvador Aznar Benitah, Russell G Jones, Miguel Reina-Campos, Santiago Valle Torres, Semir Beyaz, Donal Brennan, Luke A J O'Neill, Rachel J Perry, Dirk Brenner.

  Immunometabolism considers the relationship between metabolism and immunity. Typically, researchers focus on either the metabolic pathways within immune cells that affect their function or the impact of immune cells on systemic metabolism. A more holistic approach that considers both these viewpoints is needed. On September 5-8, 2022, experts in the field of immunometabolism met for the Keystone symposium "Immunometabolism at the Crossroads of Obesity and Cancer" to present recent research across the field of immunometabolism, with the setting of obesity and cancer as an ideal example of the complex interplay between metabolism, immunity, and cancer. Speakers highlighted new insights on the metabolic links between tumor cells and immune cells, with a focus on leveraging unique metabolic vulnerabilities of different cell types in the tumor microenvironment as therapeutic targets and demonstrated the effects of diet, the microbiome, and obesity on immune system function and cancer pathogenesis and therapy. Finally, speakers presented new technologies to interrogate the immune system and uncover novel metabolic pathways important for immunity.

Keywords:  cancer; immunity; immunometabolism; immunotherapy; metabolism; obesity

DOI:  https://doi.org/10.1111/nyas.14976
Eur J Haematol. 2023 Mar 20.

Venous Thromboembolism in Metastatic Pancreatic Cancer.

Lauren Laderman, Krishnalatha Sreekrishnanilayam, Ramesh K Pandey, Elizabeth Handorf, Aryeh Blumenreich, Kristen A Sorice, Shannon M Lynch, Khadija Cheema, Lavanya Nagappan, Iberia R Sosa, Efrat Dotan, Namrata Vijayvergia.

   BACKGROUND: Pancreatic cancer (PC) carries a high risk of venous thromboembolism (VTE). Several risk assessment models (RAMs) predict benefit of thromboprophylaxis in solid tumors; however, none are verified in metastatic pancreatic cancer (mPC).
METHODS: A retrospective mPC cohort treated at an academic cancer center from 2010-16 was investigated for VTE incidence (VTEmets). Multivariable regression analysis was used to assess multiple VTE risk factors. Overall survival (OS) was compared between mPC groups with and without VTE. Survival was analyzed using Kaplan-Meier survival plots and Cox proportional hazards regressions.
RESULTS: 400 mPC patients (median age 66; 52% males) were included. 87% had performance status of ECOG 0-1; 70% had advanced stage at PC diagnosis. Incidence of VTEmets was 17.5%; median time of occurrence 3.48 months after mPC diagnosis. Survival analysis started at median VTE occurrence. Median OS was 10.5 months in VTEmets vs. 13.4 in non-VTE group. Only advanced stage (OR 3.7, p=0.001) correlated with increased VTE risk.
CONCLUSIONS: The results suggest mPC carries a significant VTE burden. VTE predicts poor outcomes from the point of median VTE occurrence. Advanced stage disease is the strongest risk factor. Future studies are needed to define risk stratification, survival benefit, and choice of thromboprophylaxis.

Keywords:  anticoagulant; metastatic pancreatic cancer; thromboprophylaxis; venous thromboembolism

DOI:  https://doi.org/10.1111/ejh.13955
J Cachexia Sarcopenia Muscle. 2023 Mar 21.

EXT418, a novel long-acting ghrelin, mitigates Lewis lung carcinoma induced cachexia in mice.

Haiming L Kerr, Kora Krumm, Ian In-Gi Lee, Barbara Anderson, Anthony Christiani, Lena Strait, Beatrice A Breckheimer, Brynn Irwin, Alice Siyi Jiang, Artur Rybachok, Amanda Chen, Lucas Caeiro, Elizabeth Dacek, Daniel B Hall, Caroline H Kostyla, Laura M Hales, Tarik M Soliman, Jose M Garcia.

   BACKGROUND: Ghrelin is a potential therapy for cachexia due to its orexigenic properties and anabolic effects on muscle and fat. However, its clinical use is limited by the short half-life of active (acylated) ghrelin (~11 min in humans). EXT418 is a novel long-acting, constitutively active ghrelin analog created by covalently linking it to a vitamin D derivative. Here, we evaluated the effects and mechanisms of action of EXT418 on Lewis lung carcinoma (LLC)-induced cachexia in mice.
METHODS: Male C57BL/6J mice (5- to 7-month-old) were implanted with 1 × 106 heat-killed (HK) or live LLC cells. When the tumour was palpable, mice were injected with vehicle (T + V) or EXT418 daily (T + 418 Daily, 0.25 mg/kg/day) or every other day (T + 418 EOD, 0.5 mg/kg/EOD) for up to 14 days, whereas HK-treated mice were given vehicle (HK + V). Subsets of T + 418 Daily or EOD-treated mice were pair-fed to the T + V group. Body composition and grip strength were evaluated before tumour implantation and at the end of the experiment. Molecular markers were probed in muscles upon termination.
RESULTS: In tumour-bearing mice, administration of EXT418 daily or EOD partially prevented weight loss (T + V vs. T + 418 Daily, P = 0.030; and vs. T + 418 EOD, P = 0.020). Similar effects were observed in whole body fat and lean body mass. Grip strength in tumour-bearing mice was improved by EXT418 daily (P = 0.010) or EOD (P = 0.008) administration compared with vehicle-treated mice. These effects of EXT418 on weight and grip strength were partially independent of food intake. EXT418 daily administration also improved type IIA (P = 0.015), IIB (P = 0.037) and IIX (P = 0.050) fibre cross-sectional area (CSA) in tibialis anterior (TA) and EXT418 EOD improved CSA of IIB fibres in red gastrocnemius (GAS; P = 0.005). In skeletal muscles, tumour-induced increases in atrogenes Fbxo32 and Trim63 were ameliorated by EXT418 treatments (TA and GAS/plantaris, PL), which were independent of food intake. EXT418 administration decreased expression of the mitophagy marker Bnip3 (GAS/PL; P ≤ 0.010). Similar effects of EXT418 EOD were observed in p62 (GAS/PL; P = 0.039). In addition, EXT418 treatments ameliorated the tumour-induced elevation in muscle Il6 transcript levels (TA and GAS/PL), independently of food intake. Il-6 transcript levels in adipose tissue and circulating IL-10 were elevated in response to the tumour but these increases were not significant with EXT418 administration. Tumour mass was not altered by EXT418.
CONCLUSIONS: EXT418 mitigates LLC-induced cachexia by attenuating skeletal muscle inflammation, proteolysis, and mitophagy, without affecting tumour mass and partially independent of food intake.

Keywords:  Cachexia; Ghrelin; Inflammation; Mitophagy; Wasting

DOI:  https://doi.org/10.1002/jcsm.13211
bioRxiv. 2023 Mar 06. pii: 2023.03.05.531191. [Epub ahead of print]

Antigen-presenting type-I conventional dendritic cells facilitate curative checkpoint blockade immunotherapy in pancreatic cancer.

Krishnan K Mahadevan, Allison M Dyevoich, Yang Chen, Bingrui Li, Hikaru Sugimoto, Amari M Sockwell, Kathleen M McAndrews, Huamin Wang, Shabnam Shalapour, Stephanie S Watowich, Raghu Kalluri.

Inflammation and tissue damage associated with pancreatitis can precede or occur concurrently with pancreatic ductal adenocarcinoma (PDAC). We demonstrate that in PDAC coupled with pancreatitis (ptPDAC), antigen-presenting type-I conventional dendritic cells (cDC1s) are specifically activated. Immune checkpoint blockade therapy (iCBT) leads to cytotoxic CD8 + T cell activation and eradication of ptPDAC with restoration of lifespan even upon PDAC re-challenge. Such eradication of ptPDAC was reversed following specific depletion of dendritic cells. Employing PDAC antigen-loaded cDC1s as a vaccine, immunotherapy-resistant PDAC was rendered sensitive to iCBT with a curative outcome. Analysis of the T-cell receptor (TCR) sequences in the tumor infiltrating CD8 + T cells following cDC1 vaccination coupled with iCBT identified unique CDR3 sequences with potential therapeutic significance. Our findings identify a fundamental difference in the immune microenvironment and adaptive immune response in PDAC concurrent with, or without pancreatitis, and provides a rationale for combining cDC1 vaccination with iCBT as a potential treatment option.

DOI: https://doi.org/10.1101/2023.03.05.531191
J Exp Med. 2023 Jun 05. pii: e20212062. [Epub ahead of print]220(6):

Stromal and therapy-induced macrophage proliferation promotes PDAC progression and susceptibility to innate immunotherapy.

Chong Zuo, John M Baer, Brett L Knolhoff, Jad I Belle, Xiuting Liu, Angela Alarcon De La Lastra, Christina Fu, Graham D Hogg, Natalie L Kingston, Marcus A Breden, Paarth B Dodhiawala, Daniel Cui Zhou, Varintra E Lander, C Alston James, Li Ding, Kian-Huat Lim, Ryan C Fields, William G Hawkins, Jason D Weber, Guoyan Zhao, David G DeNardo.

Tumor-associated macrophages (TAMs) are abundant in pancreatic ductal adenocarcinomas (PDACs). While TAMs are known to proliferate in cancer tissues, the impact of this on macrophage phenotype and disease progression is poorly understood. We showed that in PDAC, proliferation of TAMs could be driven by colony stimulating factor-1 (CSF1) produced by cancer-associated fibroblasts. CSF1 induced high levels of p21 in macrophages, which regulated both TAM proliferation and phenotype. TAMs in human and mouse PDACs with high levels of p21 had more inflammatory and immunosuppressive phenotypes. p21 expression in TAMs was induced by both stromal interaction and/or chemotherapy treatment. Finally, by modeling p21 expression levels in TAMs, we found that p21-driven macrophage immunosuppression in vivo drove tumor progression. Serendipitously, the same p21-driven pathways that drive tumor progression also drove response to CD40 agonist. These data suggest that stromal or therapy-induced regulation of cell cycle machinery can regulate both macrophage-mediated immune suppression and susceptibility to innate immunotherapy.

DOI: https://doi.org/10.1084/jem.20212062
Biophys J. 2023 Mar 17. pii: S0006-3495(23)00196-0. [Epub ahead of print]

Crawling, waving, inch worming, dilating, and pivoting mechanics of migrating cells: Lessons from Ken Jacobson.

Alex Mogilner, Mariya Savinov.

Research on the locomotion of single cells on hard, flat surfaces brought insight into the mechanisms of leading-edge protrusion, spatially graded adhesion, front-rear coordination, and how intracellular and traction forces are harnessed to execute various maneuvers. Here we highlight how, by studying a variety of cell types, shapes and movements, Ken Jacobson and his collaborators made several discoveries that triggered the mechanistic understanding of cell motility. We then review the recent advancements and current perspectives in this field.

DOI: https://doi.org/10.1016/j.bpj.2023.03.023
Heliyon. 2023 Mar;9(3): e14007

Dynamic modeling of the cellular senescence gene regulatory network.

José Américo Nabuco Leva Ferreira de Freitas, Oliver Bischof.

  Cellular senescence is a cell fate that prominently impacts physiological and pathophysiological processes. Diverse cellular stresses induce it, and dramatic gene expression changes accompany it. However, determining the interactions comprising the gene regulatory network (GRN) governing senescence remains challenging. Recent advances in signal processing techniques provide opportunities to reconstruct GRNs. Here, we describe a GRN for senescence integrating time-series transcriptome and transcription factor depletion datasets. Specifically, we infer a set of differential equations using the "Sparse Identification of Nonlinear Dynamics" (SINDy) algorithm, discriminate genes with potential hidden regulators, validate the inferred GRN for time-points not included in the training data, and comprehensively benchmark our approach. Our work is a proof of concept for a data-driven GRN reconstruction method, consolidating an iterative, powerful mathematical platform for senescence modeling that can be used to test hypotheses in silico and has the potential for future discoveries of clinical impact.

Keywords:  Aging; Bioinformatics; Gene-regulatory network; Nonlinear dynamics; Senescence; Systems biology

DOI:  https://doi.org/10.1016/j.heliyon.2023.e14007
Trends Pharmacol Sci. 2023 Mar 22. pii: S0165-6147(23)00041-X. [Epub ahead of print]

Small-molecule correctors and stabilizers to target p53.

Maryam M J Fallatah, Fiona V Law, Warren A Chow, Peter Kaiser.

  The tumor suppressor p53 is the most frequently mutated protein in human cancer and tops the list of high-value precision oncology targets. p53 prevents initiation and progression of cancer by inducing cell-cycle arrest and various forms of cell death. Tumors have thus evolved ways to inactivate p53, mainly by TP53 mutations or by hyperactive p53 degradation. This review focuses on two types of p53 targeting compounds, MDM2 antagonists and mutant p53 correctors. MDM2 inhibitors prevent p53 protein degradation, while correctors restore tumor suppressor activity of p53 mutants by enhancing thermodynamic stability. Herein we explore both novel and repurposed p53 targeting compounds, discuss their mode of action, and examine the challenges in advancing them to the clinic.

Keywords:  MDM2 antagonists; TP53; cancer; mutant reactivation; nutlins; p53; small molecules

DOI:  https://doi.org/10.1016/j.tips.2023.02.007
Mol Ther. 2023 Mar 21. pii: S1525-0016(23)00138-7. [Epub ahead of print]

RAS Degraders: The New Frontier for RAS Driven Cancers.

Taylor E Escher, Karla J F Satchell.

The function and significance of RAS proteins in cancer have been widely studied for decades. In 2013, the National Cancer Institute (NCI) established the RAS Initiative to explore innovative approaches for attacking the proteins encoded by mutant forms ofRAS genes and to create effective therapies for RAS-driven cancers. This initiative spurred researchers to develop novel approaches and to discover small molecules targeting this protein that was at one time termed "undruggable". More recently, advanced efforts in RAS degraders including PROTACs, linker-based degraders, and direct proteolysis degraders have been explored as novel strategies to target RAS for cancer treatment. These RAS degraders present new opportunities for RAS therapies and may prove fruitful in understanding basic cell biology. Novel delivery strategies will further enhance the efficacy of these therapeutics. In this review, we summarize recent efforts to develop RAS degraders, including PROTACs and E3 adaptor and ligase fusions as cancer therapies. This review also details the direct RAS protease degrader, RAS/RAP1-specific endopeptidase (RRSP) that directly and specifically cleaves RAS.

DOI: https://doi.org/10.1016/j.ymthe.2023.03.017
Nature. 2023 Mar 22.

RHOJ controls EMT-associated resistance to chemotherapy.

Maud Debaugnies, Sara Rodríguez-Acebes, Jeremy Blondeau, Marie-Astrid Parent, Manuel Zocco, Yura Song, Viviane de Maertelaer, Virginie Moers, Mathilde Latil, Christine Dubois, Katia Coulonval, Francis Impens, Delphi Van Haver, Sara Dufour, Akiyoshi Uemura, Panagiota A Sotiropoulou, Juan Méndez, Cédric Blanpain.

The resistance of cancer cells to therapy is responsible for the death of most patients with cancer1. Epithelial-to-mesenchymal transition (EMT) has been associated with resistance to therapy in different cancer cells2,3. However, the mechanisms by which EMT mediates resistance to therapy remain poorly understood. Here, using a mouse model of skin squamous cell carcinoma undergoing spontaneous EMT during tumorigenesis, we found that EMT tumour cells are highly resistant to a wide range of anti-cancer therapies both in vivo and in vitro. Using gain and loss of function studies in vitro and in vivo, we found that RHOJ-a small GTPase that is preferentially expressed in EMT cancer cells-controls resistance to therapy. Using genome-wide transcriptomic and proteomic profiling, we found that RHOJ regulates EMT-associated resistance to chemotherapy by enhancing the response to replicative stress and activating the DNA-damage response, enabling tumour cells to rapidly repair DNA lesions induced by chemotherapy. RHOJ interacts with proteins that regulate nuclear actin, and inhibition of actin polymerization sensitizes EMT tumour cells to chemotherapy-induced cell death in a RHOJ-dependent manner. Together, our study uncovers the role and the mechanisms through which RHOJ acts as a key regulator of EMT-associated resistance to chemotherapy.

DOI: https://doi.org/10.1038/s41586-023-05838-7
BMJ Case Rep. 2023 Mar 20. pii: e253557. [Epub ahead of print]16(3):

Pancreatic adenocarcinoma with brain metastases.

Ngie Chang Law, Christopher Lomma.

  Brain metastases are rare for patients with pancreatic adenocarcinoma. The incidence of brain metastasis may increase as improved systemic treatment regimens improve overall survival. Given the low incidence of brain metastasis, recognition of disease and management remain a challenge. We report three cases of metastatic pancreatic adenocarcinoma with brain metastases, review the literature and discuss its management principles.

Keywords:  Neurosurgery; Pancreatic cancer; Radiotherapy

DOI:  https://doi.org/10.1136/bcr-2022-253557
Curr Opin Clin Nutr Metab Care. 2023 Feb 10.

Metabolic and histomorphological changes of adipose tissue in cachexia.

Alessio Molfino, Giovanni Imbimbo, Maurizio Muscaritoli.

PURPOSE OF REVIEW: To describe the role of the main changes occurring in adipose tissue during cachexia and how these affects patient's outcomes, with a specific focus on cancer.
RECENT FINDINGS: In cachexia, the changes within the adipose tissue have been recently described as the presence of inflammatory infiltration (T-lymphocytes and macrophages), enhanced fibrosis, and the occurrence of beige adipocytes (i.e., browning). The latter one is a process driving cachexia enhancing thermogenesis, primarily via modulation of uncoupling protein 1. Also, increased lipolysis of white adipose tissue, especially in cancer, via higher expression of hormone sensible and adipose tissue triglyceride lipases, was detected in experimental models and in human adipose tissue. Other systemic metabolic alterations occur in association with changes in adiposity, including insulin resistance and increased inflammation, all conditions associated with a worse outcome. Moreover, these profound metabolic alterations were shown to be implicated in several consequences, including extreme and progressive unvoluntary body weight loss.
SUMMARY: Alterations in adiposity occur early during cachexia. Adipose tissue atrophy, as well as metabolic changes of white adipose tissues were observed to be pivotal in cachexia, and to be implicated in several clinical complications and poor prognosis.Further research is necessary to clarify the mechanisms underlying the loss of adiposity and therefore to identify novel therapeutic options to counteract this phenomenon in cachexia.

DOI: https://doi.org/10.1097/MCO.0000000000000923
Acc Chem Res. 2023 Mar 21.

The Road to Quantitative Lipid Biochemistry in Living Cells.

Juan M Iglesias-Artola, André Nadler.

ConspectusTraditional cell biological techniques are not readily suitable for studying lipid signaling events because genetic perturbations are much slower than the interconversion of lipids in complex metabolic networks. For this reason, novel chemical biological approaches have been developed. One approach is to chemically modify a lipid with a so-called "caging group" that renders it inactive, but this cage can be removed photochemically inside cells to release the bioactive molecule. These caged compounds offer unique advantages for studying the kinetics of cellular biochemistry and have been extensively used in the past. However, a limitation of conventional caged compounds is their ability to diffuse freely inside the cell, which does not permit localized activation below optical precision. This poses a challenge for studying lipid signaling as lipid function inside cells is tightly linked to their parent membrane. An ideal lipid probe should, therefore, be restricted to a single organelle membrane or preferentially to a single leaflet. We first demonstrated the plasma-membrane-specific photorelease of fatty acids by employing sulfonated caging groups. Using these caged fatty acid probes we demonstrated that lipid localization determines signaling outcome. Generalizing this approach, we designed a so-called "click cage" that can be coupled to lipids and offers the possibility to attach organelle targeting groups via click chemistry. Using this strategy, we have synthesized plasma membrane, lysosomal, mitochondria, and endoplasmic-reticulum-targeted lipids that can be used to dissect organelle-specific signaling events. To reduce the synthetic effort associated with generating caged compounds, we designed a coumarin triflate reagent that allows the direct functionalization of phosphate- or carboxylate-containing compounds. With this novel reagent, we synthesized a small library of photocaged G-protein-coupled receptor (GPCR) ligands to study the underlying lipid signaling dynamics. Most recently, we have focused on quantifying the kinetics of lipid signaling for different diacylglycerol (DAG) species using plasma-membrane-targeted caged DAGs. Using this approach, we quantitatively measured lipid-protein affinities and lipid transbilayer dynamics in living cells. After analyzing DAGs with different acyl chain length and saturation degree, we discovered that affinities can vary by up to an order of magnitude. This finding clearly shows that cells are able to distinguish between individual DAG species, thereby demonstrating that lipid diversity matters in cellular signal processing. Although the recent advances have yielded valuable tools to study lipid signaling, challenges remain on specifically targeting the different leaflets of organelle membranes. Furthermore, it is necessary to simplify the experimental approaches required for parametrizing and corroborating quantitative kinetic models of lipid signaling. In the future, we envision that the application of leaflet-specific caged lipids to model membrane systems will be of crucial importance for understanding lipid asymmetry.

DOI: https://doi.org/10.1021/acs.accounts.2c00804