bims-cagime Biomed News
on Cancer, aging and metabolism
Issue of 2023‒07‒02
29 papers selected by
Kıvanç Görgülü
Technical University of Munich
  1. Acinar-to-Ductal Metaplasia (ADM): On the Road to Pancreatic Intraepithelial Neoplasia (PanIN) and Pancreatic Cancer.
  2. Reprogramming tumour-associated macrophages to outcompete cancer cells.
  3. Update on the treatment of cancer cachexia.
  4. Increased glucose availability sensitizes pancreatic cancer to chemotherapy.
  5. scKINETICS: inference of regulatory velocity with single-cell transcriptomics data.
  6. Integrated Analysis of the RASH Study with the Use of the "Burden of Therapy" (BOTh®TM) Methodology-A Novel Tool for Assessing Adverse Events in Metastatic Pancreatic Cancer.
  7. Dual inhibition of KRASG12D and pan-ERBB is synergistic in pancreatic ductal adenocarcinoma.
  8. Mapping cellular senescence networks in human diabetic foot ulcers.
  9. Spatially resolved single-cell translatomics at molecular resolution.
  10. Interferon signaling promotes tolerance to chromosomal instability during metastatic evolution in renal cancer.
  11. A membrane-sensing mechanism links lipid metabolism to protein degradation at the nuclear envelope.
  12. Longitudinal characterisation of cachexia in patients undergoing surgical resection for cancer.
  13. Beggars banquet: Metabolism in the tumor immune microenvironment and cancer therapy.
  14. Cancer aneuploidies are shaped primarily by effects on tumour fitness.
  15. Effect of extracellular matrix fiber cross-linkage on cancer cell motility and surrounding matrix deformation.
  16. Drosophila Screening Identifies Dual Inhibition of MEK and AURKB as an Effective Therapy for Pancreatic Ductal Adenocarcinoma.
  17. Senopathies-Diseases Associated with Cellular Senescence.
  18. Flux estimation analysis systematically characterizes the metabolic shifts of the central metabolism pathway in human cancer.
  19. Pulmonary metastasectomy is associated with survival after lung-only recurrence in pancreatic cancer.
  20. Branched-chain actin dynamics polarizes vesicle trajectories and partitions apicobasal epithelial membrane domains.
  21. CELA3B immunostaining is a highly specific marker for acinar cell carcinoma of the pancreas.
  22. Dissecting Interleukin-6 Classic and Trans-signaling in Inflammation and Cancer.
  23. A Novel HRD Signature Is Predictive of FOLFIRINOX Benefit in Metastatic Pancreatic Cancer.
  24. Systemic coagulopathy promotes host lethality in a new Drosophila tumor model.
  25. GDF15 promotes weight loss by enhancing energy expenditure in muscle.
  26. Extracting nanoscale membrane morphology from single-molecule localizations.
  27. Phase separation of FSP1 promotes ferroptosis.
  28. Long noncoding RNA MALAT1 is dynamically regulated in leader cells during collective cancer invasion.
  29. Laser Ablation and Intravital Microscopy to Study Intestinal Remodeling.
  1. Int J Mol Sci. 2023 Jun 09. pii: 9946. [Epub ahead of print]24(12):
    Acinar-to-Ductal Metaplasia (ADM): On the Road to Pancreatic Intraepithelial Neoplasia (PanIN) and Pancreatic Cancer.
    Louis Marstrand-Daucé, Diane Lorenzo, Anaïs Chassac, Pascal Nicole, Anne Couvelard, Cécile Haumaitre.
      Adult pancreatic acinar cells show high plasticity allowing them to change in their differentiation commitment. Pancreatic acinar-to-ductal metaplasia (ADM) is a cellular process in which the differentiated pancreatic acinar cells transform into duct-like cells. This process can occur as a result of cellular injury or inflammation in the pancreas. While ADM is a reversible process allowing pancreatic acinar regeneration, persistent inflammation or injury can lead to the development of pancreatic intraepithelial neoplasia (PanIN), which is a common precancerous lesion that precedes pancreatic ductal adenocarcinoma (PDAC). Several factors can contribute to the development of ADM and PanIN, including environmental factors such as obesity, chronic inflammation and genetic mutations. ADM is driven by extrinsic and intrinsic signaling. Here, we review the current knowledge on the cellular and molecular biology of ADM. Understanding the cellular and molecular mechanisms underlying ADM is critical for the development of new therapeutic strategies for pancreatitis and PDAC. Identifying the intermediate states and key molecules that regulate ADM initiation, maintenance and progression may help the development of novel preventive strategies for PDAC.
    Keywords:  acinar-to-ductal metaplasia (ADM); inflammation; pancreatic ductal adenocarcinoma (PDAC); pancreatic intraepithelial neoplasia (PanIN); pancreatitis; proliferation; regeneration; trans-differentiation; tumorigenesis
    DOI:  https://doi.org/10.3390/ijms24129946
  2. Nature. 2023 Jun 28.
    Reprogramming tumour-associated macrophages to outcompete cancer cells.
    Xian Zhang, Shun Li, Isha Malik, Mytrang H Do, Liangliang Ji, Chun Chou, Wei Shi, Kristelle J Capistrano, Jing Zhang, Ting-Wei Hsu, Briana G Nixon, Ke Xu, Xinxin Wang, Andrea Ballabio, Laura S Schmidt, W Marston Linehan, Ming O Li.
      In metazoan organisms, cell competition acts as a quality control mechanism to eliminate unfit cells in favour of their more robust neighbours1,2. This mechanism has the potential to be maladapted, promoting the selection of aggressive cancer cells3-6. Tumours are metabolically active and are populated by stroma cells7,8, but how environmental factors affect cancer cell competition remains largely unknown. Here we show that tumour-associated macrophages (TAMs) can be dietarily or genetically reprogrammed to outcompete MYC-overexpressing cancer cells. In a mouse model of breast cancer, MYC overexpression resulted in an mTORC1-dependent 'winner' cancer cell state. A low-protein diet inhibited mTORC1 signalling in cancer cells and reduced tumour growth, owing unexpectedly to activation of the transcription factors TFEB and TFE3 and mTORC1 in TAMs. Diet-derived cytosolic amino acids are sensed by Rag GTPases through the GTPase-activating proteins GATOR1 and FLCN to control Rag GTPase effectors including TFEB and TFE39-14. Depletion of GATOR1 in TAMs suppressed the activation of TFEB, TFE3 and mTORC1 under the low-protein diet condition, causing accelerated tumour growth; conversely, depletion of FLCN or Rag GTPases in TAMs activated TFEB, TFE3 and mTORC1 under the normal protein diet condition, causing decelerated tumour growth. Furthermore, mTORC1 hyperactivation in TAMs and cancer cells and their competitive fitness were dependent on the endolysosomal engulfment regulator PIKfyve. Thus, noncanonical engulfment-mediated Rag GTPase-independent mTORC1 signalling in TAMs controls competition between TAMs and cancer cells, which defines a novel innate immune tumour suppression pathway that could be targeted for cancer therapy.
    DOI:  https://doi.org/10.1038/s41586-023-06256-5
  3. Drug Discov Today. 2023 Jun 27. pii: S1359-6446(23)00205-2. [Epub ahead of print] 103689
    Update on the treatment of cancer cachexia.
    Kenichi Nishie, Tomomi Nishie, Seiichi Sato, Masayuki Hanaoka.
      Cancer cachexia is a complex multifaceted syndrome involving functional impairment and changes in body composition that cannot be reversed by nutritional support. Cancer cachexia is characterized by decreased skeletal muscle mass, increased lipolysis, and decreased food intake. Cancer cachexia decreases chemotherapy tolerance as well as quality of life. However, because no fully effective interventions are available, cancer cachexia remains an unmet need in cancer treatment. In recent years, several discoveries and treatments for cancer cachexia have been studied, and guidelines have been published. We believe that the development of effective strategies for the diagnosis and treatment of cancer cachexia will lead to breakthroughs in cancer treatment.
    Keywords:  anorexia; cachexia; cancer therapy; malnutrition; weight loss
    DOI:  https://doi.org/10.1016/j.drudis.2023.103689
  4. Nat Commun. 2023 Jun 28. 14(1): 3823
    Increased glucose availability sensitizes pancreatic cancer to chemotherapy.
    Ali Vaziri-Gohar, Jonathan J Hue, Ata Abbas, Hallie J Graor, Omid Hajihassani, Mehrdad Zarei, George Titomihelakis, John Feczko, Moeez Rathore, Sylwia Chelstowska, Alexander W Loftus, Rui Wang, Mahsa Zarei, Maryam Goudarzi, Renliang Zhang, Belinda Willard, Li Zhang, Adam Kresak, Joseph E Willis, Gi-Ming Wang, Curtis Tatsuoka, Joseph M Salvino, Ilya Bederman, Henri Brunengraber, Costas A Lyssiotis, Jonathan R Brody, Jordan M Winter.
      Pancreatic Ductal Adenocarcinoma (PDAC) is highly resistant to chemotherapy. Effective alternative therapies have yet to emerge, as chemotherapy remains the best available systemic treatment. However, the discovery of safe and available adjuncts to enhance chemotherapeutic efficacy can still improve survival outcomes. We show that a hyperglycemic state substantially enhances the efficacy of conventional single- and multi-agent chemotherapy regimens against PDAC. Molecular analyses of tumors exposed to high glucose levels reveal that the expression of GCLC (glutamate-cysteine ligase catalytic subunit), a key component of glutathione biosynthesis, is diminished, which in turn augments oxidative anti-tumor damage by chemotherapy. Inhibition of GCLC phenocopies the suppressive effect of forced hyperglycemia in mouse models of PDAC, while rescuing this pathway mitigates anti-tumor effects observed with chemotherapy and high glucose.
    DOI:  https://doi.org/10.1038/s41467-023-38921-8
  5. Bioinformatics. 2023 Jun 30. 39(Supplement_1): i394-i403
    scKINETICS: inference of regulatory velocity with single-cell transcriptomics data.
    Cassandra Burdziak, Chujun Julia Zhao, Doron Haviv, Direna Alonso-Curbelo, Scott W Lowe, Dana Pe'er.
      MOTIVATION: Transcriptional dynamics are governed by the action of regulatory proteins and are fundamental to systems ranging from normal development to disease. RNA velocity methods for tracking phenotypic dynamics ignore information on the regulatory drivers of gene expression variability through time.RESULTS: We introduce scKINETICS (Key regulatory Interaction NETwork for Inferring Cell Speed), a dynamical model of gene expression change which is fit with the simultaneous learning of per-cell transcriptional velocities and a governing gene regulatory network. Fitting is accomplished through an expectation-maximization approach designed to learn the impact of each regulator on its target genes, leveraging biologically motivated priors from epigenetic data, gene-gene coexpression, and constraints on cells' future states imposed by the phenotypic manifold. Applying this approach to an acute pancreatitis dataset recapitulates a well-studied axis of acinar-to-ductal transdifferentiation whilst proposing novel regulators of this process, including factors with previously appreciated roles in driving pancreatic tumorigenesis. In benchmarking experiments, we show that scKINETICS successfully extends and improves existing velocity approaches to generate interpretable, mechanistic models of gene regulatory dynamics.
    AVAILABILITY AND IMPLEMENTATION: All python code and an accompanying Jupyter notebook with demonstrations are available at http://github.com/dpeerlab/scKINETICS.
    DOI:  https://doi.org/10.1093/bioinformatics/btad267
  6. Curr Oncol. 2023 06 17. 30(6): 5828-5834
    Integrated Analysis of the RASH Study with the Use of the "Burden of Therapy" (BOTh®TM) Methodology-A Novel Tool for Assessing Adverse Events in Metastatic Pancreatic Cancer.
    Klara Dorman, Stefan Boeck, Robert J Snijder, Jens T Siveke, Michael Schenk, Julia Mayerle, Karel Caca, Jens Freiberg-Richter, Ludwig Fischer von Weikersthal, Frank Kullmann, Anke Reinacher-Schick, Martin Fuchs, Stephan Kanzler, Volker Kunzmann, Thomas J Ettrich, Danmei Zhang, Swantje Held, Ayad Abdul-Ahad, Michael von Bergwelt-Baildon, Volker Heinemann, Michael Haas.
      This analysis of the RASH trial (NCT01729481) aimed at gaining a better understanding of the "Burden of Therapy" (BOTh®TM) in pancreatic ductal adenocarcinoma (PDAC). In the RASH study, 150 patients with newly diagnosed metastatic PDAC were treated with gemcitabine plus erlotinib (gem/erlotinib) for four weeks. Patients who developed a skin rash during this four-week run-in phase continued with the gem/erlotinib treatment, while rash-negative patients were switched to FOLFIRINOX. The study demonstrated a 1-year survival rate of rash-positive patients who received gem/erlotinib as first-line treatment that was comparable to previous reports of patients receiving FOLFIRINOX. To understand whether these comparable survival rates may be accompanied by better tolerability of the gem/erlotinib treatment compared to FOLFIRINOX, the BOTh®TM methodology was used to continuously quantify and depict the burden of therapy generated by treatment emergent events (TEAEs). Sensory neuropathy was significantly more common in the FOLFIRINOX arm, and prevalence as well as severity increased over time. In both arms, the BOTh®TM associated with diarrhea decreased over the course of treatment. The BOTh®TM caused by neutropenia was comparable in both arms but decreased in the FOLFIRINOX arm over time, possibly due to chemotherapy dose reductions. Overall, gem/erlotinib was associated with a slightly higher overall BOTh®TM, but the difference was not statistically significant (p = 0.6735). In summary, the BOTh®TM analysis facilitates the evaluation of TEAEs. In patients fit for intense chemotherapeutic regimens, FOLFIRINOX is associated with a lower BOTh®TM than gem/erlotinib.
    Keywords:  FOLFIRINOX; burden of therapy; erlotinib; gemcitabine; pancreatic cancer; quality of life; rash
    DOI:  https://doi.org/10.3390/curroncol30060436
  7. Cancer Res. 2023 Jun 28. pii: CAN-23-1313. [Epub ahead of print]
    Dual inhibition of KRASG12D and pan-ERBB is synergistic in pancreatic ductal adenocarcinoma.
    Kevin Christian Montecillo Gulay, Xinlian Zhang, Vasiliki Pantazopoulou, Jay Patel, Edgar Esparza, Deepa Sheik Pran Babu, Satoshi Ogawa, Jonathan Weitz, Isabella Ng, Evangeline S Mose, Minya Pu, Dannielle D Engle, Andrew M Lowy, Hervé Tiriac.
      Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a low survival rate. Recently, new drugs that target KRASG12D, a common mutation in PDAC, have been developed. We studied one of these compounds, MRTX1133, and found it was specific and effective at low nanomolar concentrations in patient-derived organoid models and cell lines harboring KRASG12D mutations. Treatment with MRTX1133 upregulated the expression and phosphorylation of EGFR and HER2, indicating that inhibition of ERBB signaling may potentiate MRTX1133 anti-tumor activity. Indeed, the irreversible pan-ERBB inhibitor, afatinib, potently synergized with MRTX1133 in vitro, and cancer cells with acquired resistance to MRTX1133 in vitro remained sensitive to this combination therapy. Finally, the combination of MRTX1133 and afatinib led to tumor regression and longer survival in orthotopic PDAC mouse models. These results suggest that dual inhibition of ERBB and KRAS signaling may be synergistic and circumvent the rapid development of acquired resistance in patients with KRAS mutant pancreatic cancer.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-23-1313
  8. Geroscience. 2023 Jun 29.
    Mapping cellular senescence networks in human diabetic foot ulcers.
    Grace T Yu, Dileep D Monie, Sundeep Khosla, Tamar Tchkonia, James L Kirkland, Saranya P Wyles.
      Cellular senescence, a cell fate defined by irreversible cell cycle arrest, has been observed to contribute to chronic age-related conditions including non-healing wounds, such as diabetic foot ulcers. However, the role of cellular senescence in the pathogenesis of diabetic foot ulcers remains unclear. To examine the contribution of senescent phenotypes to these chronic wounds, differential gene and network analyses were performed on publicly available bulk RNA sequencing of whole skin biopsies of wound edge diabetic foot ulcers and uninvolved diabetic foot skin. Wald tests with Benjamini-Hochberg correction were used to evaluate differential gene expression. Results showed that cellular senescence markers, CDKN1A, CXCL8, IGFBP2, IL1A, MMP10, SERPINE1, and TGFA, were upregulated, while TP53 was downregulated in diabetic foot ulcers compared to uninvolved diabetic foot skin. NetDecoder was then used to identify and compare context-specific protein-protein interaction networks using known cellular senescence markers as pathway sources. The diabetic foot ulcer protein-protein interaction network demonstrated significant perturbations with decreased inhibitory interactions and increased senescence markers compared to uninvolved diabetic foot skin. Indeed, TP53 (p53) and CDKN1A (p21) appeared to be key regulators in diabetic foot ulcer formation. These findings suggest that cellular senescence is an important mediator of diabetic foot ulcer pathogenesis.
    Keywords:  Cellular senescence; Diabetic foot ulcer; Network analysis; Skin aging; Wound healing
    DOI:  https://doi.org/10.1007/s11357-023-00854-x
  9. Science. 2023 Jun 30. 380(6652): eadd3067
    Spatially resolved single-cell translatomics at molecular resolution.
    Hu Zeng, Jiahao Huang, Jingyi Ren, Connie Kangni Wang, Zefang Tang, Haowen Zhou, Yiming Zhou, Hailing Shi, Abhishek Aditham, Xin Sui, Hongyu Chen, Jennifer A Lo, Xiao Wang.
      The precise control of messenger RNA (mRNA) translation is a crucial step in posttranscriptional gene regulation of cellular physiology. However, it remains a challenge to systematically study mRNA translation at the transcriptomic scale with spatial and single-cell resolution. Here, we report the development of ribosome-bound mRNA mapping (RIBOmap), a highly multiplexed three-dimensional in situ profiling method to detect cellular translatome. RIBOmap profiling of 981 genes in HeLa cells revealed cell cycle-dependent translational control and colocalized translation of functional gene modules. We mapped 5413 genes in mouse brain tissues, yielding spatially resolved single-cell translatomic profiles for 119,173 cells and revealing cell type-specific and brain region-specific translational regulation, including translation remodeling during oligodendrocyte maturation. Our method detected widespread patterns of localized translation in neuronal and glial cells in intact brain tissue networks.
    DOI:  https://doi.org/10.1126/science.add3067
  10. Nat Cancer. 2023 Jun 26.
    Interferon signaling promotes tolerance to chromosomal instability during metastatic evolution in renal cancer.
    Luigi Perelli, Federica Carbone, Li Zhang, Justin K Huang, Courtney Le, Hania Khan, Francesca Citron, Edoardo Del Poggetto, Tony Gutschner, Hideo Tomihara, Melinda Soeung, Rosalba Minelli, Sanjana Srinivasan, Michael Peoples, Truong Nguyen Anh Lam, Sebastian Lundgren, Ruohan Xia, Cihui Zhu, Alaa M T Mohamed, Jianhua Zhang, Kanishka Sircar, Alessandro Sgambato, JianJun Gao, Eric Jonasch, Giulio F Draetta, Andrew Futreal, Ziad Bakouny, Eliezer M Van Allen, Toni Choueiri, Sabina Signoretti, Pavlos Msaouel, Kevin Litchfield, Samra Turajlic, Linghua Wang, Ying Bei Chen, Renzo G Di Natale, A Ari Hakimi, Virginia Giuliani, Timothy P Heffernan, Andrea Viale, Christopher A Bristow, Nizar M Tannir, Alessandro Carugo, Giannicola Genovese.
      Molecular routes to metastatic dissemination are critical determinants of aggressive cancers. Through in vivo CRISPR-Cas9 genome editing, we generated somatic mosaic genetically engineered models that faithfully recapitulate metastatic renal tumors. Disruption of 9p21 locus is an evolutionary driver to systemic disease through the rapid acquisition of complex karyotypes in cancer cells. Cross-species analysis revealed that recurrent patterns of copy number variations, including 21q loss and dysregulation of the interferon pathway, are major drivers of metastatic potential. In vitro and in vivo genomic engineering, leveraging loss-of-function studies, along with a model of partial trisomy of chromosome 21q, demonstrated a dosage-dependent effect of the interferon receptor genes cluster as an adaptive mechanism to deleterious chromosomal instability in metastatic progression. This work provides critical knowledge on drivers of renal cell carcinoma progression and defines the primary role of interferon signaling in constraining the propagation of aneuploid clones in cancer evolution.
    DOI:  https://doi.org/10.1038/s43018-023-00584-1
  11. J Cell Biol. 2023 Sep 04. pii: e202304026. [Epub ahead of print]222(9):
    A membrane-sensing mechanism links lipid metabolism to protein degradation at the nuclear envelope.
    Shoken Lee, Jake W Carrasquillo Rodrı Guez, Holly Merta, Shirin Bahmanyar.
      Lipid composition determines organelle identity; however, whether the lipid composition of the inner nuclear membrane (INM) domain of the ER contributes to its identity is not known. Here, we show that the INM lipid environment of animal cells is under local control by CTDNEP1, the master regulator of the phosphatidic acid phosphatase lipin 1. Loss of CTDNEP1 reduces association of an INM-specific diacylglycerol (DAG) biosensor and results in a decreased percentage of polyunsaturated containing DAG species. Alterations in DAG metabolism impact the levels of the resident INM protein Sun2, which is under local proteasomal regulation. We identify a lipid-binding amphipathic helix (AH) in the nucleoplasmic domain of Sun2 that prefers membrane packing defects. INM dissociation of the Sun2 AH is linked to its proteasomal degradation. We suggest that direct lipid-protein interactions contribute to sculpting the INM proteome and that INM identity is adaptable to lipid metabolism, which has broad implications on disease mechanisms associated with the nuclear envelope.
    DOI:  https://doi.org/10.1083/jcb.202304026
  12. Curr Opin Support Palliat Care. 2023 Jun 30.
    Longitudinal characterisation of cachexia in patients undergoing surgical resection for cancer.
    Leo R Brown, Barry J A Laird, Stephen J Wigmore, Richard J E Skipworth.
      PURPOSE OF REVIEW: The complexity of the cancer cachexia phenotype has undoubtedly hindered researchers' understanding of this devastating syndrome. The presence and magnitude of host-tumour interactions are rarely considered during clinical decision-making within the current staging paradigm. Furthermore, treatment options for those patients who are identified as suffering from cancer cachexia remain extremely limited.RECENT FINDINGS: Previous attempts to characterise cachexia have largely focussed on individual surrogate disease markers, often studied across a limited timeframe. While the adverse prognostic value of clinical and biochemical features is evident, the relationships between these are less clear. Investigation of patients with earlier-stage disease could allow researchers to identify markers of cachexia that precede the refractory stage of the wasting process. Appreciation of the cachectic phenotype within 'curative' populations may aid our understanding of the syndrome's genesis and provide potential routes for prevention, rather than treatment.
    SUMMARY: Holistic, longitudinal characterisation of cancer cachexia, across all at-risk and affected populations, is of vital importance for future research in the field. This paper presents the protocol for an observational study aiming to create a robust and holistic characterisation of surgical patients with, or at risk of, cancer cachexia.
    DOI:  https://doi.org/10.1097/SPC.0000000000000660
  13. Cell Metab. 2023 Jun 20. pii: S1550-4131(23)00213-9. [Epub ahead of print]
    Beggars banquet: Metabolism in the tumor immune microenvironment and cancer therapy.
    Weiping Zou, Douglas R Green.
      Metabolic programming in the tumor microenvironment (TME) alters tumor immunity and immunotherapeutic response in tumor-bearing mice and patients with cancer. Here, we review immune-related functions of core metabolic pathways, key metabolites, and crucial nutrient transporters in the TME, discuss their metabolic, signaling, and epigenetic impact on tumor immunity and immunotherapy, and explore how these insights can be applied to the development of more effective modalities to potentiate the function of T cells and sensitize tumor cell receptivity to immune attack, thereby overcoming therapeutic resistance.
    Keywords:  T cell; checkpoint; immunotherapy; metabolism; metabolite; tumor microenvironment
    DOI:  https://doi.org/10.1016/j.cmet.2023.06.003
  14. Nature. 2023 Jun 28.
    Cancer aneuploidies are shaped primarily by effects on tumour fitness.
    Juliann Shih, Shahab Sarmashghi, Nadja Zhakula-Kostadinova, Shu Zhang, Yohanna Georgis, Stephanie H Hoyt, Michael S Cuoco, Galen F Gao, Liam F Spurr, Ashton C Berger, Gavin Ha, Veronica Rendo, Hui Shen, Matthew Meyerson, Andrew D Cherniack, Alison M Taylor, Rameen Beroukhim.
      Aneuploidies-whole-chromosome or whole-arm imbalances-are the most prevalent alteration in cancer genomes1,2. However, it is still debated whether their prevalence is due to selection or ease of generation as passenger events1,2. Here we developed a method, BISCUT, that identifies loci subject to fitness advantages or disadvantages by interrogating length distributions of telomere- or centromere-bounded copy-number events. These loci were significantly enriched for known cancer driver genes, including genes not detected through analysis of focal copy-number events, and were often lineage specific. BISCUT identified the helicase-encoding gene WRN as a haploinsufficient tumour-suppressor gene on chromosome 8p, which is supported by several lines of evidence. We also formally quantified the role of selection and mechanical biases in driving aneuploidy, finding that rates of arm-level copy-number alterations are most highly correlated with their effects on cellular fitness1,2. These results provide insight into the driving forces behind aneuploidy and its contribution to tumorigenesis.
    DOI:  https://doi.org/10.1038/s41586-023-06266-3
  15. Biochem Biophys Res Commun. 2023 Jun 20. pii: S0006-291X(23)00762-3. [Epub ahead of print]673 44-50
    Effect of extracellular matrix fiber cross-linkage on cancer cell motility and surrounding matrix deformation.
    Seiji Omata, Keisuke Fukuda, Yurie Sakai, Kenoki Ohuchida, Yasuyuki Morita.
      Cancer incidence is increasing annually, and the invasion of cancer into the stroma significantly affects cancer metastasis. The stroma primarily comprises an abundant extracellular matrix (ECM) that interacts closely with cancer cells. Cancer cells use the ECM as a scaffold to migrate from a tumor via mechanical actions such as pushing and pulling the fibers. The purpose of this study is to clarify the effects of elastic modulus differences on cell migration behavior based on the same ECM fiber structure. We observe temporal changes in the morphology of cancer cells and the surrounding ECM to elucidate the relationship between changes in the mechanical properties of the ECM and the invasive behavior of cancer cells. We analyze the shape and migration distance of cancer cells and the displacement field of the ECM by varying the fiber elastic modulus but fixing the ECM density. Increasing the elastic modulus results in a protruding cell shape, which indicates the maximum displacement of the ECM around the cell. Additionally, differences in cell migration speed and dispersion based on the elastic modulus are observed. The behavior of cells with increasing elasticity is classified via cluster analysis. Owing to the chemical cross-linking of the fibers, some cells cannot deform the surrounding tissue. This is attributable to the gel state of the ECM and microscopic fluctuations in the fiber density around the cells. We successfully assessed the effect of changes in the ECM modulus on cell mortality and morphology to reveal the mechanism of cancer invasion.
    DOI:  https://doi.org/10.1016/j.bbrc.2023.06.019
  16. Cancer Res. 2023 Jun 28. OF1-OF12
    Drosophila Screening Identifies Dual Inhibition of MEK and AURKB as an Effective Therapy for Pancreatic Ductal Adenocarcinoma.
    Sho Sekiya, Junki Fukuda, Ryodai Yamamura, Takako Ooshio, Yusuke Satoh, Shinya Kosuge, Reo Sato, Kanako C Hatanaka, Yutaka Hatanaka, Tomoko Mitsuhashi, Toru Nakamura, Yoshihiro Matsuno, Satoshi Hirano, Masahiro Sonoshita.
      Significant progress has been made in understanding the pathogenesis of pancreatic ductal adenocarcinoma (PDAC) by generating and using murine models. To accelerate drug discovery by identifying novel therapeutic targets on a systemic level, here we generated a Drosophila model mimicking the genetic signature in PDAC (KRAS, TP53, CDKN2A, and SMAD4 alterations), which is associated with the worst prognosis in patients. The '4-hit' flies displayed epithelial transformation and decreased survival. Comprehensive genetic screening of their entire kinome revealed kinases including MEK and AURKB as therapeutic targets. Consistently, a combination of the MEK inhibitor trametinib and the AURKB inhibitor BI-831266 suppressed the growth of human PDAC xenografts in mice. In patients with PDAC, the activity of AURKB was associated with poor prognosis. This fly-based platform provides an efficient whole-body approach that complements current methods for identifying therapeutic targets in PDAC.SIGNIFICANCE: Development of a Drosophila model mimicking genetic alterations in human pancreatic ductal adenocarcinoma provides a tool for genetic screening that identifies MEK and AURKB inhibition as a potential treatment strategy.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-22-3762
  17. Biomolecules. 2023 06 08. pii: 966. [Epub ahead of print]13(6):
    Senopathies-Diseases Associated with Cellular Senescence.
    Oleh Lushchak, Markus Schosserer, Johannes Grillari.
      Cellular senescence describes a stable cell cycle arrest state with a characteristic phenotype. Senescent cells accumulate in the human body during normal aging, limiting the lifespan and promoting aging-related, but also several non-related, pathologies. We propose to refer to all diseases whose pathogenesis or progression is associated with cellular senescence as "senopathies". Targeting senescent cells with senolytics or senomorphics is likely to mitigate these pathologies. Examples of senopathies include cardiovascular, metabolic, musculoskeletal, liver, kidney, and lung diseases and neurodegeneration. For all these pathologies, animal studies provide clear mechanistic evidence for a connection between senescent cell accumulation and disease progression. The major persisting challenge in developing novel senotherapies is the heterogeneity of senescence phenotypes, causing a lack of universal biomarkers and difficulties in discriminating senescent from non-senescent cells.
    Keywords:  age-related disease; aging; cellular senescence; geroscience; pathology; senescence-associated secretory phenotype (SASP); senolytic; senomorphic; senopathy; senotherapy
    DOI:  https://doi.org/10.3390/biom13060966
  18. Front Oncol. 2023 ;13 1117810
    Flux estimation analysis systematically characterizes the metabolic shifts of the central metabolism pathway in human cancer.
    Grace Yang, Shaoyang Huang, Kevin Hu, Alex Lu, Jonathan Yang, Noah Meroueh, Pengtao Dang, Yijie Wang, Haiqi Zhu, Sha Cao, Chi Zhang.
      Introduction: Glucose and glutamine are major carbon and energy sources that promote the rapid proliferation of cancer cells. Metabolic shifts observed on cell lines or mouse models may not reflect the general metabolic shifts in real human cancer tissue.Method: In this study, we conducted a computational characterization of the flux distribution and variations of the central energy metabolism and key branches in a pan-cancer analysis, including the glycolytic pathway, production of lactate, tricarboxylic acid (TCA) cycle, nucleic acid synthesis, glutaminolysis, glutamate, glutamine, and glutathione metabolism, and amino acid synthesis, in 11 cancer subtypes and nine matched adjacent normal tissue types using TCGA transcriptomics data.
    Result: Our analysis confirms the increased influx in glucose uptake and glycolysis and decreased upper part of the TCA cycle, i.e., the Warburg effect, in almost all the analyzed cancer. However, increased lactate production and the second half of the TCA cycle were only seen in certain cancer types. More interestingly, we failed to detect significantly altered glutaminolysis in cancer tissues compared to their adjacent normal tissues. A systems biology model of metabolic shifts through cancer and tissue types is further developed and analyzed. We observed that (1) normal tissues have distinct metabolic phenotypes; (2) cancer types have drastically different metabolic shifts compared to their adjacent normal controls; and (3) the different shifts in tissue-specific metabolic phenotypes result in a converged metabolic phenotype through cancer types and cancer progression.
    Discussion: This study strongly suggests the possibility of having a unified framework for studies of cancer-inducing stressors, adaptive metabolic reprogramming, and cancerous behaviors.
    Keywords:  TCA cycle; cancer metabolism; flux estimation; glutaminolysis; systems biology
    DOI:  https://doi.org/10.3389/fonc.2023.1117810
  19. Surgery. 2023 Jun 28. pii: S0039-6060(23)00303-3. [Epub ahead of print]
    Pulmonary metastasectomy is associated with survival after lung-only recurrence in pancreatic cancer.
    Christina M Stuart, Michael J Kirsch, Yaxu Zhuang, Cheryl L Meguid, Toshitaka Sugawara, Kathryn L Colborn, Wells Messersmith, Christopher Lieu, Ana L Gleisner, Marco Del Chiaro, Richard D Schulick, Robert A Meguid.
      BACKGROUND: After surgical resection of pancreatic ductal adenocarcinoma, 14% of patients have lung-only recurrence. We hypothesize that in patients with isolated lung metastases from pancreatic ductal adenocarcinoma, pulmonary metastasectomy offers a survival benefit with minimal additional morbidity after resection.METHODS: This was a single-institution, retrospective study of patients who underwent definitive resection of pancreatic ductal adenocarcinoma and later developed isolated lung metastases between 2009 and 2021. Patients were included if they carried a diagnosis of pancreatic ductal adenocarcinoma, underwent pancreatic resection with curative intent, and subsequently developed lung metastases. Patients were excluded if they developed multiple sites of recurrence.
    RESULTS: We identified 39 patients with pancreatic ductal adenocarcinoma and isolated lung metastases, 14 of whom underwent pulmonary metastasectomy. During the study period, 31 (79%) patients died. Across all patients, there was an overall survival of 45.9 months, a disease-free interval of 22.8 months, and survival after recurrence of 22.5 months. Survival after recurrence was significantly longer in patients who underwent pulmonary metastasectomy than those who did not (30.8 months vs 18.6 months, P < .01). There was no difference in overall survival between groups. However, patients who underwent pulmonary metastasectomy were significantly more likely to be alive 3 years after their diagnosis (100.0% vs 64%, P = .02) and 2 years after recurrence (79% vs 32%, P < .01) than those in who did not undergo pulmonary metastasectomy. No mortalities occurred related to pulmonary metastasectomy, and procedure-related morbidity was 7%.
    CONCLUSION: Patients who underwent pulmonary metastasectomy for isolated pulmonary pancreatic ductal adenocarcinoma metastases had significantly longer survival after recurrence and clinically meaningful survival benefit with minimal additional morbidity after pulmonary resection.
    DOI:  https://doi.org/10.1016/j.surg.2023.05.008
  20. Sci Adv. 2023 Jun 28. 9(26): eade4022
    Branched-chain actin dynamics polarizes vesicle trajectories and partitions apicobasal epithelial membrane domains.
    Gholamali Jafari, Liakot A Khan, Hongjie Zhang, Edward Membreno, Siyang Yan, Graham Dempsey, Verena Gobel.
      In prevailing epithelial polarity models, membrane- and junction-based polarity cues such as the partitioning-defective PARs specify the positions of apicobasal membrane domains. Recent findings indicate, however, that intracellular vesicular trafficking can determine the position of the apical domain, upstream of membrane-based polarity cues. These findings raise the question of how vesicular trafficking becomes polarized independent of apicobasal target membrane domains. Here, we show that the apical directionality of vesicle trajectories depends on actin dynamics during de novo polarized membrane biogenesis in the C. elegans intestine. We find that actin, powered by branched-chain actin modulators, determines the polarized distribution of apical membrane components, PARs, and itself. Using photomodulation, we demonstrate that F-actin travels through the cytoplasm and along the cortex toward the future apical domain. Our findings support an alternative polarity model where actin-directed trafficking asymmetrically inserts the nascent apical domain into the growing epithelial membrane to partition apicobasal membrane domains.
    DOI:  https://doi.org/10.1126/sciadv.ade4022
  21. PLoS One. 2023 ;18(6): e0287528
    CELA3B immunostaining is a highly specific marker for acinar cell carcinoma of the pancreas.
    Ria Uhlig, Nina Bröker, Sören Weidemann, Natalia Gorbokon, Anne Menz, Franziska Büscheck, Andreas M Luebke, Devita Putri, Martina Kluth, Claudia Hube-Magg, Andrea Hinsch, Maximilian Lennartz, Viktor Reiswich, Doris Höflmayer, Christoph Fraune, Katharina Möller, Christian Bernreuther, Patrick Lebok, Guido Sauter, Sarah Minner, Stefan Steurer, Eike Burandt, Rainer Krech, David Dum, Andreas Marx, Ronald Simon, Till Krech, Till S Clauditz, Frank Jacobsen.
      Chymotrypsin-like elastase family member 3B (CELA3B, elastase-3B) is a pancreatic enzyme with digestive function in the intestine. Since RNA analyses of normal tissues suggest that CELA3B expression is limited to the pancreas, the potential diagnostic utility of CELA3B immunohistochemistry for the distinction of pancreatic from extrapancreatic cancers and in the distinction of acinar cell carcinoma from ductal adenocarcinoma was assessed. CELA3B expression was successfully analyzed in 13,223 tumor samples from 132 different tumor types and subtypes as well as 8 samples each of 76 different normal tissue types by immunohistochemistry in a tissue microarray format (TMA). In normal tissues, CELA3B immunostaining was only seen in acinar cells and in a fraction of ductal cells of the pancreas as well as on some apical membranes of surface epithelial cells of the intestine. Among tumors, CELA3B immunostaining was seen in 12 of 16 (75%) acinar cell carcinoma of the pancreas including 6 cases with strong staining (37.5%) as well as in 5 of 13,207 other tumors (0.04%). These included 1.2% of 91 adenoid cystic carcinomas, 1.2% of 246 mucoepidermoid carcinomas and 0.8% of 127 acinic cell carcinomas of salivary glands. Our data show a good sensitivity (75%) and a high specificity (99.9%) of CELA3B immunohistochemistry for diagnosing acinar cell carcinoma of the pancreas.
    DOI:  https://doi.org/10.1371/journal.pone.0287528
  22. Methods Mol Biol. 2023 ;2691 207-224
    Dissecting Interleukin-6 Classic and Trans-signaling in Inflammation and Cancer.
    Christoph Garbers, Stefan Rose-John.
      Interleukin-6 (IL-6) is a cytokine synthesized by many cells in the human body. IL-6 binds to a membrane-bound receptor (IL-6R), which is only present on hepatocytes, some epithelial cells, and some leukocytes. The complex of IL-6 and IL-6R binds to the ubiquitously expressed receptor subunit gp130, which forms a homodimer and thereby initiates intracellular signaling, e.g., the JAK/STAT and MAPK pathways. Proteases can cleave the membrane-bound IL-6R from the cell surface and generate a soluble IL-6R (sIL-6R), which retains its ability to bind IL-6. The IL-6/sIL-6R complex associates with gp130 and induces signaling even on cells which do not express the IL-6R. This paradigm has been called IL-6 trans-signaling, whereas signaling via the membrane-bound IL-6R is referred to as classic signaling. We have generated several molecular tools to differentiate between both pathways and to analyze the consequences of cellular IL-6 signaling in vivo. One of these tools is soluble gp130Fc, which selectively inhibits IL-6 trans-signaling. This protein under the WHO name Olamkicept has successfully undergone phase II clinical trials in patients with autoimmune diseases. Here, in this chapter, we describe several molecular tools to differentiate between IL-6 classic and trans-signaling and to analyze the consequences of cellular IL-6 signaling in vivo.
    Keywords:  Cancer; IL-6 trans-signaling; Inflammation; Interleukin-6; Interleukin-6 receptor; Soluble gp130
    DOI:  https://doi.org/10.1007/978-1-0716-3331-1_16
  23. Oncologist. 2023 Jun 24. pii: oyad178. [Epub ahead of print]
    A Novel HRD Signature Is Predictive of FOLFIRINOX Benefit in Metastatic Pancreatic Cancer.
    Kuei-Ting Chen, Russell Madison, Jay Moore, Dexter Jin, Zoe Fleischmann, Justin Newberg, Alexa Schrock, Neeru Bhardwaj, Katherine T Lofgren, Jie He, Garrett Frampton, Priti Hegde, David Fabrizio, Michael J Pishvaian, Ericka Ebot, Aatur Singhi, Ethan Sokol.
      BACKGROUND: Pancreatic cancer (PC) represents an aggressive disease with median overall survival (OS) of less than 1 year in the front-line setting. FOLFIRINOX and gemcitabine and paclitaxel (GP) are standard of care options for these patients; however, optimal selection of therapy is challenging.METHODS: Comprehensive genomic profiling was performed on 8358 PC patients. Outcomes were available for 1149 metastatic PC patients treated with 1L FOLFIRINOX or GP. A scar-based measure of HRD was called using a machine learning-based algorithm incorporating copy number and indel features.
    RESULTS: A scar-based HRD signature (HRDsig) was identified in 9% of patients. HRDsig significantly co-occurred with biallelic alterations in BRCA1/2, PALB2, BARD1, and RAD51C/D, but encompassed a larger population than that defined by BRCA1/BRCA2/PALB2 (9% vs. 6%). HRDsig was predictive of 1L FOLFIRNOX chemotherapy benefit with doubled OS relative to gemcitabine and paclitaxel (GP) (rwOS aHR 0.37 [0.22-0.62]), including 25% of the population with long-term (2 year+) survival in a real-world cohort of patients. Less benefit from FOLFIRINOX was observed in the HRDsig(-) population. Predictive value was seen in both the BRCA1/2/PALB2 mutant and wildtype populations, suggesting additional value to mutational profiling.
    CONCLUSION: A scar-based HRD biomarker was identified in a significant fraction of PC patients and is predictive of FOLFIRINOX benefit. Incorporating a biomarker like HRDsig could identify the right patients for platinum chemotherapy and potentially reduce FOLFIRINOX use by over 40%, minimizing toxicities with similar survival outcomes. Confirmatory studies should be performed.
    Keywords:  biomarker; genomics; homologous recombination repair; pancreatic neoplasms; platinum
    DOI:  https://doi.org/10.1093/oncolo/oyad178
  24. Curr Biol. 2023 Jun 20. pii: S0960-9822(23)00747-9. [Epub ahead of print]
    Systemic coagulopathy promotes host lethality in a new Drosophila tumor model.
    Tsai-Ching Hsi, Katy L Ong, Jorian J Sepers, Jung Kim, David Bilder.
      Malignant tumors trigger a complex network of inflammatory and wound repair responses, prompting Dvorak's characterization of tumors as "wounds that never heal."1 Some of these responses lead to profound defects in blood clotting, such as disseminated intravascular coagulopathy (DIC), which correlate with poor prognoses.2,3,4 Here, we demonstrate that a new tumor model in Drosophila provokes phenotypes that resemble coagulopathies observed in patients. Fly ovarian tumors overproduce multiple secreted components of the clotting cascade and trigger hypercoagulation of fly blood (hemolymph). Hypercoagulation occurs shortly after tumor induction and is transient; it is followed by a hypocoagulative state that is defective in wound healing. Cellular clotting regulators accumulate on the tumor over time and are depleted from the body, suggesting that hypocoagulation is caused by exhaustion of host clotting components. We show that rescuing coagulopathy by depleting a tumor-produced clotting factor improves survival of tumor-bearing flies, despite the fact that flies have an open (non-vascular) circulatory system. As clinical studies suggest that lethality in patients with high serum levels of clotting components can be independent of thrombotic events,5,6 our work establishes a platform for identifying alternative mechanisms by which tumor-driven coagulopathy triggers early mortality. Moreover, it opens up exploration of other conserved mechanisms of host responses to chronic wounds.
    Keywords:  Tumor-host; carcinoma; clotting; coagulopathy; drosophila; innate immunity; ovarian cancer; paraneoplasia; pre-clinical disease model; wound response
    DOI:  https://doi.org/10.1016/j.cub.2023.05.071
  25. Nature. 2023 Jun 28.
    GDF15 promotes weight loss by enhancing energy expenditure in muscle.
    Dongdong Wang, Logan K Townsend, Geneviève J DesOrmeaux, Sara M Frangos, Battsetseg Batchuluun, Lauralyne Dumont, Rune Ehrenreich Kuhre, Elham Ahmadi, Sumei Hu, Irena A Rebalka, Jaya Gautam, Maria Joy Therese Jabile, Chantal A Pileggi, Sonia Rehal, Eric M Desjardins, Evangelia E Tsakiridis, James S V Lally, Emma Sara Juracic, A Russell Tupling, Hertzel C Gerstein, Guillaume Paré, Theodoros Tsakiridis, Mary-Ellen Harper, Thomas J Hawke, John R Speakman, Denis P Blondin, Graham P Holloway, Sebastian Beck Jørgensen, Gregory R Steinberg.
      Caloric restriction that promotes weight loss is an effective strategy for treating non-alcoholic fatty liver disease and improving insulin sensitivity in people with type 2 diabetes1. Despite its effectiveness, in most individuals, weight loss is usually not maintained partly due to physiological adaptations that suppress energy expenditure, a process known as adaptive thermogenesis, the mechanistic underpinnings of which are unclear2,3. Treatment of rodents fed a high-fat diet with recombinant growth differentiating factor 15 (GDF15) reduces obesity and improves glycaemic control through glial-cell-derived neurotrophic factor family receptor α-like (GFRAL)-dependent suppression of food intake4-7. Here we find that, in addition to suppressing appetite, GDF15 counteracts compensatory reductions in energy expenditure, eliciting greater weight loss and reductions in non-alcoholic fatty liver disease (NAFLD) compared to caloric restriction alone. This effect of GDF15 to maintain energy expenditure during calorie restriction requires a GFRAL-β-adrenergic-dependent signalling axis that increases fatty acid oxidation and calcium futile cycling in the skeletal muscle of mice. These data indicate that therapeutic targeting of the GDF15-GFRAL pathway may be useful for maintaining energy expenditure in skeletal muscle during caloric restriction.
    DOI:  https://doi.org/10.1038/s41586-023-06249-4
  26. Biophys J. 2023 Jun 23. pii: S0006-3495(23)00398-3. [Epub ahead of print]
    Extracting nanoscale membrane morphology from single-molecule localizations.
    Zach Marin, Lukas A Fuentes, Joerg Bewersdorf, David Baddeley.
      Membrane surface reconstruction at the nanometer scale is required for understanding mechanisms of subcellular shape change. This historically has been the domain of electron microscopy, but extraction of surfaces from specific labels is a difficult task in this imaging modality. Existing methods for extracting surfaces from fluorescence microscopy have poor resolution or require high-quality super-resolution data that is manually cleaned and curated. Here we present NanoWrap, a new method for extracting surfaces from generalized single-molecule localization microscopy (SMLM) data. This makes it possible to study the shape of specifically-labelled membraneous structures inside of cells. We validate NanoWrap using simulations and demonstrate its reconstruction capabilities on SMLM data of the endoplasmic reticulum and mitochondria. NanoWrap is implemented in the open-source Python Microscopy Environment.
    DOI:  https://doi.org/10.1016/j.bpj.2023.06.010
  27. Nature. 2023 Jun 28.
    Phase separation of FSP1 promotes ferroptosis.
    Toshitaka Nakamura, Clara Hipp, André Santos Dias Mourão, Jan Borggräfe, Maceler Aldrovandi, Bernhard Henkelmann, Jonas Wanninger, Eikan Mishima, Elena Lytton, David Emler, Bettina Proneth, Michael Sattler, Marcus Conrad.
      Ferroptosis is evolving as a highly promising approach to combat difficult-to-treat tumour entities including therapy-refractory and dedifferentiating cancers1-3. Recently, ferroptosis suppressor protein-1 (FSP1), along with extramitochondrial ubiquinone or exogenous vitamin K and NAD(P)H/H+ as an electron donor, has been identified as the second ferroptosis-suppressing system, which efficiently prevents lipid peroxidation independently of the cyst(e)ine-glutathione (GSH)-glutathione peroxidase 4 (GPX4) axis4-6. To develop FSP1 inhibitors as next-generation therapeutic ferroptosis inducers, here we performed a small molecule library screen and identified the compound class of 3-phenylquinazolinones (represented by icFSP1) as potent FSP1 inhibitors. We show that icFSP1, unlike iFSP1, the first described on-target FSP1 inhibitor5, does not competitively inhibit FSP1 enzyme activity, but instead triggers subcellular relocalization of FSP1 from the membrane and FSP1 condensation before ferroptosis induction, in synergism with GPX4 inhibition. icFSP1-induced FSP1 condensates show droplet-like properties consistent with phase separation, an emerging and widespread mechanism to modulate biological activity7. N-terminal myristoylation, distinct amino acid residues and intrinsically disordered, low-complexity regions in FSP1 were identified to be essential for FSP1-dependent phase separation in cells and in vitro. We further demonstrate that icFSP1 impairs tumour growth and induces FSP1 condensates in tumours in vivo. Hence, our results suggest that icFSP1 exhibits a unique mechanism of action and synergizes with ferroptosis-inducing agents to potentiate the ferroptotic cell death response, thus providing a rationale for targeting FSP1-dependent phase separation as an efficient anti-cancer therapy.
    DOI:  https://doi.org/10.1038/s41586-023-06255-6
  28. Proc Natl Acad Sci U S A. 2023 07 04. 120(27): e2305410120
    Long noncoding RNA MALAT1 is dynamically regulated in leader cells during collective cancer invasion.
    Ninghao Zhu, Mona Ahmed, Yanlin Li, Joseph C Liao, Pak Kin Wong.
      Cancer cells collectively invade using a leader-follower organization, but the regulation of leader cells during this dynamic process is poorly understood. Using a dual double-stranded locked nucleic acid (LNA) nanobiosensor that tracks long noncoding RNA (lncRNA) dynamics in live single cells, we monitored the spatiotemporal distribution of lncRNA during collective cancer invasion. We show that the lncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) is dynamically regulated in the invading fronts of cancer cells and patient-derived spheroids. MALAT1 transcripts exhibit distinct abundance, diffusivity, and distribution between leader and follower cells. MALAT1 expression increases when a cancer cell becomes a leader and decreases when the collective migration process stops. Transient knockdown of MALAT1 prevents the formation of leader cells and abolishes the invasion of cancer cells. Taken together, our single-cell analysis suggests that MALAT1 is dynamically regulated in leader cells during collective cancer invasion.
    Keywords:  biosensor; bladder cancer; lncRNA; metastasis; single cell analysis
    DOI:  https://doi.org/10.1073/pnas.2305410120
  29. J Vis Exp. 2023 06 09.
    Laser Ablation and Intravital Microscopy to Study Intestinal Remodeling.
    Dimitrios Laskaris, Maria Azkanaz, Mijke A de Vreij-Kruidenier, Doreen van Rijswoud-Ram, Hendrik A Messal, Jacco van Rheenen.
      Investigating intestinal recovery in vivo is an exquisite technical challenge. A lack of longitudinal imaging protocols has prevented deeper insights into the cell and tissue scale dynamics that orchestrate intestinal regeneration. Here, we describe an intravital microscopy method that locally induces tissue damage at the single crypt scale and follows the regenerative response of the intestinal epithelium in living mice. Single crypts or larger intestinal fields were ablated by a high-intensity multiphoton infrared laser in a time- and space-controlled manner. Subsequent long-term repetitive intravital imaging enabled the tracking of the damaged areas over time and allowed for the monitoring of crypt dynamics during tissue recovery over a period of multiple weeks. Crypt remodeling events such as crypt fission, fusion, and disappearance were observed in the neighboring tissue upon laser-induced damage. This protocol enables the study of crypt dynamics both in homeostatic and pathophysiological settings, such as aging and tumor initiation.
    DOI:  https://doi.org/10.3791/64756
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