bims-tumime Biomed News
on Tumor microenvironment and metabolism
Issue of 2024‒04‒21
seven papers selected by
Alex Muir, University of Chicago
  1. Macropinocytosis at the crossroad between nutrient scavenging and metabolism in cancer.
  2. Regulation of fatty acid delivery to metastases by tumor endothelium.
  3. Metabolic programming of organ-specific natural killer cell responses.
  4. Serine enrichment in tumors promotes regulatory T cell accumulation through sphinganine-mediated regulation of c-Fos.
  5. Diet and Cancer Metabolism.
  6. Metabolic difference between patient-derived xenograft model of pancreatic ductal adenocarcinoma and corresponding primary tumor.
  7. CRISPR-Cas9 screening identifies KRAS-induced COX-2 as a driver of immunotherapy resistance in lung cancer.
  1. Curr Opin Cell Biol. 2024 Apr 15. pii: S0955-0674(24)00038-3. [Epub ahead of print]88 102359
    Macropinocytosis at the crossroad between nutrient scavenging and metabolism in cancer.
    Elena Rainero.
      Macropinocytosis (MP), the actin-dependent bulk uptake of extracellular fluids, plays a central role in nutrient scavenging, allowing cancer cells to sustain their growth in the hypoxic and nutrient-deprived microenvironment often found in solid tumours. The lack of soluble nutrients and several oncogenic signalling pathways, with RAS being the most studied, push MP-dependent internalisation of extracellular proteins, which are then digested in the lysosomes, replenishing the intracellular nutrient pools. This review will highlight recent advances in understanding how MP is regulated in hypoxic cancers, how it impinges on chemoresistance, and how different MP cargos facilitate tumour growth. Finally, I will highlight the crosstalk between MP and extracellular matrix receptors.
    DOI:  https://doi.org/10.1016/j.ceb.2024.102359
  2. bioRxiv. 2024 Apr 03. pii: 2024.04.02.587724. [Epub ahead of print]
    Regulation of fatty acid delivery to metastases by tumor endothelium.
    Deanna N Edwards, Shan Wang, Wenqiang Song, Laura C Kim, Verra M Ngwa, Yoonha Hwang, Kevin C Ess, Mark R Boothby, Jin Chen.
      Tumor metastasis, the main cause of death in cancer patients, requires outgrowth of tumor cells after their dissemination and residence in microscopic niches. Nutrient sufficiency is a determinant of such outgrowth 1 . Fatty acids (FA) can be metabolized by cancer cells for their energetic and anabolic needs but impair the cytotoxicity of T cells in the tumor microenvironment (TME) 2, 3 , thereby supporting metastatic progression. However, despite the important role of FA in metastatic outgrowth, the regulation of intratumoral FA is poorly understood. In this report, we show that tumor endothelium actively promotes tumor growth and restricts anti-tumor cytolysis by transferring FA into developing metastatic tumors. This process uses transendothelial fatty acid transport via endosome cargo trafficking in a mechanism that requires mTORC1 activity. Thus, tumor burden was significantly reduced upon endothelial-specific targeted deletion of Raptor, a unique component of the mTORC1 complex (Rptor ECKO ). In vivo trafficking of a fluorescent palmitic acid analog to tumor cells and T cells was reduced in Rptor ECKO lung metastatic tumors, which correlated with improved markers of T cell cytotoxicity. Combination of anti-PD1 with RAD001/everolimus, at a low dose that selectively inhibits mTORC1 in endothelial cells 4 , impaired FA uptake in T cells and reduced metastatic disease, corresponding to improved anti-tumor immunity. These findings describe a novel mechanism of transendothelial fatty acid transfer into the TME during metastatic outgrowth and highlight a target for future development of therapeutic strategies.
    DOI:  https://doi.org/10.1101/2024.04.02.587724
  3. Immunol Rev. 2024 Apr 17.
    Metabolic programming of organ-specific natural killer cell responses.
    Rebecca B Delconte, Joseph C Sun.
      Cells of the mammalian innate immune system have evolved to protect the host from various environmental or internal insults and injuries which perturb the homeostatic state of the organism. Among the lymphocytes of the innate immune system are natural killer (NK) cells, which circulate and survey host tissues for signs of stress, including infection or transformation. NK cells rapidly eliminate damaged cells in the blood or within tissues through secretion of cytolytic machinery and production of proinflammatory cytokines. To perform these effector functions while traversing between the blood and tissues, patrolling NK cells require sufficient fuel to meet their energetic demands. Here, we highlight the ability of NK cells to metabolically adapt across tissues, during times of nutrient deprivation and within tumor microenvironments. Whether at steady state, or during viral infection and cancer, NK cells readily shift their nutrient uptake and usage in order to maintain metabolism, survival, and function.
    Keywords:  NK cells; cancer; immunity; immunometabolism
    DOI:  https://doi.org/10.1111/imr.13333
  4. Sci Immunol. 2024 Apr 19. 9(94): eadg8817
    Serine enrichment in tumors promotes regulatory T cell accumulation through sphinganine-mediated regulation of c-Fos.
    Sicong Ma, Roger Sandhoff, Xiu Luo, Fuwei Shang, Qiaozhen Shi, Zhaolong Li, Jingxia Wu, Yanan Ming, Frank Schwarz, Alaa Madi, Nina Weisshaar, Alessa Mieg, Marvin Hering, Ferdinand Zettl, Xin Yan, Kerstin Mohr, Nora Ten Bosch, Zhe Li, Gernot Poschet, Hans-Reimer Rodewald, Nina Papavasiliou, Xi Wang, Pu Gao, Guoliang Cui.
      CD4+ regulatory T (Treg) cells accumulate in the tumor microenvironment (TME) and suppress the immune system. Whether and how metabolite availability in the TME influences Treg cell differentiation is not understood. Here, we measured 630 metabolites in the TME and found that serine and palmitic acid, substrates required for the synthesis of sphingolipids, were enriched. A serine-free diet or a deficiency in Sptlc2, the rate-limiting enzyme catalyzing sphingolipid synthesis, suppressed Treg cell accumulation and inhibited tumor growth. Sphinganine, an intermediate metabolite in sphingolipid synthesis, physically interacted with the transcription factor c-Fos. Sphinganine c-Fos interactions enhanced the genome-wide recruitment of c-Fos to regions near the transcription start sites of target genes including Pdcd1 (encoding PD-1), which promoted Pdcd1 transcription and increased inducible Treg cell differentiation in vitro in a PD-1-dependent manner. Thus, Sptlc2-mediated sphingolipid synthesis translates the extracellular information of metabolite availability into nuclear signals for Treg cell differentiation and limits antitumor immunity.
    DOI:  https://doi.org/10.1126/sciimmunol.adg8817
  5. Cold Spring Harb Perspect Med. 2024 Apr 15. pii: a041549. [Epub ahead of print]
    Diet and Cancer Metabolism.
    Jason W Locasale, Marcus D Goncalves, Maira Di Tano, Guillermo Burgos-Barragan.
      Diet and exercise are modifiable lifestyle factors known to have a major influence on metabolism. Clinical practice addresses diseases of altered metabolism such as diabetes or hypertension by altering these factors. Despite enormous public interest, there are limited defined diet and exercise regimens for cancer patients. Nevertheless, the molecular basis of cancer has converged over the past 15 years on an essential role for altered metabolism in cancer. However, our understanding of the molecular mechanisms that underlie the impact of diet and exercise on cancer metabolism is in its very early stages. In this work, we propose conceptual frameworks for understanding the consequences of diet and exercise on cancer cell metabolism and tumor biology and also highlight recent developments. By advancing our mechanistic understanding, we also discuss actionable ways that such interventions could eventually reach the mainstay of both medical oncology and cancer control and prevention.
    DOI:  https://doi.org/10.1101/cshperspect.a041549
  6. BMC Cancer. 2024 Apr 17. 24(1): 485
    Metabolic difference between patient-derived xenograft model of pancreatic ductal adenocarcinoma and corresponding primary tumor.
    Shi Wen, Xianchao Lin, Wei Luo, Yu Pan, Fei Liao, Zhenzhao Wang, Bohan Zhan, Jianghua Feng, Heguang Huang.
      BACKGROUND: Patients-derived xenograft (PDX) model have been widely used for tumor biological and pathological studies. However, the metabolic similarity of PDX tumor to the primary cancer (PC) is still unknown.METHODS: In present study, we established PDX model by engrafting primary tumor of pancreatic ductal adenocarcinoma (PDAC), and then compared the tumor metabolomics of PC, the first generation of PDX tumor (PDXG1), and the third generation of PDX tumor (PDXG3) by using 1H NMR spectroscopy. Then, we assessed the differences in response to chemotherapy between PDXG1 and PDXG3 and corresponding metabolomic differences in drug-resistant tumor tissues. To evaluate the metabolomic similarity of PDX to PC, we also compared the metabolomic difference of cell-derived xenograft (CDX) vs. PC and PDX vs. PC.
    RESULTS: After engraftment, PDXG1 tumor had a low level of lactate, pyruvate, citrate and multiple amino acids (AAs) compared with PC. Metabolite sets enrichment and metabolic pathway analyses implied that glycolysis metabolisms were suppressed in PDXG1 tumor, and tricarboxylic acid cycle (TCA)-associated anaplerosis pathways, such as amino acids metabolisms, were enhanced. Then, after multiple passages of PDX, the altered glycolysis and TCA-associated anaplerosis pathways were partially recovered. Although no significant difference was observed in the response of PDXG1 and PDXG3 to chemotherapy, the difference in glycolysis and amino acids metabolism between PDXG1 and PDXG3 could still be maintained. In addition, the metabolomic difference between PC and CDX models were much larger than that of PDX model and PC, indicating that PDX model still retain more metabolic characteristics of primary tumor which is more suitable for tumor-associated metabolism research.
    CONCLUSIONS: Compared with primary tumor, PDX models have obvious difference in metabolomic level. These findings can help us design in vivo tumor metabolomics research legitimately and analyze the underlying mechanism of tumor metabolic biology thoughtfully.
    DOI:  https://doi.org/10.1186/s12885-024-12193-x
  7. Cancer Res. 2024 Apr 18.
    CRISPR-Cas9 screening identifies KRAS-induced COX-2 as a driver of immunotherapy resistance in lung cancer.
    Jesse Boumelha, Andrea de Castro, Nourdine Bah, Hongui Cha, Sophie de Carné Trécesson, Sareena Rana, Mona Tomaschko, Panayiotis Anastasiou, Edurne Mugarza, Christopher Moore, Robert Goldstone, Philip East, Kevin Litchfield, Se-Hoon Lee, Miriam Molina-Arcas, Julian Downward.
      Oncogenic KRAS impairs anti-tumor immune responses. As effective strategies to combine KRAS inhibitors and immunotherapies have so far proven elusive, a better understanding of how oncogenic KRAS drives immune evasion is needed to identify approaches that could sensitize KRAS-mutant lung cancer to immunotherapy. In vivo CRISPR-Cas9 screening in an immunogenic murine lung cancer model identified mechanisms by which oncogenic KRAS promotes immune evasion, most notably via upregulation of immunosuppressive cyclooxygenase-2 (COX-2) in cancer cells. Oncogenic KRAS potently induced COX-2 in both mouse and human lung cancer, which was suppressed using KRAS inhibitors. COX-2 acted via prostaglandin E2 (PGE2) to promote resistance to immune checkpoint blockade (ICB) in lung adenocarcinoma. Targeting COX-2/PGE2 remodeled the tumor microenvironment by inducing pro-inflammatory polarization of myeloid cells and influx of activated cytotoxic CD8+ T cells, which increased the efficacy of ICB. Restoration of COX-2 expression contributed to tumor relapse after prolonged KRAS inhibition. These results provide the rationale for testing COX-2/PGE2 pathway inhibitors in combination with KRASG12C inhibition or ICB in patients with KRAS-mutant lung cancer.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-23-2627
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