bims-tucedo Biomed News
on Tumor cell dormancy
Issue of 2022‒07‒24
twenty-two papers selected by
Isabel Puig Borreil
Vall d’Hebron Institute of Oncology

  1. Cancer Discov. 2022 Jul 22. OF1
      Combined arginine depletion, GCN2 kinase inhibition, and senolytic therapy reduces HCC growth.
  2. Cancer Cell. 2022 Jul 11. pii: S1535-6108(22)00295-1. [Epub ahead of print]
      In a recent publication in Nature, Fane et al. establish WNT5A as a central, age-sensitive regulator of the dormancy-to-reactivation axis of melanoma. They show that aged fibroblasts in the lungs suppress WNT5A signaling induced at the primary tumor site to awaken dormant melanoma cells and promote the outgrowth of metastases.
  3. Cancer Discov. 2022 Jul 22. OF1
      A 4D live imaging system identified LGR5+ p27+ cancer stem cells that persist after chemotherapy and contribute to disease relapse.
  4. Oncogene. 2022 Jul 19.
      Tumor metastasis is the leading cause of cancer-associated mortality. Unfortunately, the underlying mechanism of metastasis is poorly understood. Expression of legumain (LGMN), an endo-lysosomal cysteine protease, positively correlates with breast cancer metastatic progression and poor prognosis. Here, we report that LGMN is secreted in the zymogen form by motile breast cancer cells. Through binding to cell surface integrin αvβ3 via an RGD motif, the autocrine pro-LGMN activates FAK-Src-RhoA signaling in cancer cells and promotes cancer cell migration and invasion independent of LGMN protease activity. Either silencing LGMN expression or mutationally abolishing pro-LGMN‒αvβ3 interaction significantly inhibits cancer cell migration and invasion in vitro and breast cancer metastasis in vivo. Finally, we developed a monoclonal antibody against LGMN RGD motif, which blocks pro-LGMN‒αvβ3 binding, and effectively suppresses cancer cell migration and invasion in vitro and breast cancer metastasis in vivo. Thus, disruption of pro-LGMN‒integrin αvβ3 interaction may be a potentially promising strategy for treating breast cancer metastasis.
  5. Sci Transl Med. 2022 Jul 06. 14(652): eabn1926
      Triple-negative breast cancer (TNBC) and ovarian carcinomas (OvCas) with BRCA1 promoter methylation (BRCA1meth) respond more poorly to alkylating agents compared to those bearing mutations in BRCA1 and BRCA2 (BRCAmut). This is a conundrum given the biologically equivalent homologous recombination deficiency (HRD) induced by these genetic and epigenetic BRCA perturbations. We dissected this problem through detailed genomic analyses of TNBC and OvCa cohorts and experimentation with patient-derived xenografts and genetically engineered cell lines. We found that despite identical downstream genomic mutational signatures associated with BRCA1meth and BRCAmut states, BRCA1meth uniformly associates with poor outcomes. Exposure of BRCA1meth TNBCs to platinum chemotherapy, either as clinical treatment of a patient or as experimental in vivo exposure of preclinical patient derived xenografts, resulted in allelic loss of BRCA1 methylation and increased BRCA1 expression and platinum resistance. These data suggest that, unlike BRCAmut cancers, where BRCA loss is a genetically "fixed" deficiency state, BRCA1meth cancers are highly adaptive to genotoxin exposure and, through reversal of promoter methylation, recover BRCA1 expression and become resistant to therapy. We further found a specific augmented immune transcriptional signal associated with enhanced response to platinum chemotherapy but only in patients with BRCA-proficient cancers. We showed how integrating both this cancer immune signature and the presence of BRCA mutations results in more accurate predictions of patient response when compared to either HRD status or BRCA status alone. This underscores the importance of defining BRCA heterogeneity in optimizing the predictive precision of assigning response probabilities in TNBC and OvCa.
  6. Sci Adv. 2022 Jul 22. 8(29): eabo0404
      Metastasizing cancer cells are able to withstand high levels of oxidative stress through mechanisms that are poorly understood. Here, we show that under various oxidative stress conditions, pancreatic cancer cells markedly expand NADPH and NADP+ pools. This expansion is due to up-regulation of glucose-6-phosphate dehydrogenase (G6PD), which stimulates the cytoplasmic nicotinamide adenine dinucleotide kinase (NADK1) to produce NADP+ while converting NADP+ to NADPH. G6PD is activated by the transcription factor TAp73, which is, in turn, regulated by two pathways. Nuclear factor-erythroid 2 p45-related factor-2 suppresses expression of the ubiquitin ligase PIRH2, stabilizing the TAp73 protein. Checkpoint kinases 1/2 and E2F1 induce expression of the TAp73 gene. Levels of G6PD and its upstream activators are elevated in metastatic pancreatic cancer. Knocking down G6PD impedes pancreatic cancer metastasis, whereas forced G6PD expression promotes it. These findings reveal an intracellular network that maintains redox homeostasis through G6PD-mediated increase in de novo NADP+ biosynthesis, which may be co-opted by tumor cells to enable metastasis.
  7. Mol Cancer. 2022 07 18. 21(1): 148
      The resistance of tumor cells to therapy severely impairs the efficacy of treatment, leading to recurrence and metastasis of various cancers. Clarifying the underlying mechanisms of therapeutic resistance may provide new strategies for overcoming cancer resistance. N6-methyladenosine (m6A) is the most prevalent RNA modification in eukaryotes, and is involved in the regulation of RNA splicing, translation, transport, degradation, stability and processing, thus affecting several physiological processes and cancer progression. As a novel type of multifunctional non-coding RNAs (ncRNAs), circular RNAs (circRNAs) have been demonstrated to play vital roles in anticancer therapy. Currently, accumulating studies have revealed the mutual regulation of m6A modification and circRNAs, and their interaction can further influence the sensitivity of cancer treatment. In this review, we mainly summarized the recent advances of m6A modification and circRNAs in the modulation of cancer therapeutic resistance, as well as their interplay and potential mechanisms, providing promising insights and future directions in reversal of therapeutic resistance in cancer.
    Keywords:  Cancer; Circular RNA; Interplay; N6-methyladenosine; Therapeutic resistance
  8. Cancer Res. 2022 Jul 20. OF1-OF11
      Circulating tumor cells are the cellular mediators of distant metastasis in solid malignancies. Their metastatic potential can be augmented by clustering with other tumor cells or nonmalignant cells, forming circulating tumor microemboli (CTM). Cell-cell interactions are key regulators within CTM that convey enhanced metastatic properties, including improved cell survival, immune evasion, and effective extravasation into distant organs. However, the cellular and molecular mechanism of CTM formation, as well as the biology of interactions between tumor cells and immune cells, platelets, and stromal cells in the circulation, remains to be determined. Here, we review the current literature on cell-cell interactions in homotypic and heterotypic CTM and provide perspectives on therapeutic strategies to attenuate CTM-mediated metastasis by targeting cell-cell interactions.
  9. Mol Syst Biol. 2022 Jul;18(7): e11168
      Similar to persister bacterial cells that survive antibiotic treatments, some cancer cells can evade drug treatments. This Commentary discusses the different classes of persister cells and their implications for developing more efficient cancer treatments.
  10. EMBO Mol Med. 2022 Jul 21. e15855
      FBXW7 is one of the most frequently mutated tumor suppressors, deficiency of which has been associated with resistance to some anticancer therapies. Through bioinformatics and genome-wide CRISPR screens, we here reveal that FBXW7 deficiency leads to multidrug resistance (MDR). Proteomic analyses found an upregulation of mitochondrial factors as a hallmark of FBXW7 deficiency, which has been previously linked to chemotherapy resistance. Despite this increased expression of mitochondrial factors, functional analyses revealed that mitochondria are under stress, and genetic or chemical targeting of mitochondria is preferentially toxic for FBXW7-deficient cells. Mechanistically, the toxicity of therapies targeting mitochondrial translation such as the antibiotic tigecycline relates to the activation of the integrated stress response (ISR) in a GCN2 kinase-dependent manner. Furthermore, the discovery of additional drugs that are toxic for FBXW7-deficient cells showed that all of them unexpectedly activate a GCN2-dependent ISR regardless of their accepted mechanism of action. Our study reveals that while one of the most frequent mutations in cancer reduces the sensitivity to the vast majority of available therapies, it renders cells vulnerable to ISR-activating drugs.
    Keywords:  FBXW7; GCN2; ISR; drug resistance; mitochondria
  11. Oncogene. 2022 Jul 22.
      Wide metastasis contributes to a high death rate in ovarian cancer, and understanding of the molecular mechanism helps to find effective targets for metastatic ovarian cancer therapy. It has been found that phospholipase A2-activating protein (PLAA) is inactivated in some cancers, but its role in cancer metastasis remains unknown. Here, we found that PLAA was significantly downregulated in ovarian cancer highly metastatic cell lines and patients, and the low expression of PLAA was associated with poorer prognosis and high-risk clinicopathological features of patients. PLAA inhibited the migration and invasion of ovarian cancer cells and metastasis of transplanted tumor in the orthotopic xenograft mouse model. Meanwhile, PLAA inhibited metastasis of ovarian cancer by inhibiting transient receptor potential channel canonical 3 (TRPC3)-mediated the intracellular Ca2+ level. Mechanistically, PLAA inhibited methyltransferase-like 3 (METTL3) expression through the ubiquitin-mediated degradation, and METTL3 stabilized TRPC3 mRNA expression via N6-methyladenosine (m6A) modification. Our study verified the function and mechanism of the PLAA-METTL3-TRPC3 axis involved in ovarian cancer metastasis, with a view to providing a potential therapeutic approach for ovarian cancer.
  12. Proc Natl Acad Sci U S A. 2022 Jul 12. 119(28): e2113465119
      The role of autophagy in cancer is complex. Both tumor-promoting and tumor-suppressive effects are reported, with tumor type, stage and specific genetic lesions dictating the role. This calls for analysis in models that best recapitulate each tumor type, from initiation to metastatic disease, to specifically understand the contribution of autophagy in each context. Here, we report the effects of deleting the essential autophagy gene Atg7 in a model of pancreatic ductal adenocarcinoma (PDAC), in which mutant KrasG12D and mutant Trp53172H are induced in adult tissue leading to metastatic PDAC. This revealed that Atg7 loss in the presence of KrasG12D/+ and Trp53172H/+ was tumor promoting, similar to previous observations in tumors driven by embryonic KrasG12D/+ and deletion of Trp53. However, Atg7 hemizygosity also enhanced tumor initiation and progression, even though this did not ablate autophagy. Moreover, despite this enhanced progression, fewer Atg7 hemizygous mice had metastases compared with animals wild type for this allele, indicating that ATG7 is a promoter of metastasis. We show, in addition, that Atg7+/- tumors have comparatively lower levels of succinate, and that cells derived from Atg7+/- tumors are also less invasive than those from Atg7+/+ tumors. This effect on invasion can be rescued by ectopic expression of Atg7 in Atg7+/- cells, without affecting the autophagic capacity of the cells, or by treatment with a cell-permeable analog of succinate. These findings therefore show that ATG7 has roles in invasion and metastasis that are not related to the role of the protein in the regulation of autophagy.
    Keywords:  ATG7; autophagy; metastasis; pancreatic cancer
  13. Br J Pharmacol. 2022 Jul 19.
      BACKGROUND AND PURPOSE: Endoplasmic reticulum (ER) stress triggers an adaptive response in tumors which fosters their cell survival and resilience to stress. Activation of the ER stress response, through its PERK branch, promotes phosphorylation of the α-subunit of the translation initiation factor eIF2alpha, repressing general protein translation and selectively augmenting the translation of ATF4 with the downstream CHOP transcription factor and the protein disulfide oxidase ERO1.EXPERIMENTAL APPROACH: Here we show that ISRIB, a small molecule that inhibits the action of the phosphorylated α-subunit of eIF2, activating protein translation, synergistically interacts with the genetic deficiency of protein disulfide oxidase ERO1, enfeebling breast tumor growth and spread.
    KEY RESULTS: ISRIB represses the CHOP signal but, surprisingly, it does not inhibit ERO1. Mechanistically ISRIB increases the ER protein load with a marked perturbing effect on ERO1-deficient triple-negative breast cancer cells, which display impaired proteostasis and have adapted to living with a low client protein load in hypoxia, while ERO1 deficiency also impairs VEGF-dependent angiogenesis. ERO1-deficient triple-negative breast cancer xenografts have an augmented ER stress response and its PERK branch. ISRIB acts synergistically with ERO1 deficiency, inhibiting the growth of triple-negative breast cancer xenografts by impairing proliferation and angiogenesis, while it is not so effective on the xenograft counterparts with ERO1.
    CONCLUSIONS AND IMPLICATIONS: These results demonstrate that ISRIB together with ERO1 deficiency synergistically shatter the PERK-dependent adaptive ER stress response by restarting protein synthesis in the setting of impaired proteostasis, finally promoting tumor cytotoxicity. Therefore, our findings suggest two surprising features in breast tumors: ERO1 is not regulated via CHOP under hypoxic conditions, and ISRIB offers a therapeutic option to efficiently inhibit tumor progression in those tumors with limited ERO1 and high PERK, and thus impaired proteostasis.
    Keywords:  ERO1 alpha; Endoplasmic reticulum Stress; ISRIB (Integrated Stress Response Inhibitor); PERK pathway; UPR (unfolded protein response); breast cancer
  14. Cancer Res. 2022 Jul 18. 82(14): 2515-2516
      Lung adenocarcinoma is the most common subtype of lung cancer, which has the second highest incidence among cancers. Immunotherapy has revolutionized lung cancer treatment, yet the checkpoint blockade response rate is less than 20% in patients with lung adenocarcinoma. As lung adenocarcinoma consists of heterogeneous histologic subsets with diverse tumor invasion phenotypes and clinical outcomes, understanding the mechanisms of resistance based on the histology subset is essential. In the current issue, Jang and colleagues demonstrated that PD-1-expressing macrophages are the dominant immune cell population in the tumor-immune microenvironment (TiME) of invasive lung adenocarcinoma and are responsible for driving tumor progression from preinvasive to invasive subtypes. PD-1-expressing macrophages are protumorigenic and highly plastic, potentially promoting invasive solid tumor development. Ablation of macrophages remodels the TiME and leads to a favorable anti-PD-1 blockade response, suggesting a potential combination therapy in patients with lung adenocarcinoma resistant to monotherapy. This current work highlights the spatiotemporal dynamics of the TiME during lung adenocarcinoma progression and the critical role of PD-1-expressing macrophages in driving tumorigenesis as well as resistance to immunotherapy. See related article by Jang et al., p. 2593.
  15. Mol Cell. 2022 Jul 21. pii: S1097-2765(22)00608-6. [Epub ahead of print]82(14): 2536-2538
      In this issue of Molecular Cell, Liu et al. (2022) report that 5'-tRFCys, a stress-induced transfer RNA-derived RNA fragment (tRF) derived from the 5' halves of cysteine tRNAs, regulates post-transcriptional gene expression, enabling the survival and lung metastasis formation of breast cancers.
  16. Nature. 2022 Jul 20.
    SU2C/PCF West Coast Prostate Cancer Dream Team
      Circulating tumour DNA (ctDNA) in blood plasma is an emerging tool for clinical cancer genotyping and longitudinal disease monitoring1. However, owing to past emphasis on targeted and low-resolution profiling approaches, our understanding of the distinct populations that comprise bulk ctDNA is incomplete2-12. Here we perform deep whole-genome sequencing of serial plasma and synchronous metastases in patients with aggressive prostate cancer. We comprehensively assess all classes of genomic alterations and show that ctDNA contains multiple dominant populations, the evolutionary histories of which frequently indicate whole-genome doubling and shifts in mutational processes. Although tissue and ctDNA showed concordant clonally expanded cancer driver alterations, most individual metastases contributed only a minor share of total ctDNA. By comparing serial ctDNA before and after clinical progression on potent inhibitors of the androgen receptor (AR) pathway, we reveal population restructuring converging solely on AR augmentation as the dominant genomic driver of acquired treatment resistance. Finally, we leverage nucleosome footprints in ctDNA to infer mRNA expression in synchronously biopsied metastases, including treatment-induced changes in AR transcription factor signalling activity. Our results provide insights into cancer biology and show that liquid biopsy can be used as a tool for comprehensive multi-omic discovery.
  17. Cell Rep. 2022 Jul 19. pii: S2211-1247(22)00933-0. [Epub ahead of print]40(3): 111127
      Both Fusobacterium nucleatum (F. nucleatum) and long non-coding RNA (lncRNA) EVADR are associated with colorectal cancer (CRC), but their relationship with CRC metastasis and the mechanisms by which EVADR promotes CRC metastasis are poorly understood. Here, we report that F. nucleatum promotes colorectal cancer cell metastasis to the liver and lung and that it can be detected in CRC-metastasis colonization in mouse models. Furthermore, F. nucleatum upregulates the expression of EVADR, which can increase the metastatic ability of CRC cells in vivo and in vitro. Mechanistically, elevated EVADR serves as a modular scaffold for the Y-box binding protein 1 (YBX1) to directly enhance the translation of epithelial-mesenchymal transition (EMT)-related factors, such as Snail, Slug, and Zeb1. These findings suggest that EVADR induced by F. nucleatum promotes colorectal cancer metastasis through YBX1-dependent translation. The EVADR-YBX1 axis may be useful for the prevention and treatment of patients with F. nucleatum-associated CRC metastasis.
    Keywords:  CP: Cancer; CRC metastasis; EVADR; Fusobacterium nucleatum; posttranscription
  18. Cell Rep. 2022 Jul 19. pii: S2211-1247(22)00899-3. [Epub ahead of print]40(3): 111097
      Neuroendocrine (NE)-like tumors secrete various signaling molecules to establish paracrine communication within the tumor milieu and to create a therapy-resistant environment. It is important to identify molecular mediators that regulate this secretory phenotype in NE-like cancer. The current study highlights the importance of a cell surface molecule, Neuropilin-2 (NRP2), for the secretory function of NE-like prostate cancer (PCa). Our analysis on different patient cohorts suggests that NRP2 is high in NE-like PCa. We have developed cell line models to investigate NRP2's role in NE-like PCa. Our bioinformatics, mass spectrometry, cytokine array, and other supporting experiments reveal that NRP2 regulates robust secretory phenotype in NE-like PCa and controls the secretion of factors promoting cancer cell survival. Depletion of NRP2 reduces the secretion of these factors and makes resistant cancer cells sensitive to chemotherapy in vitro and in vivo. Therefore, targeting NRP2 can revert cellular secretion and sensitize PCa cells toward therapy.
    Keywords:  CP: Cancer; IL8; VAMP2; neuroendocrine; neuropilin-2; prostate cancer; secretion; synapsin-1
  19. Methods Mol Biol. 2022 ;2535 211-220
      The ability of the cancer cells to survive hostile environment depends on their cellular stress response mechanisms. These mechanisms also help them to develop resistance to chemotherapies. Autophagy and more specifically organelle specific autophagy is one such adaptive mechanism that promotes drug resistance in cancer cells. Endoplasmic reticulum-specific autophagy or ER-phagy has been more recently described to overcome ER-stress through the degradation of damaged ER. ER-resident proteins such as FAM134B act as ER-phagy receptors to specifically target damaged ER for degradation through autophagy. Moreover, we had recently deciphered that ER-phagy facilitates cancer cell survival during hypoxic stress and we predict that this process could play a critical role in the development of drug resistance in cancer cells. Therefore, here, we provide a lay description of how ER-phagy could be investigated biochemically by Western blot analysis and silencing ER-phagy receptor genes using small interfering RNAs (siRNA).
    Keywords:  Autophagy; Cancer; Chemotherapy; Drug resistance; ER-phagy; FAM134B; Hypoxia; LC3
  20. Nat Commun. 2022 Jul 16. 13(1): 4141
      Organotropism during cancer metastasis occurs frequently but the underlying mechanism remains poorly understood. Here, we show that lysosomal protein transmembrane 5 (LAPTM5) promotes lung-specific metastasis in renal cancer. LAPTM5 sustains self-renewal and cancer stem cell-like traits of renal cancer cells by blocking the function of lung-derived bone morphogenetic proteins (BMPs). Mechanistic investigations showed that LAPTM5 recruits WWP2, which binds to the BMP receptor BMPR1A and mediates its lysosomal sorting, ubiquitination and ultimate degradation. BMPR1A expression was restored by the lysosomal inhibitor chloroquine. LAPTM5 expression could also serve as an independent predictor of lung metastasis in renal cancer. Lastly, elevation of LAPTM5 expression in lung metastases is a common phenomenon in multiple cancer types. Our results reveal a molecular mechanism underlying lung-specific metastasis and identify LAPTM5 as a potential therapeutic target for cancers with lung metastasis.