bims-tucedo Biomed News
on Tumor cell dormancy
Issue of 2020‒09‒06
27 papers selected by
Isabel Puig Borreil
Vall d’Hebron Institute of Oncology


  1. Cancer Cell. 2020 Aug 25. pii: S1535-6108(20)30413-X. [Epub ahead of print]
    Li C, Sun YD, Yu GY, Cui JR, Lou Z, Zhang H, Huang Y, Bai CG, Deng LL, Liu P, Zheng K, Wang YH, Wang QQ, Li QR, Wu QQ, Liu Q, Shyr Y, Li YX, Chen LN, Wu JR, Zhang W, Zeng R.
      We integrate the genomics, proteomics, and phosphoproteomics of 480 clinical tissues from 146 patients in a Chinese colorectal cancer (CRC) cohort, among which 70 had metastatic CRC (mCRC). Proteomic profiling differentiates three CRC subtypes characterized by distinct clinical prognosis and molecular signatures. Proteomic and phosphoproteomic profiling of primary tumors alone successfully distinguishes cases with metastasis. Metastatic tissues exhibit high similarities with primary tumors at the genetic but not the proteomic level, and kinase network analysis reveals significant heterogeneity between primary colorectal tumors and their liver metastases. In vivo xenograft-based drug tests using 31 primary and metastatic tumors show personalized responses, which could also be predicted by kinase-substrate network analysis no matter whether tumors carry mutations in the drug-targeted genes. Our study provides a valuable resource for better understanding of mCRC and has potential for clinical application.
    Keywords:  colorectal cancer; drug testing model; metastasis; phosphorylation; proteogenomic
    DOI:  https://doi.org/10.1016/j.ccell.2020.08.002
  2. Cell Mol Immunol. 2020 Sep 02.
    Zeng X, Zhou J, Xiong Z, Sun H, Yang W, Mok MTS, Wang J, Li J, Liu M, Tang W, Feng Y, Wang HK, Tsang SW, Chow KL, Yeung PC, Wong J, Lai PB, Chan AW, To KF, Chan SL, Xia Q, Xue J, Chen X, Yu J, Peng S, Sung JJ, Kuang M, Cheng AS.
      The liver is an immunologically tolerant organ and a common metastatic site of multiple cancer types. Although a role for cancer cell invasion programs has been well characterized, whether and how liver-intrinsic factors drive metastatic spread is incompletely understood. Here, we show that aberrantly activated hepatocyte-intrinsic cell cycle-related kinase (CCRK) signaling in chronic liver diseases is critical for cancer metastasis by reprogramming an immunosuppressive microenvironment. Using an inducible liver-specific transgenic model, we found that CCRK overexpression dramatically increased both B16F10 melanoma and MC38 colorectal cancer (CRC) metastasis to the liver, which was highly infiltrated by polymorphonuclear-myeloid-derived suppressor cells (PMN-MDSCs) and lacking natural killer T (NKT) cells. Depletion of PMN-MDSCs in CCRK transgenic mice restored NKT cell levels and their interferon gamma production and reduced liver metastasis to 2.7% and 0.7% (metastatic tumor weights) in the melanoma and CRC models, respectively. Mechanistically, CCRK activated nuclear factor-kappa B (NF-κB) signaling to increase the PMN-MDSC-trafficking chemokine C-X-C motif ligand 1 (CXCL1), which was positively correlated with liver-infiltrating PMN-MDSC levels in CCRK transgenic mice. Accordingly, CRC liver metastasis patients exhibited hyperactivation of hepatic CCRK/NF-κB/CXCL1 signaling, which was associated with accumulation of PMN-MDSCs and paucity of NKT cells compared to healthy liver transplantation donors. In summary, this study demonstrates that immunosuppressive reprogramming by hepatic CCRK signaling undermines antimetastatic immunosurveillance. Our findings offer new mechanistic insights and therapeutic targets for liver metastasis intervention.
    Keywords:  Cell cycle related kinase; liver immune microenvironment; liver metastasis; myeloid-derived suppressor cell; natural killer T cell
    DOI:  https://doi.org/10.1038/s41423-020-00534-2
  3. Theranostics. 2020 ;10(21): 9620-9643
    Logotheti S, Marquardt S, Gupta SK, Richter C, Edelhäuser BAH, Engelmann D, Brenmoehl J, Söhnchen C, Murr N, Alpers M, Singh KP, Wolkenhauer O, Heckl D, Spitschak A, Pützer BM.
      Long non-coding RNAs (lncRNAs) have emerged as integral components of E2F1-regulated gene regulatory networks (GRNs), but their implication in advanced or treatment-refractory malignancy is unknown. Methods: We combined high-throughput transcriptomic approaches with bioinformatics and structure modeling to search for lncRNAs that participate in E2F1-activated prometastatic GRNs and their phenotypic targets in the highly-relevant case of E2F1-driven aggressive bladder cancer (BC). RNA immunoprecipitation was performed to verify RNA-protein interactions. Functional analyses including qRT-PCR, immunoblotting, luciferase assays and measurement of extracellular fluxes were conducted to validate expression and target gene regulation. Results: We identified E2F1-responsive lncRNA-SLC16A1-AS1 and its associated neighboring protein-coding gene, SLC16A1/MCT1, which both promote cancer invasiveness. Mechanistically, upon E2F1-mediated co-transactivation of the gene pair, SLC16A1-AS1 associates with E2F1 in a structure-dependent manner and forms an RNA-protein complex that enhances SLC16A1/MCT1 expression through binding to a composite SLC16A1-AS1:E2F1-responsive promoter element. Moreover, SLC16A1-AS1 increases aerobic glycolysis and mitochondrial respiration and fuels ATP production by fatty acid β-oxidation. These metabolic changes are accompanied by alterations in the expression of the SLC16A1-AS1:E2F1-responsive gene PPARA, a key mediator of fatty acid β-oxidation. Conclusions: Our results unveil a new gene regulatory program by which E2F1-induced lncRNA-SLC16A1-AS1 forms a complex with its transcription factor that promotes cancer metabolic reprogramming towards the acquisition of a hybrid oxidative phosphorylation/glycolysis cell phenotype favoring BC invasiveness.
    Keywords:  E2F1; RNA-protein complex; SLC16A1-AS1; bladder cancer; metabolic reprogramming
    DOI:  https://doi.org/10.7150/thno.44176
  4. Cancer Discov. 2020 Sep;10(9): 1261-1262
    Carter H.
      Yu and colleagues combined computational and experimental techniques to identify a new post-transcriptional regulator of metastatic potential in colon cancer. This study reveals that the RNA-binding protein RBMS1 is a positive regulator of mRNA stability for multiple genes, including the tumor suppressor AKAP12 and a WNT pathway interacting protein, SDCBP, and its loss is a common event associated with poor prognosis.See related article by Yu et al., p. 1410.
    DOI:  https://doi.org/10.1158/2159-8290.CD-20-0993
  5. JCI Insight. 2020 Sep 03. pii: 136215. [Epub ahead of print]5(17):
    Li Y, Su X, Rohatgi N, Zhang Y, Brestoff JR, Shoghi KI, Xu Y, Semenkovich CF, Harris CA, Peterson LL, Weibaecher KN, Teitelbaum SL, Zou W.
      Obesity predisposes to cancer and a virtual universality of nonalcoholic fatty liver disease (NAFLD). However, the impact of hepatic steatosis on liver metastasis is enigmatic. We find that while control mice were relatively resistant to hepatic metastasis, those which were lipodystrophic or obese, with NAFLD, had a dramatic increase in breast cancer and melanoma liver metastases. NAFLD promotes liver metastasis by reciprocal activation initiated by tumor-induced triglyceride lipolysis in juxtaposed hepatocytes. The lipolytic products are transferred to cancer cells via fatty acid transporter protein 1, where they are metabolized by mitochondrial oxidation to promote tumor growth. The histology of human liver metastasis indicated the same occurs in humans. Furthermore, comparison of isolates of normal and fatty liver established that steatotic lipids had enhanced tumor-stimulating capacity. Normalization of glucose metabolism by metformin did not reduce steatosis-induced metastasis, establishing the process is not mediated by the metabolic syndrome. Alternatively, eradication of NAFLD in lipodystrophic mice by adipose tissue transplantation reduced breast cancer metastasis to that of control mice, indicating the steatosis-induced predisposition is reversible.
    Keywords:  Cancer; Hepatology; Obesity; Oncology
    DOI:  https://doi.org/10.1172/jci.insight.136215
  6. Cancers (Basel). 2020 Sep 01. pii: E2482. [Epub ahead of print]12(9):
    Samuel SM, Varghese E, Koklesová L, Líšková A, Kubatka P, Büsselberg D.
      Despite the leaps and bounds in achieving success in the management and treatment of breast cancers through surgery, chemotherapy, and radiotherapy, breast cancer remains the most frequently occurring cancer in women and the most common cause of cancer-related deaths among women. Systemic therapeutic approaches, such as chemotherapy, although beneficial in treating and curing breast cancer subjects with localized breast tumors, tend to fail in metastatic cases of the disease due to (a) an acquired resistance to the chemotherapeutic drug and (b) the development of intrinsic resistance to therapy. The existence of cancer stem cells (CSCs) plays a crucial role in both acquired and intrinsic chemoresistance. CSCs are less abundant than terminally differentiated cancer cells and confer chemoresistance through a unique altered metabolism and capability to evade the immune response system. Furthermore, CSCs possess active DNA repair systems, transporters that support multidrug resistance (MDR), advanced detoxification processes, and the ability to self-renew and differentiate into tumor progenitor cells, thereby supporting cancer invasion, metastasis, and recurrence/relapse. Hence, current research is focusing on targeting CSCs to overcome resistance and improve the efficacy of the treatment and management of breast cancer. Studies revealed that metformin (1, 1-dimethylbiguanide), a widely used anti-hyperglycemic agent, sensitizes tumor response to various chemotherapeutic drugs. Metformin selectively targets CSCs and improves the hypoxic microenvironment, suppresses the tumor metastasis and inflammation, as well as regulates the metabolic programming, induces apoptosis, and reverses epithelial-mesenchymal transition and MDR. Here, we discuss cancer (breast cancer) and chemoresistance, the molecular mechanisms of chemoresistance in breast cancers, and metformin as a chemo-sensitizing/re-sensitizing agent, with a particular focus on breast CSCs as a critical contributing factor to acquired and intrinsic chemoresistance. The review outlines the prospects and directions for a better understanding and re-purposing of metformin as an anti-cancer/chemo-sensitizing drug in the treatment of breast cancer. It intends to provide a rationale for the use of metformin as a combinatory therapy in a clinical setting.
    Keywords:  cancer; cancer stem cells; chemoresistance; metformin; multidrug resistance
    DOI:  https://doi.org/10.3390/cancers12092482
  7. Nat Commun. 2020 Sep 01. 11(1): 4387
    Li P, Lu M, Shi J, Hua L, Gong Z, Li Q, Shultz LD, Ren G.
      The role of neutrophils in solid tumor metastasis remains largely controversial. In preclinical models of solid tumors, both pro-metastatic and anti-metastatic effects of neutrophils have been reported. In this study, using mouse models of breast cancer, we demonstrate that the metastasis-modulating effects of neutrophils are dictated by the status of host natural killer (NK) cells. In NK cell-deficient mice, granulocyte colony-stimulating factor-expanded neutrophils show an inhibitory effect on the metastatic colonization of breast tumor cells in the lung. In contrast, in NK cell-competent mice, neutrophils facilitate metastatic colonization in the same tumor models. In an ex vivo neutrophil-NK cell-tumor cell tri-cell co-culture system, neutrophils are shown to potentially suppress the tumoricidal activity of NK cells, while neutrophils themselves are tumoricidal. Intriguingly, these two modulatory effects by neutrophils are both mediated by reactive oxygen species. Collectively, the absence or presence of NK cells, governs the net tumor-modulatory effects of neutrophils.
    DOI:  https://doi.org/10.1038/s41467-020-18125-0
  8. Cell Metab. 2020 Sep 01. pii: S1550-4131(20)30421-6. [Epub ahead of print]32(3): 321-323
    Stuani L, Sarry JE.
      Metabolic dialogue between tumors and their microenvironment emerges as a key regulator of chemoresistance, the major barrier for the treatment of several cancers. In this issue of Cell Metabolism, van Gastel et al. decipher the pivotal role of stromal glutamine-derived aspartate to sustain pyrimidine biosynthesis in chemoresistant acute myeloid leukemia (AML) and thus state it as a target for anti-cancer therapy.
    DOI:  https://doi.org/10.1016/j.cmet.2020.08.008
  9. Cancer Res. 2020 Sep 01. pii: canres.1192.2020. [Epub ahead of print]
    Lu Y, Liu Y, Oeck S, Zhang GJ, Schramm A, Glazer PM.
      Development of resistance remains the key obstacle to the clinical efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI). Hypoxia is a key microenvironmental stress in solid tumors associated with acquired resistance to conventional therapy. Consistent with our previous studies, we show here that long-term, moderate hypoxia promotes resistance to the EGFR TKI osimertinib (AZD9291) in the NSCLC cell line H1975, which harbors two EGFR mutations including T790M. Hypoxia-induced resistance was associated with development of epithelial-mesenchymal transition (EMT) coordinated by increased expression of ZEB-1, an EMT activator. Hypoxia induced increased fibroblast growth factor receptor 1 (FGFR1) expression in NSCLC cell lines H1975, HCC827 and YLR086, and knockdown of FGFR1 attenuated hypoxia-induced EGFR TKI resistance in each line. Upregulated expression of FGFR1 by hypoxia was mediated through the MAPK pathway and attenuated induction of the pro-apoptotic factor BIM. Consistent with this, inhibition of FGFR1 function by the selective small molecular inhibitor BGJ398 enhanced EGFR TKI sensitivity and promoted upregulation of BIM levels. Furthermore, inhibition of MEK activity by trametinib showed similar effects. In tumor xenografts in mice, treatment with either BGJ398 or trametinib enhanced response to AZD9291 and improved survival. These results suggest that hypoxia is a driving force for acquired resistance to EGFR TKIs through increased expression of FGFR1. The combination of EGFR TKI and FGFR1 or MEK inhibitors may offer an attractive therapeutic strategy for NSCLC.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-20-1192
  10. J Hematol Oncol. 2020 Sep 03. 13(1): 119
    Li H, Dai W, Xia X, Wang R, Zhao J, Han L, Mo S, Xiang W, Du L, Zhu G, Xie J, Yu J, Liu N, Huang M, Zhu J, Cai G.
      Tumor metastasis accounts for the majority of cancer-related deaths; it is therefore important to develop preclinical models that faithfully recapitulate disease progression. Here, we generated paired organoids derived from primary tumors and matched liver metastases in the same colorectal cancer (CRC) patients. Despite the fact that paired organoids exhibit comparable gene expression and cell morphology, organoids from metastatic lesions demonstrate more aggressive phenotypes, tumorigenesis, and metastatic capacity than those from primary lesions. Transcriptional analyses of the paired organoids reveal signature genes and pathways altered during the progression of CRC, including SOX2. Further study shows that inducible knockdown of SOX2 attenuated invasion, proliferation, and liver metastasis outgrowth. Taken together, we use patient-derived paired primary and metastatic cancer organoids to model CRC metastasis and illustrate that SOX2 is associated with CRC progression and may serve as a potential prognostic biomarker and therapeutic target of CRC.
    Keywords:  Colorectal cancer; Paired organoids; Preclinical model; SOX2; Tumor metastasis
    DOI:  https://doi.org/10.1186/s13045-020-00957-4
  11. Nat Immunol. 2020 Aug 31.
    Kumagai S, Togashi Y, Kamada T, Sugiyama E, Nishinakamura H, Takeuchi Y, Vitaly K, Itahashi K, Maeda Y, Matsui S, Shibahara T, Yamashita Y, Irie T, Tsuge A, Fukuoka S, Kawazoe A, Udagawa H, Kirita K, Aokage K, Ishii G, Kuwata T, Nakama K, Kawazu M, Ueno T, Yamazaki N, Goto K, Tsuboi M, Mano H, Doi T, Shitara K, Nishikawa H.
      Immune checkpoint blockade has provided a paradigm shift in cancer therapy, but the success of this approach is very variable; therefore, biomarkers predictive of clinical efficacy are urgently required. Here, we show that the frequency of PD-1+CD8+ T cells relative to that of PD-1+ regulatory T (Treg) cells in the tumor microenvironment can predict the clinical efficacy of programmed cell death protein 1 (PD-1) blockade therapies and is superior to other predictors, including PD ligand 1 (PD-L1) expression or tumor mutational burden. PD-1 expression by CD8+ T cells and Treg cells negatively impacts effector and immunosuppressive functions, respectively. PD-1 blockade induces both recovery of dysfunctional PD-1+CD8+ T cells and enhanced PD-1+ Treg cell-mediated immunosuppression. A profound reactivation of effector PD-1+CD8+ T cells rather than PD-1+ Treg cells by PD-1 blockade is necessary for tumor regression. These findings provide a promising predictive biomarker for PD-1 blockade therapies.
    DOI:  https://doi.org/10.1038/s41590-020-0769-3
  12. Cancer Discov. 2020 Sep 04.
      Lymphatic melanoma cells had less ferroptosis than cells injected intravenously or subcutaneously.
    DOI:  https://doi.org/10.1158/2159-8290.CD-RW2020-128
  13. Cancers (Basel). 2020 Aug 29. pii: E2451. [Epub ahead of print]12(9):
    Fiocchetti M, Solar Fernandez V, Segatto M, Leone S, Cercola P, Massari A, Cavaliere F, Marino M.
      Components of tumor microenvironment, including tumor and/or stromal cells-derived factors, exert a critical role in breast cancer (BC) progression. Here we evaluated the possible role of neuroglobin (NGB), a monomeric globin that acts as a compensatory protein against oxidative and apoptotic processes, as part of BC microenvironment. The extracellular NGB levels were evaluated by immunofluorescence of BC tissue sections and by Western blot of the culture media of BC cell lines. Moreover, reactive oxygen species (ROS) generation, cell apoptosis, and cell migration were evaluated in different BC cells and non-tumorigenic epithelial mammary cells treated with BC cells (i.e., Michigan Cancer Foundation-7, MCF-7) conditioned culture media and extracellular NGB. Results demonstrate that NGB is a component of BC microenvironment. NGB is released in tumor microenvironment by BC cells only under oxidative stress conditions where it can act as autocrine/paracrine factor able to communicate cell resilience against oxidative stress and chemotherapeutic treatment.
    Keywords:  17β-Estradiol; apoptosis; breast cancer; docetaxel; neuroglobin; oxidative stress; stress adaptation and resistance; tumor microenvironment
    DOI:  https://doi.org/10.3390/cancers12092451
  14. Cancer Discov. 2020 Sep;10(9): 1255-1257
    Montal ED, White RM.
      Alicea and colleagues demonstrate that aged fibroblasts secrete lipids into the tumor microenvironment, allowing for nutrient exchange with melanoma cells. This supportive function of fibroblasts results in increased resistance to BRAF/MEKi therapy in the context of an aged microenvironment, providing crucial mechanistic insight into age-related drug resistance.See related article by Alicea et al., p. 1282.
    DOI:  https://doi.org/10.1158/2159-8290.CD-20-0949
  15. Cancers (Basel). 2020 Sep 01. pii: E2470. [Epub ahead of print]12(9):
    Aulas A, Finetti P, Lyons SM, Bertucci F, Birnbaum D, Acquaviva C, Mamessier E.
      Cancer treatments are constantly evolving with new approaches to improve patient outcomes. Despite progresses, too many patients remain refractory to treatment due to either the development of resistance to therapeutic drugs and/or metastasis occurrence. Growing evidence suggests that these two barriers are due to transient survival mechanisms that are similar to those observed during stress response. We review the literature and current available open databases to study the potential role of stress response and, most particularly, the involvement of Stress Granules (proteins) in cancer. We propose that Stress Granule proteins may have prognostic value for patients.
    Keywords:  CAPRIN-1; G3BP1; G3BP2; TIA-1; TIAR; USP10; biomarker; cancer prognosis; cell death; metastasis; pro-survival properties; resistance; stress granules
    DOI:  https://doi.org/10.3390/cancers12092470
  16. J Clin Invest. 2020 Sep 01. pii: 137552. [Epub ahead of print]
    de Heer EC, Jalving M, Harris AL.
      Hypoxia-inducible factors (HIFs) and the HIF-dependent cancer hallmarks angiogenesis and metabolic rewiring are well-established drivers of breast cancer aggressiveness, therapy resistance, and poor prognosis. Targeting of HIF and its downstream targets in angiogenesis and metabolism has been unsuccessful so far in the breast cancer clinical setting, with major unresolved challenges residing in target selection, development of robust biomarkers for response prediction, and understanding and harnessing escape mechanisms. This Review discusses the pathophysiological role of HIFs, angiogenesis, and metabolism in breast cancer and the challenges of targeting these features in breast cancer patients. Rational therapeutic combinations, especially with immunotherapy and endocrine therapy, seem most promising in the clinical exploitation of the intricate interplay of HIFs, angiogenesis, and metabolism in breast cancer cells and the tumor microenvironment.
    DOI:  https://doi.org/10.1172/JCI137552
  17. Nature. 2020 Sep 02.
    Punovuori K, Wickström SA.
      
    Keywords:  Biomechanics; Cancer; Medical research
    DOI:  https://doi.org/10.1038/d41586-020-02490-3
  18. Oncogene. 2020 Sep 03.
    Lian EY, Hyndman BD, Moodley S, Maritan SM, Mulligan LM.
      Pancreatic ductal adenocarcinoma (PDAC) is a therapeutically challenging disease with poor survival rates, owing to late diagnosis and early dissemination. These tumors frequently undergo perineural invasion, spreading along nerves regionally and to distant sites. The RET receptor tyrosine kinase is implicated in increased aggressiveness, local invasion, and metastasis in multiple cancers, including PDAC. RET mediates directional motility and invasion towards sources of its neurotrophic factor ligands, suggesting that it may enhance perineural invasion of tumor cells towards nerves. RET is expressed as two main isoforms, RET9 and RET51, which differ in their protein interactions and oncogenic potentials, however, the contributions of RET isoforms to neural invasion have not been investigated. In this study, we generated total RET and isoform-specific knockdown PDAC cell lines and assessed the contributions of RET isoforms to PDAC invasive spread. Our data show that RET activity induces cell polarization and actin remodeling through activation of CDC42 and RHOA GTPases to promote directional motility in PDAC cells. Further, we show that RET interacts with the adaptor protein TKS5 to induce invadopodia formation, enhance matrix degradation and promote tumor cell invasion through a SRC and GRB2-dependent mechanism. Finally, we show that RET51 is the predominant isoform contributing to these RET-mediated invasive processes in PDAC. Together, our work suggests that RET expression in pancreatic cancers may enhance tumor aggressiveness by promoting perineural invasion, and that RET expression may be a valuable marker of invasiveness, and a potential therapeutic target in the treatment of these cancers.
    DOI:  https://doi.org/10.1038/s41388-020-01448-z
  19. Mol Cancer Res. 2020 Aug 31. pii: molcanres.0334.2020. [Epub ahead of print]
    Hanley CJ, Henriet E, Sirka OK, Thomas GJ, Ewald AJ.
      Collective invasion can be led by breast cancer cells expressing basal epithelial markers, typified by keratin-14 (KRT14). We analyzed gene expression data from The Cancer Genome Atlas and demonstrated a significant correlation between a KRT14+ invasion signature and a stromal mediated extracellular matrix (ECM) organization module. We then developed a novel co-culture model of tumor organoids with autologous stromal cells. Co-culture significantly increased KRT14 expression and invasion of organoids from both luminal and basal murine breast cancer models. However, stromal cell conditioned medium induced invasion but not KRT14 expression. Cancer cells released TGF-β and that signaling pathway was required for stromal cell-induced invasion and KRT14 expression. Mechanistically, TGF-β induced NOX4 expression in stromal cells and NOX4 inhibition reduced invasion and KRT14 expression. In summary, we developed a novel co-culture model and revealed dynamic molecular interactions between stromal cells and cancer cells that regulate both basal gene expression and invasive behavior. Implications: Fibroblasts within mammary tumors can regulate the molecular phenotype and invasive behavior of breast cancer cells.
    DOI:  https://doi.org/10.1158/1541-7786.MCR-20-0334
  20. Mol Cancer. 2020 Sep 02. 19(1): 135
    Sun W, Ren Y, Lu Z, Zhao X.
      Pancreatic cancer (PaCa) is an insidious and highly metastatic malignancy, with a 5-year survival rate of less than 5%. So far, the pathogenesis and progression mechanisms of PaCa have been poorly characterized. Exosomes correspond to a class of extracellular nanovesicles, produced by a broad range of human somatic and cancerous cells. These particular nanovesicles are mainly composed by proteins, genetic substances and lipids, which mediate signal transduction and material transport. A large number of studies have indicated that exosomes may play decisive roles in the occurrence and metastatic progression of PaCa. This article summarizes the specific functions of exosomes and their underlying molecular mechanisms in mediating the initiation and metastatic capability of PaCa.
    Keywords:  Exosome; Metastasis; Pancreatic cancer; Tumor biomarker; Tumorigenesis
    DOI:  https://doi.org/10.1186/s12943-020-01255-w
  21. Cancers (Basel). 2020 Aug 30. pii: E2459. [Epub ahead of print]12(9):
    Yang PL, Liu LX, Li EM, Xu LY.
      Chemoradiotherapy is one of the most effective and extensively used strategies for cancer treatment. Signal transducer and activator of transcription 3 (STAT3) regulates vital biological processes, such as cell proliferation and cell growth. It is constitutively activated in various cancers and limits the application of chemoradiotherapy. Accumulating evidence suggests that STAT3 regulates resistance to chemotherapy and radiotherapy and thereby impairs therapeutic efficacy by mediating its feedback loop and several target genes. The alternative splicing product STAT3β is often identified as a dominant-negative regulator, but it enhances sensitivity to chemotherapy and offers a new and challenging approach to reverse therapeutic resistance. We focus here on exploring the role of STAT3 in resistance to receptor tyrosine kinase (RTK) inhibitors and radiotherapy, outlining the potential of targeting STAT3 to overcome chemo(radio)resistance for improving clinical outcomes, and evaluating the importance of STAT3β as a potential therapeutic approach to overcomes chemo(radio)resistance. In this review, we discuss some new insights into the effect of STAT3 and its subtype STAT3β on chemoradiotherapy sensitivity, and we explore how these insights influence clinical treatment and drug development for cancer.
    Keywords:  STAT3; STAT3β; chemoresistance; radioresistance; target therapy
    DOI:  https://doi.org/10.3390/cancers12092459
  22. Lancet Oncol. 2020 Sep;pii: S1470-2045(20)30234-5. [Epub ahead of print]21(9): e419-e430
    Ochoa de Olza M, Navarro Rodrigo B, Zimmermann S, Coukos G.
      Notable advances have been achieved in the treatment of cancer since the advent of immunotherapy, and immune checkpoint inhibitors have shown clinical benefit across a wide variety of tumour types. Nevertheless, most patients still progress on these treatments, highlighting the importance of unravelling the underlying mechanisms of primary resistance to immunotherapy. A well described biomarker of non-responsiveness to immune checkpoint inhibitors is the absence or low presence of lymphocytes in the tumour microenvironment, so-called cold tumours. There are five mechanisms of action that have the potential to turn cold tumours into so-called hot and inflamed tumours, hence increasing the tumour's responsiveness to immunotherapy-increasing local inflammation, neutralising immunosuppression at the tumour site, modifying the tumour vasculature, targeting the tumour cells themselves, or increasing the frequency of tumour-specific T cells. In this Review, we discuss preclinical data that serves as the basis for ongoing immunotherapy clinical trials for the treatment of non-immunoreactive tumours, as well as reviewing clinical and translational data where available. We explain how improving our understanding of the underlying mechanisms of primary resistance to immunotherapy will help elucidate an increasingly granular view of the tumour microenvironment cellular composition, functional status, and cellular localisation, with the goal of further therapy refinement.
    DOI:  https://doi.org/10.1016/S1470-2045(20)30234-5
  23. Mol Cancer. 2020 Sep 02. 19(1): 134
    Wang W, Zhao M, Cui L, Ren Y, Zhang J, Chen J, Jia L, Zhang J, Yang J, Chen G, Ashby CR, Wu C, Chen ZS, Wang L.
      BACKGROUND: Cisplatin is a first-line drug for the treatment of human non-small cell lung cancer (NSCLC); however, the majority of patients will develop drug resistance after treatment. In order to overcome cisplatin resistance, it is important to understand the mechanisms underlying the resistance.METHODS: A gene microarray was used to screen for genes related to cisplatin resistance in NSCLC cell lines. Subsequently, the correlation between the HDAC, RXR and HtrA1 genes, in NSCLC, were verified using gene manipulation. Immunohistochemical staining was used to detect HDAC, RXR and HtrA1 expression in NSCLC specimens. Proliferation, migration and invasion assays were performed in vitro and in vivo to determine the role of the HDAC/RXR/HtrA1 signaling axis in cisplatin resistance, and luciferase reporter analysis and ChIP assays were performed to ascertain the mechanisms by which HDAC and RXR regulate the expression of HtrA1. Furthermore, in vitro and in vivo experiments were conducted in NSCLC cisplatin-resistant NSCLC to elucidate the effect of the low molecular weight compound, DW22, which targets the NSCLC cisplatin resistance HDAC/RXR/HtrA1 signaling pathway.
    RESULTS: HtrA1 was identified as a cisplatin resistance-related gene in NSCLC cells. The regulation of HtrA1 by HDAC and RXR significantly decreased the efficacy of cisplatin in NSCLC cells resistant to cisplatin. Immunohistochemistry results showed a negative relationship between HDAC1 and HtrA1, and a positive relationship between RXRα and HtrA1 in NSCLC patients' tissues. Notably, the expression of HDAC1 and HtrA1 can be considered as biomarkers for the efficacy of platinum-based drugs and prognosis in NSCLC patients. Mechanistically, the heterodimers of the nuclear receptor RXR, in combination with the enzyme, HDAC, regulate the transcription of HtrA1 in NSCLC cells. The rescue of HtrA1 expression by dual targeting of HDAC and RXR with the compound, DW22, significantly inhibited the proliferation, migration and invasion of NSCLC cells resistant to cisplatin, and induced NSCLC cell apoptosis.
    CONCLUSION: Our results indicate that HtrA1, a cisplatin resistance-related gene, is synergistically regulated by HDAC and RXR in NSCLC. Targeting the HDAC/RXR/HtrA1 signaling axis can rescue HtrA1 expression and reverse cisplatin resistance in NSCLC.
    Keywords:  Cisplatin resistance; HDAC; HtrA1; Lung cancer; RXR
    DOI:  https://doi.org/10.1186/s12943-020-01256-9
  24. Theranostics. 2020 ;10(21): 9443-9457
    Zhou X, Li Y, Wang W, Wang S, Hou J, Zhang A, Lv B, Gao C, Yan Z, Pang D, Lu K, Ahmad NH, Wang L, Zhu J, Zhang L, Zhuang T, Li X.
      Objective: Esophageal squamous cell carcinoma (ESCC) is one of the most commonly diagnosed cancer types in China. Recent genomic sequencing analysis indicated the over-activation of Hippo/YAP signaling might play important roles for the carcinogenic process and progression for ESCC patients. However, little is known about the molecular mechanisms that controls Hippo signaling activity in ESCC. Our previous studies indicated that PLCE1-an important risk factor for ESCC-linked to ESCC progression through snail signaling, during this period, we found PARK2 was an important downstream target of PLCE1-snail axis. PARK2 was decreased in ESCC human samples, and correlated with good prognosis in ESCC patients. Further research showed that PARK2 could inhibit YAP, which functions as key downstream effectors of the Hippo pathway. Here, we aim to reveal the molecular mechanisms of PARK2 modulated Hippo pathway in ESCC. Methods: To evaluate the function of PARK2 in ESCC, we used a tissue microarray (TMA) of 223 human ESCC patients and immunohistochemistry to analyze the correlation between PARK2 expression and clinicopathologic variables. Depletion of endogenous PARK2 and YAP from ESCC cells using CRISPR/Cas9 technologies. Flow cytometry and EdU cell proliferation assay were used to detect proliferation of ESCC cells. Nude mice subcutaneous injection and Ki-67 staining were used to evaluate tumor growth in vivo. Migration and invasion assays were performed. In addition, lung metastasis models in mice were used to validate the function of PARK2 in vivo. Identification of PARK2 involved in hippo pathway was achieved by expression microarray screening, double immunofluorescence staining and co-immunoprecipitation assays. The RNA-seq analysis results were validated through quantitative real-time PCR (qRT-PCR) analysis. The protein half-life of YAP was analyzed by Cycloheximide assay, and the TEAD activity was detected by Luciferase reporter assays. Results: Clinical sample of ESCC revealed that low PARK2 expression correlated with late tumor stage (P < 0.001), poor differentiation (P < 0.04), lymph node (P < 0.001) and distant metastasis (P = 0.0087). Multivariate Cox proportional regression analysis further revealed that PARK2 expression (P = 0.032) is an independent prognostic factor for the overall survival of ESCC patients. Besides, the immunohistochemistry results showed that PARK2 negatively correlated with YAP protein level (P < 0.001). PARK2 depletion promotes ESCC progression both through Hippo/YAP axis, while PARK2 overexpression suppresses ESCC tumor progression by Hippo signaling. Co-IP and ubiquitination assays revealed that PARK2 could interact with YAP in the cytosol and promotes YAP K48-linked ubiquitination at K90 sites. Conclusion: Clinical sample analysis and mechanistic study have validated PARK2 as a tumor suppressor for ESCC. Multivariate Cox proportional regression analysis further revealed that PARK2 is an independent prognostic factor for the overall survival of ESCC patients. Cellular and molecular mechanisms in this study showed that PARK2 associated with YAP protein in the cytosol, promoted YAP ubiquitination and proteasome-dependent degradation in ESCC cells. Therefore, as a novel modulator for Hippo signaling, modulation of PARK2 activity or gene expression level could be an appealing strategy to treat esophageal.
    Keywords:  ESCC; Hippo; PARK2; Ubiquitin; YAP
    DOI:  https://doi.org/10.7150/thno.46078
  25. Oncogene. 2020 Aug 31.
    Murray AS, Hyland TE, Sala-Hamrick KE, Mackinder JR, Martin CE, Tanabe LM, Varela FA, List K.
      Breast cancer progression is accompanied by increased expression of extracellular and cell-surface proteases capable of degrading the extracellular matrix as well as cleaving and activating downstream targets. The type II transmembrane serine proteases (TTSPs) are a family of cell-surface proteases that play critical roles in numerous types of cancers. Therefore, the aim of this study was to identify novel and uncharacterized TTSPs with differential expression in breast cancer and to determine their potential roles in progression. Systematic in silico data analysis followed by immunohistochemical validation identified increased expression of the TTSP family member, TMPRSS13 (transmembrane protease, serine 13), in invasive ductal carcinoma patient tissue samples compared to normal breast tissue. To test whether loss of TMPRSS13 impacts tumor progression, TMPRSS13 was genetically ablated in the oncogene-induced transgenic MMTV-PymT tumor model. TMPRSS13 deficiency resulted in a significant decrease in overall tumor burden and growth rate, as well as a delayed formation of detectable mammary tumors, thus suggesting a causal relationship between TMPRSS13 expression and the progression of breast cancer. Complementary studies using human breast cancer cell culture models revealed that siRNA-mediated silencing of TMPRSS13 expression decreases proliferation, induces apoptosis, and attenuates invasion. Importantly, targeting TMPRSS13 expression renders aggressive triple-negative breast cancer cell lines highly responsive to chemotherapy. At the molecular level, knockdown of TMPRSS13 in breast cancer cells led to increased protein levels of the tumor-suppressive protease prostasin. TMPRSS13/prostasin co-immunoprecipitation and prostasin zymogen activation experiments identified prostasin as a potential novel target for TMPRSS13. Regulation of prostasin levels may be a mechanism that contributes to the pro-oncogenic properties of TMPRSS13 in breast cancer. TMPRSS13 represents a novel candidate for targeted therapy in combination with standard of care chemotherapy agents in patients with hormone receptor-negative breast cancer or in patients with tumors refractory to endocrine therapy.
    DOI:  https://doi.org/10.1038/s41388-020-01436-3
  26. Mol Cancer Res. 2020 Sep 02. pii: molcanres.0187.2020. [Epub ahead of print]
    Zhang HJ, Chang WJ, Jia CY, Qiao L, Zhou J, Chen Q, Zheng XW, Zhang JH, Li HC, Yang ZY, Liu ZH, Liu GC, Ji SP, Lu F.
      Lung cancer, especially lung adenocarcinoma (LUAD), is one of the most common neoplasms worldwide. However, the mechanisms underlying its initiation, development, and metastasis are still poorly understood. Destrin (DSTN) is a member of ADF/cofilin family. Its detailed biological function remains unknown, although it is reported that DSTN is involved in cytoskeleton remodeling and regulation of actin filament turnover. Recent evidence has shown that high expression of cofilin-1 is associated with invasion and poor prognosis of several types of human tumors, but the detailed mechanism is still entirely unclear, particularly in lung cancer tumorigenesis and malignancy. Here, we report that DSTN was highly expressed in a mouse lung cancer model induced by urethane and in clinical LUAD tissue samples. Its expression level was positively correlated with cancer development, as well as metastasis to the liver and lymph nodes. Consistently, it was directly associated with the poor prognosis of LUAD patients. Furthermore, we also found that DSTN promotes cell proliferation, invasion and migration in vitro, and facilitates subcutaneous tumor formation and lung metastasis via intravenous injection in vivo. Mechanically, DSTN associates with and facilitates nuclear translocation of β-catenin, which promotes epithelial-mesenchymal transition (EMT). Taken together, our results indicated that DSTN enhances lung cancer malignancy through facilitating β-catenin nuclear translocation and inducing EMT. Combined with multivariate analyses, DSTN might potentially serve as a therapeutic target and an independent prognostic marker of LUAD. Implications: This finding indicated DSTN facilitates β-catenin nuclear translocation and promotes malignancy in lung adenocarcinoma.
    DOI:  https://doi.org/10.1158/1541-7786.MCR-20-0187