Telomerase limits chromosomal instability and promotes tumor progression at the ‘crisis’ stage of in vivo carcinogenesis

AbstractSuper-enhancers or stretch enhancers (SEs) consist of large clusters of active transcription enhancers which promote the expression of critical genes that define cell identity during development and disease. However, the role of many super-enhancers in tumor cells remains unclear. This study aims to explore the function and mechanism of a new super-enhancer in various tumor cells. A new super-enhancer that exists in a variety of tumors named EphA2-Super-enhancer (EphA2-SE) was found using multiple databases and further identified. CRISPR/Cas9-mediated deletion of EphA2-SE results in the significant downregulation of its target gene EphA2. Mechanistically, we revealed that the core active region of EphA2-SE comprises E1 component enhancer, which recruits TCF7L2 and FOSL2 transcription factors to drive the expression of EphA2, induce cell proliferation and metastasis. Bioinformatics analysis of RNA-seq data and functional experiments in vitro illustrated that EphA2-SE deletion inhibited cell growth and metastasis by blocking PI3K/AKT and Wnt/β-catenin pathway in HeLa, HCT-116 and MCF-7 cells. Overexpression of EphA2 in EphA2-SE−/− clones rescued the effect of EphA2-SE deletion on proliferation and metastasis. Subsequent xenograft animal model revealed that EphA2-SE deletion suppressed tumor proliferation and survival in vivo. Taken together, these findings demonstrate that EphA2-SE plays an oncogenic role and promotes tumor progression in various tumors by recruiting FOSL2 and TCF7L2 to drive the expression of oncogene EphA2.

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Tumor-associated macrophages: potential therapeutic strategies and future prospects in cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-001341 ◽

2021 ◽

Vol 9 (1) ◽

pp. e001341

Author(s):

Chunxiao Li ◽

Xiaofei Xu ◽

Shuhua Wei ◽

Ping Jiang ◽

Lixiang Xue ◽

...

Keyword(s):

Tumor Microenvironment ◽

Tumor Progression ◽

Cancer Cells ◽

Poor Prognosis ◽

Tumor Immunotherapy ◽

Therapeutic Strategies ◽

Preclinical Studies ◽

Future Prospects ◽

Tumor Associated Macrophages

Macrophages are the most important phagocytes in vivo. However, the tumor microenvironment can affect the function and polarization of macrophages and form tumor-associated macrophages (TAMs). Usually, the abundance of TAMs in tumors is closely associated with poor prognosis. Preclinical studies have identified important pathways regulating the infiltration and polarization of TAMs during tumor progression. Furthermore, potential therapeutic strategies targeting TAMs in tumors have been studied, including inhibition of macrophage recruitment to tumors, functional repolarization of TAMs toward an antitumor phenotype, and other therapeutic strategies that elicit macrophage-mediated extracellular phagocytosis and intracellular destruction of cancer cells. Therefore, with the increasing impact of tumor immunotherapy, new antitumor strategies to target TAMs are now being discussed.

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Inhibition of Glycolysis Suppresses Cell Proliferation and Tumor Progression In Vivo: Perspectives for Chronotherapy

International Journal of Molecular Sciences ◽

10.3390/ijms22094390 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4390

Author(s):

Jana Horváthová ◽

Roman Moravčík ◽

Miroslava Matúšková ◽

Vladimír Šišovský ◽

Andrej Boháč ◽

...

Keyword(s):

Cell Proliferation ◽

Tumor Progression ◽

Umbilical Vein ◽

Cell Metabolism ◽

High Rate ◽

Ki 67 ◽

Immunodeficient Mice ◽

Inhibition Of Glycolysis

A high rate of glycolysis is considered a hallmark of tumor progression and is caused by overexpression of the enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3). Therefore, we analyzed the possibility of inhibiting tumor and endothelial cell metabolism through the inhibition of PFKFB3 by a small molecule, (E)-1-(pyridin-4-yl)-3-(quinolin-2-yl)prop-2-en-1-one (PFK15), as a promising therapy. The effects of PFK15 on cell proliferation and apoptosis were analyzed on human umbilical vein endothelial cells (HUVEC) and the human colorectal adenocarcinoma cell line DLD1 through cytotoxicity and proliferation assays, flow cytometry, and western blotting. The results showed that PFK15 inhibited the proliferation of both cell types and induced apoptosis with decreasing the Bcl-2/Bax ratio. On the basis of the results obtained from in vitro experiments, we performed a study on immunodeficient mice implanted with DLD1 cells. We found a reduced tumor mass after morning PFK15 treatment but not after evening treatment, suggesting circadian control of underlying processes. The reduction in tumor size was related to decreased expression of Ki-67, a marker of cell proliferation. We conclude that inhibition of glycolysis can represent a promising therapeutic strategy for cancer treatment and its efficiency is circadian dependent.

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DNA-Replikationsstress, Mitose und genomische Instabilität

BIOspektrum ◽

10.1007/s12268-021-1525-5 ◽

2021 ◽

Vol 27 (1) ◽

pp. 10-13

Author(s):

Alicia Konrath ◽

Ann-Kathrin Schmidt ◽

Holger Bastians

Keyword(s):

Dna Replication ◽

Tumor Progression ◽

Chromosome Aberrations ◽

Chromosomal Instability ◽

Chromosome Instability ◽

Replication Stress ◽

Functional Link ◽

Structural Chromosome ◽

Genomische Instabilität

AbstractChromosomal instability (CIN) is a hallmark of cancer and contributes to tumorigenesis and tumor progression. While structural CIN (S-CIN) leads to structural chromosome aberrations, whole chromosome instability (W-CIN) is defined by perpetual gains or losses of chromosomes during mitosis causing aneuploidy. Mitotic defects, but also abnormal DNA replication (replication stress) can lead to W-CIN. However, the functional link between replication stress, mitosis and aneuploidy is little understood.

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Blocking Migration of Polymorphonuclear Myeloid-Derived Suppressor Cells Inhibits Mouse Melanoma Progression

Cancers ◽

10.3390/cancers13040726 ◽

2021 ◽

Vol 13 (4) ◽

pp. 726

Author(s):

Christopher Groth ◽

Ludovica Arpinati ◽

Merav E. Shaul ◽

Nina Winkler ◽

Klara Diester ◽

...

Keyword(s):

Tumor Progression ◽

Checkpoint Inhibitors ◽

Suppressor Cells ◽

Receptor Expression ◽

Myeloid Derived Suppressor Cells ◽

Melanoma Progression ◽

Relative Contribution ◽

Immunosuppressive Tumor Microenvironment ◽

Metastatic Sites

Background: Despite recent improvement in the treatment of malignant melanoma by immune-checkpoint inhibitors, the disease can progress due to an immunosuppressive tumor microenvironment (TME) mainly represented by myeloid-derived suppressor cells (MDSC). However, the relative contribution of the polymorphonuclear (PMN) and monocytic (M) MDSC subsets to melanoma progression is not clear. Here, we compared both subsets regarding their immunosuppressive capacity and recruitment mechanisms. Furthermore, we inhibited PMN-MDSC migration in vivo to determine its effect on tumor progression. Methods: Using the RET transgenic melanoma mouse model, we investigated the immunosuppressive function of MDSC subsets and chemokine receptor expression on these cells. The effect of CXCR2 inhibition on PMN-MDSC migration and tumor progression was studied in RET transgenic mice and in C57BL/6 mice after surgical resection of primary melanomas. Results: Immunosuppressive capacity of intratumoral M- and PMN-MDSC was comparable in melanoma bearing mice. Anti-CXCR2 therapy prolonged survival of these mice and decreased the occurrence of distant metastasis. Furthermore, this therapy reduced the infiltration of melanoma lesions and pre-metastatic sites with PMN-MDSC that was associated with the accumulation of natural killer (NK) cells. Conclusions: We provide evidence for the tumor−promoting properties of PMN-MDSC as well as for the anti-tumor effects upon their targeting in melanoma bearing mice.

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NLRP7 deubiquitination by USP10 promotes tumor progression and tumor-associated macrophage polarization in colorectal cancer

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-01920-y ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Bing Li ◽

Zhi-Peng Qi ◽

Dong-Li He ◽

Zhang-Han Chen ◽

Jing-Yi Liu ◽

...

Keyword(s):

Tumor Progression ◽

Acceptor Site ◽

Protein Levels ◽

Qrt Pcr ◽

Chemokine Ligand ◽

Specific Protease ◽

Ubiquitin Specific Protease ◽

Chemokine Ligand 2

Abstract Background NOD-like receptors affect multiple stages of cancer progression in many malignancies. NACHT, LRR, and PYD domain-containing protein 7 (NLRP7) is a member of the NOD-like receptor family, although its role in tumorigenesis remains unclear. By analyzing clinical samples, we found that NLRP7 protein levels were upregulated in colorectal cancer (CRC). We proposed the hypothesis that a high level of NLRP7 in CRC may promote tumor progression. Here, we further investigated the role of NLRP7 in CRC and the underlying mechanism. Methods NLRP7 expression in human CRC and adjacent non-tumorous tissues was examined by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry. The effect of NLRP7 in CRC progression was investigated in vitro and in vivo. Proteins interacting with NLRP7 were identified by immunoprecipitation and mass spectrometry analysis while immunofluorescence staining revealed the cellular location of the proteins. Cellular ubiquitination and protein stability assays were applied to demonstrate the ubiquitination effect on NLRP7. Cloning and mutagenesis were used to identify a lysine acceptor site that mediates NLRP7 ubiquitination. Cytokines/chemokines affected by NLRP7 were identified by RNA sequencing, qRT-PCR, and enzyme-linked immunosorbent assay. Macrophage phenotypes were determined using qRT-PCR, flow cytometry, and immunohistochemistry. Results NLRP7 protein levels, but not mRNA levels, were upregulated in CRC, and increased NLRP7 protein expression was associated with poor survival. NLRP7 promoted tumor cell proliferation and metastasis in vivo and in vitro and interacted with ubiquitin-specific protease 10, which catalyzed its deubiquitination in CRC cells. NLRP7 stability and protein levels in CRC cells were modulated by ubiquitination and deubiquitination, and NLRP7 was involved in the ubiquitin-specific protease 10 promotion of tumor progression and metastasis in CRC. K379 was an important lysine acceptor site that mediates NLRP7 ubiquitination in CRC cells. In CRC, NLRP7 promoted the polarization of pro-tumor M2-like macrophages by inducing the secretion of C-C motif chemokine ligand 2. Furthermore, NLRP7 promoted NF-κB nuclear translocation and activation of C-C motif chemokine ligand 2 transcription. Conclusions We showed that NLRP7 promotes CRC progression and revealed an as-yet-unidentified mechanism by which NLRP7 induces the polarization of pro-tumor M2-like macrophages. These results suggest that NLRP7 could serve as a biomarker and novel therapeutic target for the treatment of CRC.

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Differentiated glioblastoma cells accelerate tumor progression by shaping the tumor microenvironment via CCN1-mediated macrophage infiltration

Acta Neuropathologica Communications ◽

10.1186/s40478-021-01124-7 ◽

2021 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Atsuhito Uneda ◽

Kazuhiko Kurozumi ◽

Atsushi Fujimura ◽

Kentaro Fujii ◽

Joji Ishida ◽

...

Keyword(s):

Tumor Microenvironment ◽

Tumor Progression ◽

Tumor Cells ◽

In Silico ◽

Tumor Tissue ◽

The Cancer Genome Atlas ◽

Macrophage Infiltration ◽

Macrophage Migration

AbstractGlioblastoma (GBM) is the most lethal primary brain tumor characterized by significant cellular heterogeneity, namely tumor cells, including GBM stem-like cells (GSCs) and differentiated GBM cells (DGCs), and non-tumor cells such as endothelial cells, vascular pericytes, macrophages, and other types of immune cells. GSCs are essential to drive tumor progression, whereas the biological roles of DGCs are largely unknown. In this study, we focused on the roles of DGCs in the tumor microenvironment. To this end, we extracted DGC-specific signature genes from transcriptomic profiles of matched pairs of in vitro GSC and DGC models. By evaluating the DGC signature using single cell data, we confirmed the presence of cell subpopulations emulated by in vitro culture models within a primary tumor. The DGC signature was correlated with the mesenchymal subtype and a poor prognosis in large GBM cohorts such as The Cancer Genome Atlas and Ivy Glioblastoma Atlas Project. In silico signaling pathway analysis suggested a role of DGCs in macrophage infiltration. Consistent with in silico findings, in vitro DGC models promoted macrophage migration. In vivo, coimplantation of DGCs and GSCs reduced the survival of tumor xenograft-bearing mice and increased macrophage infiltration into tumor tissue compared with transplantation of GSCs alone. DGCs exhibited a significant increase in YAP/TAZ/TEAD activity compared with GSCs. CCN1, a transcriptional target of YAP/TAZ, was selected from the DGC signature as a candidate secreted protein involved in macrophage recruitment. In fact, CCN1 was secreted abundantly from DGCs, but not GSCs. DGCs promoted macrophage migration in vitro and macrophage infiltration into tumor tissue in vivo through secretion of CCN1. Collectively, these results demonstrate that DGCs contribute to GSC-dependent tumor progression by shaping a mesenchymal microenvironment via CCN1-mediated macrophage infiltration. This study provides new insight into the complex GBM microenvironment consisting of heterogeneous cells.

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