[HTML][HTML] MicroRNA-491 regulates the proliferation and apoptosis of CD8+ T cells

T Yu, QF Zuo, L Gong, LN Wang, QM Zou, B Xiao - Scientific reports, 2016 - nature.com
T Yu, QF Zuo, L Gong, LN Wang, QM Zou, B Xiao
Scientific reports, 2016nature.com
T lymphocyte-mediated immune responses are critical for antitumour immunity; however, T
cell function is impaired in the tumour environment. MicroRNAs are involved in regulation of
the immune system. While little is known about the function of intrinsic microRNAs in CD8+ T
cells in the tumour microenvironment. Here, we found that miR-491 was upregulated in
CD8+ T cells from mice with colorectal cancer. Retroviral overexpression of miR-491 in
CD8+ and CD4+ T cells inhibited cell proliferation and promoted cell apoptosis and …
Abstract
T lymphocyte-mediated immune responses are critical for antitumour immunity; however, T cell function is impaired in the tumour environment. MicroRNAs are involved in regulation of the immune system. While little is known about the function of intrinsic microRNAs in CD8+ T cells in the tumour microenvironment. Here, we found that miR-491 was upregulated in CD8+ T cells from mice with colorectal cancer. Retroviral overexpression of miR-491 in CD8+ and CD4+ T cells inhibited cell proliferation and promoted cell apoptosis and decreased the production of interferon-γ in CD8+ T cells. We found that miR-491 directly targeted cyclin-dependent kinase 4, the transcription factor T cell factor 1 and the anti-apoptotic protein B-cell lymphoma 2-like 1 in CD8+ T cells. Furthermore, tumour-derived TGF-β induced miR-491 expression in CD8+ T cells. Taken together, our results suggest that miR-491 can act as a negative regulator of T lymphocytes, especially CD8+ T cells, in the tumour environment; thus, this study provides a novel insight on dysfunctional CD8+ T cells during tumourigenesis and cancer progression. In conclusion, miR-491 may be a new target for antitumour immunotherapy.
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