目的：探讨miR-202-5p对口腔鳞状细胞癌（oral squamous carcinoma，OSCC）细胞生长、集落形成、迁移和侵袭的影响及其可能的机制。方法：通过qPCR法检测OSCC细胞系（Tca8113和SCC-4）和口腔角质细胞HOK中miR-202-5p和T细胞核因子c3（nuclear factor of activated T-cells isoform c3，NFATc3）mRNA的表达水平；将miR-202-5p mimic或/和NFATc3过表达质粒转染入Tca8113和SCC-4细胞，用MTT和集落形成实验检测转染对细胞增殖的影响，划痕伤口愈合实验和Transwell实验检测转染对细胞迁移和侵袭的影响，用Western blotting实验检测转染对NFATc3蛋白表达的影响；通过双荧光素酶报告基因实验验证miR-202-5p 对候选靶基因 NFATc3 的直接调控作用。结果：与正 常 口 腔 角 质 细 胞 HOK 相 比 ，miR-202-5p 在 OSCC 细胞Tca8113和SCC-4中呈低表达（均P<0.01），NFATc3 mRNA和蛋白质表达显著升高（P<0.01）。在Tca8113细胞和SCC-4细胞中，过表达miR-202-5p可显著抑制细胞生长、集落形成、迁移、侵袭以及细胞中NFATc3表达（均P<0.01）。NFATc3被证实是miR-202-5p的靶基因，过表达NFATc3能逆转miR-202-5p对OSCC细胞生长、迁移和侵袭的抑制作用。结论：miR-202-5p通过下调NFATc3表达发挥其肿瘤抑制功能，导致OSCC细胞的生长、迁移和侵袭受到抑制。

Objective: To investigate the effect of miR-202-5p on the viability, colony formation, migration and invasion of oral squamous cell carcinoma (OSCC) cells, and to elucidate its possible mechanism. Methods: The mRNA expression levels of miR-202-5p and nuclear factor of activated T-cells isoform c3 (NFATc3) in OSCC cell lines(Tca8113 and SCC-4) were detected by qPCR. miR-202-5p mimics or/and NFATc3 overexpression plasmids were transfected into Tca8113 cells and SCC-4 cells. Cell proliferation was detected by MTT assay and colony formation assay; cell migration and invasion were detected by Wound-healing assay and Transwell assay; the expression level of NFATc3 protein was detected by Western blotting. The direct regulation of miR-202-5p on the candidate target gene NFATc3 was verified by Dual luciferase reporter gene assay. Results: Compared with the normal oral keratinocytes HOK, the expression level of miR-202-5p was significantly decreased in OSCC cell lines (P<0.01), and the mRNA and protein expressions of NFATc3 were significantly increased (P<0.01). Over-expression of miR-202-5p significantly inhibited cell viability, colony formation,migration, invasion, and the expression level of NFATc3 in Tca8113 cells and SCC-4 cells (all P<0.01). NFATc3 was proved to be a target gene of miR-202-5p. Over-expression of NFATc3 could reverse the inhibitory effect of miR-202-5p on the growth, migration and invasion of OSCC cells. Conclusion: miR-202-5p exerts its tumor suppressor function by down-regulating NFATc3 directly, leading to the inhibition of growth, migration and invasion of OSCC cells.

重庆市卫健委医学科研计划资助项目（No. 2016MSXM046）