miR-99 inhibits cervical carcinoma cell proliferation by targeting TRIB2.

MicroRNAs (miRNAs) have significant roles in cell processes, including proliferation, apoptosis and stress responses. To investigate the involvement of miR-99 in the inhibition of HeLa cell proliferation, an miR-99 gene expression vector (pU6.1/miR-99), which overexpressed miR-99 in HeLa cells after transient transfection, was constructed. The expression of miR-99 was detected by qPCR. Cell proliferation and apoptosis were analyzed by cell viability, proliferation and apoptosis assays, as well as by electron microscopy. The results showed that overexpression of miR-99 in HeLa cells increased the HeLa cell mortality rate. Moreover, miR-99 overexpression was able to markedly inhibit HeLa cell proliferation according to the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cell apoptosis rate was significantly higher in pU6.1/miR-99-treated cells compared with that in the control cultures. Increases in intracellular electron density, as well as the proportion of nuclear plasma, blebbing phenomena and apoptotic bodies were observed in pU6.1/miR-99-treated cells compared with control cultures according to electron microscopy analysis. The Tribbles 2 (TRIB2) 3′-untranslated region was also observed to be targeted by miR-99 and the results further demonstrated that miR-99 was able to negatively regulate TRIB2 expression in HeLa cells The results indicate that miR-99 acts as a tumor suppressor gene in HeLa cells, establishing a theoretical basis for its application in cancer therapeutics.

微小RNA（miRNAs）在细胞过程中具有重要作用，包括增殖、凋亡和应激反应。为了研究miR - 99在抑制HeLa细胞增殖中的作用，构建了一个miR - 99基因表达载体（pU6.1/miR - 99），该载体在瞬时转染后可使HeLa细胞中miR - 99过表达。通过实时定量聚合酶链反应（qPCR）检测miR - 99的表达。通过细胞活力、增殖和凋亡检测以及电子显微镜分析细胞增殖和凋亡情况。结果表明，HeLa细胞中miR - 99的过表达提高了HeLa细胞的死亡率。此外，根据3 -（4，5 - 二甲基噻唑 - 2 - 基）- 2，5 - 二苯基四氮唑溴盐（MTT）检测，miR - 99过表达能够显著抑制HeLa细胞增殖。与对照培养物相比，pU6.1/miR - 99处理的细胞凋亡率显著更高。通过电子显微镜分析，与对照培养物相比，在pU6.1/miR - 99处理的细胞中观察到细胞内电子密度增加，以及核质比例、起泡现象和凋亡小体增加。还观察到Tribbles 2（TRIB2）3′ - 非翻译区是miR - 99的靶标，结果进一步表明miR - 99能够负调控HeLa细胞中TRIB2的表达。结果表明miR - 99在HeLa细胞中作为肿瘤抑制基因发挥作用，为其在癌症治疗中的应用奠定了理论基础。