Department of Hepatology and Pancreatology, Shanghai East Hospital, Tongji University, Shanghai, P.R. China.
Eur Rev Med Pharmacol Sci. 2018 Oct;22(20):6667-6677. doi: 10.26355/eurrev_201810_16143.
DJ-1 expression is elevated in a variety of tumors and is related to the survival of tumor cells under adverse stimuli. DJ-1 3'-untranslated region (3'-UTR) contains the target of miR-128-3p, and the expression of miR-128-3p is decreased in hepatoma cells. Therefore, we speculate and address in this study, that miR-128-3p can regulate DJ-1 expression in hepatocellular carcinoma (HCC) and play an important role in HCC cells survival.
MiR-128-3p and DJ-1 expression in HCC cell lines were measured using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot analysis. Dual luciferase reporter assay was adopted to confirm the miR-128-3p binding sequences in the 3'-UTR of DJ-1. Sorafenib-induced apoptosis was evaluated by flow cytometry, and the apoptosis-associated proteins were detected by Western blot analysis. Overexpression of miR-128-3p and DJ-1 were achieved via transfection with miR-128-3p mimic and DJ-1 plasmid, respectively.
We revealed that miR-128-3p expression was downregulated, while DJ-1 expression was upregulated in HCC cell lines, and DJ-1 expression can be regulated by miR-128-3p via directly binding to it. Moreover, functional assays showed that overexpression of miR-128-3p sensitized HCC cells to sorafenib-induced apoptosis, and this phenomenon was partly abolished by DJ-1. Mechanistically, PTEN/PI3K/Akt signaling pathway was found to participate in the miR-128-3p induced sensitivity to sorafenib via DJ-1.
We conclude that miR-128-3p overexpression sensitized HCC to sorafenib-induced apoptosis via PTEN/PI3K/Akt signaling pathway by regulating DJ-1 expression.
DJ-1 在多种肿瘤中表达升高，与肿瘤细胞在不利刺激下的存活有关。DJ-1 的 3'-非翻译区（3'-UTR）含有 miR-128-3p 的靶标，并且 miR-128-3p 在肝癌细胞中的表达降低。因此，我们推测并在本研究中探讨，miR-128-3p 可以调节肝癌细胞（HCC）中 DJ-1 的表达，并在 HCC 细胞存活中发挥重要作用。
通过定量实时聚合酶链反应（qRT-PCR）和 Western blot 分析测量 HCC 细胞系中 miR-128-3p 和 DJ-1 的表达。采用双荧光素酶报告基因检测法证实 DJ-1 3'-UTR 中的 miR-128-3p 结合序列。通过流式细胞术评估索拉非尼诱导的细胞凋亡，并通过 Western blot 分析检测凋亡相关蛋白。通过转染 miR-128-3p 模拟物和 DJ-1 质粒分别实现 miR-128-3p 和 DJ-1 的过表达。
我们揭示了 miR-128-3p 的表达在 HCC 细胞系中下调，而 DJ-1 的表达上调，并且 DJ-1 的表达可以通过直接与其结合而受到 miR-128-3p 的调节。此外，功能测定表明，miR-128-3p 的过表达使 HCC 细胞对索拉非尼诱导的凋亡敏感，而这种现象部分被 DJ-1 所消除。在机制上，发现 PTEN/PI3K/Akt 信号通路通过 DJ-1 参与了 miR-128-3p 诱导的索拉非尼敏感性。
我们得出结论，miR-128-3p 通过调节 DJ-1 表达，通过 PTEN/PI3K/Akt 信号通路使 HCC 对索拉非尼诱导的凋亡敏感。
