背景:环状RNA(circularRNAs)是非编码RNA。越来越多的证据表明,circRNAs在人类生物过程中起着关键作用,尤其是肿瘤发生,和发展。然而,circRNAs在肝细胞癌(HCC)中的确切作用机制尚不清楚.
方法:使用生物信息学工具和RT-qPCR来鉴定circdhPR的作用,来自二氢蝶啶还原酶(DHPR)基因座的circRNA,在HCC和癌旁组织中。采用Kaplan-Meier分析和Cox比例风险模型分析circdhPR表达与患者预后的相关性。慢病毒载体用于建立稳定的circdhpr过表达细胞。体外和体内研究表明,circDHPR会影响肿瘤的增殖和转移。机械测定,包括西方印迹,免疫组织化学,双荧光素酶报告分析,荧光原位杂交,和RNA免疫沉淀,已经证明了circDHPR的分子机制。
结果:CircDHPR在HCC中下调,低circDHPR表达与低总生存率和无病生存率相关。CircDHPR过表达在体外和体内抑制肿瘤生长和转移。进一步的系统研究表明,circdhpr结合miR-3194-5p,RASGEF1B的上游调节器。这种内源性竞争抑制了miR-3194-5p的沉默效应。我们证实,circdhpr过表达抑制肝癌的生长和转移,通过海绵miR-3194-5p上调RASGEF1B的表达,被认为是Ras/MAPK信号通路的抑制因子。
结论:环状DHPR表达异常导致细胞增殖失控,肿瘤发生,和转移。CircDHPR可作为HCC的生物标志物和治疗靶标。
BACKGROUND: Circular RNAs (circRNAs) are noncoding RNAs. Accumulating evidence suggests that circRNAs play a critical role in human biological processes, especially tumorigenesis, and development. However, the exact mechanisms of action of circRNAs in hepatocellular carcinoma (HCC) remain unclear.
METHODS: Bioinformatic tools and RT-qPCR were used to identify the role of circDHPR, a circRNA derived from the dihydropteridine reductase (
DHPR) locus, in HCC and para-carcinoma tissues. Kaplan-Meier analysis and the Cox proportional hazard model were used to analyze the correlation between circDHPR expression and patient prognosis. Lentiviral vectors were used to establish stable circDHPR-overexpressing cells. In vitro and in vivo studies have shown that tumor proliferation and metastasis are affected by circDHPR. Mechanistic assays, including Western blotting, immunohistochemistry, dual-luciferase reporter assays, fluorescence in situ hybridization, and RNA immunoprecipitation, have demonstrated the molecular mechanism underlying circDHPR.
RESULTS: CircDHPR was downregulated in HCC, and low circDHPR expression was associated with poor overall survival and disease-free survival rates. CircDHPR overexpression inhibits tumor growth and metastasis in vitro and in vivo. Further systematic studies revealed that circDHPR binds to miR-3194-5p, an upstream regulator of RASGEF1B. This endogenous competition suppresses the silencing effect of miR-3194-5p. We confirmed that circDHPR overexpression inhibited HCC growth and metastasis by sponging miR-3194-5p to upregulate the expression of RASGEF1B, which is regarded as a suppressor of the Ras/MAPK signaling pathway.
CONCLUSIONS: Aberrant circDHPR expression leads to uncontrolled cell proliferation, tumorigenesis, and metastasis. CircDHPR may serve as a biomarker and therapeutic target for HCC.