Hu Jiejun, Cai Dong, Zhao Zhibo, Zhong Guo-Chao, Gong Jianping
Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Front Oncol. 2021 Apr 16;11:659676. doi: 10.3389/fonc.2021.659676. eCollection 2021.
Hepatocellular carcinoma (HCC), the most common malignant tumor, has high fatality and recurrence rates. Accumulating evidence shows that heterogeneous nuclear ribonucleoprotein C (HNRNPC), which is mainly involved in RNA splicing, export, and translation, promotes progression and metastasis of multiple tumor types; however, the effects of HNRNPC in HCC are unknown. In the present study, high levels of HNRNPC were detected in tumor tissues compared with para-tumor tissues by immunohistochemical and western blot assays. Furthermore, Cox proportional hazards regression models, the Kaplan-Meier method, and clinicopathologic features analysis showed that HNRNPC was not only an independent prognostic factor for both overall and disease-free survival in HCC but also a predictor of large tumor size and advanced tumor stage. Functional experiments revealed that silencing of HNRNPC not only led to arrest of more HCC cells at G0/G1 phase to inhibit their proliferation, but also suppressed EMT process to block their invasion, and migration ; this was related to the Ras/MAPK signaling pathway. In addition, blocking of HCC cell proliferation regulated by HNRNPC silencing was observed . Finally, rescue tests showed that after recovery of Ras/MAPK signaling pathway activity by treatment with Ras agonists, the proliferation, migration, and invasion suppression of Huh-7 and Hep 3B cell lines caused by HNRNPC knockdown was partially reversed. Taken together, these results indicate that HNRNPC knockdown inhibits HCC cell proliferation, migration and invasion, in part the Ras/MAPK signaling pathway. Thus, HNRNPC may have an important role in the progression of HCC and represents a promising biomarker for evaluation of prognosis and a potential therapeutic target in HCC patients.
肝细胞癌(HCC)是最常见的恶性肿瘤,具有高死亡率和复发率。越来越多的证据表明,主要参与RNA剪接、输出和翻译的异质性核糖核蛋白C(HNRNPC)促进多种肿瘤类型的进展和转移;然而,HNRNPC在HCC中的作用尚不清楚。在本研究中,通过免疫组织化学和蛋白质印迹分析检测到肿瘤组织中HNRNPC水平高于癌旁组织。此外,Cox比例风险回归模型、Kaplan-Meier方法和临床病理特征分析表明,HNRNPC不仅是HCC总体生存和无病生存的独立预后因素,也是肿瘤体积大和肿瘤分期晚的预测指标。功能实验表明,沉默HNRNPC不仅导致更多HCC细胞停滞在G0/G1期以抑制其增殖,还抑制EMT过程以阻断其侵袭和迁移;这与Ras/MAPK信号通路有关。此外,观察到HNRNPC沉默对HCC细胞增殖的调节作用。最后,挽救实验表明,用Ras激动剂处理恢复Ras/MAPK信号通路活性后,HNRNPC敲低对Huh-7和Hep 3B细胞系增殖、迁移和侵袭的抑制作用部分逆转。综上所述,这些结果表明,HNRNPC敲低抑制HCC细胞增殖、迁移和侵袭,部分是通过Ras/MAPK信号通路实现的。因此,HNRNPC可能在HCC进展中起重要作用,是评估预后的有前景的生物标志物和HCC患者潜在的治疗靶点。