RNase L下调LncRNA-ATB 抑制肝癌转移的作用机制研究

Metastasis is an important factor leading to malignant progression of liver cancer. It is important to find the key molecules that affect the metastasis of hepatocellular carcinoma. Endoribonuclease L（RNase L) is an enzyme of RNA, which plays an important role through cleavage of endogenous or exogenous RNA. RNase L can inhibit the inducing factors（HBV and HCV）of liver cancer, but it has not been reported the effect of RNase L on metastasis of liver cancer. The previous study showed that the expression of RNase L in HCC tissues was significantly lower than that in the adjacent tumor, RNase L could inhibit Huh7 and other cell migration, and influence the expression of lncRNA-ATB. Combined with the role of RNase L as anti-oncogene and the previous results , we put forward the hypothesis that : 1.RNase L can inhibit the metastasis of hepatocellular carcinoma cells in vitro and in vivo; 2. the inhibitory effect of RNase L on the metastasis of liver cancer by regulating the lncRNA-ATB pathway. This project through the cell invasion and metastasis, cell adhesion, angiogenesis and inhibition of tumorigenicity experiments to confirm the inhibition of RNase L on metastasis of hepatocellular carcinoma cells; RIP, RNA half-life and RNA cleavage assay in vitro are used to confirm the molecular mechanism of RNase L regulating lncRNA-ATB . The project will provide new targets and theoretical basis for targeted therapy of liver cancer.

转移是导致肝癌恶性进展的重要因素，找到影响转移的关键分子尤为重要。糖核核酸酶 L（RNase L）是RNA内切酶，通过剪切内源或外源RNA发挥作用。RNase L可抑制能诱发肝癌的HBV 及HCV，但是否影响肝癌转移未见报道。课题组前期研究发现：RNase L在肝癌组织表达明显低于癌旁，可抑制Huh7等细胞转移，影响转移相关lncRNA-ATB表达。结合文献RNase L的抑癌基因作用及前期结果，提出假设：1. RNase L在体内外可抑制肝癌细胞转移；2. RNase L 可通过调节lncRNA-ATB通路抑制肝癌转移。本项目拟通过细胞侵袭转移、细胞黏附、血管形成及裸鼠成瘤等实验研究RNase L对肝癌细胞转移的抑制作用；通过共转染、RIP、RNA半衰期及RNA体外转录加工等实验研究RNase L通过lncRNA-ATB抑制转移的机制。本研究将为肝癌的靶向治疗提供新靶点及理论依据。

转移是导致肝癌恶性进展的重要因素，找到影响肝癌转移的关键分子尤为重要。核糖核酸酶L（RNase L）是RNA内切酶，通过剪切内源或外源RNA发挥作用。RNase L可抑制能诱发肝癌的HBV及HCV，在抗病毒中发挥重要作用，但是否影响肝癌转移未见报道。在本项目中，我们主要研究了RNase L及其调节的LncRNA-B38在肝癌细胞侵袭及迁移中的作用及机制。检测了人肝癌及癌旁组织中RNase L及LncRNA-B38的表达并分析了LncRNA-B38与肝癌转移的相关性；通过Transwell实验检测LncRNA-B38对多种肝癌细胞系侵袭转移的影响；通过原位杂交、基因芯片、实时定量PCR及Western blot等实验对lncRNA-B38的定位及下游调节基因进行检测，分析其影响侵袭转移的机制。通过上述实验，我们证实了RNase L及LncRNA-B38在肝癌中表达下降；首次揭示了LncRNA-B38与肝癌患者的肿瘤转移相关。明确了LncRNA-B38在肝癌细胞中的定位，主要定位于细胞质中。功能研究中，发现RNase L及LncRNA-B38可抑制HepG2、SK-Hep-1等多种肝癌细胞的侵袭及迁移。机制研究中，证明了lncRNA-B38能够调节Vimentin、ICAM-1、ZO-1及相关microRNA分子miR-221和miR-222的表达。推测其通过抑制EMT及影响细胞粘附等过程抑制肝癌细胞的侵袭及迁移。科学意义：发现了影响肝癌侵袭转移的新通路，为相关研究提供了新的理论基础。