Xu Jingchao, Jia Li, Ma Hongye, Li Yanping, Ma Zhenhai, Zhao Yongfu
Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, 116027, Liaoning Province, China.
Tumour Biol. 2014 Apr;35(4):3809-17. doi: 10.1007/s13277-013-1521-5. Epub 2013 Dec 18.
The objective of this study is to clarify the possible role and mechanism of Axl in the tumorigenicity and metastasis process of hepatocellular carcinoma. The mRNA and protein expression levels of Axl in MHCC97-H and MHCC97-L cell lines were evaluated by real-time PCR and Western blot analysis. The key factor of phosphatidylinositol-3-kinase (PI3K)/Akt-p21-activated kinases-1 (PAK1) signaling pathway was studied after Axl expression was downregulated by shRNA. Finally, we analyzed the expression status of Axl protein expression in hepatocellular carcinoma tissues and its relationship with the prognosis of hepatocellular carcinoma. Axl was observed to be higher expressed in MHCC97-H cell lines compared to MHCC97-L cell lines. The downregulation of Axl in MHCC97-H cell lines resulted in the inhibition of the invasion ability of MHCC97-H cells both in vitro and in vivo. Interestingly, blocking PI3K/Akt signaling pathway by LY294002 or Akt siRNA could remarkably inhibit the PAK1 activation and cell invasion. Finally, the Axl protein expression was positively correlated with differentiation, lymph node metastasis, and clinical stage in patients with hepatocellular carcinoma patients (all P < 0.01). These findings suggest that Axl can also regulate the metastasis process of hepatocellular carcinoma and may serve as a new prognostic marker and therapeutic target for treating hepatocellular carcinoma metastasis.
本研究的目的是阐明Axl在肝细胞癌致瘤性和转移过程中的可能作用及机制。通过实时PCR和蛋白质印迹分析评估Axl在MHCC97-H和MHCC97-L细胞系中的mRNA和蛋白质表达水平。在用短发夹RNA下调Axl表达后，研究磷脂酰肌醇-3-激酶（PI3K）/蛋白激酶B（Akt）-p21激活激酶-1（PAK1）信号通路的关键因子。最后，我们分析了Axl蛋白在肝细胞癌组织中的表达状态及其与肝细胞癌预后的关系。观察到与MHCC97-L细胞系相比，Axl在MHCC97-H细胞系中高表达。在MHCC97-H细胞系中下调Axl导致MHCC97-H细胞在体外和体内的侵袭能力均受到抑制。有趣的是，用LY294002或Akt小干扰RNA阻断PI3K/Akt信号通路可显著抑制PAK1激活和细胞侵袭。最后，Axl蛋白表达与肝细胞癌患者的分化、淋巴结转移及临床分期呈正相关（均P<0.01）。这些发现表明，Axl也可调节肝细胞癌的转移过程，可能作为治疗肝细胞癌转移的新的预后标志物和治疗靶点。
