CXCR4/Akt信号通路对食管癌细胞侵袭和肿瘤转移的调控作用

Regulation of CXCR4/Akt Signaling Pathway on Esophageal Cancer Cell Invasion and Tumor Metastasis

多项研究发现CXCR4在各种类型的癌症中高表达,然而尚不清楚CXCR4在食管癌细胞生长和转移中的作用。本研究检测了CXCR4在食管癌组织和细胞系(TE-1)中的表达,并通过转染CXCR4-短发夹RNA(CXCR4-sh RNA)慢病毒来敲低TE-1细胞中CXCR4的表达。应用PI3K/AKT抑制剂LY294002(50μmol/L)处理TE-1细胞12 h来考察AKT信号在食管癌细胞生长和转移中的作用;应用蛋白质印迹分析检测AKT和Rho家族蛋白(RhoA,Rac-1和Cdc42)的表达;应用CCK-8实验检测细胞增殖;Transwell实验检测细胞侵袭;对雄性BALB/c-nu/nu裸鼠皮下注射转染CXCR4-shRNA的TE-1细胞建立肿瘤异种移植模型。研究显示,CXCR4在食管癌组织中的表达水平明显高于癌旁组织,并且与TNM分期和淋巴结转移有关。CXCR4在人食管鳞状细胞癌细胞系(TE-1)中的表达水平明显高于人正常食管上皮细胞系(human normal esophageal epithelial cell line,HEEC)。敲低CXCR4能抑制食管鳞状细胞癌细胞的增殖和侵袭能力,并抑制肿瘤异种移植裸鼠的肿瘤形成。敲低CXCR4抑制了AKT的磷酸化及RhoA、Rac-1和Cdc42的表达。此外,PI3K/AKT抑制剂LY294002处理显著降低了TE-1细胞中AKT的磷酸化,并降低了RhoA、Rac-1和Cdc42的表达。本研究表明,CXCR4在食管癌患者中上调,与不良预后相关。下调CXCR4的表达可在体内和体外抑制食管癌肿瘤的生长和转移。下调CXCR4可通过抑制AKT信号的激活来抑制Rho家族粘附/侵袭相关蛋白的表达,从而抑制肿瘤转移。

A number of studies have found that CXCR4 is highly expressed in various types of cancer,but it is unclear what role CXCR4 plays in the growth and metastasis of esophageal cancer cells.This study examined the expression of CXCR4 in esophageal cancer tissues and cell lines(TE-1).CXCR4-short hairpin RNA(CXCR4-sh RNA)lentivirus was transfected to knock down CXCR4 expression in TE-1 cells.PI3 K/AKT inhibitor LY294002(50μmol/L)was used to treat TE-1 cells for 12 h to investigate the role of AKT signaling in the growth and metastasis of esophageal cancer cells.Western blotting analysis was used to detect the expression of AKT and Rho family proteins(RhoA,Rac-1 and Cdc42).CCK-8 test was used to detect cell proliferation.Transwell assay was used to detect cell invasion.Male BALB/c-nu/nu nude mice were injected subcutaneously with TEX cells transfected with CXCR4-shRNA to establish a tumor xenograft model.Studies showed that the expression level of CXCR4 in esophageal cancer tissues was significantly higher than in adjacent tissues,and it was related to TNM stage and lymph node metastasis.The expression level of CXCR4 in human esophageal squamous cell carcinoma cell line(TE-1)was significantly higher than that in human normal esophageal epithelial cell line(HEEC).Knockdown of CXCR4 inhibited the proliferation and invasion of esophageal squamous cell carcinoma cells,and inhibited tumor formation in xenograft nude mice.Knockdown of CXCR4 inhibited the phosphorylation of AKT and the expression of RhoA,Rac-1 and Cdc42.In addition,treatment with the PI3 K/AKT inhibitor LY294002 significantly reduced AKT phosphorylation and reduced the expression of RhoA,Rac-1,and Cdc42 in TE-1 cells.This study shows that CXCR4 is upregulated in patients with esophageal cancer and is associated with poor prognosis.Down-regulating the expression of CXCR4 can inhibit the growth and metastasis of esophageal cancer tumors in vitro and in vivo.Down-regulating CXCR4 can inhibit the expression of Rho family adhesion/invasion-related proteins by inhibiting the activation of AKT signals,thereby inhibiting tumor metastasis.