敲减TDO2通过调控PI3K/AKT信号通路抑制宫颈鳞状细胞癌增殖和转移的作用机制

Knockdown of TDO2 inhibits the proliferation and metastasis of cervical squamous cell carcinoma by regulating the PI3K/AKT signaling pathway

目的研究色氨酸2,3-双加氧酶(tryptophan 2,3-dioxygenase,TDO2)在宫颈鳞状细胞癌(cervical squamous cell carcinoma,CSCC)中表达的临床意义及促进CSCC细胞增殖和转移能力的作用及机制。方法采用免疫组化检测TDO2在CSCC组织和配对的癌旁组织中的表达水平,并分析TDO2的表达与CSCC患者临床病理参数及预后的关系。培养CSCC细胞SiHa,随机分为对照组si-NC和实验组si-TDO2,分别转染NC siRNA和TDO2 siRNA,western blotting检测各组细胞中TDO2的表达;CCK8实验和平板克隆实验检测各组细胞的增殖能力;Transwell实验检测各组细胞的转移能力;Western blotting检测各组细胞中PI3K/AKT信号通路相关蛋白PI3K、pPI3K、AKT和pAKT的表达。结果免疫组化结果显示与癌旁组织比较,TDO2在CSCC组织中的表达增加(P<0.05),TDO2高表达与CSCC患者、肿瘤浸润深度、淋巴结转移、FIGO分期、KI67指数和预后均相关(P<0.05);与si-NC组比较,si-TDO2组SiHa细胞中TDO2蛋白表达减少(P<0.05);与si-NC组比较,si-TDO2组SiHa细胞的增殖和转移能力降低(P<0.05),SiHa组细胞中PI3K/AKT信号通路相关蛋白pPI3K和pAKT蛋白表达降低(P<0.05),PI3K和AKT蛋白表达无明显变化(P>0.05)。结论TDO2在CSCC组织中表达增加,可能通过激活PI3K/AKT信号通路促进CSCC的增殖和转移能力。TDO2是治疗CSCC的潜在分子靶点。

Objective To detect the expression level of tryptophan 2,3-dioxygenase(TDO2)in cervical squamous cell carcinoma(CSCC)and to explore its clinical significance in promoting the proliferation and metastasis of CSCC cells,and the underlying mechanism.Methods Immunohistochemistry was performed to detect the expression level of TDO2 in CSCC tissues and paired paracancerous tissues.The correlation of TDO2 expression with pathological parameters and prognosis of CSCC was analyzed.The CSCC cell line SiHa was transfected with NC siRNA or TDO2 siRNA,followed by the detection of expression level of TDO2 via Western blotting.Cell proliferation was detected by Cell Counting Kit-8(CCK-8)assay and colony formation assay,and cell metastasis was detected by Transwell assay.Western blotting was performed to detect protein expressions of phosphatidylinositol 3-kinase(PI3K),pPI3K,protein kinase B(AKT),and pAKT.Results Immunohistochemical results showed that TDO2 was significantly upregulated in CSCC tissues than that of paired paracancerous tissues(P<0.05).The high expression of TDO2 was correlated with tumor infiltration depth,lymph node metastasis,International Federation of Gynaecology and Obstetrics(FIGO)staging,Ki67 index and prognosis of CSCC patients(P<0.05).Compared with those transfected with si-NC,transfection of si-TDO2 significantly inhibited the proliferation and metastasis of SiHa cells,and downregulated protein expression of TDO2,pPI3K and pAKT(all P<0.05),while the protein expressions of PI3K and AKT were not changed(P>0.05).Conclusion TDO2 is overexpressed in CSCC tissues.It promotes the proliferation and metastasis of CSCC by activating the PI3K/AKT signaling pathway.TDO2 is a potential molecular target for CSCC.