免疫相关基因HCST对肾透明细胞癌预后的影响及其机制

目的:分析造血细胞信号转导因子(hematopoietic cell signal transducer,HCST)在肾透明细胞癌（clear cell renal cell carcinoma,ccRCC）中的表达及与ccRCC预后、免疫浸润的关系，探讨HCST对ccRCC细胞生长侵袭的影响及其作用机制。方法:利用TCGA数据库分析HCST基因在ccRCC组织中的表达水平。Cox比例风险模型分析HCST表达水平及临床特征与ccRCC患者预后的关系。肿瘤免疫评分数据库（tumor immune estimation resource,TIMER）分析ccRCC组织中HCST表达水平与免疫细胞浸润程度的相关性。体外培养ACHN细胞，分为对照组、siRNA阴性对照组和HCST siRNA组。MTT法、流式细胞实验和Transwell实验分别检测各组ACHN细胞增殖、凋亡和侵袭活性。蛋白质印迹法检测caspase-3、Bax、Bcl-2、E-cadherin、N-cadherin和Vimentin蛋白的表达。结果:与正常肾脏组织比较，HCST mRNA在ccRCC组织中的表达显著上调，且与肿瘤的分期、淋巴转移及远处转移正相关(P＜0.01)。HCST高表达、肿瘤T分期及M分期是影响ccRCC患者预后的独立危险因素(P＜0.05)。ccRCC中HCST表达与CD8+T细胞、树突状细胞、NK细胞及Treg细胞的浸润程度正相关(P＜0.001)。与对照组比较，HCST siRNA组ACHN细胞的增殖活性、侵袭能力、Bcl-2、N-cadherin和Vimentin蛋白表达水平显著降低(P＜0.05)，ACHN细胞凋亡活性、caspase-3、Bax和E-cadherin蛋白表达水平显著升高(P＜0.05)。siRNA阴性对照组与对照组比较上述各指标，差异无统计学意义(P＜0.05)。结论:HCST在ccRCC中表达上调，且与ccRCC患者的免疫浸润和预后相关。沉默HCST的表达可抑制ccRCC细胞的增殖与侵袭、促进其凋亡。

Effect of immune related gene HCST on prognosis of clear cell renal cell carcinoma and its mechanism

Objective:To identify the expression of hematopoietic cell signal transducer (HCST) in clear cell renal cell carcinoma (ccRCC) and its relationship with the prognosis and immune infiltration of ccRCC,and to explore the effects of HCST on cell growth and invasion in ccRCC and its mechanism.Methods:HCST expression level in ccRCC tissues was analyzed by using TCGA database.The relationships between HCST expression level and clinical features and prognosis of ccRCC patients were determined by Cox proportional-hazards model.Tumor immune estimation resource (TIMER) was utilized to analyze the correlation between the expression level of HCST and immune cell infiltration in ccRCC.ACHN cells were cultured in vitro and divided into three groups:Control group,negative control siRNA (NC siRNA) group and HCST siRNA group.After transfection,MTT assay,flow cytometry assay and transwell assay were performed to detect the proliferation,apoptosis and invasiveness of ACHN cells,respectively.Western blot was used to determine the protein levels of caspase-3,Bax,Bcl-2,E-cadherin,N-cadherin and Vimentin.Results:Compared with normal kidney tissues,the expression of HCST mRNA was significantly up-regulated in ccRCC tissues,and showed a positive correlation with tumor stage,distant metastasis and lymph node metastasis (P＜0.01).High expression of HCST,pathological T stage and M stage were independent risk factors for the prognosis of ccRCC patients (P＜0.05).TIMER database analysis revealed a positive correlation between HCST expression and infiltration degree of CD8+ T cells,dendritic cells,NK cells and Treg cells (P＜0.001).Compared with control group,the cell viability,invasiveness,Bcl-2,N-cadherin and Vimentin protein expression levels were significantly decreased in HCST siRNA group (P＜0.05),and the apoptosis activity,caspase-3,Bax and E-cadherin were significantly increased (P＜0.05).There was no significant difference in the above indicators between the control group and NC siRNA group (P＞0.05).Conclusion:In ccRCC,HCST is highly expressed and is associated with immune infiltration and a poor prognosis.Silencing HCST could inhibit the proliferation and invasion and promote apoptosis of ccRCC cells.