GPRC5A基因在肺腺癌中的表达及临床意义

Expression of GPRC5A in lung adenocarcinoma and its clinical significance

目的了解G蛋白偶联受体C型家族5A(GPRC5A)基因在肺腺癌组织及癌旁正常组织中的表达,并探讨其临床意义。方法分别采用Real-time PCR和Western blot法检测25例肺腺癌组织及癌旁正常组织GPRC5A mRNA和蛋白表达水平。应用免疫组化法检测93例肺腺癌组织及癌旁正常组织GPRC5A蛋白的表达情况,并分析GPRC5A蛋白的表达与临床病理特征及预后的关系。结果 25例肺腺癌组织中GPRC5A mRNA和蛋白表达水平均明显低于癌旁正常组织(均P<0.05)。93例肺腺癌中GPRC5A蛋白低表达率为55.9%,均表达在胞质和胞膜中。GPRC5A蛋白的表达与肿瘤分化程度、TNM分期及淋巴结转移均有关(均P<0.05),而与性别、年龄、肿瘤大小均无关(均P>0.05)。Kaplan-Meier生存曲线显示,GPRC5A高表达的患者3年生存率为73.7%,高于低表达患者的39.4%,差异有统计学意义(P<0.01)。结论 GPRC5A在肺腺癌组织中低表达,其低表达与肿瘤分化程度、TNM分期、淋巴结转移及预后密切相关,可作为估计生存率的独立指标。

Objective To detect the expression of G protein-coupled receptor class C group 5 member A（GPRC5A） in human lung adenocarcinoma and to investigate its clinical significance. Methods The expression of GPRC5 A mRNA and protein were detected by Real-time PCR and Western blot in 25 cases of lung adenocarcinoma tissues and adjacent non-tumor tissues,respectively. Immunohistochemistry was used to detect the expression of GPRC5 A in 93 cases of lung adenocarcinoma and adjacent normal tissues. The clinical significance of GPRC5 A expression in lung adenocarcinoma was analyzed. Results The expression of GPRC5 A mRNA and protein in lung adenocarcinoma tissues were significantly lower than those in adjacent normal tissues（both P 0.05）. Immunohistochemistry showed that the low expression rate of GPRC5 A was 55.9% in 93 cases of lung adenocarcinoma. The low expression of GPRC5 A was correlated with the degree of histologic differentiation, clinical stage, and lymph node metastasis（all P〈0.05）, while not correlated with gender, age and tumor size（all P 0.05）. Kaplan-Meier survival curve showed that the 3-year survival rate of patients with overexpressed GPRC5 A was 73.7%, which was higher than that of low expression patients（39.4%, P 0.01）. Conclusion The expression of GPRC5 A is downregulated in lung adenocarcinoma.Downreguation of GPRC5 A expression is significantly associated with the degree of histologic differentiation, clinical stage, lymph node metastasis and prognosis of patients with lung adenocarcinoma.