EGFR、蛋白激酶B在宫颈癌中表达及EGFR胞外区基因突变的研究

The expressions of EGFR and PKB protein in cervical cancer and EGFR extracellular region gene mutation

目的:探讨宫颈癌中表皮生长因子受体(EGFR)、蛋白激酶B(PKB/Akt)的表达及EGFR胞外区基因突变的规律和临床意义,为宫颈癌的发生发展机制和靶向个性化治疗提供实验依据。方法:采用免疫组化SP法检测EGFR、Akt蛋白在16例正常宫颈组织、40例宫颈上皮内瘤变(CIN)组织和60例宫颈癌组织中的表达,并分析其与宫颈癌临床病理的关系。采用酚氯仿法抽提60例宫颈癌组织中DNA,PCR+DNA双向测序法检测EGFR胞外IV亚区基因突变。结果:正常宫颈组、CIN组及宫颈癌组中EGFR蛋白的阳性表达率分别为13.33%、43.33%及76.67%,Akt蛋白的阳性表达率分别为6.25%、35.00%及68.33%,差异有统计学意义(P<0.05)。宫颈癌组织中,EGFR表达水平与病理类型、细胞分化程度和临床分期有关(P<0.05),但与患者年龄和淋巴结转移无关(P>0.05);Akt表达水平与细胞分化程度和临床分期有关(P<0.05),但与患者年龄、病理类型和淋巴结转移无关(P>0.05)。60例宫颈癌中EGFR基因外显子15突变率为3.33%(2/60),突变类型G→A,未发现外显子14突变。宫颈癌组织中EGFR、Akt表达呈正相关性(r=0.556,P<0.05)。结论:EGFR、Akt可作为检测宫颈癌及癌前病变的重要参考指标,也为宫颈癌的多靶点联合治疗提供新思路;宫颈癌中EGFR胞外区可有基因突变,但突变率很低,关于其突变的规律和意义有待进一步研究。

Objective：To investigate the epidermal growth factor receptor （EGFR）, protein kinase B （Akt） expression and significance in cervical cancer;and to analyze the inci- dence of EGFR extracellular region gene mutation in cervical cancer, which provided gene de- tection methods and theoretical basis for the cervical cancer targeted treatment. Methods：The immunohistochemical was used to detect EGFR, Akt expression in 16 cases of normal control, 40 cases with cervical intraepithelial neoplasm（CIN） and 60 cases with cervical cancer. DNA were extracted from 60 cases of cervical cancer by the routine phenol-chloroform method, which were used for PCR amplification and direct sequence for EGFR extracellular region gene muta- tion. Results：The positive rates of EGFR and Akt were 13.33% and 6.25% in normal cervical tissues,43.33% and 35.00% in CIN lesions,76.67% and 68.33% in carcinoma respective- ly. The positive expression rate of EGFR in cervical cancer tissues was correlated with the path- ological type,degree of tumor differentiation and clinical staging （P〈0.05） ,which was no re- lated to age and lymph node metastasis （P〉0.05）. The positive expression rate of Akt in cervi- cal cancer tissues was correlated with the degree of tumor differentiation and clinical staging （P〈0.05 ） which was no related to age ,pathological type and lymph node metastasis （P〉0.05）. Only two cases EGFR extracellular domain IV 15 exon mutations （G→A） were detected in 60 cases （3.33%） cervical cancer while no EGFR extracellular domain IV 14 exon mutations was detected. In cervical cancer,the positive expression rate of EGFR and Akt was positively corre- lated with positive expression rate of Akt （P〈0.05）. Conclusion： EGFR and Akt are closely associated with precancerous lesions and cervical cancer, and provide new information regarding the treatment strategies for cervical cancer combination therapy. The mutation rate of EGFR ex- tracellular domain was low,there may be other potential or unknown mutation points in human cervical cancer.