肺癌组织p53基因突变与肿瘤耐药基因表达的相关性及其临床意义

目的探讨p53基因突变与肿瘤耐药基因表达状况及肺癌耐药的关系。方法应用免疫组织化学法检测66例肺癌及其癌旁组织的突变型P53蛋白及耐药相关蛋白的表达水平。其中31例肺癌及其癌旁组织应用聚合酶链测定单链构象多态性(PCRSSCP)银染法及逆转录聚合酶链测定(RTPCR)法检测p53基因第5～8外显子突变情况及各种耐药基因的mRNA表达水平;12例应用三磷酸腺苷肿瘤化疗敏感实验(ATPTCA)检测肺癌细胞对诺维本、卡铂、依托泊苷、表柔比星、5氟尿嘧啶、博莱霉素的敏感性。结果突变型P53蛋白与P糖蛋白(Pgp)、多药耐药相关蛋白(MRP1)、谷胱甘肽S转移酶π(GSTπ)的表达状况存在着相关性(r分别为047、033、044,P均<005);ATPTCA结果显示突变型P53蛋白的表达状况及其与Pgp、MRP的共表达均和诺维本及卡铂的耐药相关(P均<005)。结论肺癌组织耐药相关蛋白的表达与p53基因突变有关,突变型P53蛋白的检出可以预示内源性耐药的存在,恢复野生型P53蛋白的功能可能有助于逆转耐药。

Correlation between p53 gene mutation and the expression of tumor drug resistance genes in lung cancer and its clinical significance

OBJECTIVE: To investigate the relationship between p53 mutation and the expression of some drug-resistance genes commonly found in lung cancer. METHODS: Sixty-six of untreated lung cancers and paracancerous tissues were obtained by surgical resection. Immunohistochemical staining was employed for detection of both mutant p53 and drug-resistance associated proteins (MDR1, MRP1, LRP, TOPO II alpha, GST-pi), PCR-SSCP and RT-PCR were used for detection of mutations of p53 exon 5-8 as well as the expression of mRNAs for the genes coding those drug-resistance associated proteins in 31/66 cases. ATP-TCA assay was also performed simultaneously in 12 out of the 31 cases for evaluation of their reaction in response to chemotherapy. RESULTS: Correlations were found between p53 mutation and expression of either Pgp or MRP1 or GST-pi (P < 0.05). There was a significant correlation between p53 mutation with simultaneous expression of Pgp and MRP1 and drug-resistance to either vinorelbine or carboplatin. CONCLUSIONS: The results suggested that p53 mutation in lung cancers was closely correlated with the expression of drug-resistance associated protein which was associated with endogenous resistance to most of chemotherapeutic drugs. It indicated that wild p53 gene therapy might be helpful for treating the endogenous drug resistance of lung cancer in chemotherapeutics.