端粒酶逆转录酶和c-myc基因在肺癌中表达的研究

Expression of telomerase reverse transcriptase and c-myc oncogene in lung cancer

目的 研究端粒酶逆转录酶 (hTERT)和c myc基因在肺癌中的表达及其与端粒酶活性的关系。方法 采用端粒重复序列扩增 (TRAP)法对肺癌组织以及癌旁非癌肺组织的端粒酶活性进行测定。用原位逆转录聚合酶链反应 (RT PCR)和免疫组织化学技术分别检测上述组织标本中hTERTmRNA与c myc蛋白表达。结果 端粒酶活性在肺癌组织中阳性率为 73 .2 % (3 0 /4 1) ,在癌旁非癌肺组织为 6.3 % (2 /3 2 ) ,P <0 .0 1。肺癌及癌旁非癌肺组织中hTERTmRNA阳性表达率分别为 78.0 % (3 2 /4 1)和 9.4% (3 /3 2 ) ,P <0 .0 1,c myc蛋白阳性表达率分别为 80 .5 % (3 3 /4 1)和 15 .6% (5 /3 2 ) ,P <0 .0 1。肺癌组织hTERTmRNA表达与端粒酶活性呈显著正相关 (r =0 .70 7,P <0 .0 1) ,同时c myc蛋白与hTERTmRNA表达亦呈明显正相关 (r =0 .60 9,P <0 .0 1)。 结论 hTERTmRNA表达增强不仅参与肺癌的发生 ,而且可能是调节肺癌端粒酶活性的限速步骤。c

Objective To investigate the expression of human telomerase reverse transcriptase(hTERT)and c-myc oncogene and its relation to telomerase activity in the carcinogenesis of lung cancer.Methods Telomerase activity was detected in tissues samples from lung cancers and adjacent non-cancer lung tissues by telomeric repeat amplification protocol(TRAP).The hTERTmRNA and c-myc oncoprotein were examined in these samples with in situ reverse transcription polymerase chain reaction and immunohistochemical method,respectively.Results The positive rates of telomerase activity and hTERT mRNA were 73.2% and 78.0% in 41 samples of lung cancers,respectively,significantly higher than those of adjacent non-cancer lung tissues group( P <0.01).It was found that c-myc oncoprotein was positive in 80.5% (33/41) samples of lung cancers and in 15.6%(5/41)adjacent non-cancer lung tissues( P < 0.01). There was a significant correlation between the expression of hTERTmRNA and telomerase activity( r =0.707, P <0.01).The expressions of c-myc oncoprotein and hTERTmRNA were also noticed to be highly correlated( r =0.609, P <0.01).Conclusion The overexpression of hTERTmRNA may play an important role in the carcinogenesis of lung cancer and telomerase activation.The c-myc oncoprotein may trans-activate hTERTmRNA overexpression,which is related to the development of lung cancer.