The Study On The Activation Of Telomerase And Deactivation Of The P16 Gene In The Pathogeness And Progression Of Non-small Lung Cancer

Objective:(1)To study the expression of human telomerase reverse transcriptase hTERT mRNA in non-small cell lung cancer and normal lung tissue samples,and to analyze the correlationship between the expression level of hTERT mRNA and the histological classification,lymph node metastasis,degree of differentiation,and clinical stages of non-small cell lung cancer.(2)To study p16 gene methylation and its protein expression in the pathogenesis and progression of non-small cell lung cancer (NSCLC),to explore the correlationship between p16 gene methylation and its protein expression.(3)To study the correlationship between the expression of hTERT mRNA and inactivation of p16 gene in non-small cell lung cancer, to explore the effect p16 gene deletion on the expression of hTERT mRNA in non-small cell lung cancer.Methods:(1)45 non-small cell lung cancer tissue samples and 21 normal lung tissue samples were selected randomly.(2)The expression of hTERT mRNA was detected using real-time quantitative PCR(RT-qPCR)assay.The p16 methylation was detected by methylation-specific-PCR(MSP).The p16 gene protein expression was detected by immunohistochemistry. Results:(1)hTERT mRNA from non-small cell lung cancer and normal lung tissue were 2.854±0.728 and 2.042±0.378,respectively(t=-4.807,P＜0.01).There was no significant association between non-small cell lung cancer hTERT mRNA expression level and patient's age,gender,degree of differentiation and the histological.There was a significant correlation between hTERT mRNA expression level and clinical stages,lymph node metastasis in non-small cell lung cancer(P＜0.05).(2)P16 gene methylation rate in non-small cell lung cancer was significantly higher than that in normal lung tissue(p＜0.01).The loss rate of p16 gene protein expression in non-small cell lung cancer was significantly higher than that in normal lung tissue (p＜0.01).p16 gene methylation was closely related to lymph node metastasis and degree of differentiation in non-small cell lung cancer(p＜0.01),p16 gene protein expression was correlated with pathological stages,types of histology,lymph node metastasis and degree of differentiation in non-small cell lung cancer(p＜0.05),p16 gene methylation was closely related to p16 gene protein expression in non-small cell lung cancer(p＜0.01).(3)The expression of hTERT mRNA was closely related to p16 gene methylation and p16 gene protein expression in non-small cell lung cancer(p＜0.01).(4)The hTERT mRNA expression rate in p16 gene deletion group is higher than that in undeletion group(p＜0.05).Conclusion:(1)The expression of hTERT mRNA and inactivation of the p16 gene might play an important role in the pathogenesis and progression of non-small cell lung cancers(NSCLC).The expression of hTERT mRNA will become a good marker in forecasting tumor occurrence,diagnosing of cancer.(2)p16 methylation might be one of the important causes of lower p16 protein expression in non-small cell lung cancer.(3)The p16 gene deactivation would activate hTERT expression. Different type of p16 gene deactivation by p16 gene deletion has different effect on the hTERT expression.(4)Real-time quantitative PCR(RT-qPCR)assay is a more sensitive and scientific method.