Study On Expression And Mutation Of K-ras Gene In Non-Small Cell Lung Cancer In Guangxi

Objective: To study the expression and mutation of K-ras gene in non-small cell lung cancer(NSCLC) and explore the relationship between the activation of K-ras gene and the clinicopathological characteristics of NSCLC in GuangXi.Methods: (1)86 specimens of NSCLC tissues,31 specimens of adjacent tissues and 17 specimens of the lung tissues of non-carcinoma were selected to detect the mRNA expression of K-ras gene; Furthermore, these NSCLC tissues and adjacent tissues were selected again to examine the point mutations of K-ras gene.The specimens were all collected from patients with NSCLC immediately after surgical resection .(2)The mRNA expression of K-ras gene was examined by reverse transcription-polymerase chain reaction ( RT–PCR ) in 86 cases of NSCLC tissues , 31 cases of adjacent tissues and 17 cases of the lung tissues of non-carcinoma ; moreover , The point mutations in codon 12,13 and 61 of K-ras gene were examined by single-strand conformation polymorphism of PCR products ( PCR-SSCP ) analysis and DNA sequencing analysis in the same NSCLC tissues and adjacent tissues.Results: (1)The mRNA expression rate of K-ras gene in NSCLC tissues, adjacent tissues and the lung tissues of non-carcinoma were 80.2%( 69/86 ), 51.6%( 16/31)and 17.6% ( 3/17 ) , the former was significantly higher than the latter two ( P<0.01 );the mRNA expression rate of K-ras gene in adjacent tissues was higher than that in the lung tissues of non-carcinoma, but the difference was not statistically significant ( P>0.0167 ) ( note : 0.0167 is a calibration value ). However,the mRNA expression of K-ras gene in NSCLC tissues was not related to age, sex, nationality, smoking history, pathological histologicol styles, degree of cell differentiation tumor,TNM stages and the state of lymph node (P>0.05) .(2)No point mutation was found in codon 12 , 13 and 61 of K-ras gene in 86 cases of NSCLC tissues and 31 cases of adjacent tissues . In this stuty , the mutation frequency of K-ras gene in NSCLC was 0 ( 0/86 ). Conclusion: (1)In this study,the mRNA expression rate of K-ras gene in NSCLC tissues was higher than that in adjacent tissues and the lung tissues of non-carcinoma , which illustrats that the expression of K-ras gene is a frequent and indicates that the expression of K-ras gene , which was not associated with development process and unfavorable prognosis , involved in the occurrence in NSCLC.(2) In this study, no point mutation in codon 12 , 13 and 61 of K-ras gene was found in NSCLC tissues,which demostrats that the mutation frequency of K-ras gene in NSCLC is extremely low. The high proportion of K-ras gene in wild-type indicats that patients with NSCLC in GuangXi could take more benefits from the therapy with EGFR-TKIs and have better prognosis. (3)The study suggests that the expression and mutation of K-ras gene have its own characteristics in NSCLC in GuangXi , which indicats that there is regional heterogeneity on the activation of K-ras gene in NSCLC.