Analysis of promoter hypermethylation of Runx3 gene in non-small cell lung carcinoma

Objective:To analyze the aberrant promoter hypermethylation of Runx3 gene in human non-small cell lung carcinoma(NSCLC).Methods: Methylation-specific PCR was performed to detect the promoter hypermethylation of Runx3 gene in 62 NSCLC tissue samples and 62 corresponding normal lung tissue samples.The effect of the aberrant methylation of Runx3 gene on the expression of Runx3 mRNA and protein was evaluated.The correlation between the aberrant methylation of Runx3 gene and the clinicopathological factors of NSCLC patients was also analyzed.Results: The promoter hypermethylation ratio of Runx3 gene in NSCLC tissues(48.4%) was significantly higher than that of the corresponding normal lung tissues(17.7%,P=0.000).The levels of p16 mRNA and protein expression in NSCLC tissues or normal lung tissues with complete or incomplete methylation were significantly lower than those with unmethylation.The aberrant methylation of Runx3 promoter was significantly correlated with tumor differentiation(P=0.041) and clinical stage(P=0.009),but not correlated with sex,age,smoking condition and tumor types of NSCLC patients(P=0.400,0.301,0.290 and 0.96,respectively).Conclusion: The aberrant methylation of Runx3 gene was associated with Runx3 downregulation,and detection of the aberrant methylation of Runx3 gene promoter in NSCLC would offer an effective method for the earlier auxiliary diagnosis of NSCLC.