Research on promoter methylation and transcriptional expression of RUNX3 gene in breast cancers

Objective To investigate the promoter methylation status and expression of tumor suppressor gene RUNX3,and their roles in the carcinogenesis and development in invasive ductal carcinoma.Methods MSP(methylation specific PCR) was used to measure the promoter methylation status of 40 cases of breast invasive ductal carcinoma and 20 cases of benign breast lesions.RUNX3 mRNA expression level was measured by reverse transcription-polymerase chain reaction(RT-PCR).Results The frequency of promoter methylation of RUNX3 gene in breast cancer was 47.5%,which was higher significantly than that of benign breast lesion(P0.05).The loss frequency of RUNX3 mRNA expression was 40.0% in breast cancers,which was higher significantly than that of benign breast lesion(P0.05).The methylation of RUNX3 promoter in breast invasive ductal carcinoma was not correlated with the age of patient and lymph node metatasis,but correlated with the histological grading(P0.05).The mRNA expression level of RUNX3 was not correlated with all the clinical pathological characters.Conclusion The promoter methylation of RUNX3 may be an important molecular change and may contribute to the lowlevel of RUNX3 mRNA expression in breast invasive ductal carcinoma,and maybe play a certain role in malignant progression.