The influence of promoter methylation of RASSF1A on RASSF1A mRNA and protein expression in gastric cancer

Objective:To investigate RASSF1A mRNA and protein expression in tissue of gastric cancer and premalignant lesion,and analyze the relationship between DNA methylation status and RASSF1A expression. Methods: RT-PCR was used to detect the RASSF1A mRNA expression.RASSF1A promoter methylation was detected with methylation-specific PCR.The expression of RASSF1A protein level was determined withWestern blot. Results:RASSF1A mRNA and protein expressions in gastric cancer tissues were significantly decreased than those in normal gastric tissues or in the leisions of moderate and severe chronic atrophic gastritis with atypical hyperplasia and ntestinal metaplasia.Methylation frequency of RASSF1A in gastric cancer tissues was higher than that in normal gastric tissues or in the leisions of moderate and severe chronic atrophic gastritis with atypical hyperplasia and ntestinal metaplasia.The methylation frequency was more higher in the tissues with loss of RASSF1A mRNA expression than that with positive expression. Conclusion: The expression of RASSF1A is reduced in the tissue of gastric cancer.Low expression of RASSF1A is associated with hypermethylation of the promoter of RASSF1A gene.The hypermethylation of the promoter of RASSF1A gene is related to the formation and development of gastric cancer.