ABSTRACT
Objective To investigate the methylation status of E-cadherin(E-cad), p16, RASSF1A, DAPK and MGMT in histologically normal salivary gland tissues and provide reference for determination of the methylation status of salivary gland tumors.Methods Methylation of E-cad, p16, RASSF1A,DAPK and MGMT was analyzed using methylation-specific polymerase chain reaction ( MSP) .The results were compared with the methylation status of these genes in salivary adenoid cystic carcinoma ( ACC) tumor tissues in our previous studies and the association between promoter methylation of E-cad, p16, RASSF1A, DAPK, and MGMT on one hand and the patients′gender, age, smoking and types of gland on the other hand was also analyzed .Results Promoter methylation was detected in 8 of the 60 (13%) salivary glands, E-cad in 4(7%), p16 in 2(4%), RASSF1A in 2(4%), DAPK in 2 (4%), and MGMT in 1(2%).Compared with our previous results, there was a significantly lower methylation ratio in promoter methylation of E-cad(P<0.01), p16 (P<0.01), RASSF1A (P<0.01),and DAPK (P<0.01) in salivary gland tissues than in ACC tumor tissues.Conclusion Promoter methylation of E-cad, p16 and RASSF1A is a rare event in histologically normal salivary gland tissues .