Expression Of Activation-Induced Cytidine Deaminase In Melanoma And Its Correlation With BRAF Mutation And Clinicopathological Features

Objective: To detect the expression of activation-induced cytidine deaminase(AID)in melanoma(in situ)and in invasive melanoma,to analyze the correlation between AID expression and B-type Raf kinase(BRAF)gene mutation,and to characterize its clinicopathological features.Methods: Using Immunohistochemistry and real-time quantitative PCR(qPCR)were used to detect the protein and mRNA expressions of AID in paraffin-embedded melanoma tissue samples.Results: The correlations between AID expression and clinicopathological features and other related factors were then comprehensively analyzed.Immunohistochemistry showed that the percentage of AID expression and protein in melanoma samples were 53.75%(43/80)and 13.04%(3/23),respectively,in the pigmented nevi samples.This difference was statistically significant(P< 0.05).qPCR showed that the expression level of AID mRNA in melanomas was significantly higher than in the pigmented nevi(P < 0.05),and the expression of AID was closely associated with BRAF mutations,the degree of invasion,lymph node metastasis,Clark grade,and prognosis(all P < 0.05),but independent of age,sex,and ethnicity(all P > 0.05).Among the 19 cases with BRAF mutations,AID protein expression was positive in 17 cases.Notably,all 15 BRAFV600 E mutation cases had a positive expression of the AID protein.Conclusion: AID may play a role in the pathogenesis of melanoma by inducing the mutation of BRAF,especially the V600 E mutation.The expression of AID was found to be closely associated with tumor infiltration,lymph node metastasis,Clark grade,BRAF mutation,and the prognosis.