Detection of promoter hypermethylation of RAR{beta}, RASSF1A, DAPK and P16/ INK4a genes in cell-free DNA from serum (s) and pleural liquid (pl) of patients (p) with pleural effusion

9637 Background: Aberrant gene promoter methylation (AM) is a major mechanism for tumour suppressor gene (TSG) silencing in all tumour types and affects their development and aggressiveness.AM of RARβ,RASSF1A, DAPK,P16/INK4a genes have shown to be involved in most tumors. Objectives: 1) to assess the concordance of gene promoter hypermethylation in paired s and pl samples of cancer p with malignant pleural effusion 2) to investigate their role as a marker of pleural effusion malignancy. Methods: We evaluated 53 consecutive p presenting pleural effusion and malignancy(24 lung,11 digestive,8 breast,4 ovary,6 others) at the General Hospital of Alicante (Spain).Hypermethylation of TSG were investigated by using methylation-specific PCR(MSP)after sodium bisulphite treatment. Results: Conventional cytology of pleural effusion samples revealed neoplastic cells in 17 of 48 p (35,5%). AM of at least one of the genes tested was detected in 24 out of 53 p (45,3%) in s and in 31 out of 53 p (58,6%) in pl. In pl 34% h...