chromosomal translocation t(3;8)(p21;q12)
Introduction
Chromosomal translocation t(3;8)(p21;q12) involving PLAG1 with constituvely expressed beta-catenin/CTNNB1 may be a cause of salivary gland pleiomorphic adenomas. Fusion occurs in the 5'- regulatory regions, leading to promoter swapping between the 2 genes & activation of PLAG1 expression in adenomas. The chimeric transcript is formed by fusion of CTNNB1 exon 1 to PLAG1 exon 3. Reciprocal fusion transcript consisting of PLAG1 exon 1 & CTNNB1 exon 2-16 is also revealed in some adenomas. Chromosomal translocation t(3;8)(p21;q12) involving PLAG1 with transcription elongation factor SII/TCEA1. The fusion transcript is composed of 5'-non-coding sequences as well as 63 nucleotides of the coding region of TCEA1 fused to the acceptor splice site of PLAG1 exon 3. The fusion transcript encodes a truncated TCEA1-PLAG1 protein of 90 AA as well as an apparently normal PLAG1 protein. Reciprocal fusion transcript PLAG1-TCEA1 is also present in one adenoma.