Standard cytogenetic analysis, fluorescence in-situ hybridization, array comparative genomic hybridization and Western blotting allowed us to demonstrate the presence of chromosome abnormalities involving the 8q11-13 region containing the pleomorphic adenoma gene 1 (PLAG1), which are classically reported in lipoblastoma, and aberrant expression of PLAG1.
PLAG1, a proto-oncogene activated in several types of tumors including pleomorphic adenoma of the salivary gland and lipoblastoma, is usually overexpressed because of chromosomal aberrations resulting in fusion genes.
There are only a few reports of the cytogenetic abnormalities in the pleomorphic adenomas (PA) that arise in children, and even less information regarding the pleomorphic adenoma gene 1 (PLAG1) and high motility group A2 (HMGA2 ) histochemical staining in PAs, or their correlation with histologic types (stromal vs epithelial predominance).
Here we have studied the expression of PLAG1 by Northern blot analysis in 47 primary benign and malignant human tumors with or without cytogenetic abnormalities of 8q12.
The target gene affected by the chromosome aberrations mapping within this interval was recently shown to be the PLAG1 gene, which encodes a novel zinc finger protein.