Fusion of the PLAG1 and CTNNB1 genes in pleomorphic adenoma of the salivary glands

ABSTRACT

The pleomorphic adenoma is the most common neoplasm involving both the major and minor salivary glands. It is a benign, slowgrowing tumor, but local recurrences can occur. The pleomorphic adenoma gene 1 (PLAG1), which is a novel zinc finger gene, is frequently activated by reciprocal chromosomal translocations involving 8q12 in a subset of salivary gland pleomorphic adenomas. This experimental study was preformed to observe the translocation patterns between PLAG1 gene and the three translocation partner genes. We also have analyzed the presence of PLAG1 transcripts by RT-PCR. CTNNB1/PLAG1 gene fusion was observed in three of nine pleomorphic adnomas. However, LIFR/PLAG1 and SII/PLAG1 gene fusions were not detectable. All of three gene fusions was not detectable in one Warthin's tumor and three inflammatory salivary gland tissues. PLAG1 transcripts were expressed in all inflammatory salivary gland tissues and tumors except for three pleomorphic adenomas. Of particular one pleomorphic adenoma showing CTNNB1/P AG1 gene fusion did not express PLAG1 transcipt. Our data indicate that gene fusion involving PLAG1 is a frequent event in pleomorphic adenoma, but correlation between gene fusion involving PLAG1 and PLAG1 transcription is not definite.