Transglutaminase-3, an esophageal cancer-related gene

Transglutaminase-5 (TGase-3) is an enzyme with the ability to catalyze the irreversible cross-linking of peptide-bound glutamine residues either with peptide-bound lysines or with primary amines, It has been implicated in the formation and assembly of the cornified cell envelope of the epidermis, ha ir follicle and perhaps other stratified squamous epithelia, We show here t he involvement of TGase-3 in human esophageal cancer, In an initial study, mRNA differential display was performed with 3 pairs of esophageal cancer t issues and matched normal adjacent mucosa by a 10-mer arbitrary primer and mixed anchored primers (GT 15N, N = A, C and C). Four differentially expres sed cDNA bands were consistently observed in all 3 normal tissues but barel y detected in their tumor counterparts. One of them was identified to be th e 3' end of TGase-3. Northern blot and dot blot analyses of 14 samples conf irmed the down-regulation of TGase-3 in malignant tissues compared with nor mal epithelia, RT-PCR revealed that TGase-3 expression was lost in 3 esopha geal carcinoma cell lines and decreased in 35/38 tumors compared with adjac ent normal mucosa, Taken together, 49/52 (94.2%) esophageal tumors presente d down-regulation of the gene. Our data suggest that alteration of TGase-3 expression is a common event in the development of human esophageal cancer. Int. J. Cancer 88:862-865, 2000. (C) 2000 Wiley-Liss, Inc.