Thymosin beta-10 gene overexpression is a general event in human carcinogenesis

The beta-thymosins comprise a family of structurally related, highly conser ved acidic polypeptides, originally isolated from calf thymus, Recently, we have demonstrated the overexpression of thymosin beta-10 (TB10) in rat thy roid transformed cell lines and in human thyroid carcinoma tissues and cell lines. To verify whether TB10 overexpression is a general event in the pro cess of carcinogenesis, we have analyzed TB10 mRNA levels in human colon ca rcinomas, germ cell tumors of different histological types, breast carcinom as, ovarian carcinomas, uterine carcinomas, colon and esophageal carcinoma cell lines. Overexpression of the TB10 gene was detected in all of the neop lastic tissues and cell lines compared to the respective normal tissues. Mo reover, the mouse model of skin carcinogenesis induced by the combined acti on of chemical carcinogens and phorbol esters was used to identify the stag e of TB10 gene induction. The expression was almost undetectable in normal keratinocytes, its induction occurred even at the papilloma stage, however a further increased expression was observed in the carcinoma derived cell l ines. Finally, immunohistochemical analysis of some breast, colon and ovary carcinoma samples by using specific anti-TB10 antibodies revealed the pres ence of the TB10 protein in all of the neoplastic tissues, but not in the r espective normal tissues. Therefore the TB10 detection may be considered a potential tool for the diagnosis of several human neoplasias.