High mobility group HMGI(Y) protein expression in human colorectal hyperplastic and neoplastic diseases

HMGI(Y) proteins are overexpressed in experimental and human malignancies, including colon, prostate and thyroid carcinomas. To determine at which ste p of the carcinogenic process HMGI(Y) induction occurs, we analysed the exp ression of the HMGI(Y) proteins in hyperplastic, preneoplastic and neoplast ic tissues of colorectal origin by immunohistochemistry. All the colorectal carcinomas were HMGI(Y)-positive, whereas no expression was detected in no rmal colon mucosa tissue, HMGI(Y) expression in adenomas was closely correl ated with the degree of cellular atypia, Only 2 of the 18 non-neoplastic po lyps tested were HMGI(Y)-positive. These data indicate that HMGI(Y) protein induction is associated with the early stager of neoplastic transformation of colon cells and only rarely with colon cell hyperproliferation, (C) 200 1 Wiley-Liss, Inc.