Expression of a tumor-associated antigen RCAS1 in hepatocellular carcinoma

RCAS1 has been reported as a tumor-associated antigen in uterine and ovaria n carcinomas. In vitro studies on RCAS1 indicated that it might function as an apoptosis-inducing factor since binding between RCAS1 and its receptor induced apoptosis in receptor-expressing cells. In this study, 68 surgicall y resected samples of hepatocellular carcinoma (HCC) were prepared and RCAS 1 expression was examined immunohistochemically, because RCAS1 was also pos itive in all HCC cell lines tested. Clinical and pathological parameters we re then compared between RCAS1-positive and -negative HCC cases. As a resul t, RCAS1 is expressed in 26.5% of HCC cases and vascular invasion is observ ed at a much higher rate in the RCAS 1positive cases (72.2%) than in RCAS 1 -negative cases (24.0%). RCAS 1 is not an antigen specific for gynecologica l cancers. In HCC cases, the RCAS1-positive percentage is not high, however , RCAS1-positive HCCs exhibited a trend towards invasive character. (C) 200 1 Elsevier Science Ireland Ltd. All rights reserved.