A new human tumor-associated antigen (TLP) is naturally expressed in rat DHD-K12 colorectal tumor cells.

Renewed interest in cancer immunotherapy has been raised by the availability of a variety of tumor-associated antigens and animal models. We have recently described the presence of a new antigen, TLP, in sera and cancer tissue from lung and colorectal cancer patients. In order to develop an experimental model suitable for preclinical studies on cancer vaccines, we investigated the presence of TLP antigen in vitro, in the DHD-K12 cell line and in vivo, in metastases induced in syngeneic BDIX rats by DHD-K12 cell injection. TLP was not detected in any tissue of healthy rats nor in normal tissues of tumor-bearing rats. This is in agreement with our previous studies, in which we had demonstrated that TLP is expressed in human colorectal cancer and adenomas but not in normal colonic mucosa. Our results indicate TLP as a possible human tumor-specific antigen naturally expressed in DHD-K12 tumor syngeneic to immunocompetent BDIX rats. Copyright 2000 Wiley-Liss, Inc.