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 availabilit y of a variety of tumor-associated antigens and animal models. We have rece ntly described the presence of a new antigen, TLP, in sera and cancer tissu e from lung and colorectal cancer patients. In order to develop an experime ntal model suitable for preclinical studies on cancer vaccines, we investig ated 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 injectio n. 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 tumo r syngeneic to immunocompetent BDIX rats. Int. J. Cancer 85:540-544, 2000. (C) 2000 Wiley-Liss, Inc.