A New Rat Colon Cancer Cell Line Metastasizes Spontaneously: Biologic Characteristics and Chemotherapeutic Response

A new cell line (RCN‐9) was established in culture from a transplantable rat colon adenocarcinoma, which was induced in the colon of a male Fischer F344 rat by subcutaneous administration of 1,2‐dimethylhydrazine. When RCN‐9 cells were injected subcutaneously or into the cecal subserosa of syngeneic rats, carcinomas with progressive growth were obtained and the development of lung (63.6%) and liver (40.0%) metastases, respectively, ensued. Antitumor effects of 5‐fluorouracil (5‐FU), adriamycin (ADM) and mitomycin C (MMC) against RCN‐9 were examined in vivo and in vitro. 5‐FU and ADM had antitumor effects both in vivo and in vitro; MMC had antitumor effects in vitro. These results show that the RCN‐9 cell line can be used both as a model to study mechanisms of metastasis from colon carcinoma and as a model in chemotherapeutic studies of metastatic disease from colon carcinoma.