Effect of 13 cis retinoic acid on early precancerous antigenic gobletcell modifications and induction of cancer during 1,2-dimethyl-hydrazine carcinogenesis in rats

Abstract
The possible effect of oral 13 cis retinoic acid (13-cis-RA) on the carcinogenic process induced by 28 weekly s.c. injections of 1,2-dimethylhydrazine (DMH) in 34 Wistar rats was investigated. Using immunohistology, precancerous and cancerous stages were compared with the same stages induced by DMH without additional 13-cis-RA in 33 rats. M1 antigens, which characterize modifications in goblet-cell differentiation occurring early in rat colonic carcinogenesis, were used to investigate the possible effect of retinoids on differentiation during precancerous stages. From 3–20 weeks after the start of the experiment, no significant differences were observed in the timing of Ml antigens in the 2 groups of rats. It was also observed that 13-cis-RA had no effect on histological lesions associated with precancerous mucosa, nor on the occurrence of intestinal adenocarcinomas. Thus, under these conditions, oral administration of 13-cis-RA did not significantly inhibit precancerous or cancerous stages of intestinal carcinoma development.