The effect of misoprostol on colon cancer

A synthetic prostaglandin E1 (PGE1) analogue, misoprostol, was investigated for its effects on the growth of colon cancer in two in vivo models. Human colon cancer cell lines C170, LIM2412 and LIM2405 were grown as subcutaneous xenografts on T-lymphocyte deficient ARC(s) nu/nu mice. Tumour volumes were found to be significantly inhibited compared with control in misoprostol-treated animals with two cell lines. C170 was inhibited by 70.5% (P = 0.0001) and LIM2412 by 68.2% (P = 0.01). LIM2405 was inhibited by 33% (P = 0.14) which was not significantly different from the control. In a second experiment, colon cancers were induced in Sprague-Dawley rats using 1,2 dimethyl-hydrazine (DMH). After 10 weeks of treatment, rats were randomized to receive a 5 week course of 20 micrograms/kg per day of oral misoprostol. Misoprostol-treated rats were found to have a similar tumour incidence and staging compared with control animals. Oral administration of misoprostol has an inhibitory effect on early tumour growth of some colonic cancers, but not on established tumours.