Anti-cancer therapy: diversion of polyamines in the gut.

The growth of a murine non-Hodgkin lymphoma (NHL) tumour, either as an intraperitoneal ascites tumour or as a solid subcutaneous tumour, has been shown to be greatly reduced by including phytohaemagglutinin (PHA), a lectin present in raw kidney bean (Phaseolus vulgaris) in the diet. The reduced rate of growth occurred in a dose-dependent manner. Based on the experimental observations it has been suggested that a competition occurs between the gut tissue undergoing hyperplasia and the developing tumour for nutrients (including polyamines) from a common body pool. This may be an important factor with regard to the observed initial low level of tumour growth following the feeding of a PHA-containing diet. Results showing that the level of hyperplasia of the small intestine in response to feeding the PHA diets was higher in non-injected mice compared to those which had been injected with tumour cells substantiated the concept of competition between gut and tumour for nutrients etc. required for growth. The observations suggest that lectins, which exhibit growth-promoting effects on the gut, may have interesting applications in the formulation of new approaches with respect to cancer treatment.