Carcinogenesis in the colon: interaction between luminal factors and genetic factors.

At last, inroads are beginning to be made into the hitherto unknown and complex area of gene-environment interactions in the colon. Interestingly, many of the studies to date would suggest: that the Apc gene is a target for such interactions; that luminal factors can regulate the level of cellular proteins of central importance in the control of cell growth/arrest; and that some of the newly discovered members of the nuclear hormone receptor superfamily may be mediating gene-environment interactions in the colon. This is a very exciting area and will presumably be the subject of intense research in the near future. By characterizing the dietary/luminal factors that interact with the genes implicated in tumour development in the colon, we will reach another level of certainty regarding the dietary components responsible for tumour formation and their underlying mechanisms. It is gratifying to see at last the fields of epidemiology and molecular biology begin to overlap, and without doubt results from this new area of research will give a new and better status to the field of making dietary recommendations to decrease the risk of developing colorectal cancer.