A National Institutes of Health Workshop Report. Cellular and molecular mechanisms for suppression and reversion of tumorigenicity. A Chemical Pathology Study Section workshop.

A workshop organized by the Chemical Pathology Study Section was convened to discuss recent findings on the suppression and/or reversal of neoplastic transformation. The existence of specific genes involved in suppressing tumorigenicity has been clearly demonstrated by molecular and cytogenetic analyses of tumor and normal cells from individuals predisposed to develop specific malignancies and by studies of hybrids between normal and neoplastic cells. The malignancy of tumor cells can be suppressed in hybrids with normal cells despite the continued expression of activated oncogenes. Reversal of the malignant state can also be affected by placing tumor cells in certain embryonic environments, such as the mouse blastocyst, or in response to differentiation inducing factors. The numerous examples of suppression and reversal of malignancy indicate that this is an important area for future study which may lead to new methods to control cancer.