The data presented here are part of an ongoing effort to examine the response of @entity35 tracheal epithelium to @entity5 promoting agents and to elucidate the mechanisms of @entity5 promotion in that epithelial tissue (see Steele, this volume). Previous studies indicated that airway epithelium is responsive to the @entity5 promoter @entity865 and that @entity865 can promote the @entity5 response in @entity35 tracheal epithelium But what are the mechanisms involved? We have divided this question into two main elements: 1) Which stages of neoplastic development are affected by @entity865 , i.e., which preneoplastic cell populations are targets for @entity865 action resulting in the acceleration and enhancement of the process of neoplastic development? 2) What effects does @entity865 have on various preneoplastic cell populations and how do such effects result in promotion? The experiments discussed here relate to the second part of the question. They suggested that @entity865 elicits a marked cytotoxic response in stably transformed RTE cell variants (see Fig. 1). These preneoplastic cell variants are clearly different from untransformed RTE cells which are triggered into cell cycle as indicated by an increase in CFE. This difference between normal and transformed cells is of considerable interest in itself since it points to a fundamental, biochemical alteration in the transformed cells. Evidence exists that transformed RTE cell lines have @entity865 receptors and that at least some of the responses elicited by @entity865 exposure, such as the induction of @entity7222 decarboxylase activity, are receptor-mediated. Whether the cytotoxic response elicited by @entity865 is receptor-mediated is presently not known.(ABSTRACT TRUNCATED AT 250 WORDS)

Contrasting responses of normal and transformed @entity35 tracheal epithelial cells to the XXXX promoter 12-O-tetradecanoylphorbol-13-acetate.

@entity35 :: ('10116', 'Species') :: ['rat'] @entity865 :: ('CHEBI:61432', 'Chemical') :: ['TPA'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity7222 :: ('CHEBI:18257', 'Chemical') :: ['ornithine']
@entity5 :: (MESH:D009369,Disease) :: ['tumor']
