Effects of retinoids on expression of the protooncogene c-myb in rat Sertoli cells.

Publisher Summary Vitamin A deficiency results in abnormal cell growth and differentiation, and its derivatives—retinol or retinoic acid—restore normal function in most tissues. The ability of retinoic acid to regulate the expression of a variety of protooncogenes such as c-myc, c-myb, and c-jun suggests that these transcription factors are coupled to the regulatory pathways involved in retinoid action. Myb—the nuclear protein product of c-myb—is a high-affinity DNA-binding protein that exhibits both transactivator and transrepressor activity associated with cell growth and differentiation. This chapter describes the transient up-regulation of c-myb mRNA in the rat Sertoli cell in response to vitamin A stimulation. The significant rise in the message for the transcription factor suggests that the nuclear protein Myb may mediate retinol-inducible gene expression. Myb can initiate regulatory changes in the genetic program of the Sertoli cell via transcriptional control. It is demonstrated in this chapter that, the c-myb protooncogene is expressed in cultured rat Sertoli cells and that its expression is stimulated by both retinol and retinoic acid.