TRANSFORMING GROWTH-FACTOR-BETA - EXPRESSION IN NORMAL AND PATHOLOGICAL CONDITIONS

Expression of the various isoforms of transforming growth factor-beta (TGF-beta) is differentially controlled both in vivo and in vitro. Cha racterization of the molecular mechanisms governing expression of TGF- beta isoforms now provides a basis for understanding the selective reg ulation of expression of the TGF-beta s by a variety of factors includ ing oncogenes and tumor suppressor genes. In addition to transcription al control, data suggest that expression of TGF-beta s is also regulat ed posttranscriptionally. Regulation of TGF-beta s by steroids and ret inoids appears to involve predominantly posttranscriptional mechanisms . Identification of these mechanisms may contribute to the understandi ng of the regulatory events controlling cellular proliferation and dif ferentiation by TGF-beta s and steroids/retinoids.