Vitamin A Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin A, including details on retinol, benefits, dosage, supplements, deficiency, information.

Retinoic acid induces TGFbeta-dependent autocrine fibroblast growth.

Fadloun A, Kobi D, Delacroix L, Dembélé D, Michel I, Lardenois A, Tisserand J, Losson R, Mengus G, Davidson I

Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP. UMR7104, 1 Rue Laurent Fries, Illkirch Cédex, France.

To evaluate the role of murine TFIID subunit TAF4 in activation of cellular genes by all-trans retinoic acid (T-RA), we have characterized the T-RA response of taf4(lox/-) and taf4(-/-) embryonic fibroblasts. T-RA regulates almost 1000 genes in taf4(lox/-) cells, but less than 300 in taf4(-/-) cells showing that TAF4 is required for T-RA regulation of most, but not all cellular genes. We further show that T-RA-treated taf4(lox/-) cells exhibit transforming growth factor (TGF)beta-dependent autocrine growth and identify a set of genes regulated by loss of TAF4 and by T-RA corresponding to key mediators of the TGFbeta signalling pathway. T-RA rapidly and potently induces expression of connective tissue growth factor (CTGF) via a conserved DR2 type response element in its proximal promoter leading to serum-free autocrine growth. These results highlight the role of TAF4 as a cofactor in the cellular response to T-RA and identify the genetic programme of a novel cross talk between the T-RA and TGFbeta pathways that leads to deregulated cell growth.

Published 17 January 2008 in Oncogene, 27(4): 477-89.
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