Transient modulation of cytoplasmic and nuclear retinoid receptors expression in differentiating human teratocarcinoma NT2 cells

Università degli Studi di Genova, Genova, Liguria, Italy
Journal of Neurochemistry (Impact Factor: 4.28). 02/2003; 84(1):94-104. DOI: 10.1046/j.1471-4159.2003.01501.x
Source: PubMed


Human embryonal carcinoma Ntera2/D1 (NT2) cells treated with retinoic acid (RA) differentiate into several cell types including post-mitotic neurons. In this study we asked if RA-induced differentiation alters the expression of RA and retinol (ROL) binding proteins. The regulation of the intracellular carrier proteins for ROL and RA, cellular retinol binding protein I (CRBP-I), and cellular retinoic acid binding protein I and II (CRABP-I, CRABP-II) were studied along with the nuclear RA receptors RARalpha, RARbeta and RARgamma2. PCR analysis of total mRNA from RA-treated cells showed a biphasic early induction of CRBP-I, CRABP-II, and RARgamma2 genes. The immediate early gene Krox-24, a zinc finger transcription factor which is up-regulated during neuronal differentiation, was also induced, but after 1 week of treatment. The induction of CRBP-I protein synthesis in differentiating NT2 cells was confirmed by western blotting and immunofluorescence experiments. Conversely, the synthetic retinoid N-(4-hydroxyphenyl)retinamide, which induces cell death, but not differentiation in different tumour cell types, did not produce the same modulation on gene expression in NT2 cells. These data suggest that the RA-specific induction of CRBP-I and CRABP-II could be an early event in the process leading to neuronal differentiation of NT2 cells.

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Available from: Francesca Isabella Tosetti
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    • "RT-PCR was performed as described previously [4] [22] [25]. The synthesized cDNA was amplified using specific primer sets for b-actin or cellular retinol binding protein I (CRBP-I), as described previously [26] [27]. The sequence of the primer set for ZNF267 was 5 0 -CCTTTCGCTGTAGTTCATAC-3 0 and 5 0 -CCGATGCACAG AAAGACCT-3 0 , the expected length of the amplified product was 538 bp. "
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