De Luca, LM;
Expression of a smaller lecithin : retinol acyl transferase transcript and reduced retinol esterification in MCF-7 cells.
BIOCHEM BIOPH RES CO
920 - 924.
Retinyl ester concentration is regulated by retinoic acid (RA) through an autoregulatory loop, which acts on lecithin:retinol acyltransferase (LRAT). me tested whether retinol esterification activity is downregulated in human mammary carcinoma cells and whether LRAT expression is RAR-regulated. Normal human mammary epithelial (HMEC) cells expressed a retinoid-upregulated 5-kb LRAT transcript and synthesized retinyl esters from H-3-retinol. Human carcinoma MCF-7 cells failed to express the 5-kb LRAT transcript and to synthesize retinyl esters. Instead, they expressed a 2.7-kb LRAT transcript. Both transcripts were upregulated by RA. Stable expression of the dominant-negative RAR alpha 403 blunted the up-regulation of LRAT mRNA by RA, We conclude that retinol esterification is decreased in MCF-7 vs normal mammary cells; that these cancer cells express a shorter (2.7 kb) LRAT transcript, and that retinoid receptors are involved in the regulation of LRAT-mediated retinyl ester synthesis by RA. (C) 2000 Academic Press.
|Title:||Expression of a smaller lecithin : retinol acyl transferase transcript and reduced retinol esterification in MCF-7 cells|
|Keywords:||LRAT, RAR, breast cancer, retinyl esters, ACID, CARCINOMA, METABOLISM, LINES|
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