Expression of a smaller lecithin:retinol acyl transferase transcript and reduced retinol esterification in MCF-7 cells

Biochem Biophys Res Commun. 2000 Dec 29;279(3):920-4. doi: 10.1006/bbrc.2000.3995.


Retinyl ester concentration is regulated by retinoic acid (RA) through an autoregulatory loop, which acts on lecithin:retinol acyltransferase (LRAT). We 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 3H-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 RARalpha403 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.

MeSH terms

  • Acyltransferases / biosynthesis
  • Acyltransferases / genetics
  • Acyltransferases / metabolism*
  • Epithelial Cells / drug effects
  • Epithelial Cells / enzymology
  • Esterification
  • Humans
  • Molecular Weight
  • RNA, Messenger / drug effects
  • RNA, Messenger / metabolism
  • Receptors, Retinoic Acid / physiology
  • Retinoids / pharmacology
  • Transcription, Genetic
  • Tritium
  • Tumor Cells, Cultured
  • Up-Regulation / drug effects
  • Vitamin A / metabolism*


  • RNA, Messenger
  • Receptors, Retinoic Acid
  • Retinoids
  • Tritium
  • Vitamin A
  • Acyltransferases
  • lecithin-retinol acyltransferase