Abstract
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 ceils 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 RARα403 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.
Original language | English (US) |
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Pages (from-to) | 920-924 |
Number of pages | 5 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 279 |
Issue number | 3 |
DOIs | |
State | Published - Dec 29 2000 |
Externally published | Yes |
Keywords
- Breast cancer
- LRAT
- RAR
- Retinyl esters
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology