Abstract
Retinoic acid modulates growth and induces differentiation and apoptosis of neuroblastoma cells in vitro, with the all-trans and 9-cis isomers having different biological properties. Transcriptional activation in response to retinoic acid isomers is mediated by retinoic acid receptors and retinoid X receptors. The differential expression of co-activators and co-repressors which preferentially interact with retinoic acid receptors or retinoid X receptors may be a mechanism leading to different cellular responses to 9-cis and all-trans retinoic acid. To test this hypothesis, we have studied the expression of the nuclear receptor co-regulators TIF1α, TIF1β, SUG1 and SMRT in the N-type and S-type neuroblastoma cell lines SH SY 5Y and SH S EP. Transcripts for all four co-regulators were expressed in these neuroblastoma cells. The expression of TIF1α, TIF1β and SUG1 did not change in response to retinoic acid; however, SMRT was induced in both neuroblastoma cell lines, but particularly by all-trans retinoic acid in SH S EP cells. An additional co-activator, Trip3, was isolated by differential mRNA display and shown to be preferentially induced by 9-cis retinoic acid in SH SY 5Y and SH S EP cells. These data suggest that retinoic acid isomer-specific induction of nuclear receptor co-regulators may determine, in part, the differential biological effects of retinoic acid isomers. Copyright (C) 1999 Federation of European Biochemical Societies.
Original language | English |
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Pages (from-to) | 415-419 |
Number of pages | 5 |
Journal | FEBS Letters |
Volume | 445 |
Issue number | 2-3 |
DOIs | |
Publication status | Published - 26 Feb 1999 |
Externally published | Yes |
Keywords
- 9-cis retinoic acid
- All-trans retinoic acid
- Co-activator
- Co-repressor
- Neuroblastoma
- SMRT
- TIF1
- Trip3