PMID- 8825126 OWN - NLM STAT- MEDLINE DCOM- 19961114 LR - 20190905 IS - 0167-6806 (Print) IS - 0167-6806 (Linking) VI - 38 IP - 1 DP - 1996 TI - The efficacy of 9-cis retinoic acid in experimental models of cancer. PG - 85-96 AB - 9-cis retinoic acid (9-cis RA) is a retinoid receptor pan-agonist that binds with high affinity to both retinoic acid receptors (RARs) and retinoid X receptors (RXRs). Using a variety of in vivo and in vitro cancer models, we present experimental data that 9-cis RA has activity as a potential chemotherapeutic agent. Treatment of the human promyelocytic leukemia cell line HL-60 with 9-cis RA decreases cell proliferation, increases cell differentiation, and increases apoptosis. Induction of apoptosis correlates with an increase in tissue transglutaminase (type II) activity. In vivo, 9-cis RA induces complete tumor regression of an early passage human lip squamous cell carcinoma xenograft. Finally, 9-cis RA inhibits the anchorage-independent growth of the human breast cancer cell lines MCF-7 and LY2 (an antiestrogen-resistant MCF-7 variant). Transient co-transfection assays indicate that 9-cis RA inhibits estrogen receptor transcription of an ERE-tk-LUC reporter through RAR or RXR receptors. These data suggest that retinoid receptors can antagonize estrogen-dependent transcription and provides one possible mechanism for the inhibition of cell growth by 9-cis RA in breast cancer cell lines. In summary, these findings present evidence that 9-cis RA has a wide range of activities in human cancer models. FAU - Gottardis, M M AU - Gottardis MM AD - Department of Pharmacology, Ligand Pharmaceuticals, San Diego CA, USA. FAU - Lamph, W W AU - Lamph WW FAU - Shalinsky, D R AU - Shalinsky DR FAU - Wellstein, A AU - Wellstein A FAU - Heyman, R A AU - Heyman RA LA - eng PT - Journal Article PT - Review PL - Netherlands TA - Breast Cancer Res Treat JT - Breast cancer research and treatment JID - 8111104 RN - 5688UTC01R (Tretinoin) SB - IM MH - Animals MH - Apoptosis/drug effects MH - Breast Neoplasms/drug therapy MH - Carcinoma, Squamous Cell/drug therapy MH - Cell Division/drug effects MH - HL-60 Cells/drug effects MH - Humans MH - Neoplasms/*drug therapy MH - Tretinoin/metabolism/pharmacology/*therapeutic use RF - 57 EDAT- 1996/01/01 00:00 MHDA- 1996/01/01 00:01 CRDT- 1996/01/01 00:00 PHST- 1996/01/01 00:00 [pubmed] PHST- 1996/01/01 00:01 [medline] PHST- 1996/01/01 00:00 [entrez] AID - 10.1007/BF01803787 [doi] PST - ppublish SO - Breast Cancer Res Treat. 1996;38(1):85-96. doi: 10.1007/BF01803787.