Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In multiple myeloma (MM), the interaction between myeloma cells and bone marrow microenvironment has an important role in the pathogenesis of MM. We first examined the inducing effect of myeloma cells on migration of human umbilical vein vascular endothelial cells (HUVECs). Five myeloma cell lines produced varying amounts of VEGF, and migration of HUVECs was induced by coculture with myeloma cells. We next examined the inhibitory effect of a novel synthetic retinoid Am80 (Tamibarotene) on both myeloma cells and HUVECs. Am80 is specific for the retinoic-acid receptor-alpha/beta, and has therapeutic effects in all-trans retinoic acid resistant acute promyelocytic leukemia. Am80 slightly inhibited the growth of both myeloma cells and HUVECs, and remarkably inhibited the growth of HUVECs stimulated by VEGF. Am80 showed little growth inhibition of bone marrow stromal cells (BMSCs), but it markedly inhibited migration of HUVECs by cocultured myeloma cells. Am80 inhibited VEGF-induced phosphorylation of VEGF receptor. In addition, VEGF-induced formation of tube-like structures in vitro and neovascularization in mouse corneas were significantly inhibited by Am80. These findings clearly demonstrate that Am80 is a potential inhibitor of angiogenesis caused by the interaction between vascular endothelial cells and myeloma cells, and might be a useful therapeutic agent against MM.
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PMID:Antimyeloma effects of a novel synthetic retinoid Am80 (Tamibarotene) through inhibition of angiogenesis. 1584 26

Tamibarotene is a new synthetic retinoid drug recently approved for relapsed or refractory acute promyelocytic leukemia (APL) in Japan. It is a specific agonist for retinoic acid receptor alpha/beta. Compared to all-trans retinoic acid (ATRA), a natural retinoid indicated for a first-line treatment of APL, tamibarotene is chemically more stable and several times more potent as an inducer of differentiation in promyelocytic leukemia cells. In contrast to ATRA, whose plasma concentration declines considerably during daily administration, tamibarotene sustains plasma level probably due to a lower affinity for cellular retinoic acid binding protein. Furthermore, adverse side effects were milder than those of ATRA in clinical trials. Clinical trials held in Japan showed that tamibarotene had efficacy in APL patients who had relapsed from ATRA-induced complete remission. Recently, better understanding of the various mechanisms of action of retinoids has stimulated great interest in its potential use for treatment of various diseases. Tamibarotene is being investigated for treatment of multiple myeloma and Crohn's disease in clinical trials. This review focuses on tamibarotene's mechanisms of action, chemical properties, pharmacokinetics and its use in APL as well as its potential use in various disorders.
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PMID:Tamibarotene. 1792 87

Tamibarotene (TM411) is a synthetic retinoic acid receptor-alpha/-beta selective retinoid that is chemically more stable than all-trans retinoic acid. This study was designed to evaluate the activity of TM411 in multiple myeloma (MM) and the effects of TM411 combined with a glucocorticoid (GC). In vitro, five human myeloma cells were treated with TM411 alone, GC alone, or TM411 + GC. Cell survival was analyzed by the tetrazolium dye assay and the Hoechst 33342/propidium iodide double-staining method. The effect of TM411 + GC was assessed by the isobologram method. In vivo, the growth-inhibitory effects of the drugs on RPMI-8226 cell xenografts established in SCID mice were examined. The effects of the agents on IL-6-mediated signaling pathways were also analyzed by Western blotting. TM411 was 2- to 10-fold more potent, in terms of its growth-inhibitory effect, than all-trans retinoic acid. The combination of TM411 and GC was found to show a markedly synergistic interaction. While increased expressions of the IL-6 receptor, phosphorylated MAPK, and Akt were observed after exposure to GC, TM411 attenuated this increase in the expressions, suggesting that such modification of the effect of GC by TM411 might be the possible mechanism underlying the synergistic interaction. Furthermore, TM411 + GC showed a supra-additive inhibitory effect in a xenograft model as compared with TM411 or GC alone. These results imply that the combination of TM411 + GC might be highly effective against MM, and suggest the need for clinical evaluation of TM411 + GC for the treatment of MM.
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PMID:Synergistic interactions between the synthetic retinoid tamibarotene and glucocorticoids in human myeloma cells. 1951 22