title: Cell cycle arrest induced by the vitamin D(3) analog EB1089 in NCI-H929 myeloma cells is associated with induction of the cyclin-dependent kinase inhibitor p27.
abstract: EB1089, a 1,25-dihydroxyvitamin D(3) analog, has been known to have potent antiproliferative properties in a variety of malignant cells in vitro and in vivo. In the present study, we analyzed the effect of EB1089 on human myeloma cell lines. EB1089 inhibited the proliferation of NCI-H929 cells and RPMI8226 cells in a dose-dependent manner among three myeloma cell lines tested. The antiproliferative effect of EB1089 on myeloma cells was related to the expression level of vitamin D receptor. To investigate the mechanism of the antiproliferative effect of EB1089, cell cycle analysis was attempted in EB1089-sensitive NCI-H929 cells. EB1089 (1 x 10(-8) M) efficiently induced G(1) arrest of the cell cycle. Analysis of G(1) regulatory proteins demonstrated that protein levels of CDK2, CDK4, cyclin D1, and cyclin A were decreased in a time-dependent manner, but not those of CDK6 and cyclin E, by EB1089. In addition, EB1089 (1 x 10(-8) M, 72 h) increased the protein level of the CDKI p27 and markedly enhanced the binding of p27 with CDK2 compared to EB1089-untreated cells. Furthermore, the activity of CDK2-associated cyclin kinase was decreased, which was accompanied by the reduction of cyclin-D1-, cyclin-E-, and cyclin-A-associated kinase activities, resulting in the hypophosphorylation of Rb protein. These results suggest that EB1089 can inhibit the proliferation of human myeloma cells, especially NCI-H929 cells, via a G(1) block in association with the induction of p27 and the reduction of CDK2 activity.
authors.affiliation: Cancer Research Center and Department of Internal Medicine, Seoul National University College of Medicine, Seoul, 110-799, Korea.
authors.forename: W H
authors.initials: WH
authors.lastname: Park
authors.forename: J G
authors.initials: JG
authors.lastname: Seol
authors.forename: E S
authors.initials: ES
authors.lastname: Kim
authors.forename: C W
authors.initials: CW
authors.lastname: Jung
authors.forename: C C
authors.initials: CC
authors.lastname: Lee
authors.forename: L
authors.initials: L
authors.lastname: Binderup
authors.forename: H P
authors.initials: HP
authors.lastname: Koeffler
authors.forename: B K
authors.initials: BK
authors.lastname: Kim
authors.forename: Y Y
authors.initials: YY
authors.lastname: Lee
mesh_terms: D000970:Antineoplastic Agents / Q000633:toxicity*; D042846:CDC2-CDC28 Kinases; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000633:toxicity; D002453:Cell Cycle / Q000187:drug effects*; D018797:Cell Cycle Proteins; D002455:Cell Division / Q000187:drug effects; D019925:Cyclin A / Q000378:metabolism; D019938:Cyclin D1 / Q000378:metabolism; D019927:Cyclin E / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016193:G1 Phase; D006801:Humans; D007700:Kinetics; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000378:metabolism; D009101:Multiple Myeloma; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D018167:Receptors, Calcitriol / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
chemical_list: D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D019925:Cyclin A; D019927:Cyclin E; D008869:Microtubule-Associated Proteins; D011518:Proto-Oncogene Proteins; D018167:Receptors, Calcitriol; D025521:Tumor Suppressor Proteins; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27; D011494:Protein Kinases; C102333:histone H1 kinase; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; C495900:CDK4 protein, human; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases; D002117:Calcitriol; C078903:seocalcitol