title: 2-D gel electrophoresis-based proteomic analysis reveals that ormeloxifen induces G0-G1 growth arrest and ERK-mediated apoptosis in chronic myeloid leukemia cells K562.
abstract: Ormeloxifen is a nonsteroidal selective estrogen receptor modulator (SERM) and has been shown to possess anticancer activities in breast and uterine cancer. Here, we show that ormeloxifen induces apoptosis in dose-dependent manner in a variety of leukemia cells, more strikingly in K562. 2-DE-gel electrophoresis of K562 cells induced with ormeloxifen showed that 57 and 30% of proteins belong to apoptosis and cell-cycle pathways, respectively. Our data demonstrate that ormeloxifen-induced apoptosis in K562 cells involves activation of extracellular signal-regulated kinases (ERKs) and subsequent cytochrome c release, leading to mitochondria-mediated caspase-3 activation. Ormeloxifen-induced apoptosis via ERK activation was drastically inhibited by prior treatment of K562 cells with ERK inhibitor PD98059. Ormeloxifen also inhibits proliferation of K562 cells by blocking them in G0-G1 phase by inhibiting c-myc promoter via ormeloxifen-induced MBP-1 (c-myc promoter-binding protein) and upregulation of p21 expression. We further show that ormeloxifen-induced apoptosis in K562 is translatable to mononuclear cells isolated from chronic myeloid leukemia (CML) patients. Thus, ormeloxifen induces apoptosis in K562 cells via phosphorylation of ERK and arrests them in G0-G1 phase by reciprocal regulation of p21 and c-myc. Therefore, inclusion of ormeloxifen in the therapy of chronic myeloid leukemia can be of potential utility.
authors.affiliation: Drug Target Discovery and Development Division, Central Drug Research Institute, CDRI (CSIR), Lucknow, Uttar Pradesh, India.
authors.forename: Pooja
authors.initials: P
authors.lastname: Pal
authors.forename: Jitendra K
authors.initials: JK
authors.lastname: Kanaujiya
authors.forename: Savita
authors.initials: S
authors.lastname: Lochab
authors.forename: Shashi B
authors.initials: SB
authors.lastname: Tripathi
authors.forename: Madan L B
authors.initials: ML
authors.lastname: Bhatt
authors.forename: Pradhyumna K
authors.initials: PK
authors.lastname: Singh
authors.forename: Sabyasachi
authors.initials: S
authors.lastname: Sanyal
authors.forename: Arun K
authors.initials: AK
authors.lastname: Trivedi
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001578:Benzopyrans / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000096:biosynthesis / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005419:Flavonoids / Q000378:metabolism / Q000494:pharmacology; D016193:G1 Phase / Q000187:drug effects*; D006801:Humans; D020287:In Situ Nick-End Labeling; D020014:K562 Cells; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D013058:Mass Spectrometry; D008928:Mitochondria / Q000378:metabolism; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000187:drug effects; D040901:Proteomics; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000187:drug effects*
chemical_list: D001578:Benzopyrans; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; C088830:DENND4A protein, human; D004268:DNA-Binding Proteins; D005419:Flavonoids; C489427:MYC protein, human; D016271:Proto-Oncogene Proteins c-myc; C508548:ormeloxifene; D048049:Extracellular Signal-Regulated MAP Kinases; D053148:Caspase 3; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one