title: Natural withanolide withaferin A induces apoptosis in uveal melanoma cells by suppression of Akt and c-MET activation.
abstract: Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. While effective therapy exists for the primary tumor, there is a lack of effective treatment for metastatic disease currently. Natural withanolide withaferin A (WA) has shown efficacy in cancers demonstrating upregulation of pro-survival pathways. The purpose of the present study is to investigate the effect of WA as a potential therapeutic agent for UM in vitro as well as in vivo. UM cells were treated with WA and several cell-based assays, such as MTS, trypan blue exclusion assay, clonogenic, wound healing, cell cycle shift, annexin V/propidium iodide, and Western blot, were performed. In vivo experiments utilized the 92.1 cells in a xenograft murine model. WA inhibits cell proliferation of uveal melanoma cells with an IC50 of 0.90, 1.66, and 2.42 μM for OMM2.3, 92.1, and MEL290 cells, respectively. Flow cytometry analysis demonstrates G2/M cell cycle arrest and apoptosis at 1 μM WA in treated cells. WA induced apoptosis partly through the suppression of c-Met, Akt, and Raf-1 signaling activation. In vivo studies using WA reduced tumor growth in 100% of animals (p = 0.015). Our observation indicates that WA is a potent drug that inhibits cell proliferation, shifts cell cycle arrest, and induces apoptosis in multiple UM cell lines in vitro. WA-mediated apoptosis in UM cells is partly mediated though the suppression of c-Met and Akt activation. WA significantly decreases UM tumor growth in vivo and justifies further evaluation of this drug for the treatment of metastatic uveal melanoma.
authors.affiliation: Department of Surgery, University of Kansas Medical Center, Kansas City, KS, USA. asamadi@kumc.edu
authors.forename: Abbas K
authors.initials: AK
authors.lastname: Samadi
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Cohen
authors.forename: Ridhwi
authors.initials: R
authors.lastname: Mukerji
authors.forename: Vamsee
authors.initials: V
authors.lastname: Chaguturu
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Barbara N
authors.initials: BN
authors.lastname: Timmermann
authors.forename: Mark S
authors.initials: MS
authors.lastname: Cohen
authors.forename: Erica A
authors.initials: EA
authors.lastname: Person
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006801:Humans; D020128:Inhibitory Concentration 50; D008545:Melanoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D016513:Mice, SCID; D015394:Molecular Structure; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism*; D013997:Time Factors; D047368:Tumor Burden / Q000187:drug effects; D014604:Uveal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D054358:Withanolides / Q000737:chemistry / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
chemical_list: D054358:Withanolides; D019859:Proto-Oncogene Proteins c-met; D051057:Proto-Oncogene Proteins c-akt; D053148:Caspase 3; C009684:withaferin A