title: Cyclin-dependent kinase inhibitor roscovitine induces cell cycle arrest and apoptosis in rabbit retinal pigment epithelial cells.
abstract: OBJECTIVE
  Cyclin-dependent kinases (CDKs) play essential roles in the intracellular control of the cell cycle. It has been postulated that roscovitine, a potent CDK2, CDK5, and CDC2 inhibitor, might inhibit cellular proliferation by arresting the cell cycle. This in vitro study investigated the antiproliferative and apoptotic effects of roscovitine in cultured rabbit retinal pigment epithelial (RPE) cells.
  
  
  METHODS
  Experiments using rabbit RPE from young pigmented rabbits were carried out using roscovitine dissolved in dimethylsulfoxide at concentrations ranging from 1 to 100 micromol. Cell proliferation was measured by an MTT assay. The cell cycle response of RPE cells to roscovitine was analyzed by flow cytometry of propidium iodide-stained nuclei. Proteins related to DNA damage in the RPE cells were then assayed by Western blot.
  
  
  RESULTS
  Roscovitine inhibited proliferation of RPE cells in a dose-dependent manner. Cell cycle analysis after treatment demonstrated an accumulation of cells arrested in the S- and G2/M phases. Flow cytometry showed that 40 microM of roscovitine increased the cell population in the sub-G1 peak, which is considered a marker of cell death by apoptosis. Western blot analysis revealed Bcl-2 decreased and Bax increased after treatment of RPE cells with roscovitine.
  
  
  CONCLUSIONS
  This study of the response of RPE cells to roscovitine demonstrated a bidirectional relationship between cell cycle control and apoptosis.
authors: Department of Ophthalmology, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Kaohsiung Hsien, Taiwan.
authors: Pei-Chang
authors: PC
authors: Wu
authors: Ming-Hong
authors: MH
authors: Tai
authors: Dan-Ning
authors: DN
authors: Hu
authors: Chien-Hsiung
authors: CH
authors: Lai
authors: Yi-Hao
authors: YH
authors: Chen
authors: Yi-Chen
authors: YC
authors: Wu
authors: Chia-Ling
authors: CL
authors: Tsai
authors: Shyi-Jang
authors: SJ
authors: Shin
authors: Hsi-Kung
authors: HK
authors: Kuo
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D004847:Epithelial Cells / Q000187:drug effects*; D005434:Flow Cytometry; D006131:Growth Inhibitors / Q000494:pharmacology*; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D011687:Purines / Q000494:pharmacology*; D011817:Rabbits; D000077546:Roscovitine; D051028:bcl-2-Associated X Protein / Q000096:biosynthesis
chemical_list: D006131:Growth Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D011687:Purines; D051028:bcl-2-Associated X Protein; D000077546:Roscovitine; D004247:DNA; D018844:Cyclin-Dependent Kinases