title: Effect of betulinic acid on the regulation of Hiwi and cyclin B1 in human gastric adenocarcinoma AGS cells.
abstract: OBJECTIVE
  To investigate the effect of betulinic acid (BA) on the proliferation, apoptosis and cell cycle of gastric adenocarcinoma cell AGS in vitro and the underlying mechanism.
  
  
  METHODS
  The effect of BA on the proliferation of AGS cells was measured by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. Apoptosis was analyzed by using Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double-labeled flow cytometry (FCM) and Hoechst 33258 staining. The influence of BA on cell cycle of AGS cells was tested by PI staining. Both FCM and reverse transcription-PCR (RT-PCR) technologies were applied to detect the expression of Hiwi and Cyclin B1.
  
  
  RESULTS
  BA exhibited significant cell proliferation inhibition, as well as its potency of inducing apoptosis in AGS cells in vitro in a time- and dose-dependent manner. The IC(50) value for 24 h was 18.25 microg/mL (95% confidence interval: 15.16 to 27.31 microg/mL). Cells treated with BA showed increased cell population in G(2)/M phase, with decreased S phase population. The expression of Hiwi and Cyclin B1 was down-regulated in BA-treated AGS cells in a dose-dependent manner.
  
  
  CONCLUSIONS
  BA exerted potent effect on growth inhibition, G(2)/M cell cycle arrest and induction of apoptosis in AGS cells in vitro, possibly associated with the down-regulation of Hiwi and its downstream target Cyclin B1 expression. The potent antitumor capacity of BA suggested that it could be a promising new experimental anticancer agent in human gastric adenocarcinoma treatment.
authors.affiliation: Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Li-jing
authors.initials: LJ
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Qi
authors.initials: Q
authors.lastname: Ma
authors.forename: Jun
authors.initials: J
authors.lastname: Fang
authors.forename: Jing
authors.initials: J
authors.lastname: He
authors.forename: Yi-quan
authors.initials: YQ
authors.lastname: Cheng
authors.forename: Qiu-ling
authors.initials: QL
authors.lastname: Wu
mesh_terms: D000230:Adenocarcinoma; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D060565:Argonaute Proteins; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D056744:Cyclin B1 / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D005434:Flow Cytometry; D006801:Humans; D020128:Inhibitory Concentration 50; D053978:Pentacyclic Triterpenes; D011506:Proteins / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000378:metabolism; D013997:Time Factors; D014315:Triterpenes / Q000008:administration & dosage / Q000494:pharmacology*; D000094062:Betulinic Acid
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D060565:Argonaute Proteins; D056744:Cyclin B1; C421088:PIWIL1 protein, human; D053978:Pentacyclic Triterpenes; D011506:Proteins; D014315:Triterpenes; D000094062:Betulinic Acid