title: Effects of cardiotoxin III on expression of genes and proteins related to G2/M arrest and apoptosis in K562 cells.
abstract: Cardiotoxin III (CTX III) is a basic polypeptide of 60-amino acid residues isolated from Naja naja atra venom, exerts its anti-proliferative activity in human leukemia K562 cells. In the present study, the expression of mRNAs and proteins related to cell cycle and apoptosis in human leukemia K562 cells induced by CTX III was investigated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Flow cytometric analysis revealed that CTX III resulted in G2/M phase arrest in the cell cycle progression, which was associated with a marked decrease in the mRNA and protein expressions of cyclin A, cyclin B1, and Cdk 2, with no detectable changes in the levels of Cdk 1, cyclin D1, and cyclin E. Moreover, the increase in apoptosis was associated with the Bax gene and protein levels significantly increased as treatment durations of CTX III increased, while the Bcl-2 mRNA and protein levels exhibited no changes. We also observed that caspase-9 and caspase-3 genes remained unchanged up to 12 h with 2 microg/ml CTX III. These molecular alterations provide an insight into CTX III-caused growth inhibition, G2/M arrest, and apoptotic death of K562 cells.
authors.affiliation: Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan 807, ROC.
authors.forename: Sheng-Huei
authors.initials: SH
authors.lastname: Yang
authors.forename: Chien-Hsun
authors.initials: CH
authors.lastname: Tsai
authors.forename: Mei-Chin
authors.initials: MC
authors.lastname: Lu
authors.forename: Yung-Ning
authors.initials: YN
authors.lastname: Yang
authors.forename: Ching-Ming
authors.initials: CM
authors.lastname: Chien
authors.forename: Sheng-Fung
authors.initials: SF
authors.lastname: Lin
authors.forename: Shinne-Ren
authors.initials: SR
authors.lastname: Lin
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects* / Q000235:genetics; D004179:Cobra Cardiotoxin Proteins / Q000494:pharmacology*; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism; D016213:Cyclins / Q000235:genetics / Q000378:metabolism; D016195:G2 Phase / Q000187:drug effects* / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D020014:K562 Cells; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D004179:Cobra Cardiotoxin Proteins; D016213:Cyclins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; C082202:cardiotoxin III, Naja naja atra; D018844:Cyclin-Dependent Kinases; D053148:Caspase 3; D053453:Caspase 9