Effects of cardiotoxin III on expression of genes and proteins related to G2/M arrest and apoptosis in K562 cells.
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.
Yang
Sheng-Huei
SH
Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan 807, ROC.
Tsai
Chien-Hsun
CH
Lu
Mei-Chin
MC
Yang
Yung-Ning
YN
Chien
Ching-Ming
CM
Lin
Sheng-Fung
SF
Lin
Shinne-Ren
SR
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
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