title: Involvement of c-jun N-terminal kinase in G2/M arrest and caspase-mediated apoptosis induced by cardiotoxin III (Naja naja atra) in K562 leukemia cells.
abstract: Cardiotoxin III (CTX III), a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom, may have a potentiality as a structural template for rational drug design in killing cancer cells. Treatment of K562 cells with 0.3 microM of CTX III resulted in G2/M phase cell cycle arrest that was associated with a marked decline in protein levels of G2/M regulatory proteins including cyclin A, cyclin B1, Cdk2 and Cdc25C. In contrast to no effect on the phosphorylation of ERK, p38 MAPK and Akt, an activation of JNK was noted when K562 cells were exposed to CTX III. CTX III-mediated G2/M phase arrest and apoptosis were reduced by treatment with the JNK-specific inhibitor SP600125, but not by ERK and p38MAPK inhibitors. Further investigation showed that the specific JNK inhibitor, SP600125, reduced the activation of caspase-3, caspase-9, and reversed the decline in the expression of cyclin B1. Taken together, our data show for the first time that JNK, but not ERK, p38MAPK or Akt signaling, plays an important role in CTX III-mediated G2/M arrest and apoptosis in K562 cancer cells.
authors: Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC.
authors: Sheng-Huei
authors: SH
authors: Yang
authors: Ching-Ming
authors: CM
authors: Chien
authors: Long-Sen
authors: LS
authors: Chang
authors: Shinne-Ren
authors: SR
authors: Lin
mesh_terms: D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D020169:Caspases / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects*; D004179:Cobra Cardiotoxin Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D004546:Elapid Venoms / Q000737:chemistry; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D016195:G2 Phase / Q000187:drug effects*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000502:physiology*; D020014:K562 Cells; D020935:MAP Kinase Signaling System / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; C534699:CCNB1 protein, human; D018797:Cell Cycle Proteins; D004179:Cobra Cardiotoxin Proteins; D019926:Cyclin B; D056744:Cyclin B1; D004546:Elapid Venoms; C082202:cardiotoxin III, Naja naja atra; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases