Mechanisms of cardiotoxin lll-induced apoptosis in human colorectal cancer colo205 cells.
Cardiotoxin III (CTX III) is a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom. This is the first report on the mechanism of the anticancer effect of CTX III in human colorectal cancer Colo205 cells. 2. Cardiotoxin III-induced Colo205 cell apoptosis was confirmed by DNA fragmentation (DNA ladder and sub-G1 formation) with an IC(50) of 4 mg/mL at 48 h. 3. Further mechanistic analysis demonstrate that CTX III induced the loss of mitochondrial membrane potential (Dym), cytochrome c release from mitochondria into the cytosol and activation of capase-9, caspase 3, as well as markedly enhancing the expression of Bax, but not Bcl-2, protein in the cells. Moreover, the CTX III-induced apoptosis was significantly blocked by the broad-spectrum caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone. 4. However, CTX III did not generate the formation of reactive oxygen species and anti-oxidants, including N-acetylcysteine, and catalase could not block CTX III-induced apoptosis in the Colo205 cells. 5. Taken together, these results suggest that CTX III may induce apoptosis through a mitochondrial- and caspase-dependent mechanism and alteration of Bax/Bcl-2 ratio in human colorectal Colo205 cancer cells.
Tsai
Chia-Houng
CH
Faculty of Medicinal and Applied Chemistry, Graduate Institute of Natural Products and Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC.
Yang
Sheng-Huei
SH
Chien
Ching-Ming
CM
Lu
Mei-Chin
MC
Lo
Chao-Sheng
CS
Lin
Yi-Hsiung
YH
Hu
Xiu-Wei
XW
Lin
Shinne-Ren
SR
D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000502:physiology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004179:Cobra Cardiotoxin Proteins / Q000494:pharmacology*; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D045304:Cytochromes c / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology; D053938:DNA Fragmentation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D006801:Humans; D008928:Mitochondria / Q000201:enzymology; D017382:Reactive Oxygen Species / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D051028:bcl-2-Associated X Protein / Q000096:biosynthesis
D000970:Antineoplastic Agents; D000975:Antioxidants; D061945:Caspase Inhibitors; D004179:Cobra Cardiotoxin Proteins; D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; C082202:cardiotoxin III, Naja naja atra; D045304:Cytochromes c; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases