Andrographolide enhances 5-fluorouracil-induced apoptosis via caspase-8-dependent mitochondrial pathway involving p53 participation in hepatocellular carcinoma (SMMC-7721) cells.
Despite recent significant advances in the treatment of human carcinoma (HCC), the results of chemotherapy to date remain unsatisfactory. 5-Fluorouracil (5-FU) still represents the cornerstone of treatment of carcinoma, and resistance to the actions of 5-FU is a major obstacle to successful chemotherapy. More effective treatment strategies may involve combinations of agents with activity against HCC. Andrographolide (ANDRO), a natural bicyclic diterpenoid lactone isolated from Andrographis paniculata, has been shown to suppress the growth of HCC cells and trigger apoptosis in vitro. To assess the suitability of ANDRO as a chemotherapeutic agent in HCC, its cytotoxic effects have been evaluated both as a single agent and in combination with 5-FU. ANDRO potentiates the cytotoxic effect of 5-FU in HCC cell line SMMC-7721 through apoptosis. ANDRO alone induces SMMC-7721 apoptosis with p53 expression, Bax conformation and caspase-3,8,9 activation. Surprisingly, the addition of ANDRO to 5-FU induces synergistic apoptosis, which could be corroborated to the increased caspase-8, p53 activity and the significant changes of Bax conformation in these cells, resulting in increased losses of mitochondrial membrane potential, increased release of cytochrome c, and activation of caspase-9 and caspase-3. Suppression of caspase-8 with the specific inhibitor z-IETD-fmk abrogates largely ANDRO/5-FU biological activity by preventing mitochondrial membrane potential disappearance, caspase-3,9 activation and subsequent apoptosis. The results suggest that ANDRO may be effective in combination with 5-FU for the treatment of HCC cells SMMC-7721.
Yang
Lu
L
Zhejiang University, College of Life Sciences, Research Center of Siyuan Natural Pharmacy and Biotoxicology, Zijinggang Campus, Hangzhou, PR China.
Wu
Dingfang
D
Luo
Kewang
K
Wu
Shihua
S
Wu
Ping
P
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000473:pathology; D053181:Caspase 8 / Q000502:physiology*; D053453:Caspase 9 / Q000502:physiology; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000502:physiology; D004224:Diterpenes / Q000494:pharmacology*; D004357:Drug Synergism; D005472:Fluorouracil / Q000494:pharmacology*; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*; D051028:bcl-2-Associated X Protein / Q000737:chemistry
D000970:Antineoplastic Agents; D004224:Diterpenes; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; C030419:andrographolide; D045304:Cytochromes c; D053181:Caspase 8; D053453:Caspase 9; D005472:Fluorouracil