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Anticancer Agents Med Chem. 2014 Nov 30. | Recent Developments Towards Podophyllotoxin Congeners as Potential Apoptosis Inducers.[Pubmed: 25469512] | Podophyllotoxin, a lignan extracted from rhizomes of Podophyllum species, is a well established lead in the development of new chemical agents for the treatment of cancer. Its semi-synthetic variant, etoposide is an anticancer drug which inhibits DNA topoisomerase II causing cell cycle arrest in the S the phase. Its clinical success and intriguing mode of action made it a much sought after skeleton for the development of better antitumor agents. Modifications were made at several positions of its skeleton with the aim to either improve its potency or to overcome drug resistance. In recent years, the structurally modified podophyllotoxins have been investigated for their apoptosis inducing ability. Although numerous reviews emphasized the occurrence, synthesis and applications of podophyllotoxins, the recent progress towards development of structurally modified podophyllotoxins possessing apoptosis inducing ability has not been previously reviewed. CONCLUSIONS: Therefore the present review focuses on the studies carried out in the design and synthesis of new podophyllotoxin derivatives and their evaluation as apoptosis inducers. | Exp Ther Med. 2014 May;7(5):1317-1322. Epub 2014 Mar 6. | Apoptosis of human gastric cancer SGC-7901 cells induced by podophyllotoxin.[Pubmed: 24940431] | Numerous studies have demonstrated that podophyllotoxin and its derivatives exhibit antitumor effects. The aim of the present study was to investigate SGC-7901 cell apoptosis and the underlying mechanism induced by podophyllotoxin. SGC-7901 cells were treated with varying concentrations of podophyllotoxin. METHODS AND RESULTS: MTT assays and flow cytometry were used to evaluate the effects of podophyllotoxin on the proliferation and apoptosis of SGC-7901 cells, while fluorescence inverted microscopy was used to observe the morphology of SGC-7901 cells that had been dyed with Hoechst 33258. In addition, laser scanning confocal microscopy was used to analyze the mitochondrial membrane potential (MMP) of SGC-7901 cells dyed with Rhodamine 123. Western blotting was performed to analyze the expression levels of cytochrome c (cyt-c), caspase-9 and caspase-3 in the SGC-7901 cells. The results indicated that podophyllotoxin was capable of inhibiting growth and inducing the apoptosis of SGC-7901 cells in a dose-dependent manner, causing cell cycle arrest at the G2/M phase. After 48 h of treatment, the apoptotic morphology of SGC-7901 cells was clear, exhibiting cell protuberance, concentrated cytoplasms and apoptotic bodies. Following 24 h of treatment, the MMP of the SGC-7901 cells decreased. In addition, after 48 h, the expression of cyt-c was shown to be upregulated, while the expression levels of pro-caspase-9 and pro-caspase-3 in the SGC-7901 cells were shown to be downregulated. CONCLUSIONS: In conclusion, apoptosis can be induced in SGC-7901 cells by podophyllotoxin, potentially via a mitochondrial pathway, indicating that podophyllotoxin may be a potent agent for cancer treatment. |
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