title: Apoptotic effect of Vibrio vulnificus cytolysin on A549 human lung adenocarcinoma             cells.
abstract: Vibrio vulnificus cytolysin (VVC) has a very strong cytotoxic effect on             various types of mammalian cells. However, the inhibitory effect of VVC on the             proliferation of human lung cancer cells has scarcely been reported. This study             aimed to analyze the effects of recombinant VVC (rVVC) on the A549 human lung             adenocarcinoma cell line and to investigate the underlying molecular mechanisms             governing these effects. This study showed that rVVC inhibited the proliferation             of A549 cells in a concentration- and time-dependent manner (as measured by the             MTT assay). rVVC failed to induce the release of intracellular lactate dehydrogenase             (LDH) from the target cells suggesting that osmotic lysis may not contribute to             its cytolysin-induced cytotoxicity. Treatment of A549 cells with an IC50 (concentration             of drug that inhibits cell growth by 50%) of rVVC resulted in morphological changes             and blebbing typical of apoptosis. Annexin-V FITC analysis by FCM indicated that             rVVC-induced apoptosis in A549 cells occurs in a dose-dependent manner. A DNA             fragmentation assay was utilized to investigate the apoptosis induced by rVVC.             The pro-apoptotic activity of rVVC was attributed to its ability to modulate,             in a concerted manner, the expression of Bcl-2 and Bax proteins, which were down-             and up-regulated, respectively. Caspase-9 and -3 were subsequently activated,             however caspase-8 was not. These results prove that rVVC effectively induces programmed             cell death and suggests that rVVC-induced apoptosis in the A549 cell line is mediated             by the regulation of Bcl-2 protein expression and the activation of caspase-9             and -3.
authors: Department of Pathology, Southern Medical University, Guangzhou, Guangdong 510515, PR China.
authors: Jiachun
authors: J
authors: Sun
authors: Jing
authors: J
authors: Zheng
authors: Guiming
authors: G
authors: Wang
authors: Yan
authors: Y
authors: Li
authors: Hong
authors: H
authors: Shen
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D000077192:Adenocarcinoma of Lung; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism; D054353:Perforin / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000633:toxicity; D041261:Vibrio vulnificus / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D051028:bcl-2-Associated X Protein; D054353:Perforin; D007770:L-Lactate Dehydrogenase; D053148:Caspase 3; D053453:Caspase 9