ABSTRACT
We investigated the effects of Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) on the proliferation and invasion of human cervical cancer cell lines, as well as the molecular pathways underlying these effects. MTT cell proliferation assays revealed a time- and concentration-dependent cytotoxic effect of PA-MSHA on HeLa cells but not H8 cells. Flow cytometry with propidium iodide and annexin-V-fluorescein isothiocyanate labeling (FITC) indicated that various concentrations of PA-MSHA could induce apoptosis and G2-M cell cycle arrest in HeLa cells. PA-MSHA also impaired the migration and invasion abilities of HeLa cells in Wound healing and Transwell invasion assays. Western blot results demonstrated that PA-MSHA reduced the expression of p-AKT, p-GSK3ß, BCL-2, Vimentin and ß-catenin, but increased the levels of PTEN, BAD, BAX and E-cadherin in HeLa cells. Importantly, PTEN siRNA induced the activity of p-AKT, while PA-MSHA partly inhibited this induction, indicating that PA-MSHA may reduce the cell proliferation and invasion potential by activating PTEN and thus inhibiting the AKT pathway in vitro. These data suggest the potential application of PA-MSHA to the treatment of human cervical cancer.
Subject(s)
Cell Proliferation/drug effects , Fimbriae Proteins/pharmacology , PTEN Phosphohydrolase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects , Uterine Cervical Neoplasms/drug therapy , Antigens, CD , Apoptosis/drug effects , Cadherins/metabolism , Cell Movement/drug effects , Female , Glycogen Synthase Kinase 3 beta/metabolism , HeLa Cells , Humans , Mannose , Neoplasm Invasiveness , PTEN Phosphohydrolase/genetics , Phosphorylation , Proto-Oncogene Proteins c-bcl-2/metabolism , Pseudomonas aeruginosa/chemistry , RNA Interference , RNA, Small Interfering/genetics , Recombinant Proteins/pharmacology , Uterine Cervical Neoplasms/pathology , Vimentin/metabolism , bcl-2-Associated X Protein/metabolism , bcl-Associated Death Protein/metabolism , beta Catenin/metabolismABSTRACT
The pathogenesis of chronic schistosomiasis is caused by irritation of the schistosome eggs trapped in liver that induce delayed hypersensitive reactions from the surrounding tissues, leading to the formation of inflammatory granuloma and subsequent fibrosis. A Schistosoma japonicum (S. japonicum) single-chain fragment variable (SjscFv) which specifically binds to the S. japonicum soluble immature egg antigen (SIEA) can be used as a target to deliver specific cytokine towards the site of hepatic fibrosis. To test this hypothesis, a novel recombinant plasmid, pVAX1/SjscFv-IL18, was constructed by fusing SjscFv to IL-18 gene with a 45bp glycine-rich linker. Furthermore, experiments on mice showed that pVAX1/SjscFv-IL18 could effectively express IL-18 in the liver and in serum. Hepatic contents of IL-2 and IFN-γ (Th1-type) in S. japonicum-infected mice vaccinated with pVAX1/SjscFv-IL18 increased significantly but those of their IL-4 and IL-10 (Th2-type) decreased as compared to the analyzed results of 4 cytokines in the liver cells of control mice vccinated with pVAX1/IL18. Consistent with the levels of Th1 and Th2 cytokines, mice vaccinated with pVAX1/SjscFv-IL18 developed much less hepatic fibrosis 20weeks after infection, which was evaluated by average volumn of granuloma and collagen contents. These data suggested that the linkage of IL-18 to the target-specific SjscFv molecule appears to be a potentially promising trial route of therapy, the hepatic fibrosis in S. japonicum-infected mice may be ameliorated through effective expression of IL18 in liver.
