ABSTRACT
Objective:To observe the localization of chicken infectious anemia virus VP3 gene in normal cells and breast cancer cells in different times and its apoptosis-inducing effect.Methods: The fundamental cloning method,inserting the VP3 gene of chicken anemia virus into the eukaryotic expression vector pEGFP-C1 was used.Then,the positive recombinant containing VP3 gene pEGFP-C1-VP3 was transfected into human breast cancer cell line MCF-7 and mouse fibroblasts L929 by FuGENE(R)6 transfection reagent in vitro respectively.After 24 hours,48 hours and 72 hours,fluorescence microscope was used to observe the distribution of VP3 in cells and the rate of apoptosis was studied on the treated MCF-7 cells by FCM(Flow Cytometry).Results: The recombinant plasmid pEGFP-C1-VP3 could be localized in the nuclei of breast cancer cells,which showed the typical nuclear changes in different stages of apoptosis.In L929 cells,pEGFP-C1-VP3 underwent a process of migration from the nucleus to the cytoplasm,which didn′t induce apoptosis of L929 cells.Conclusion: VP3 located in the nucleus of MCF-7 breast cancer cells,which can led to cancer cell death by inducing apoptosis,and the apoptosis rate was higher than the control group with time dependence.VP3 located in the cytoplasm of normal cells,and didn′t induce apoptosis.
ABSTRACT
In the present study recombinant VP3 (rVP3) was expressed in E.coli BL21 (DE3) (pLysS) and its polyclonal antibodies were characterized. SDS–PAGE analysis revealed that the expression of recombinant protein was maximum when induced with 1.5 mM IPTG for 6 h at 37ºC. The 6×His-tagged fusion protein was purified on Ni-NTA and confirmed by Western blot using CAV specific antiserum. Rabbits were immunized with purified rVP3 to raise anti-VP3 polyclonal antibodies. Polyclonal serum was tested for specificity and used for confirming expression of VP3 in HeLa cells transfected with pcDNA.cav.vp3 by indirect fluorescent antibody test (IFAT), flow cytometry and Western blot. Available purified rVP3 and polyclonal antibodies against VP3 may be useful to understand its functions which may lead to application of VP3 in cancer therapeutics.
ABSTRACT
Objective: To investigate the inhibitory effect of eukaryotic expression vector (attenuated salmonella typhimurium) carrying tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and Chicken anemia virus VP3 gene on gastric cancer cells in vitro and in vivo. Methods: The cloning vectors pBud-TRAIL, pBud-VP3, and pBud-TRAIL-VP3 were transformed into attenuated Salmonella typhimurium by electric transformation technique. The S. typhimurium-based carriers were then transfected into gastric cancer cells, line SGC-7901 after stability assay. The expression of fusion green fluorescent protein was examined using fluorescent microscopy after 24 h. MTT assay was used to examine the inhibition of cell growth. Flow cytometry was used to detect cycle distribution and apoptosis rates of cells. The expression of caspase-3 and caspase-9 was assayed by immunohistochemistry method. Salmonella typhimurium carrying recombinant plasmid was administrated orally in sarcoma-bearing mice; 8 weeks later RT-PCR was used to detect the expression of cloning vectors in tumor tissue. Meanwhile, the sizes of tumors were also determined. Results: The recombinant plasmids were stably transformed into attenuated Salmonella typhimurium, and the plasmids was satisfactorily expressed in gastric cancer cells via attenuated Salmonella typhimurium. TRAIL and VP3 inhibited the proliferation of gastric cancer cells after 48 h. Flow cytometry analysis showed that the pBud-TRAIL-VP3 obviously enhanced apoptosis rates of gastric cancer cells. TRAIL and VP3 jointly increased the expression of caspase-3 and caspase-9. In vivo study showed that TRAIL and VP3 genes were expressed in tumor tissue and could inhibit the tumor growth(P<0.05). Conclusion: Attenuated Salmonella typhimurium-mediated TRAIL and VP3 transfection of gastric cancer cells can inhibit cell growth in vitro and in vivo. The joint effect of TRAIL and VP3 is correlated with the increase of caspase-3 and caspase-9 expression.
ABSTRACT
Summary: Receptor mediated gene delivery is a new gene transfer strategy. Asialoglycoprotein receptor (ASGP-R), the receptor of asialoorosomucoid (Asor), is specially expressed on the surface of hepatocyte. In this paper, the nuclide 131I was combined with Asor to form a kind of soluble nuclide-protein complex, which can be specifically endocytosed into hepatocyte by ASGP-R. After intravenous injection of the complex into experimental animals, the deposition of Asor in vivo and the targeting quality of hepatocyte was detected by ECT. This research testified the feasibility of targeting Asor complex delivery to hepatocyte mediated by ASGP-R in vivo, and provided foundation for the genetic diagnosis and gene therapy of hepatic cell-related diseases.