To obtain an anti-tumor peptide of Tumstatin and detect its biological activity,the nucleotide sequence encoding 185-203 amino acids(19peptide)of Tumstatin was synthesized and inserted into the fusion protein vector p...To obtain an anti-tumor peptide of Tumstatin and detect its biological activity,the nucleotide sequence encoding 185-203 amino acids(19peptide)of Tumstatin was synthesized and inserted into the fusion protein vector pTYB2.After identification by sequencing and restriction endonucle-ases,the recombined vector was transformed into BL-21(DE3)E.coli competent cells.Transformed E.coli BL-21(DE3)were induced by isopropyl-β-thiogalactopyranoside(IPTG),and then expressed.By 1,4-dithiothreitol(DTT)reduction,the soluble 19peptide was obtained from a chitin affinity chromatograph.The biological activity of 19peptide was determined by 3-[4,5-dimethylthiazol-2-y1]-2,5-dipheny-tetrazolium bromide(MTT)assay,cell growth curve,the effect of the ascitic fluid transfevent H22 hepatoma on mice and via histopathological slices.The purified 19peptide directly inhibited proliferation and migration of murine B16 melanoma cells,SMMC-7721hepatoma carcinoma cells and human umbilical vein endothelial cells(HUVEC).The tumor inhibition rate of mice ascitic fluid transfevent H22 hepatoma was 48.46%.Histopathological slices showed that it could promote tumor tissue necrosis and decrease the density of blood vessels.With higher anti-tumor activity,19peptide has the potential to become a novel,potent anti-tumor agent.展开更多
AIM: There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU).Therefore the objective of this study was to determine the combined effects of adenovirus-med...AIM: There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU).Therefore the objective of this study was to determine the combined effects of adenovirus-mediated wild-type (wt) p53 gene transfer and 5-FU chemotherapy on pancreatic cancer cells with different p53 gene status.METHODS: Human pancreatic cancer cell lines Capan-1^p53mut,Capan-2^p53wt, FAMPAC^p53mut, PANG1^p53mut, and rat pancreatic cancer cell lines AS^p53wt and DSL6A^p53null were used for in vitro studies. Following infection with different ratios of Adp53-particles (MOI) in combination with 5-FU, proliferation of tumor cells and apoptosis were quantified by cell proliferation assay (WST-1) and FACS (PI-staining). In addition, DSL6A syngeneic pancreatic tumor cells were inoculated subcutaneously in to Lewis rats for in vivostudies.Tumor size, apoptosis (TUNEL) and survival were determined.RESULTS: Ad-p53 gene transfer combined with 5-FU significantly inhibited tumor cell proliferation and substantially enhanced apoptosis in all four cell lines with an alteration in the p53 gene compared to those two cell lines containing wt-p53. In vivo experiments showed the most effective tumor regression in animals treated with Ad-p53 plus 5-FU. Both in vitroand in vivoanalyses revealed that a sublethal dose of Ad-p53 augmented the apoptotic response induced by 5-FU.CONCLUSION: Our results suggest that Ad-p53 may synergistically enhance 5-FU-chemosensitivity most strikingly in pancreatic cancer cells lacking p53 function. These findings illustrate that the anticancer efficacy of this combination treatment is dependent on the p53 gene status of the target tumor cells.展开更多
基金This paper was supported by the National Natural Science Foundation of China(Grant No.30472035)Heilongjiang Province Natural Science Foundation of China(No.TD2005-21)Heilongjiang Province Educational Science Foundation of China(No.11511104).
文摘To obtain an anti-tumor peptide of Tumstatin and detect its biological activity,the nucleotide sequence encoding 185-203 amino acids(19peptide)of Tumstatin was synthesized and inserted into the fusion protein vector pTYB2.After identification by sequencing and restriction endonucle-ases,the recombined vector was transformed into BL-21(DE3)E.coli competent cells.Transformed E.coli BL-21(DE3)were induced by isopropyl-β-thiogalactopyranoside(IPTG),and then expressed.By 1,4-dithiothreitol(DTT)reduction,the soluble 19peptide was obtained from a chitin affinity chromatograph.The biological activity of 19peptide was determined by 3-[4,5-dimethylthiazol-2-y1]-2,5-dipheny-tetrazolium bromide(MTT)assay,cell growth curve,the effect of the ascitic fluid transfevent H22 hepatoma on mice and via histopathological slices.The purified 19peptide directly inhibited proliferation and migration of murine B16 melanoma cells,SMMC-7721hepatoma carcinoma cells and human umbilical vein endothelial cells(HUVEC).The tumor inhibition rate of mice ascitic fluid transfevent H22 hepatoma was 48.46%.Histopathological slices showed that it could promote tumor tissue necrosis and decrease the density of blood vessels.With higher anti-tumor activity,19peptide has the potential to become a novel,potent anti-tumor agent.
文摘AIM: There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU).Therefore the objective of this study was to determine the combined effects of adenovirus-mediated wild-type (wt) p53 gene transfer and 5-FU chemotherapy on pancreatic cancer cells with different p53 gene status.METHODS: Human pancreatic cancer cell lines Capan-1^p53mut,Capan-2^p53wt, FAMPAC^p53mut, PANG1^p53mut, and rat pancreatic cancer cell lines AS^p53wt and DSL6A^p53null were used for in vitro studies. Following infection with different ratios of Adp53-particles (MOI) in combination with 5-FU, proliferation of tumor cells and apoptosis were quantified by cell proliferation assay (WST-1) and FACS (PI-staining). In addition, DSL6A syngeneic pancreatic tumor cells were inoculated subcutaneously in to Lewis rats for in vivostudies.Tumor size, apoptosis (TUNEL) and survival were determined.RESULTS: Ad-p53 gene transfer combined with 5-FU significantly inhibited tumor cell proliferation and substantially enhanced apoptosis in all four cell lines with an alteration in the p53 gene compared to those two cell lines containing wt-p53. In vivo experiments showed the most effective tumor regression in animals treated with Ad-p53 plus 5-FU. Both in vitroand in vivoanalyses revealed that a sublethal dose of Ad-p53 augmented the apoptotic response induced by 5-FU.CONCLUSION: Our results suggest that Ad-p53 may synergistically enhance 5-FU-chemosensitivity most strikingly in pancreatic cancer cells lacking p53 function. These findings illustrate that the anticancer efficacy of this combination treatment is dependent on the p53 gene status of the target tumor cells.
