title: [Optimization of extracting method and inhibitory action of recombinant human endostatin in bladder cancer].
abstract: OBJECTIVE
  To explore the optimal method for protein expression in rhES (recombinant human endostatin) and study the anti-tumor activities of rhES in solid tumor and established cell line.
  
  
  METHODS
  Different IPTG concentrations, the timing of adding IPTG into the culture medium and the different time of expression were employed to explore the optimized conditions of protein expression. Activity examination: (1) animal experiment: nude mice bearing subcutaneous cancer in treated group and controlled group were observed. (2) cellular experiment: the inhibitory effect of rhES in T-24 established cell line were observed by MTT assay and cancer cell growth curve.
  
  
  RESULTS
  The expression of rhES protein was 58.65%. Of all the E. coli body proteins, the protein purity after purification was 96.22%. Activity examination indicated that rhES could inhibit the growth of solid tumor and the established cell line. In animal experiment, the tumor inhibition rate was 66.8%. Cell experiment: the 50% inhibitory concentration (IC(50)) was 22 microg/ml. The cell population decreased 58.75% than the control group at Day 7 in the tumor cell growth curve.
  
  
  CONCLUSIONS
  A high expression and activity of rhES protein can be obtained by the optimized expression conditions. rhES can inhibit the cellular growth in both solid tumor and established cell line of bladder cancer.
authors.affiliation: Department of Urology, First Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
authors.forename: Ming-hua
authors.initials: MH
authors.lastname: Ren
authors.forename: Shao-bin
authors.initials: SB
authors.lastname: Ni
authors.forename: Qi-yin
authors.initials: QY
authors.lastname: Chen
authors.forename: Wan-hai
authors.initials: WH
authors.lastname: Xu
authors.forename: Chang-lin
authors.initials: CL
authors.lastname: Wang
authors.forename: Yi-ming
authors.initials: YM
authors.lastname: Fu
authors.forename: Zhi-xing
authors.initials: ZX
authors.lastname: Jiao
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Zhong-shan
authors.initials: ZS
authors.lastname: Zhao
authors.forename: Xing-han
authors.initials: XH
authors.lastname: Liu
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D043169:Endostatins / Q000235:genetics*; D005260:Female; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011994:Recombinant Proteins / Q000235:genetics; D014162:Transfection; D001749:Urinary Bladder Neoplasms / Q000628:therapy*
chemical_list: D043169:Endostatins; D011994:Recombinant Proteins