title: The anti-cancerous activity of recombinant trichosanthin on prostate cancer cell PC3.
abstract: BACKGROUND
  Trichosanthin produced in the root tube of Trichosanthes kirilowii shows anti-tumor activity on a series of cancer cells including Hela, MCF-7, HL-60. But there is little information about its effect on the carcinogenesis of prostate cancer.
  
  
  OBJECTIVE
  This work was designed to study the role of trichosanthin on prostate cancer cells PC3.
  
  
  METHODS
  Trichosanthin was expressed in BL21 strain and purified by affinity chromatography. MTT assay was designed to determine the effect of trichosanthin on growth of PC3 cells at doses of 10, 20, 40, 60, 80, and 120 μg/ml. Then the effect of 50 μg/ml rTCS alone or combined with 2 μM IL-2 on PC3 cell proliferation was analyzed. And the mechanism of rTCS was studied by western blot. After that the in vivo effect of rTCS combined with IL-2 was explored in mice bearing PC3 xenograft tumor.
  
  
  RESULTS
  Trichosanthin was successfully expressed in BL21 and purified by 100 mM imidazole. It was shown to inhibit proliferation of PC3 cells in a dose-dependent manner with IC50 50.6 μg/ml. When combined with cytokine IL-2, a significant synergic effect was obtained. The inhibition rate on PC3 was around 50 % in combination group while only 35.5 % in single rTCS group at 50 μg/ml. Further, the expression of full length caspase-8 and Bcl-2 decreased significantly while cleaved caspase-8 and Bax were up-regulated, which suggest that caspase-8-mediated apoptosis pathway may be activated by rTCS in PC3 cells. Moreover, our data demonstrated that tumor volume and tumor weight were significantly reduced in rTCS-treated or rTCS/IL-2-treated nude mice bearing PC3 xenograft tumor compared with control. And significant difference was also found between rTCS and rTCS/IL-2 group.
  
  
  CONCLUSIONS
  This study demonstrates that rTCS is a potential agent with high in vitro and in vivo anti-tumor activity on PC3 cells. And rTCS combined with IL-2 is a promising strategy in treating patients with prostate cancer in future.
authors.affiliation: Department of Laboratory Medicine, The Second Affiliated Hospital of Southeast University, Zhongfu Road 1-1, Nanjing, 210003, China.|Department of Biochemistry and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210093, China.
authors.forename: JinLong
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Neonatology, The Taizhou People's Hospital, Taizhou, 225300, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Pharmacy, The Second Affiliated Hospital of Southeast University, Nanjing, 210003, China.
authors.forename: ZhaoLi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Laboratory Medicine, The Second Affiliated Hospital of Southeast University, Zhongfu Road 1-1, Nanjing, 210003, China.
authors.forename: NianYue
authors.initials: N
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine, The Second Affiliated Hospital of Southeast University, Zhongfu Road 1-1, Nanjing, 210003, China. tangb_1210@sina.com.
authors.forename: YongChen
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005562:Formazans; D008297:Male; D051379:Mice; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011994:Recombinant Proteins / Q000494:pharmacology; D015203:Reproducibility of Results; D013778:Tetrazolium Salts; D013997:Time Factors; D015978:Trichosanthin / Q000494:pharmacology*; D047368:Tumor Burden
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005562:Formazans; D011994:Recombinant Proteins; D013778:Tetrazolium Salts; C079782:MTT formazan; D015978:Trichosanthin
keywords: Interleukin IL-2; Prostate cancer cells PC3; Trichosanthin; Tumor