Potent anti-tumor and prolonged survival effects of E. coli-derived non-glycosylated kringle domain of tissue-type plasminogen activator

Int J Oncol. 2006 Feb;28(2):361-7.


The two-kringle domain of tissue-type plasminogen activator (TK1-2) has been identified as a novel angiogenesis inhibitor. In the previous study, purified Pichia-derived TK1-2 has been shown to suppress in vivo growth of human lung and colon cancer cells. Here, we demonstrate that E. coli-derived non-glycosylated TK1-2 suppresses tumor growth more potently than Pichia-derived TK1-2 and prolongs the survival of tumor bearing mice. The recombinant TK1-2 prepared through E. coli expression, His-tag affinity chromatography and in vitro refolding was injected intraperitoneally once daily into nude mice 7 days after subcutaneous implantation with PC14 lung cancer cells (n=10). Measurement of tumor volumes indicated that low-dose TK1-2 treatment (10 mg/kg) suppressed tumor growth by approximately 85.2% (p<0.01), while high-dose TK1-2 treatment (50 mg/kg) even more potently inhibited tumor growth (>93.8%) (p<0.005). Treatment of TK1-2 also prolonged the survival of tumor-bearing mice in a dose-dependent fashion. In an independent HCT116 xenograft model, E. coli-derived TK1-2 was more effective in suppressing tumor growth than Pichia-derived TK1-2. Immunohistochemical analysis of tumor tissue also revealed that the expression of VEGF, SMA-alpha, TNF-alpha and angiogenin was less positive in the E. coli-derived TK1-2-treated group than in the Pichia-derived TK1-2-treated group. These results suggest that E. coli-derived refolded, non-glycosylated TK1-2 can be used more effectively as an anti-cancer agent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / prevention & control*
  • Dose-Response Relationship, Drug
  • Escherichia coli
  • HCT116 Cells
  • Humans
  • Kringles / genetics
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Lung Neoplasms / prevention & control*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Nude
  • Recombinant Proteins / pharmacology
  • Ribonuclease, Pancreatic / metabolism
  • Tissue Plasminogen Activator / genetics
  • Tissue Plasminogen Activator / pharmacology*
  • Tumor Necrosis Factor-alpha / metabolism
  • Vascular Endothelial Growth Factor A / metabolism
  • Xenograft Model Antitumor Assays


  • Antineoplastic Agents
  • Recombinant Proteins
  • Tumor Necrosis Factor-alpha
  • Vascular Endothelial Growth Factor A
  • angiogenin
  • Ribonuclease, Pancreatic
  • Tissue Plasminogen Activator