A novel role of tissue factor pathway inhibitor-2 in apoptosis of malignant human gliomas

Int J Oncol. 2001 Sep;19(3):591-7. doi: 10.3892/ijo.19.3.591.

Abstract

Tissue factor pathway inhibitor-2 (TFPI-2) is a 32 kDa serine protease inhibitor found at high levels in extracellular matrix. Recombinant human TFPI-2 has recently been shown to be a strong inhibitor of trypsin, plasmin, plasma kallikrein, and factor XIa amidolytic activity. Earlier studies in our laboratory showed that the expression of TFPI-2 is lost during tumor progression in human gliomas. We stably transfected this protease inhibitor in multiform glioblastoma cell line (SNB-19) and in low-grade glioma cell line (Hs683) in sense and antisense orientation respectively. This confirmed that the upregulation/down-regulation of TFPI-2 plays a significant role in the invasive behavior of human gliomas both in vitro and in vivo models. Collectively, these results suggested an idea to determine whether TFPI-2 is necessary for cell survival and inhibition of tumor formation in nude mice, due to apoptosis of intracerebrally injected SNB-19 cells. In the present study we determined p-ERK levels and found that they are decreased in TFPI-2 over-expressed clones (SNB-19) and increased in TFPI-2 down-regulated clones (Hs683). We also checked the levels of BAX/BCl-2, caspases (for e.g., 9, 7, 3, 8), PARP, cytochrome-c and Apaf-1. Moreover, the increase of apoptosis in vitro is associated with increased and decreased expression of apoptotic protein BAX in sense clones (SNB-19) and antisense clones (Hs683) respectively, when compared to controls and vice versa with Bcl-2 the anti-apoptotic protein. Caspases (9, 7 and 3), cytochrome-c, Apaf-1 and PARP levels are increased in SNB-19 and decreased in Hs683. Caspase 8 was not expressed in either cell line. Caspases 9 and 3 activity assay revealed higher activity in sense clones (SNB-19) but lesser in antisense clones (Hs683) compared to controls. This is the first report of TFPI-2 playing a novel role in cell survival in human gliomas.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Apoptosis*
  • Apoptotic Protease-Activating Factor 1
  • Blotting, Western
  • Caspases / metabolism
  • Cytochrome c Group / metabolism
  • Down-Regulation
  • Factor VIIa / antagonists & inhibitors
  • Genetic Vectors
  • Glioma / metabolism
  • Glioma / pathology*
  • Glycoproteins / genetics
  • Glycoproteins / physiology*
  • Humans
  • Mitogen-Activated Protein Kinases / metabolism
  • Proteins / metabolism
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Serine Proteinase Inhibitors / genetics
  • Serine Proteinase Inhibitors / physiology*
  • Transfection
  • Tumor Cells, Cultured / metabolism
  • Tumor Cells, Cultured / pathology*
  • bcl-2-Associated X Protein

Substances

  • APAF1 protein, human
  • Apoptotic Protease-Activating Factor 1
  • BAX protein, human
  • Cytochrome c Group
  • Glycoproteins
  • Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Serine Proteinase Inhibitors
  • bcl-2-Associated X Protein
  • tissue-factor-pathway inhibitor 2
  • Mitogen-Activated Protein Kinases
  • Factor VIIa
  • Caspases