SEARCH

SEARCH BY CITATION

Keywords:

  • Apoptosis;
  • IkB;
  • TNF;
  • Bax;
  • Gene therapy

Tumor necrosis factor-α (TNF), which was initially supposed to be a promising cancer therapeutic reagent, does not kill most types of cancer cells partly due to the activation of an anti-apoptotic gene, NF-kB. NF-kB forms an inactive complex with the inhibitor kappa B alpha (IkBα), which is rapidly phosphorylated and degraded in response to various extracellular signals. To disrupt this protective mechanism, we introduced an inhibitor kappa B alpha (IkBdN) gene, a deletion mutant gene lacking the nucleotides for the N-terminal 36 amino acids of IkBα, into human glioma cells (U251, T-98G, and U-373MG) via an adenoviral (Adv) vector in addition to treatment of the glioma cells with recombinant TNF. Immunohistochemical analysis revealed that NF-kB was translocated to nuclei by TNF treatment in U251 and T-98G cells, but not in U-373MG cells. Neither transduction of IkBdN nor treatment with TNF protein alone induced apoptosis in U251 and T-98G cells, whereas both cell lines underwent drastic TNF-induced apoptosis after transduction of IkBdN. On the other hand, U-373MG cells were refractory to TNF-induced apoptosis even when they were transduced with the IkBdN gene. U-373MG cells underwent drastically increased apoptosis when co-transduced with the IkBdN and Bax gene in the presence of TNF. Adv-mediated transfer of IkBdN or IkBdN plus Bax may be a promising therapeutic approach to treat gliomas through TNF-mediated apoptosis.