Inhibition of NF-kappaB, clonogenicity, and radiosensitivity of human cancer cells.

نویسندگان

  • F Pajonk
  • K Pajonk
  • W H McBride
چکیده

BACKGROUND Activation of the transcription factor NF-kappaB is part of the immediate early response of tissues to ionizing irradiation. This pathway has been shown to protect cells from tumor necrosis factor-alpha, chemotherapy, and radiation therapy-induced apoptosis (programmed cell death). However, because the role of NF-kappaB as a modifier of the intrinsic radiosensitivity of cancer cells is less clear, we have studied the impact of NF-kappaB on the intrinsic radiosensitivity of human cancer cells. METHODS We used PC3 prostate cancer cells and HD-MyZ Hodgkin's lymphoma cells transduced with an adenovirus vector that contains a gene encoding a form of IkappaB (an inhibitor of NF-kappaB) that cannot be phosphorylated. This form of IkappaB will remain bound to NF-kappaB; thus, NF-kappaB cannot be activated. We monitored NF-kappaB activity with a gel-shift assay and used a colony-forming assay to assess clonogenicity and radiosensitivity. RESULTS Constitutive DNA-binding activity of NF-kappaB was dramatically decreased in PC3 cells transduced with the IkappaB super-repressor gene. The clonogenicity of transduced PC3 cells declined to 19.6% of that observed for untreated control cells, a finding similar to one we have previously demonstrated for IkappaB-transduced HD-MyZ cells. However, inhibition of NF-kappaB activity in the surviving PC3 and HD-MyZ cells failed to alter their intrinsic radiosensitivity. CONCLUSIONS We conclude that activation of NF-kappaB does not determine the intrinsic radiosensitivity of cancer cells, at least for the cell lines tested in this study.

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عنوان ژورنال:
  • Journal of the National Cancer Institute

دوره 91 22  شماره 

صفحات  -

تاریخ انتشار 1999