Ionizing radiation as a response-enhancing agent for CD95-mediated apoptosis.
CD95 (Fas/APO-1) is a death receptor on the surface of a wide variety of cell types. In most cells examined, ionizing radiation acts as a response-enhancing agent for CD95-mediated cell death. Although DNA-damaging radiation appears to modulate CD95-mediated signals through multiple mechanisms, the only well-characterized mechanism is activation of the tumor-suppressor protein p53, which transcriptionally regulates the expression of CD95 on various cell types. The ligand for CD95 is expressed by activated lymphocytes and natural-killer cells, which produce factors that sensitize cells resistant to CD95-mediated cell death. Ligation of CD95 on irradiated tumor cells might be achievable using emerging modalities that reactivate the stalled anti-tumor immune response.
Sheard
M A
MA
Department of Cellular and Molecular Oncology, Masaryk Memorial Cancer Institute, Brno, Czech Republic. sheard@mou.cz
D000818:Animals; D017209:Apoptosis; D006801:Humans; D007694:Killer Cells, Natural / Q000378:metabolism / Q000528:radiation effects; D008024:Ligands; D008214:Lymphocytes / Q000378:metabolism / Q000528:radiation effects; D008954:Models, Biological; D009369:Neoplasms / Q000188:drug therapy / Q000532:radiotherapy; D011839:Radiation, Ionizing; D015398:Signal Transduction / Q000528:radiation effects; D014158:Transcription, Genetic; D019014:fas Receptor / Q000378:metabolism*
D008024:Ligands; D019014:fas Receptor