Radiation-induced expression of functional Fas ligand in EBV-positive human nasopharyngeal carcinoma cells

✍ Scribed by Bassam Abdulkarim; Siham Sabri; Eric Deutsch; Sabine Vaganay; Elisabetta Marangoni; William Vainchenker; Pierre Bongrand; Pierre Busson; Jean Bourhis

• Book ID: 102650014
• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: French
• Weight: 519 KB
• Volume: 86
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(20000415)86:2<229::aid-ijc12>3.0.co;2-1

✦ Synopsis

Ionizing radiation remains a major therapeutic tool against human cancers, especially epithelial tumors, which account for the majority of human malignancies. Although Fas and Fas-L are essential determinants of apoptosis, few data support their role in the cytotoxic effect of ionizing radiation. Epstein-Barr-virus (EBV)-positive nasopharyngeal carcinoma (NPC) were chosen to address this question owing to their known sensitivity to ionizing radiation and their constitutive expression of the Fas-receptor. We here report that, in xenografted NPC cells, Fas-L expression, which was very low in basal conditions, was dramatically increased by tumor irradiation. Both the Fas receptor and the Fas ligand were found to be functional in this model, and a high proportion of irradiated NPC cells underwent apoptosis following tumor irradiation. Induction of Fas-L expression and apoptosis were observed for doses as low as 2 Gy. These data show an increase in Fas-L expression upon irradiation exposure, and strongly suggest that, in some epithelial malignancies, Fasmediated apoptosis can play a major role in the anti-tumor effect of ionizing radiation, in the range of doses used for therapeutic applications.