Efficient growth suppression and apoptosis in human laryngeal carcinoma cell line HEP-2 induced by an adeno-associated virus expressing human FAS ligand.

Abstract

Apoptosis induced by Fas/FasL system has been proposed as a gene therapy methold for various cancers. We used adeno-associated virus-expressing enhanced green fluorescent protein (EGFP)-human FasL (AAV-EGFP-hFasL) to deliver FasL into Hep-2 cells, cytotoxicity was detected by MTS assay , apoptosis was confirmed by flow cytometry. We also treated the xenograft of Hep-2 tumor in nude mice with intratumoral injection of AAV-EGFP-hFasL. The size of the xenograft, the apoptosis in the xenograft, and the survival rate of the inoculated mice were then evaluated. Hep-2 cells infected with AAV-EGFP-hFasL showed increased apoptosis rate and killing effect compared with AAV-EGFP-infected cells. In addition intratumoral injections of AAV-EGFP-hFasL into Hep-2 xenografts induced significant growth suppression of tumors. Our findings suggest that the introduction of FasL into head and neck squamous cell carcinoma may induce significant apoptosis, and adeno-associated virus may be a useful vehicle for gene therapy.