Combination of apoptin with photodynamic therapy induces nasopharyngeal carcinoma cell death in vitro and in vivo

Photodynamic therapy has been developed as a viable treatment for cancer, while apoptin is an apoptosis-inducing protein. This study was undertaken to evaluate the feasibility and efficacy of apoptin with photodynamic therapy (PDT) in the treatment of nasopharyngeal carcinoma (NPC). RT-PCR and western blotting were used to detect the expression of apoptin in CNE-2 NPC cells. MTT and flow cytometry analysis were used to detect cell proliferation and cell apoptosis, respectively. Transmission electron microscopy was used to observe cell structures. Hematoxylin and eosin staining was used to observe the xenograft morphology. The expression of apoptin was analyzed by RT-PCR and western blotting in CNE-2 cells stably transfected with PVP3 plasmid. Apoptin restrained cell proliferation and enhanced cell apoptosis compared to controls. Furthermore, we demonstrated that apoptin augmented the effect of PDT with stronger cell proliferation restraint and cell apoptosis and induced severe ultrastructural morphology changes compared to controls. Additionally, we found that the combination of apoptin and PDT produced the strongest inhibition of xenograft growth and tumor necrosis in in vivo experiments. Collectively, we show that apoptin in combination with PDT has a better therapeutic effect in NPC than PDT therapy or apoptin gene therapy alone.