Therapeutic effect of an oncolytic herpes simplex virus vector against human nasopharyngeal carcinoma cell subcutaneous tumors in nude mice

Abstract

Objective To assess the efficacy of a herpes simplex virus (HSV) vector, G47Δ, in the treatment of human nasopharyngeal carcinoma cell subcutaneous tumors in nude mice. Methods Human nasopharyngeal carcinoma cells (CNE-2) were cultured in vitro. A bilateral subcutaneous nasopharyngeal tumor model was then established in Balb-c nude mice by subcutaneous injection of CNE2 cells. When tumors were approximately 5 mm in maximal diameter, mice were unilaterally (the left side) inoculated with 50 μL of 2×106/μL G47Δ or virus buffer twice a week. Tumor size was measured using an external caliper and tumor volume was calculated (V=a×b2/2). When the diameter of tumor reached 18 mm, the mice were sacrificed. Tumor size and survival time were compared between the two groups. Results In the bilateral subcutaneous nasopharyngeal tumor model, compared with the non-virus treatment side, the subcutaneous tumors treated with G47Δ grew slowly and finally disappeared (P<0.01). The survival time of the virus group was significantly longer than that of the control group (χ2=12.11, P=0.005). Conclusion Intratumoral inoculation of G47Δ could effectively cure nasopharyngeal carcinoma subcutaneous tumors in nude mice, suggesting that G47Δ may be used for clinical therapy of nasopharyngeal carcinoma if further clinical trials can confirm our findings. Key words: Cancer therapy; Herpes simplex virus; Oncolytic virus; Gene therapy; Nasopharyngeal carcinoma