Effect of a novel oncolytic herpes simplex virus type II on lung adenocarcinoma

Objective To establish the subcutaneous transplantation tumor models with Lewis lung adenocarcinoma in C57BL/6 mice, and to observe the influence of oHSV2, DDP and drug combination on tumor volume, median survival time and weight of tumor-burdened mice. Methods Subcutaneous transplantation tumor models were established with Lewis lung adenocarcinoma in tumor-burdened mice. Tumor-burdened mice were randomly divided into the control group, oHSV2 group, DDP group, oHSV2/DDP sequential group, DDP/oHSV2 sequential group and oHSV2+ DDP combination group with 12 rats in each group using the random number table method. The tumor size and weight of mice were measured every 3 days. Results On the 21st day, the tumor size of tumor-burdened mice in every group was as follows: control group (1.82±0.06)cm3, oHSV2 group (0.63±0.05)cm3, DDP group (0.58±0.03)cm3, oHSV2/DDP sequential group (0.49±0.05)cm3, DDP/oHSV2 sequential group (0.42±0.04)cm3, and the difference was statistically significant (F=1 359.01, P=0.000). The data in oHSV2+ DDP group were put away because of premature death in mice. The differences were statistically significant between control group and oHSV2 group (P=0.000), control group and DDP group (P=0.000), control group and oHSV2/DDP sequential group (P=0.000), control group and DDP/oHSV2 sequential group (P=0.000), oHSV2 group and DDP group (P=0.017), DDP group and DDP/oHSV2 sequential group (P=0.000), oHSV2/DDP sequential group and DDP/oHSV2 sequential group (P=0.001). The weight of tumor-burdened mice in every group was listed as follows: control group (21.64±0.40)g, oHSV2 group (21.34±0.37)g, DDP group (15.96±0.43)g, oHSV2/DDP sequential group (19.04±0.31)g, DDP/oHSV2 sequential group (16.34±0.30)g, and the difference was statistically significant (F=588.67, P=0.000). The difference was not statistically significant between control group and oHSV2 group (P=0.076). However, the differences were statistically significant between control group and DDP group (P=0.000), control group and oHSV2/DDP sequential group (P=0.000), control group and DDP/oHSV2 sequential group (P=0.000), oHSV2 group and DDP group (P=0.000), oHSV2 group and oHSV2/DDP sequential group (P=0.000), DDP group and DDP/oHSV2 group (P=0.013), oHSV2/DDP sequential group and DDP/oHSV2 sequential group (P=0.000). The median survival time of tumor-burdened mice in every group was displayed as follows: control group 23 d , oHSV2 group 32 d, DDP group 30 d, oHSV2/DDP sequential group 37 d, DDP/oHSV2 sequential group 39 d, oHSV2+ DDP combination group 16 d, and the difference was statistically significant (χ2=120.81, P=0.000). The differences were statistically significant between control group and oHSV2 group (χ2=10.88, P=0.001), control group and DDP group (χ2=10.69, P=0.001), oHSV2 group and DDP/oHSV2 sequential group (χ2=10.09, P=0.001), DDP group and DDP/oHSV2 sequential group (χ2=9.67, P=0.002). However, the differences were not statistically significant between oHSV2 group and DDP group (χ2=0.00, P=0.996), oHSV2/DDP sequential group and DDP/oHSV2 sequential group (χ2=2.70, P=0.100). Conclusion On the premise of that the weight of mice is no affected, oHSV2 can inhibit the tumor size and prolong the median survival time of tumor-burdened mice effectively, and the effect of DDP/oHSV2 sequential group is the most significant. This article provides an experimental basis for exploring therapeutic methods of lung adenocarcinoma. Key words: Oncolytic virus; Cisplatin; Lung neoplasms