重组溶瘤单纯疱疹病毒抑制小鼠结肠癌肺转移瘤的实验研究

The Inhibitory Effects of Recombinant Oncolytic Herpes Simplex Virus-1 on Lung Metastasis of Colon Cancer in Mice

探讨携载p53和IL-12的重组溶瘤单纯疱疹病毒(Oncolytic Herpes Simplex Virus-1,oHSV)MH1004和MH1006对小鼠结肠癌皮下移植瘤和肺转移瘤的治疗作用.蚀斑法和MTT法分析重组oHSV对结肠癌细胞CT26的感染和溶瘤特性;小鼠背部皮下注射CT26建立皮下移植瘤模型,瘤内注射重组oHSV后分析小鼠血清中IL-12含量,观察肿瘤大小和小鼠生存率;小鼠尾静脉注射CT26建立肺转移模型,尾静脉注射重组oHSV后显微观察肺组织中肿瘤细胞浸润,观察肺脏肿瘤结节和小鼠生存率.重组oHSV能够感染CT26并高效复制和抑制肿瘤细胞.皮下移植瘤小鼠治疗12 d后观察到抑瘤效应,MH1004和MH1006组21 d时肿瘤体积(2477.31±2017.02 mm3和1414.36±1639.19 mm3)均极显著小于Mock组(7682.92±2648.74 mm3)(P<0.01),42 d时生存率(均为100%)明显高于HSV-wt和Mock组(均为50%);MH1006组小鼠血清中IL-12含量增加,第16 d时极显著高于Mock组(P<0.01);治疗后肿瘤消失小鼠血清中IL-12含量明显增高.肺转移瘤小鼠治疗后,MH1004和MH1006组小鼠肺脏肿瘤结节数在治疗5 d、9 d和13 d时均极显著低于Mock组(P<0.01),13 d极显著低于HSV-wt组(P<0.01),且o HSV治疗小鼠肺组织浸润的肿瘤细胞明显减少;60 d时MH1004组、MH1006组、HSV-wt组和Mock组的生存率依次为83.3%、66.7%、66.7%和50%,MH1004组和MH1006组死亡小鼠肺脏肿瘤结节少于Mock组和HSV-wt组.携载IL-12和p53的重组o HSV经尾静脉注射治疗小鼠结肠癌肺转移瘤效果显著,该研究为转移瘤治疗提供了新的思路.

To investigate the inhibitory effects of the recombinant oHSV carrying p53(MH1004)or IL-12(MH1006)on the models of subcutaneous xenograft and lung metastasis of colon cancer in mice,the infection ability and oncolytic property of the recombinant oHSVs in colon cancer cell line CT26 were detected by plaque and MTT analysis.The murine model of subcutaneous xenograft was established by subcutaneous inoculation CT26 cells,subsequently the oHSVs were injected intratumorally,then the IL-12 content in the mice serum was tested,and the tumor volume and survival rate of the mice were measured.The murine model of lung metastasis of colon cancer was established by inoculation CT26 cells through caudal vein,subsequently the o HSVs were injected through caudal vein,then tumor cell infiltration of the lungs was observed with microscope,and the tumor nodules in the lungs and survival rate of the mice were measured.HSV-wt and virus storage(Mock)groups were used as controls of the above experiments.The o HSVs were able to infect CT26 cells,then replicate efficiently and inhibit tumor cell proliferation.The inhibition of subcutaneous tumors was observed after 12 d of treatment;and after 21 d,the tumor volume of MH1004(2127.31±2017.02 mm^3)and MH1006(1414.36±1639.19 mm^3)was significant smaller than that of Mock(P<0.01);after 42 d,the survival rates of MH1004 and MH1006(both 100%)were significant higher than that of Mock and HSV-wt(both 50%);the IL-12 content in the mice serum of MH1006 increased after treatment and was significantly higher than that of Mock after 16 d of treatment(P<0.01),and the IL-12 content in the serum of the mice whose tumor have disappeared was increased significantly.After 5 d,9 d,and 13 d treatment to the lung metastasis of colon cancer in mice,the number of the tumor nodule in the lungs from MH1004 and MH1006 was highly significant lower than that from Mock(P<0.01),and after 13 d that the number of the tumor nodule in the lungs from MH1004 and MH1006 was also significantly lower than that from HSV-wt(P<0.01),moreover,the tumor cell infiltration of the lungs from o HSVs treatment was decreased significantly;after 60 d,the survival rates of MH1004,MH1006,HSV-wt and Mock group were 83.3%,66.7%,66.7%and 50%respectively;the number of the tumor nodule in the lungs of the dead mice from MH1004 and MH1006 was significantly lower than that from HSV-wt and Mock.Inoculation oHSVs armed with p53 or IL-12 via caudal vein is a highly effective treatment for the lung metastasis of colon cancer in mice.This study provides a new idea for the treatment of metastatic tumors.