目的：观察溶瘤痘苗病毒VVΔTKΔN1L-RFP和VVΔTKΔN1L-mIL-21对小鼠乳腺癌细胞系JC、TUBO和4T1的体内外治疗效果。方法: 采用MTT法比较VVΔTKΔN1L-RFP和VVΔTKΔN1L-mIL-21两种病毒在不同质量浓度下对乳腺癌JC、TUBO和4T1细胞的体外杀伤效果，用TCID50法检测病毒在三株乳腺癌细胞株中的复制能力，用ELISA法检测两种病毒感染细胞后上清液中mIL-21的水平。建立三阴性乳腺癌4T1和Her-2扩增型乳腺癌TUBO细胞移植瘤模型，检测两种病毒的治疗作用。结果: VVΔTKΔN1L-RFP和VVΔTKΔN1L-mIL-21两种病毒在乳腺癌JC、TUBO和4T1细胞中均具有复制能力，低剂量的病毒就对乳腺癌细胞产生明显的杀伤效应；VVΔTKΔN1L-mIL-21感染的细胞上清中检测到高表达的mIL-21蛋白。在4T1乳腺癌细胞移植瘤模型中，病毒治疗无明显效果(P>0.05)；在TUBO乳腺癌细胞移植瘤模型中，两种病毒均能显著抑制肿瘤生长（P<0.05或P<0.01），延长荷瘤小鼠生存期（P<0.01)。结论: VVΔTKΔN1L-RFP和VVΔTKΔN1L-mIL-21 两种病毒在乳腺癌细胞中具有特异性增殖并杀伤肿瘤细胞的能力，在体内两种病毒对Her-2扩增型和三阴性乳腺癌具有不同的治疗效果。

Objective:To evaluate the in vitro and in vivo efficacy of tumor-targeted oncolytic vaccinia virus (VV) vectors, VVΔTKΔN1L-RFP and VVΔTKΔN1L-mIL-21, on murine breast cancer cell lines (JC, TUBO and 4T1).Methods: The cytotoxicity of the viruses (VVΔTKΔN1L-RFP and VVΔTKΔN1L-mIL-21) at different mass concentrations on JC, TUBO and 4T1 cells was compared by MTT assay. The replication ability of the two viruses in the three cell lines was tested by TCID50. ELISA assay was performed to detect mIL-21 expression in the supernatants of the culture medium of three cell lines after virus infection. Orthotopic models of triple negative breast cancer (4T1) and Her-2 amplified breast cancer (TUBO) in the BALB/c mice were established to investigate the antitumor efficacy of the two VVs. Results:The two viruses were all able to replicate in breast cancer JC, TUBO and 4T1 cell lines, and low dose of VV caused significant cytotoxicity against breast cancer cell lines. High level of mIL-21 protein was detected in the cell culture supernatants after VVΔTKΔN1L-mIL-21 infection. In the orthotopic 4T1 breast cancer model, the viruses did not show significant anti-tumor effect (P>0.05); however, in the orthotopic TUBO breast cancer model, tumor growth was significantly inhibited by both viruses (P<0.05，P<0.01), and the survival time（P<0.01) of tumor bearing mouse was prolonged in both VVΔTKΔN1L-RFP and VVΔTKΔN1L-mIL-21 treatment group. Conclusion: Both VVΔTKΔN1L-RFP and VVΔTKΔN1L-mIL-21viruses could specifically replicate and showed cell killing effect on breast cancer cells. The two viruses have different in vivo therapeutic effects on Her-2 gene amplified breast cancer and triple negative breast cancer.

国家自然科学基金资助项目（No. 81272525，No. 81201792）