[The therapeutic effect of HSV1-hGM-CSF combined with doxorubicin on the mouse breast cancer model].

To evaluate the oncolytic effect of herpes simplex virus type 1 which carried recombined human granulocyte-macrophage colony-stimulating factor (HSV1-hGM-CSF) on the mouse breast cancer cell line 4T1 and compare the anticancer effects of HSV1-hGM-CSF, doxorubicin alone or combination on the breast cancer in mice. We investigated the cytotoxic effect on 4T1 cells the cell growth, cell apoptosis and cell cycle of 4T1 cells treated with oncolytic HSV1-hGM-CSF at different MOIs (0, 0.5, 1 and 2) and doxorubicin at different concentrations (0, 2, 4 and 8 μg/ml). The effects of oncolytic HSV1-hGM-CSF and doxorubicin on the tumor growth, survival time and their side effects on the mouse breast cancer model were observed. Both oncolytic HSV1-hGM-CSF and doxorubicin significantly inhibited the proliferation of 4T1 cells . Doxorubicin induced the G(2)/M phase arrest of 4T1 cells, while the cytotoxicity of oncolytic HSV1-hGM-CSF was no cell cycle-dependent.At day 16 after treatment with doxorubicin and HSV1-hGM-CSF, the tumor volume of 4T1 tumor bearing mice were (144.40±27.68)mm(3,) (216.80±57.18)mm(3,) (246.10±21.90)mm(3,) (327.50±44.24)mm(3,) (213.30±32.31)mm(3) and (495.80±75.87)mm(3) in the groups of doxorubicin combined with high dose HSV1-hGM-CSF, doxorubicin combined with low dose HSV1-hGM-CSF, doxorubicin alone, high dose HSV1-hGM-CSF alone, low dose HSV1-hGM-CSF alone and control, respectively.Compared with the control group, both doxorubicin and HSV1-hGM-CSF treatment exhibited significant reduction of primary tumor volume in vivo (<0.001). The median survival times were 48, 50, 40, 42, 43 and 37 days in the six groups mentioned above, respectively. The median survival period of doxorubicin alone, high dose HSV1-hGM-CSF alone and low dose HSV1-hGM-CSF alone were significantly longer than that of control (<0.05). Synergistic effect of sequential treatment with doxorubicin and oncolytic HSV1-hGM-CSF is observed in 4T1 mouse breast cancer.