Modulation of MMP-2 and TIMP-2 by low dose radiation in mice bearing S180 sarcoma

Objective To investigate the inhibition of low dose radiation（LDR） on S180 sarcomas and its modulation of MMP-2 and TIMP-2 in mice.Methods S180 subcutaneously implanted tumor model mice were randomly divided into two groups： control（N） and low dose radiation（LDR） groups. N mice were sacrificed after 12 h, whereas LDR mice were sacrificed after 12（LDR-12 h）, 24（LDR-24 h）, 48（LDR-48 h）, and 72（LDR-72 h） h. Thereafter, we measured the tumor volumes. Histopathology was performed, and P-V immunohistochemistry was applied to assess MMP-2 and TIMP-2 expression.Results Compared with the control group, the tumor growth was significantly inhibited in the LDR groups（P 〈 0.05）. MMP-2 expression was considerably reduced in LDR-24h（P 〈 0.05） and LDR-48h（P 〈 0.05）, whereas the change of TIMP-2 was not obvious in the LDR groups（P 〉 0.05） in contrast to that of the control group.Conclusion LDR can effectively suppress the growth of S180 implanted tumors by reducing MMP-2, which is associated with invasion and metastasis.