ABSTRACT
Objective To investigate the effects of doxycycline on the expressions of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metaloproteinase-1 (TIMP-1) in breast cancer lung metastasis model mice (BCML-TAⅡ99), and the mechanism thereof. Methods The BCML-TAⅡ99 mouse model was established. The immunohistochemical staining was performed to detect the expressions of MMP-9 and TIMP-1 in BCML-TAⅡ99 model mice and controls. Results The metastasis rate was significantly lower in treatment group than that of control group. The expression of MMP-9 was significantly reduced, but the expression of TIMP-1 was significantly increased, in treatment group compared with those of control group (P<0.05). Conclusion Doxycycline can inhibit tumor growth and metastasis in breast cancer with 1ung metastasis model mice by regulating MMP-9 and TIMP-1 expressions.