ABSTRACT
<p><b>OBJECTIVE</b>To investigate the influence of siRNA-mediated down-regulation of CD147 on growth, proliferation and movement of human breast cancer cell line MDA-MB-231.</p><p><b>METHODS</b>The protein expression of CD147, MMP-2 and TIMP-2 of the MDA-MB-231 cells were analyzed by ABC. Lentiviral expression vector of CD147 gene was constructed and transfected into MDA-MB-231 cells. RT-PCR and Western blot were used to detect the mRNA and protein level changes of CD147 genes to identify the optimal time point, followed by detection of changes of mRNA and protein expression of MMP-2 and TIMP-2 genes. CCK-8 reagent method and cell scratch test were used to detect the proliferation and migration change of MDA-MB-231 cells. The nude mouse model of breast cancer by hypodermic injection with MDA-MB-231 cells was established to document the effect of CD147 siRNA on the tumor transplants.</p><p><b>RESULTS</b>After transfection of lentiviral expression vector of CD147 gene, protein of CD147, MMP-2 and TIMP-2 were weakly or negative expressed, significantly weaker than those of control group (P < 0.01). After 72 hours of transfection, average down-regulation rate of CD147 and MMP-2 were 96.03% ± 0.84% and 96.03% ± 0.84%, respectively. Both CD147 mRNA and MMP-2 mRNA expression were down-regulated (P < 0.05), while TIMP-2 mRNA expression showed no significant deference (P > 0.05). No less than 2 days after transfection, cell growth of MDA-MB-231 cell line was found significantly inhibited (P < 0.05). After 24 hours of transection, average migration distance of MDA-MB-231 cell line and control group were (0.64 ± 0.12) mm and (4.69 ± 0.85) mm, respectively, which indicated a lower migrate speed. Down regulation of CD147 led to reduction of volume and mass of nude mouses. The growth of the carcinoma transplant was inhibited upon siRNA-mediated down-regulation of CD147 (P < 0.05), with an average tumor mass of (1.85 ± 0.98) g and both reduction of tumor size and tumor mass.</p><p><b>CONCLUSIONS</b>CD147 may alter the MMP-2/TIMP-2 balance in MDA-MB-231 cells. CD147 gene silencing inhibits the proliferation and migration of MDA-MB-231 cells and the growth of carcinoma transplants in nude mice.</p>