Fig. 4

Functional analysis of TNBC cells after TIMP-1 knockdown. a Inactivation of endogenous TIMP-1 in MDA-468 cells using shRNA. The knockdown efficiency was confirmed using real-time PCR and ELISA assays. The data are presented as the mean ± SD. b Inactivation of endogenous TIMP-1 in MDA-231 cells using shRNAs. shTIMP1-1# and shTIMP1-3# were more efficient in knocking down TIMP-1 compared with the sh-control in both cell lines. The data are presented as the mean ± SD. c, d Knockdown TIMP-1 expression induced cell cycle arrest at the G1 phase in MDA-468 and MDA-231 cells. e, f Colony formation was reduced in TIMP-1 knockdown MDA-468 and MDA-231 cells. g CCK-8 assays showed that cell growth was restrained in TIMP-1 knockdown MDA-468 cells. * indicates significant difference as compared to control cells (p < 0.05). h TIMP-1 knockdown did not significantly disrupt cell invasion in MDA-468 cells. Representative images of invasive cells are shown. The data are presented as the mean ± SD; scale bar, 200 μm