Figure 3

Silencing of ST8SIA4 inhibits the progression of MDA-MB-231 cells both in vitro and in vivo. (a) The ST8SIA4 expression from breast cancer tissues and MDA-MB-231 cells was obviously compared with that in adjacent tissues and MCF-7 cells by IHC and immunofluorescence staining. Red fluorescence: ST8SIA4; DAPI staining for nuclear DNA. (b) ST8SIA4 protein levels were increased notably in MDA-MB-231 cells compared with MCF-7 cells by western blot analysis. (c) ST8SIA4 transcript was decreased apparently in MDA-MB-231 cells by short hairpin RNA (shRNA) treatment. The distinct reduction of ST8SIA4 was observed at the protein level by western blot analysis. (d) Growth curves of MDA-MB-231 ST8SIA4 shRNA cells were compared with control cells with the CCK-8 assay (*P<0.05). (e) The ability of migration and invasion was compared in MDA-MB-231 ST8SIA4 shRNA and control shRNA cells based on wound healing (*P<0.05). (f) In vitro ECMatrix gel analysis was performed to compare cell invasion between MDA-MB-231 ST8SIA4 shRNA cells and control group (*P<0.05). (g) A decrease of mean tumor volume in mice group with MDA-MB-231 ST8SIA4 shRNA tumors was observed, as compared with the control group (*P<0.05). (h) Reduced regulation of ST8SIA4 and Ki67 was also shown by IHC staining in xenograft tumors derived from MDA-MB-231 ST8SIA4 shRNA cells (× 400). Values shown are mean±s.d. from three independent experiments