We performed this research mainly to explore the effect of
bone sialoprotein (BSP) silence by
siRNA on the adhesion ability to bone matrix of bone-seeking
breast cancer cells (MDA-MB-231BO). Also we aimed to provide experimental data for prevention and treatment of
breast cancer bone
metastasis by targeting BSP. We explored the effects of BSP gene silence on characteristics of bone-seeking
breast cancer cells: proliferation by MTS[3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner
salt] assay, bone adhesion ability by a mouse bone adhesion model in vitro, morphology of the cells by SEM, and secretion of
transforming growth factor-beta1 (TGF-beta1) and
receptor activator of nuclear factor-kappa B ligand (RANKL) by ELISA kits. We performed intra-cardiac injection in nude mice to explore bone metastatic ability of different cell lines. The results showed that knockdown of BSP significantly inhibited the proliferation of MDA-MB-231BO cells and their adhesion to bone matrix. We also observed bone destruction caused by
bone resorption around some adhering cells. The appearances of the cells changed in BSP gene silenced group, and the secretion of
TGF-beta1 and RANKL decreased. The results showed BSP gene silence can partial inhibition bone
metastasis of
breast cancer cells in nude mice by X-ray assay and
hematoxylin-
eosin staining. Based on our research,
siRNA-mediated BSP silencing can inhibit proliferation and adhesion to bone matrix of bone-seeking
breast cancer cells and change their surface structure, thus inhibits their bone metastatic ability.