RT Journal Article
SR Electronic
T1 Silencing of syndecan-binding protein enhances the inhibitory effect of tamoxifen and increases cellular sensitivity to estrogen
JF Cancer Biology and Medicine
JO Cancer Biol Med
FD China Anti-Cancer Association
SP 29
OP 38
DO 10.20892/j.issn.2095-3941.2017.0122
VO 15
IS 1
A1 Zhang, Jun
A1 Qian, Xiaolong
A1 Liu, Fangfang
A1 Guo, Xiaojing
A1 Gu, Feng
A1 Fu, Li
YR 2018
UL http://www.cancerbiomed.org/content/15/1/29.abstract
AB Objective: Tamoxifen is used as a complementary treatment for estrogen receptor (ER)-positive breast cancer (BCa), but many patients developed resistance. The aim of this study was to examine the role of syndecan-binding protein (SDCBP) silencing in ER-positive BCa cells.Methods: In MCF-7/T47D cells, the effects of SDCBP silence/overexpression on cell proliferation and estrogenic response were examined. Cell proliferation was examined using the MTT assay and cell cycle regulators were examined by Western blot. Estrogen response was examined from a luciferase activity and evaluation of transcript levels of pS2 and progesterone receptor (PR) upon estrogen administration. Samples of ER-positive BCa were stained with ERα, PR, and SDCBP antibodies, and their expression correlations were analyzed.Results: We found that SDCBP silencing inhibited the proliferation of ER-positive BCa cells and arrested a greater number of cells in the G1 phase of the cell cycle compared to tamoxifen alone, while SDCBP overexpression limited the anti-cancer effects of tamoxifen. SDCBP silencing and overexpression also enhanced and attenuated the estrogenic response, respectively. Expression of SDCBP was negatively correlated with PR, ERα, and the PR/ERα ratio in ER-positive BCa tissue samples.Conclusions: SDCBP may be involved in tamoxifen resistance in ER-positive BCa. Tamoxifen treatment combined with SDCBP silencing may provide a novel treatment for endocrine therapy-resistant BCa.