Abstract：
OBJECTIVE: As an antagonist of bone morphogenetic protein (BMP), Noggin facilitates osteolytic bone metastases from breast cancer. The present study aimed to further dissect its role in oestrogen receptor (ER) positive breast cancer.
METHODS: Noggin expression in ER positive breast cancer cell lines (MCF-7 and T-47D) was determined under conditions of oestrogen deprivation and treatment with 17-β-oestradiol (E2). Activation of Smad1/5/8 in the oestrogen-regulated Noggin was examined using recombinant human BMP7 (rhBMP7) and a BMP receptor inhibitor (LDN-193189). The influence of Noggin on cellular functions was evaluated in MCF-7 and T-47D cell lines. Responses to tamoxifen and chemotherapy drugs were determined in MCF-7 and T-47D cells with Noggin over-expression using MTT assay.
RESULTS: Noggin expression was negatively correlated with ERα in breast cancers. Noggin was up-regulated upon oestrogen deprivation, an effect that was eliminated by E2 Furthermore, increased levels of phosphorylated Smad1/5/8 were observed in the oestrogen-deprived MCF-7 and T-47D cells, which was prevented by E2 and LDN-193189, respectively. BMP7-induced Noggin expression and activation of Smad1/5/8 was also prevented by E2 and LDN-193189. Noggin over-expression resulted in an increase in the proliferation of both MCF-7 and T-47D cells. MCF-7 and T-47D cells over-expressing Noggin exhibited a good tolerance to tamoxifen (TAM), DTX, and 5-FU, but the percentage of viable cells was higher compared with the controls.
CONCLUSIONS: Noggin expression can be repressed by oestrogen through inference with the BMP/Smad signalling. Over-expression of Noggin promotes the proliferation of MCF-7 and T-47D cells, contributing to drug resistance.
METHODS: Noggin expression in ER positive breast cancer cell lines (MCF-7 and T-47D) was determined under conditions of oestrogen deprivation and treatment with 17-β-oestradiol (E2). Activation of Smad1/5/8 in the oestrogen-regulated Noggin was examined using recombinant human BMP7 (rhBMP7) and a BMP receptor inhibitor (LDN-193189). The influence of Noggin on cellular functions was evaluated in MCF-7 and T-47D cell lines. Responses to tamoxifen and chemotherapy drugs were determined in MCF-7 and T-47D cells with Noggin over-expression using MTT assay.
RESULTS: Noggin expression was negatively correlated with ERα in breast cancers. Noggin was up-regulated upon oestrogen deprivation, an effect that was eliminated by E2 Furthermore, increased levels of phosphorylated Smad1/5/8 were observed in the oestrogen-deprived MCF-7 and T-47D cells, which was prevented by E2 and LDN-193189, respectively. BMP7-induced Noggin expression and activation of Smad1/5/8 was also prevented by E2 and LDN-193189. Noggin over-expression resulted in an increase in the proliferation of both MCF-7 and T-47D cells. MCF-7 and T-47D cells over-expressing Noggin exhibited a good tolerance to tamoxifen (TAM), DTX, and 5-FU, but the percentage of viable cells was higher compared with the controls.
CONCLUSIONS: Noggin expression can be repressed by oestrogen through inference with the BMP/Smad signalling. Over-expression of Noggin promotes the proliferation of MCF-7 and T-47D cells, contributing to drug resistance.
摘要：
目的：作为骨形态发生蛋白（BMP）的拮抗剂，Noggin促进乳腺癌的溶骨性骨转移。本研究旨在进一步剖析其在雌激素受体（ER）阳性乳腺癌中的作用。
方法：在雌激素剥夺和用17-β-雌二醇（E2）处理的条件下，测定ER阳性乳腺癌细胞系（MCF-7和T-47D）中的Noggin表达。使用重组人BMP7（rhBMP7）和BMP受体抑制剂（LDN-193189）检查了雌激素调节的Noggin中Smad1/5/8的激活。在MCF-7和T-47D细胞系中评价Noggin对细胞功能的影响。使用MTT测定法在具有Noggin过表达的MCF-7和T-47D细胞中确定对他莫昔芬和化疗药物的反应。
结果：Noggin在乳腺癌中的表达与ERα呈负相关。Noggin在雌激素剥夺后上调，此外，E2消除了这种影响，在雌激素剥夺的MCF-7和T-47D细胞中观察到磷酸化Smad1/5/8水平升高，分别由E2和LDN-193189阻止。E2和LDN-193189也阻止了BMP7诱导的Noggin表达和Smad1/5/8的激活。Noggin过表达导致MCF-7和T-47D细胞的增殖增加。过表达Noggin的MCF-7和T-47D细胞对他莫昔芬（TAM）表现出良好的耐受性，DTX,5-FU,但活细胞的百分比高于对照组。
结论：Noggin的表达可以通过BMP/Smad信号的推断而被雌激素抑制。过表达Noggin促进MCF-7和T-47D细胞增殖,有助于耐药性。
方法：在雌激素剥夺和用17-β-雌二醇（E2）处理的条件下，测定ER阳性乳腺癌细胞系（MCF-7和T-47D）中的Noggin表达。使用重组人BMP7（rhBMP7）和BMP受体抑制剂（LDN-193189）检查了雌激素调节的Noggin中Smad1/5/8的激活。在MCF-7和T-47D细胞系中评价Noggin对细胞功能的影响。使用MTT测定法在具有Noggin过表达的MCF-7和T-47D细胞中确定对他莫昔芬和化疗药物的反应。
结果：Noggin在乳腺癌中的表达与ERα呈负相关。Noggin在雌激素剥夺后上调，此外，E2消除了这种影响，在雌激素剥夺的MCF-7和T-47D细胞中观察到磷酸化Smad1/5/8水平升高，分别由E2和LDN-193189阻止。E2和LDN-193189也阻止了BMP7诱导的Noggin表达和Smad1/5/8的激活。Noggin过表达导致MCF-7和T-47D细胞的增殖增加。过表达Noggin的MCF-7和T-47D细胞对他莫昔芬（TAM）表现出良好的耐受性，DTX,5-FU,但活细胞的百分比高于对照组。
结论：Noggin的表达可以通过BMP/Smad信号的推断而被雌激素抑制。过表达Noggin促进MCF-7和T-47D细胞增殖,有助于耐药性。
