SDF-1α,a ligand for the chemokine receptor CXCR4,is well known for mediating the migration of breast cancer cells.In a previous study we demonstrated that a synthetic 21-mer peptide antagonist of CXCR4（NT21MP） deri...SDF-1α,a ligand for the chemokine receptor CXCR4,is well known for mediating the migration of breast cancer cells.In a previous study we demonstrated that a synthetic 21-mer peptide antagonist of CXCR4（NT21MP） derived from the viral macrophage inflammatory protein Ⅱ could antagonize tumor growth in vivo by inhibiting cellular proliferation and inducing apoptosis in breast cancer cells.However,the role of SDF-1α in the signaling pathways underlying the proliferation of human breast cancer cells and associated signaling pathways and inhibiting signal pathways of NT21MP remained unclear.The present study investigated the mechanism of NT21MP on anti-tumor in breast cancer in vitro.The effect of NT21MP on the viability of cells was determined by the MTT assay.Annexin V-FITC and PI staining was performed to detect early stage apoptosisin SKBR3 cells treated with SDF-1α and AMD3100 or NT21MP.Western blotting techniques were used to assay the composition of phosphoproteomics and total proteins present in the SKBR3 breast cancer cells.RT-PCR and Western blotting technique were used to detect the effect of NT21MP and AMD3100 on Bcl-2 and Bax expression.The results indicated that SDF-1α prevented apoptosis and promoted the proliferation of SKBR3 human breast cancer cells.As compared with untreated SKBR3 cells,Treatment with SDF-1α significantly increased cell viability,and NT21MP abolished the protective effects of SDF-1α dose-dependently（P0.05）.There was a significant decrease in the percentage of apoptotic cells after SDF-1α treatment as compared with control group（2.7%±0.2% vs.5.7%±0.4%,P0.05）.But pretreatment of SKBR3 cells with NT21MP significantly attenuated the antiapoptotic effects of SDF-1α as compared with SKBR3 cells without NT21MP pretreatment.The proliferative and anti-apoptotic effects of SDF-1α in SKBR3 cells were associated with an increase in AKT and ERK1/2 phosphorylation as well as a decrease in Bax expression and an increase in Bcl-2 expression.These changes in intracellular processes were blocked by NT21MP in a dose-dependent manner（P0.05）.In conclusion,NT21MP efficiently inhibits SDF-1α-induced proliferation and antiapoptosis in SKBR3 cells by reducing the levels of phosphorylated AKT and ERK1/2,as well as decreasing the ratio of expression of Bcl-2 relative to Bax.展开更多
目的构建细胞穿膜肽PEP-1与vMIP-Ⅱ融合基因的表达质粒,原核表达、纯化并鉴定PEP1-vMIP-Ⅱ融合蛋白,鉴定该蛋白的穿膜功能,研究其对血管增生相关基因表达的影响。方法将化学合成的细胞穿膜肽PEP1和vMIP-Ⅱ基因克隆到原核表达载体pET15b...目的构建细胞穿膜肽PEP-1与vMIP-Ⅱ融合基因的表达质粒,原核表达、纯化并鉴定PEP1-vMIP-Ⅱ融合蛋白,鉴定该蛋白的穿膜功能,研究其对血管增生相关基因表达的影响。方法将化学合成的细胞穿膜肽PEP1和vMIP-Ⅱ基因克隆到原核表达载体pET15b,构建pET15b-pep-1-vMIP-Ⅱ质粒。表达纯化后,Western-blot鉴定蛋白,荧光共聚焦显微镜观察融合蛋白的穿膜功能。Real time PCR检测该蛋白作用对HMEC-1细胞内血管增生相关基因表达的改变。结果 DNA测序和酶切结果鉴定了pET15b-PEP1-vMIP-Ⅱ载体构建正确,Western blot鉴定纯化的融合蛋白PEP1-vMIP-Ⅱ与所预测相对分子质量相符。激光共聚焦显微镜检测到该蛋白能够进入细胞,在HMEC-1细胞内上调了促血管增生基因VEGFA和VEGFC的表达。结论成功构建了pET15b-PEP1-vMIP-Ⅱ载体,表达纯化的PEP1-vMIP-Ⅱ融合蛋白具有穿透细胞膜的功能,且能显著上调促进血管增生基因VEGFA和VEGFC的表达。展开更多
基金supported by a grant from the National Natural Sciences Foundation of China (No. 81071848)a grant from a Key Program of Anhui Educational Committee(No. KJ2010A240)
文摘SDF-1α,a ligand for the chemokine receptor CXCR4,is well known for mediating the migration of breast cancer cells.In a previous study we demonstrated that a synthetic 21-mer peptide antagonist of CXCR4（NT21MP） derived from the viral macrophage inflammatory protein Ⅱ could antagonize tumor growth in vivo by inhibiting cellular proliferation and inducing apoptosis in breast cancer cells.However,the role of SDF-1α in the signaling pathways underlying the proliferation of human breast cancer cells and associated signaling pathways and inhibiting signal pathways of NT21MP remained unclear.The present study investigated the mechanism of NT21MP on anti-tumor in breast cancer in vitro.The effect of NT21MP on the viability of cells was determined by the MTT assay.Annexin V-FITC and PI staining was performed to detect early stage apoptosisin SKBR3 cells treated with SDF-1α and AMD3100 or NT21MP.Western blotting techniques were used to assay the composition of phosphoproteomics and total proteins present in the SKBR3 breast cancer cells.RT-PCR and Western blotting technique were used to detect the effect of NT21MP and AMD3100 on Bcl-2 and Bax expression.The results indicated that SDF-1α prevented apoptosis and promoted the proliferation of SKBR3 human breast cancer cells.As compared with untreated SKBR3 cells,Treatment with SDF-1α significantly increased cell viability,and NT21MP abolished the protective effects of SDF-1α dose-dependently（P0.05）.There was a significant decrease in the percentage of apoptotic cells after SDF-1α treatment as compared with control group（2.7%±0.2% vs.5.7%±0.4%,P0.05）.But pretreatment of SKBR3 cells with NT21MP significantly attenuated the antiapoptotic effects of SDF-1α as compared with SKBR3 cells without NT21MP pretreatment.The proliferative and anti-apoptotic effects of SDF-1α in SKBR3 cells were associated with an increase in AKT and ERK1/2 phosphorylation as well as a decrease in Bax expression and an increase in Bcl-2 expression.These changes in intracellular processes were blocked by NT21MP in a dose-dependent manner（P0.05）.In conclusion,NT21MP efficiently inhibits SDF-1α-induced proliferation and antiapoptosis in SKBR3 cells by reducing the levels of phosphorylated AKT and ERK1/2,as well as decreasing the ratio of expression of Bcl-2 relative to Bax.
文摘目的构建细胞穿膜肽PEP-1与vMIP-Ⅱ融合基因的表达质粒,原核表达、纯化并鉴定PEP1-vMIP-Ⅱ融合蛋白,鉴定该蛋白的穿膜功能,研究其对血管增生相关基因表达的影响。方法将化学合成的细胞穿膜肽PEP1和vMIP-Ⅱ基因克隆到原核表达载体pET15b,构建pET15b-pep-1-vMIP-Ⅱ质粒。表达纯化后,Western-blot鉴定蛋白,荧光共聚焦显微镜观察融合蛋白的穿膜功能。Real time PCR检测该蛋白作用对HMEC-1细胞内血管增生相关基因表达的改变。结果 DNA测序和酶切结果鉴定了pET15b-PEP1-vMIP-Ⅱ载体构建正确,Western blot鉴定纯化的融合蛋白PEP1-vMIP-Ⅱ与所预测相对分子质量相符。激光共聚焦显微镜检测到该蛋白能够进入细胞,在HMEC-1细胞内上调了促血管增生基因VEGFA和VEGFC的表达。结论成功构建了pET15b-PEP1-vMIP-Ⅱ载体,表达纯化的PEP1-vMIP-Ⅱ融合蛋白具有穿透细胞膜的功能,且能显著上调促进血管增生基因VEGFA和VEGFC的表达。
