BDE-209暴露通过STAT3信号通路促进三阴性乳腺癌细胞的迁移

Decarbromodiphenyl ether(BDE-209)exposure promotes migration of triple-negative breast cancer cells through STAT3 signaling pathway

目的 通过检测在人体中含量较高的新型污染物——十溴联苯醚(BDE-209)暴露对三阴性乳腺癌细胞MDE-MB-231迁移能力的影响,探讨BDE-209暴露对三阴性乳腺癌(triple-negative breast cancer, TNBC)发展的影响及其可能的作用机制。方法 将TNBC细胞MDA-MB-231分为3组:空白对照组(仅含DMEM高糖培养液)、溶剂对照组(含2%DMSO的DMEM高糖培养液)、BDE-209暴露组(在DMEM高糖培养液中加入0.02、0.2、2、20、200、2 000 ng/mL BDE-209),暴露24 h后采用CCK-8实验根据半数抑制浓度(IC50)确定BDE-209的暴露浓度。划痕实验与Transwell小室检测BDE-209暴露对MDA-MB-231细胞迁移能力的影响。运用Western blot和细胞免疫组织化检测信号转导和转录活化因子3(signal transducers and activators of transcription 3,STAT3)及其磷酸化(p-STAT3)的表达水平。采用小鼠荷瘤实验检测BDE-209暴露对于TNBC肿瘤组织中STAT3的表达与活化的影响。结果 与空白对照组比较,BDE-209暴露即可显著提高MDA-MB-231细胞的迁移能力(P<0.01),且呈剂量依赖效应。Western blot和细胞免疫组化检测结果显示,BDE-209暴露显著提高TNBC肿瘤细胞STAT3及p-STAT3的表达(P<0.05)。TNBC荷瘤小鼠结果表明STAT3及p-STAT3在BDE-209(200 ng/mL)暴露后TNBC细胞形成的肿瘤组织中表达量均显著提高。以STAT3抑制剂(STAT3-IN-1)抑制STAT3信号通路后,BDE-209暴露后增加MDA-MB-231的迁移能力受到显著抑制(P<0.001)。结论 BDE-209暴露可通过上调STAT3的表达与活化增加TNBC细胞的迁移能力,促进TNBC的转移。

Objective To explore the exposure of decarbromo diphenyl ether(BDE-209),a new persistent organic pollutant(POP)with the highest level in human body,on the migration of triple-negative breast cancer(TNBC)cell line MDE-MB-231,and explore the effects of its exposure on the development of TNBC and underlying mechanism in the process.Methods MDA-MB-231 cells were divided into blank control group(high glucose DMEM),solvent control group(2%DMSO in high glucose DMEM)and BDE-209 exposure groups(0.02,0.2,2,20,200 and 2000 ng/mL BDE-209 in high glucose DMEM).In 24 h after culture,CCK-8 assay was used to determine the IC_(50)value of BDE-209.Scratch wound assay and Transwell assay were employed to determine the effect of BDE-209 exposure on migration ability of MDA-MB-231 cells.The protein levels of signal transducers and activators of transcription 3(STAT3)and its phosphorylation level(p-STAT3)were detected with Western blotting and immunocytochemical assay.The effect of BDE-209 exposure on the expression and activation of STAT3 in tumor-bearing mice with transplantation of 4T1 cells.Results BDE-209 exposure significantly promoted the migration of MDA-MB-231 cells,in a dose-dependent manner,when compared with blank control cells(P0.01).Western blotting and immunocytochemical assay showed that BDE-209 exposure enhanced the expression of STAT3 and p-STAT3 in MDA-MB-231 cells(P0.05).In tumor-bearing mice,the expression levels of STAT3 and p-STAT3 were obviously enhanced in the TNBC tissues after exposure to 200 ng/mL BDE-209.While,treatment of STAT3 inhibitor STAT3-IN-1 could notably suppress the migration of MDA-MB-231 cells induced by BDE-209 exposure(P0.001).Conclusion BDE-209 exposure promotes the migration ability of TNBC cells via up-regulation and activation of STAT3,and thus improve the metastasis.