Proteomic definition of normal human luminal and myoepithelial breast cells purified from reduction mammoplasties

Normal human luminal and myoepithelial breast cells separately purified from a set of 10 reduction mammoplasties by using a double antibody magnetic affinity cell sorting and Dynabead immunomagnetic technique were used in two-dimensional gel proteome studies. A total of 43,302 proteins were detected across the 20 samples, and a master image for each cell type comprising a total of 1,738 unique proteins was derived. Differential analysis identified 170 proteins that were elevated 2-fold or more between the two breast cell types, and 51 of these were annotated by tandem mass spectrometry. Muscle-specific enzyme isoforms and contractile intermediate filaments including tropomyosin and smooth muscle (SM22) alpha protein were detected in the myoepithelial cells, and a large number of cytokeratin subclasses and isoforms characteristic of luminal cells were detected in this cell type. A further 134 nondifferentially regulated proteins were also annotated from the two breast cell types, making this the most extensive study to date of the protein expression map of the normal human breast and the basis for future studies of purified breast cancer cells.

本研究采用双抗体磁亲和细胞分选结合磁珠免疫磁珠（Dynabead）技术，从10例乳腺缩小成形术样本中分别纯化得到正常人乳腺腔上皮细胞与肌上皮细胞，并将其用于二维凝胶蛋白质组学研究。20份样本中共检测到43302种蛋白质，同时为两种细胞类型分别构建了包含1738种唯一蛋白质的主电泳图谱。差异表达分析筛选出两种乳腺细胞间表达上调2倍及以上的蛋白质共170种，其中51种通过串联质谱（tandem mass spectrometry）完成了注释。肌上皮细胞中检测到肌肉特异性酶同工型与收缩性中间丝蛋白，包括原肌球蛋白及平滑肌（SM22）α蛋白；腔上皮细胞则检出大量其特征性的细胞角蛋白亚型与同工型。此外还从两种乳腺细胞中注释得到134种无差异表达的蛋白质。本研究是迄今为止针对正常人乳腺蛋白质表达图谱最全面的研究，同时也为后续纯化乳腺癌细胞的相关研究奠定了基础。