School of Biomedical Engineering and Med-X Research Institute, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, PR China.
Proteomics. 2012 Jan;12(1):32-6. doi: 10.1002/pmic.201100323. Epub 2011 Nov 29.
Secreted proteins play important roles in physiological and pathological processes. However, effective proteomic detection of low-abundant secreted proteins is often shielded by the presence of a large amount of intracellular proteins released from unavoidable dead cells during cell culture. In the present study, we applied lectin affinity capture approach to enrich the secreted proteins in the conditioned media (CM) of three human breast cell lines (MCF-10A, MCF-7, and MDA-MB-231). Lectin capture showed efficient enrichment of the secreted proteins in CM of all three cell lines and significantly increased the number of secreted proteins detected: from 183 to 292 for MCF-10A, 196 to 325 for MCF-7, and 194 to 368 for MDA-MB-231. Based on more comprehensive profiling of the secreted proteins, we identified 92 secreted proteins which were both upregulated in MCF-7 and MDA-MB-231, with 82 only found in lectin-captured samples. It should be noted that among these 82 potential biomarkers, 59 were not reported in the previous proteomic studies of breast cancer. These data indicate that the lectin capture approach is a powerful means to move toward more comprehensive analysis and comparison of secretomes.
分泌蛋白在生理和病理过程中起着重要作用。然而，在细胞培养过程中，不可避免的死细胞会释放大量的细胞内蛋白，这常常会屏蔽对低丰度分泌蛋白的有效蛋白质组学检测。在本研究中，我们应用凝集素亲和捕获法来富集三种人乳腺癌细胞系（MCF-10A、MCF-7 和 MDA-MB-231）的条件培养基（CM）中的分泌蛋白。凝集素捕获在所有三种细胞系的 CM 中都能有效地富集分泌蛋白，并显著增加了检测到的分泌蛋白数量：MCF-10A 从 183 种增加到 292 种，MCF-7 从 196 种增加到 325 种，MDA-MB-231 从 194 种增加到 368 种。基于对分泌蛋白的更全面分析，我们鉴定了 92 种在 MCF-7 和 MDA-MB-231 中均上调的分泌蛋白，其中 82 种仅在凝集素捕获的样本中发现。值得注意的是，在这些 82 个潜在的生物标志物中，有 59 个在以前的乳腺癌蛋白质组学研究中没有报道过。这些数据表明，凝集素捕获方法是一种强大的手段，可以更全面地分析和比较分泌组。
