一种用于通过蛋白质印迹法定量福尔马林固定石蜡包埋组织中蛋白质表达的新型蛋白质提取方法的开发与验证。
Development and validation of a novel protein extraction methodology for quantitation of protein expression in formalin-fixed paraffin-embedded tissues using western blotting.
作者信息
Nirmalan Niroshini J, Harnden Patricia, Selby Peter J, Banks Rosamonde E
机构信息
Clinical and Biomedical Proteomics Group, Cancer Research UK Clinical Centre, Leeds, UK.
出版信息
J Pathol. 2009 Mar;217(4):497-506. doi: 10.1002/path.2504.
The development of efficient formaldehyde cross-link reversal strategies will make the vast diagnostic tissue archives of pathology departments amenable to prospective and retrospective translational research, particularly in biomarker-driven proteomic investigations. Heat-induced antigen retrieval strategies (HIARs) have achieved varying degrees of cross-link reversal, potentially enabling archival tissue usage for proteomic applications outside its current remit of immunohistochemistry (IHC). While most successes achieved so far have been based on retrieving tryptic peptide fragments using shot-gun proteomic approaches, attempts at extracting full-length, non-degraded, immunoreactive proteins from archival tissue have proved challenging. We have developed a novel heat-induced antigen retrieval strategy using SDS-containing Laemmli buffer for efficient intact protein recovery from formalin-fixed tissues for subsequent analysis by western blotting. Protocol optimization and comparison of extraction efficacies with frozen tissues and current leader methodology is presented. Quantitative validation of methodology was carried out in a cohort of matched tumour/normal, frozen/FFPE renal tissue samples from 10 patients, probed by western blotting for a selected panel of seven proteins known to be differentially expressed in renal cancer. Our data show that the protocol enables efficient extraction of non-degraded, full-length, immunoreactive protein, with tumour versus normal differential expression profiles for a majority of the panel of proteins tested being comparable to matched frozen tissue controls (rank correlation, r = 0.7292, p < 1.825e-09). However, the variability observed in extraction efficacies for some membrane proteins emphasizes the need for cautious interpretation of quantitative data from this subset of proteins. The method provides a viable, cost-effective quantitative option for the validation of potential biomarker panels through a range of clinical samples from existing diagnostic archives, provided that validation of the method is first carried out for the specific proteins under study.
高效甲醛交联逆转策略的发展将使病理科大量的诊断组织档案适用于前瞻性和回顾性转化研究,特别是在生物标志物驱动的蛋白质组学研究中。热诱导抗原修复策略(HIARs)已实现了不同程度的交联逆转,这有可能使存档组织可用于当前免疫组织化学(IHC)范围之外的蛋白质组学应用。虽然目前取得的大多数成功都是基于使用鸟枪法蛋白质组学方法检索胰蛋白酶肽片段,但从存档组织中提取全长、未降解的免疫反应性蛋白质的尝试已证明具有挑战性。我们开发了一种新型热诱导抗原修复策略,使用含SDS的Laemmli缓冲液从福尔马林固定组织中高效回收完整蛋白质,以便随后通过蛋白质印迹法进行分析。本文介绍了方案优化以及与冷冻组织和当前领先方法的提取效率比较。在10名患者的一组匹配的肿瘤/正常、冷冻/FFPE肾组织样本中进行了方法的定量验证,通过蛋白质印迹法检测了一组选定的七种已知在肾癌中差异表达的蛋白质。我们的数据表明,该方案能够高效提取未降解的全长免疫反应性蛋白质,对于大多数测试的蛋白质组,肿瘤与正常的差异表达谱与匹配的冷冻组织对照相当(等级相关性,r = 0.7292,p < 1.825e - 09)。然而,在一些膜蛋白提取效率中观察到的变异性强调了对这一子集蛋白质的定量数据进行谨慎解释的必要性。该方法为通过现有诊断档案中的一系列临床样本验证潜在生物标志物组提供了一种可行、经济高效的定量选择,前提是首先针对所研究的特定蛋白质对该方法进行验证。