Cancer Research UK Clinical Centre, Leeds Institute of Molecular Medicine, St. James's University Hospital, Leeds, UK.
Proteomics Clin Appl. 2009 Sep;3(9):1112-22. doi: 10.1002/prca.200900015.
During the initial phases of a study focussed on discovering new urinary biomarkers for renal cell carcinoma, a number of challenges and limitations were identified, which we subsequently investigated. The purpose of this report is to provide insight into experimental design for such investigations and potential confounding factors that can impact on such studies. Sixty urine samples from 20 patients with clear cell renal cell carcinoma and ten live renal transplant donor patients, pre- and post-nephrectomy, were profiled using SELDI-TOF-MS incorporating stringent quality control and in-house data processing/analysis. There were 65 significantly differentially expressed peaks (five solitary peaks and four peak clusters that increased post nephrectomy and four peak clusters that decreased). Peak 3934 Da m/z and peaks within 11731-11961 Da m/z, which increased post nephrectomy were identified as the 36 amino acid isoform of β-defensin-1 and β(2) -microglobulin, respectively. However, changes in these two protein forms were also seen in healthy donors following nephrectomy implying a relationship with kidney removal per se rather than tumour removal. This study indicates the difficulties in identifying SELDI peaks for subsequent validation and illustrates the need for appropriate controls in biomarker studies to determine whether changes are indirect consequences of treatment.
在一项专注于发现肾细胞癌新的尿生物标志物的研究的初始阶段，我们确定了一些挑战和限制，并随后对其进行了研究。本报告的目的是提供此类研究的实验设计和可能影响此类研究的潜在混杂因素的深入了解。使用 SELDI-TOF-MS 对 20 例透明细胞肾细胞癌患者和 10 例活体肾移植供体患者的 60 个尿液样本进行了分析，其中包括严格的质量控制和内部数据处理/分析。有 65 个差异显著的表达峰（5 个孤立峰和 4 个术后增加的峰簇和 4 个术后减少的峰簇）。确定 3934 Da m/z 峰和术后增加的 11731-11961 Da m/z 范围内的峰分别为β-防御素-1 和β(2)-微球蛋白的 36 个氨基酸同工型。然而，在肾切除术后健康供体中也观察到这两种蛋白质形式的变化，这表明与肾切除本身有关，而不是与肿瘤切除有关。本研究表明了鉴定 SELDI 峰以进行后续验证的困难，并说明了在生物标志物研究中需要适当的对照来确定变化是否是治疗的间接后果。
