Optimization of enrichment for MALDI TOF/TOF identification of cancer biomarkers

描述（由申请人提供）：早期发现癌症和癌前病变可提高患者生存率。本研究优化了发现肝细胞癌（HCC）患者血清中多肽和蛋白（P/P）的诊断方法。为了鉴定HCC的生物标志物，我们建立了血清低分子量（LMW）部分的富集方法，用于基质辅助激光解吸电离飞行时间（MALDI- TOF/TOF）质谱法（MS）。该方法允许高通量群体筛选以及通过TOF/TOF测序鉴定感兴趣的肽。我们在一组HCC病例和匹配对照中测试了生物标志物发现方法，确定了一组预测HCC的P/P，预测准确率超过90%。在这项研究中，我们建议将方法调整为使用WCX和Cu-IMAC磁珠进行互补富集，扩大研究范围，包括与恶性前肝病（150例，150例匹配对照，50例肝硬化）的比较，并开始通过测序鉴定候选生物标志物。样本来自我们正在埃及进行的HCC病例对照研究，埃及是一个丙型肝炎感染和HCC流行的国家。我们的目标是确定生物标志物，以改善HCC的早期检测，并追踪慢性病毒感染到癌症的自然进展。生物标记物的鉴定将通过MALDI-TOF/TOF测序和互补液相色谱/质谱法进行验证。确定临床适用的早期癌症生物标志物对疾病管理和患者健康具有潜在的深远影响。这些生物标志物可用于筛选高风险人群，发现疾病的早期迹象；设计和测试改进的化学预防策略；并跟踪治疗后的疾病进展。P/P的识别有望为靶向疾病管理产生新的假设。

DESCRIPTION (provided by applicant): Early detection of cancer and precancerous conditions improves patient survival. This study optimizes methods for discovery of a diagnostic set of peptides and proteins (P/P) in serum of patients with hepatocellular carcinoma (HCC). To identify biomarkers of HCC, we developed enrichment of low molecular weight (LMW) fraction of serum for matrix assisted laser desorption ionization-time of flight (MALDI- TOF/TOF) mass spectrometry (MS). This method allows high-throughput population screening as well as identification of the peptides of interest by TOF/TOF sequencing. We tested the biomarker discovery method on a pilot set of HCC cases and matched controls, which identified a set of P/P predictive of HCC with greater than 90% prediction accuracy. In this study, we propose to adjust the method to complementary enrichment using WCX and Cu-IMAC magnetic beads, expand the study to include a comparison with premalignant liver disease (150 cases, 150 matched controls, 50 cirrhosis), and to begin identification of the biomarker-candidates by sequencing. The samples come from our ongoing case-control study of HCC in Egypt, a country with an epidemic of hepatitis C infection and HCC. Our goal is to identify biomarkers that would improved early detection of HCC and track the natural progression of chronic viral infection to cancer. The identity of the biomarkers will be verified by MALDI-TOF/TOF sequencing and complementary liquid chromatography/mass spectrometry methods. Defining clinically applicable biomarkers of early-stage cancer has potentially far-reaching consequences for disease management and patient health. The biomarkers could be used to screen high risk populations for early signs of disease; to design and test improved chemoprevention strategies; and to follow disease progression after treatment. Identification of the P/P is expected to generate new hypotheses for targeted disease management.