Markers of Early Pancreatic Cancer

项目描述（由申请人提供）：本项目的总体目标是开发新的胰腺癌血清和胰液标志物，用于诊断患者的疾病症状，并识别早期无症状胰腺癌患者。NCI项目评审小组（PRO）将其列为研究重点——“确定并开发早期发现胰腺癌及其‘前体’的监测和诊断方法”。一组敏感和特异性的胰腺腺癌标志物将极大地促进这种疾病的早期诊断和早期发现。我们将研究旨在检测血清或胰液中胰腺肿瘤的三种标记策略。每个目标都集中在特定的、特征明确的蛋白质或DNA标记物上，这些标记物已经成为第二阶段研究的主题。血清MIC-1 （aim # 1）对CA19-9的总体诊断敏感性较高。对于目标2，我们将重新评估一个众所周知的胰腺癌标志物，突变KRAS。以往的研究发现其在胰腺中的检测缺乏区分胰腺癌和胰腺炎所需的特异性。为了克服这种疾病特异性的缺乏，我们开发了一种新的、高度敏感和特异性的检测方法（“LigAmp”）来检测和量化点突变，如突变的KRAS。我们的初步2期研究表明，量化突变KRAS显著提高了其诊断效用。对于目标#3，我们将使用一种新的突变检测方法，当p53和pi 6等基因以低浓度存在于临床样品（如胰液）中时，该方法可以检测出这些基因中的未知突变（限制稀释pcr，或“LD-PCR”和异源双工分析（HA））。我们将3A的结果与p53基因芯片的结果进行比较。我们将追求的具体目标是：1：测定血清MIC-1的敏感性和特异性；1A：作为早期胰腺癌的标志物。IB：作为无症状胰腺癌高风险人群的预测指标，1C；以确定MIC-1不过表达的胰腺癌的生物学和临床意义。目标2A：开发和验证5种KRAS和1种BRAF LigAmp检测，以生产用于目标2B的面板。2B：证明LigAmp在胰腺癌患者和适当对照者的胰腺液和血清中检测和量化KRAS2和BRAF突变的诊断效用。3一个;为了证明一种新的检测方法（限制稀释PCR或LD-PCR与异源双工分析（HA））的诊断效用，以检测和量化患有胰腺疾病或接受胰腺癌筛查的患者胰液中的低丰度p53和pi 6突变。3 b;比较aim 3A （LD/PCR/HA）与p53 GeneChip检测胰腺液中p53突变的能力。我们还将确定结合来自这3个目标的标记的结果的诊断效用。

DESCRIPTION (provided by applicant): The overall goal of this project is to develop new serum and pancreatic juice markers of pancreatic cancer that can be used to diagnose patients with symptoms of their disease and to identify patients with early asymptomatic pancreatic cancer. The NCI Program review group (PRO) cited as a research priority- "to identify and develop surveillance and diagnostic methods for the early detection of pancreatic cancer and its' precursors'". A panel of sensitive and specific markers of pancreatic adenocarcinoma would greatly facilitate the early diagnosis and early detection of this disease. We will examine three marker strategies that aim to detect pancreatic neoplasia in serum or in pancreatic juice. Each aim focuses on specific, well-characterized protein or DNA markers that have already been the subject of phase 2 studies. One marker, serum MIC-1 (aim #l) has superior overall diagnostic sensitivity to CA19-9. For aim #2 we will re-evaluate a well-known marker of pancreatic cancer, mutant KRAS. Previous studies have found that its detection in the pancreas lacks the necessary specificity to differentiate pancreatic cancer from pancreatitis. To overcome this lack of disease specificity, we have developed a novel, highly sensitive and specific assay ("LigAmp") to detect and quantify point mutations such as mutant KRAS. Our preliminary phase 2 studies indicate that quantifying mutant KRAS significantly improves its diagnostic utility. For aim #3 we will use a novel mutation detection approach that can detect unknown mutations in genes such as p53 and pi 6 when they are present at low concentration in clinical samples such as pancreatic juice (limiting dilution-PCR, or "LD-PCR" and heteroduplex analysis (HA)). We will compare the results of 3A with those obtained using p53 Gene chips. The specific aims we will pursue are: Aim; 1: To determine the sensitivity and specificity of serum MIC-1; 1A: as a marker of early pancreatic cancer. IB: as a predictor of asymptomatic pancreatic cancer in a population at high risk of developing this disease, and 1C; to determine the biological and clinical significance of pancreatic cancers that do not overexpress MIC-1. Aim 2A: To develop and validate five KRAS and one BRAF LigAmp assays to produce a panel for use in aim 2B. 2B: To demonstrate the diagnostic utility of LigAmp to detect and quantify KRAS2 and BRAF mutations in pancreatic juice and in serum from patients with pancreatic cancer and appropriate controls. 3A; To demonstrate the diagnostic utility of a novel assay (Limiting dilution PCR or LD-PCR with Heteroduplex analysis (HA)) to detect and quantify low abundance p53 and pi 6 mutations in the pancreatic juice of patients with pancreatic disease or undergoing pancreatic cancer screening. 3B; To compare the results of aim 3A (LD/PCR/HA) with p53 GeneChip for their ability to detect p53 mutations in pancreatic juice. We will also determine the diagnostic utility of combining the results of the markers derived from these 3 Aims.