Exosome-based microRNA biomarkers for Non-invasive and Early Detection of Pancreatic Cancer

项目摘要：胰腺癌是一种高度侵袭性的恶性肿瘤，估计将成为 到2026年，癌症相关死亡的第二大原因。胰腺导管腺癌(PDAC) 占所有胰腺癌病例的90%，总体五年生存率约为8%，是 严重的癌症。在PDAC中，只有15%-20%的患者存在局部的、可切除的、潜在可治愈的肿瘤 在初步诊断时。然而，目前还没有得到满足的临床需求缺乏高度健壮的 早期发现PDAC的诊断策略。MicroRNAs(MiRNAs)是一种小的非编码RNA， 调节与包括PDAC在内的所有人类癌症有关的基因，因此可能是理想的生物标志物。的确， 循环中的无细胞miRNAs(cf-miRNAs)已被证明具有诊断潜力。此外，最近的 发现癌细胞在称为外小体的细胞外小泡中主动分泌miRNAs (exo-miRNAs)使该领域发生了革命性的变化，因为肿瘤来源的外体货物能够识别癌症- 特定的分子标记。在前一个资助周期中，我们进行了公正和全基因组的 基于测序的miRNA分析方法，以及严格的生物信息学和机器学习 算法，以及1)确定了由5个cf-miRNAs和8个exo-miRNAs组成的小组，这些小组可以有力地识别患有 早期pdac；2)将cf-miRNAs和exo-miRNAs组合成“转录切割标记”，优于 单独的生物标志物小组，包括早期(I/II期)疾病的患者；3)联合 我们与CA19-9的转录切割签名进一步提高了诊断性能；以及4)最重要的是， 显示我们的转录特征准确地识别了CA19-9阴性的PDAC患者。 在这次竞争的续签申请中，我们将在以往成功的基础上，致力于实现4个具体目标。 在目标1中，我们将通过继续招募PDAC患者和 癌前肿瘤(PNS)，包括那些患有胰腺囊性肿瘤(PCN)和有家族风险的人， 另一个重点是种族/少数族裔人口患者的登记和标本采集。 在目标2中，我们将进一步验证转录签名，并确定其在预期队列中的表现 在早期PDAC患者中的比例。在目标3，我们将确定我们的转录本的临床意义 在术前采集的血浆中检测高度不典型增生和浸润性癌存在的标志 来自临床诊断为PCNS的患者。在目标4中，我们将评估我们的转录签名的能力 在诊断前血浆标本中检测PDAC的最早阶段，并确定在诊断前 疾病表现。我们提出的项目将是第一个在临床上可行的、敏感的、特异的、 以及可靠的基于血液的检测，以在可能的早期阶段识别PDAC患者。如果成功， 该项目将推动一种简单、方便、廉价的非侵入性检测方法在临床上的应用。 这将深刻改变PDAC的早期检测，并与其他癌症相关。

PROJECT SUMMARY: Pancreatic cancer is a highly aggressive malignancy that is estimated to become the second leading cause of cancer-related deaths by 2026. Pancreatic ductal adenocarcinoma (PDAC) accounts for >90% of all pancreatic cancer cases and has an overall five-year survival rate of ~8%, the lowest among the major cancers. In PDAC, only 15–20% of patients present with localized, resectable, potentially curable tumors at initial diagnosis. However, currently there is an unmet clinical need for the lack of availability of highly robust diagnostic strategies for the early detection of PDAC. MicroRNAs (miRNAs) are small non-coding RNAs that regulate genes implicated in every human cancer, including PDAC, and may thus be ideal biomarkers. Indeed, circulating cell-free miRNAs (cf-miRNAs) have been shown to have diagnostic potential. Furthermore, the recent discovery that cancer cells actively excrete miRNAs in small extracellular vesicles called exosomes (exo-miRNAs) has revolutionized the field, as tumor-derived exosomal cargo enables the identification of cancer- specific molecular markers. During the previous cycle of funding, we performed unbiased and genome-wide sequencing-based miRNA profiling approaches, together with rigorous bioinformatics and machine-learning algorithms, and 1) identified panels of 5 cf-miRNAs and 8 exo-miRNAs that could robustly identify patients with early-stage PDAC; 2) combined the cf- and exo-miRNAs into a “transcriptomic signature” that was superior to individual biomarker panels, including patients with early-stage (stage I/II) disease; 3) showed that combining our transcriptomic signature with CA19-9 further improved diagnostic performance; and 4) most importantly, showed that our transcriptomic signature accurately identified patients with PDAC who were CA19-9-negative. In this competing renewal application, we will build upon our previous success by undertaking 4 specific aims. In Aim 1, we will expand our biorepository via continued prospective enrollment of patients with PDAC and precancerous neoplasms (PNs), including those with pancreatic cystic neoplasms (PCNs) and familial risk, with an additional focus on enrollment of and specimen collection from patients of racial/ethnic minority populations. In Aim 2, we will further validate the transcriptomic signature and establish its performance in prospective cohorts of patients with early-stage PDAC. In Aim 3, we will determine the clinical significance of our transcriptomic signature to detect the presence of high-grade dysplasia and invasive cancer in pre-operative plasma collected from patients clinically diagnosed as PCNs. In Aim 4, we will evaluate the ability of our transcriptomic signature to detect PDAC at its earliest stages in pre-diagnosis plasma specimens and to determine lead time before disease presentation. Our proposed project will be the first to establish a clinically feasible, sensitive, specific, and robust blood-based assay for identifying patients with PDAC at the earliest possible stages. If successful, this project will advance a simple, facile, and inexpensive non-invasive assay for routine clinical implementation that will profoundly transform the early detection of PDAC, with relevance for other cancers.