Multiplexed Single-Cell Analysis of EGFR and HER2 Activity in Gastric Cancer Cell

描述(申请人提供)：除肺癌外，全球范围内胃癌导致的死亡人数比其他任何癌症都多。虽然西方国家的胃癌发病率相对较低，但该地区的患者很少出现在疾病的早期阶段。随之而来的高死亡率产生了改善治疗的迫切需要。针对胃癌治疗的分子靶向治疗方法，如激酶抑制剂，正在进行深入的研究。特别令人感兴趣的是抑制HER2和EGFR激酶的药物，这是人类表皮生长因子受体(HER)家族的受体酪氨酸激酶，在胃癌亚群中表现出异常活性。目前，FDA已经批准使用HER2抑制剂曲妥珠单抗治疗一些胃癌，几种EGFR抑制剂正在进行II期和III期临床试验，以评估与细胞毒性化疗联合治疗胃癌的疗效。随着这些靶向药物的出现，迫切需要准确地确定患者是否有资格接受抗Her治疗。这项工作建议开发一种工具，通过直接在单细胞水平上分析HER2和EGFR激酶的异常活性来解决当前诊断技术的许多局限性。通过使用非天然侧链文库对多肽支架进行迭代组合优化，将产生高选择性的HER2和EGFR激酶多肽底物 功能。装载有荧光标记底物的单个细胞将被裂解并使用由荧光显微镜和具有激光诱导荧光检测的高灵敏度毛细管电泳仪组成的单细胞分析系统进行分析。这项技术非常适合于小型临床活检，将同时应用于胃癌模型和患者样本，以便在单细胞水平上定量评估EGFR和HER2信号失调。 公共卫生相关性：这项工作将开发一种诊断工具，用于多路、选择性地量化单个胃癌细胞中HER2和EGFR激酶的活性。这项技术将能够改进针对HER2和EGFR激酶的靶向癌症治疗的患者资格评估。

DESCRIPTION (provided by applicant): Gastric cancer causes more deaths worldwide than any other cancer, with the exception of lung cancer. Though the incidence of gastric cancer in Western nations is relatively low, patients in this region rarely present at an early stage of the disease. Consequent high mortality rates create a pressing need for improved treatment. Molecularly targeted therapies such as kinase inhibitors are under intensive investigation for treatment of gastric cancer. Of particular interest are drugs inhibiting HER2 and EGFR kinases, receptor tyrosine kinases of the human epidermal growth factor receptor (HER) family that demonstrate aberrant activity in subsets of gastric cancer. Currently, the FDA has approved the use of the HER2 inhibitor trastuzumab for the treatment of some gastric cancers, and several EGFR inhibitors are being evaluated in phase II and III clinical trials for efficacy in gastric caner therapy in combination with cytotoxic chemotherapy. With the advent of these targeted agents has arisen an urgent need to accurately determine patient eligibility for anti-HER treatment. This work proposes to develop a tool that addresses many of the limitations of current diagnostic technologies by directly assaying aberrant activity of HER2 and EGFR kinases at the single cell level. Highly selective peptide substrates of HER2 and EGFR kinase will be generated via iterative combinatorial optimization of a peptide scaffold using libraries of non-native side chain functionalities. Single cells loaded with fluorescently labeled substrates will be lysed and analyzed with a single-cell analysis system comprised of a fluorescence microscope and an exquisitely sensitive capillary electrophoresis system with laser-induced fluorescence detection. Ideally suited to small clinical biopsies, this technology will be applied both to gastric cancer models and to patient samples in order to quantitatively evaluate EGFR and HER2 signaling dysregulation at the single-cell level. PUBLIC HEALTH RELEVANCE: This work will develop a diagnostic tool for multiplexed, selective quantification of HER2 and EGFR kinase activities in single gastric cancer cells. This technology will enable improved evaluation of patient eligibility for targeted cancer therapies directed against HER2 and EGFR kinases.