Combating Cetuximab Resistance in Colorectal Cancer

对抗结直肠癌中的西妥昔单抗耐药性

• 批准号: 9287314
• 负责人: YUESHENG ZHANG
• 金额: $ 40.06万
• 依托单位: ROSWELL PARK CANCER INSTITUTE CORP
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9287314
• 关键词: Address; Adverse effects; Affinity; Anticoagulants; BRAF gene; Binding; Cancer Model; Cell Culture Techniques; Cell Line; Cell Surface Receptors; Cells; Cetuximab; Clinical; Coagulation Process; Collagen; Colorectal Cancer; Data; Development; Dimerization; Dipeptidases; ERBB2 gene; Endocytosis; Enoxaparin; Epidermal Growth Factor Receptor; Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor; ErbB4 gene; Extracellular Domain; Family member; Foundations; Goals; Heterodimerization; Human; In Vitro; Injectable; KRAS2 gene; Ligand Binding; Malignant Neoplasms; Medical; Metabolism; Modeling; Monoclonal Antibodies; Mus; Mutate; Mutation; Normal Cell; Oncogenic; Outcome; PIK3CA gene; Patients; Peptide Hydrolases; Pharmaceutical Preparations; Phosphorylation; Play; Proteins; Publishing; Receptor Protein-Tyrosine Kinases; Recombinants; Research; Resistance; Role; Signal Transduction; Signaling Molecule; Signaling Protein; Small Interfering RNA; Solid; Testing; Therapeutic; Toxic effect; Treatment Efficacy; Tyrosine Kinase Inhibitor; X-Pro dipeptidase; Xenograft Model; base; cancer cell; cancer therapy; cancer type; clinical efficacy; colon cancer cell line; combat; dimer; gain of function mutation; hypoxia inducible factor 1; in vivo; knock-down; member; mutant; novel; overexpression; panitumumab; receptor binding; research clinical testing; response; targeted agent; therapeutic target; tool; translational study; tumor

Epidermal growth factor receptor (EGFR), an oncogenic receptor tyrosine kinase, is a major therapeutic target in several types of cancers. Two EGFR monoclonal antibodies (mAbs) are used to treat EGFR- positive colorectal cancer (CRC), including cetuximab (CTX) and panitumumab, which have the same mechanism of action. Unfortunately, primary and acquired resistance to the mAbs is very common: response in only 10-20% patients and lasts typically for 3-12 months. Current approach to combating the resistance is to combine the mAb with agent(s) that targets compensatory or altered downstream signaling molecules (ErbB2, cMET, KRAS, BRAF and PIK3CA), but clinical efficacy of such approach is uncertain. Importantly, we found that hPEPDG278D, a recombinant enzymatically inactive mutant of human peptidase D, strongly inhibits the proliferation of all tested CTX-resistant CRC cell lines, and silences EGFR, ErbB2 and their downstream signaling molecules in these cells. Our results suggest that EGFR and ErbB2 are pivotal therapeutic targets in CTX-resistant CRC cells. We recently showed: a) hPEPDG278D specifically binds to the extracellular domain of EGFR and ErbB2, disrupts their signaling units and directs them for degradation via endocytosis, and therefore is a novel dual inhibitor of EGFR and ErbB2; b) it selectively inhibits cancer cells overexpressing EGFR and/or ErbB2 in vitro and in vivo; c) it does not show toxicities in mouse studies. The goal of our proposal is to further evaluate hPEPDG278D for overcoming CTX resistance and to substantiate the novel concept that EGFR and ErbB2 remain critical therapeutic targets in CTX-resistant CRC cells. We hypothesize that hPEPDG278D overcomes CTX resistance by suppressing both ErbB2 and CTX-insensitive EGFR, and propose three Aims to test the hypothesis. Aim 1 is to determine the therapeutic efficacy of hPEPDG278D against CTX-resistant CRC tumors in vivo, using both orthotoptic tumor models and patient- derived xenograft models. Oncogenic ErbB3 and ErbB4 (other EGFR members) as well as cMET are also implicated in CTX resistance in CRC. Aim 2 is to investigate whether hPEPDG278D indirectly suppresses ErbB3, ErbB4 and cMET by disrupting their heterodimerization with EGFR or ErbB2, using both cell lines and treated tumors from Aim 1. Besides targeting ErbB2, hPEPDG278D also targets both CTX-sensitive and -insensitive EGFR. Aim 3 is to determine the mechanisms by which hPEPDG278D targets CTX-insensitive (mutated or wild type) EGFR in relevant CRC cell lines. In summary, it is a widely accepted concept in the field that CRC resistance to CTX and other EGFR inhibitors results largely from activation of other signaling proteins (ErbB2, cMET, KRAS, BRAF or PI3K). We expect to show that the main reason for resistance to CTX is the insensitivity of EGFR to CTX along with ErbB2 overexpression; the impact of this paradigm- shifting concept on translational studies on EGFR-positive cancers should be significant. Findings from the project may also lay a solid foundation for clinical evaluation of hPEPDG278D against CRC and other cancers.

表皮生长因子受体 (EGFR) 是一种致癌受体酪氨酸激酶，是一种主要的治疗药物 靶向多种癌症。两种 EGFR 单克隆抗体 (mAb) 用于治疗 EGFR- 阳性结直肠癌（CRC），包括西妥昔单抗（CTX）和帕尼单抗，它们具有相同的 作用机制。不幸的是，对单克隆抗体的原发性和获得性耐药性非常常见： 仅 10-20% 的患者有反应，并且通常持续 3-12 个月。目前的应对方法 抵抗是将单克隆抗体与针对补偿性或改变下游信号传导的药物结合起来 分子（ErbB2、cMET、KRAS、BRAF 和 PIK3CA），但这种方法的临床疗效尚不确定。 重要的是，我们发现 hPEPDG278D 是人肽酶 D 的重组酶失活突变体， 强烈抑制所有测试的 CTX 耐药 CRC 细胞系的增殖，并沉默 EGFR、ErbB2 和 这些细胞中的下游信号分子。我们的结果表明 EGFR 和 ErbB2 至关重要 CTX 耐药 CRC 细胞的治疗靶点。我们最近表明：a) hPEPDG278D 特异性结合 EGFR 和 ErbB2 的胞外结构域，破坏它们的信号传导单元并指导它们通过 内吞作用，因此是一种新型 EGFR 和 ErbB2 双重抑制剂； b) 它选择性地抑制癌细胞 在体外和体内过度表达 EGFR 和/或 ErbB2； c) 在小鼠研究中未显示出毒性。这 我们提案的目标是进一步评估 hPEPDG278D 克服 CTX 耐药性并证实 EGFR 和 ErbB2 仍然是 CTX 耐药 CRC 细胞的关键治疗靶点的新概念。我们 假设 hPEPDG278D 通过抑制 ErbB2 和 CTX 不敏感来克服 CTX 耐药性 EGFR，并提出三个目标来检验该假设。目标1是确定治疗效果 hPEPDG278D 使用正交肿瘤模型和患者模型在体内对抗 CTX 耐药性 CRC 肿瘤 衍生的异种移植模型。致癌性 ErbB3 和 ErbB4（其他 EGFR 成员）以及 cMET 也属于 与 CRC 中的 CTX 耐药有关。目标 2 是研究 hPEPDG278D 是否间接抑制 使用两种细胞系，通过破坏 ErbB3、ErbB4 和 cMET 与 EGFR 或 ErbB2 的异二聚化 并治疗来自目标 1 的肿瘤。除了靶向 ErbB2 外，hPEPDG278D 还靶向 CTX 敏感和 -EGFR不敏感。目标 3 是确定 hPEPDG278D 靶向 CTX 不敏感的机制 相关 CRC 细胞系中的（突变型或野生型）EGFR。综上所述，这是一个被广泛接受的概念。 CRC 对 CTX 和其他 EGFR 抑制剂的耐药性很大程度上是由于其他信号传导的激活所致 蛋白质（ErbB2、cMET、KRAS、BRAF 或 PI3K）。我们希望表明抵制的主要原因 CTX 是 EGFR 对 CTX 不敏感以及 ErbB2 过表达；这种范式的影响—— EGFR 阳性癌症转化研究概念的转变应该具有重要意义。调查结果来自 该项目还可能为 hPEPDG278D 针对 CRC 和其他癌症的临床评估奠定坚实的基础。