Gene-Targeted Apoptosis as a Treatment for HER2-Positive Breast Cancer

基因靶向细胞凋亡治疗 HER2 阳性乳腺癌

• 批准号: 8877004
• 负责人: Faye A Rogers
• 金额: $ 21.73万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-10 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8877004
• 关键词: Antibodies; Antineoplastic Agents; Apoptosis; Binding; Biological Assay; Breast Cancer Cell; Breast Cancer Patient; Breast Cancer Treatment; Cell Line; Cell physiology; Cells; Clinical; Complex; DNA; DNA Binding; DNA Damage; DNA Repair; DNA Repair Pathway; DNA Structure; Data; Drug Targeting; Drug effect disorder; Drug resistance; ERBB2 gene; Effectiveness; Equilibrium; Foundations; Gene Amplification; Gene Dosage; Gene Targeting; Genes; Genome; Genomics; Goals; Growth; HER2 inhibition; Human; Induction of Apoptosis; Major Groove; Malignant Neoplasms; Mammary Neoplasms; Methods; Modeling; Molecular; Mus; Neoplasm Metastasis; Normal Cell; Normal tissue morphology; Nucleotide Excision Repair; Nude Mice; Oligonucleotides; Pathway interactions; Pharmaceutical Preparations; Phenotype; Predictive Factor; Predisposition; Prognostic Factor; Proteins; Research; Resistance; Roche brand of trastuzumab; Signal Pathway; Signal Transduction; Site; Stretching; Structure; Therapeutic; Toxic effect; Treatment Efficacy; Work; Xenograft Model; Xenograft procedure; anticancer activity; cancer cell; cancer therapy; cell growth; combat; design; experience; improved; in vivo; innovation; malignant breast neoplasm; mouse model; neoplastic cell; novel; novel therapeutics; public health relevance; receptor; repaired; response; targeted treatment; therapeutic target; tool; treatment strategy; triplex DNA; tumor; tumor growth

 DESCRIPTION (provided by applicant): The ability to target HER2-driven breast cancers using anticancer agents with mechanisms of actions that are independent of the HER2 cellular growth function, represents a powerful new tool to circumvent drug resistance experienced with traditional HER2-targeted therapies. We have discovered that manipulation of the balance between the DNA repair response and apoptosis pathways provides an alternative strategy to induce targeted apoptosis in HER2-amplified breast cancers. Preliminary work has determined that triplex DNA formed at chromosomal sites by endogenous triplex-forming oligonucleotides (TFOs) can induce apoptosis in human cells. Importantly, apoptosis induction occurs only in response to formation of multiple triplex structures; and not one or two, since the nucleotide excision repair pathway is capable of efficiently repairing a low level of damage. Triplex DNA can be created when TFOs bind as third strands within the major groove of duplex DNA at specific polypurine stretches. HER2-positive breast cancers can have upwards of 25-50 copies of the HER2 gene. Moreover this gene contains several polypurine sites that are conducive to triplex formation. This supplies multiple potential triplex target sites within the malignant cells and creates a distinction between tumor cells and normal cells, which lack HER2 gene amplification. As a result, the level of toxicity induced by HER2-targeted TFOs in normal tissues should be low. This creates the foundation for a new therapeutic alternative in the treatment of HER2-positive breast cancers. We have already designed sequence-specific TFOs, which will bind to their target HER2 sequence, create multiple triplex DNA structures, and specifically activate apoptosis in tumor cells. We will evaluate the efficacy of these molecules using cell growth, clonogenic and apoptosis assays. We will examine the mechanisms involved in triplex-induced apoptosis, with emphasis on components of the DNA damage response pathway that provide crosstalk with apoptosis pathways, and establish whether the mechanisms involved are independent of HER2 cellular function. We will also investigate the potential for gene-targeted apoptosis to inhibit the growth and metastasis of HER2-positive breast cancers in an athymic nude mouse model. Targeting of the HER2 gene on a genomic level using DNA-binding molecules to induce triplex structures provides a novel therapeutic option for the treatment of HER2-positive breast cancers. This approach offers an alternative method to target HER2 by manipulating the cell's DNA damage response machinery, and thus represents a new paradigm for gene-targeted drugs.

 描述（由申请方提供）：使用作用机制不依赖于HER 2细胞生长功能的抗癌药物靶向HER 2驱动的乳腺癌的能力代表了一种强大的新工具，可避免传统HER 2靶向治疗出现的耐药性。我们已经发现，DNA修复反应和细胞凋亡途径之间的平衡的操纵提供了一种替代策略，以诱导靶向细胞凋亡的HER 2扩增的乳腺癌。初步工作已经确定，由内源性三链体形成寡核苷酸（TFO）在染色体位点形成的三链体DNA可以诱导人类细胞凋亡。重要的是，凋亡诱导仅在响应于多个三链体结构的形成时发生;而不是一个或两个，因为核苷酸切除修复途径能够有效地修复低水平的损伤。当TFO作为第三链结合在双链体DNA的大沟内的特定聚嘌呤段时，可以产生三链体DNA。HER 2阳性乳腺癌可以具有25-50个HER 2基因拷贝。此外，该基因含有几个多嘌呤位点，有利于三链体的形成。这在恶性细胞内提供了多个潜在的三重靶位点 并在肿瘤细胞和缺乏HER 2基因扩增的正常细胞之间产生区别。因此，HER 2靶向TFO在正常组织中诱导的毒性水平应该较低。这为治疗HER 2阳性乳腺癌的新治疗替代方案奠定了基础。我们已经设计了序列特异性的TFO，它将与它们的靶HER 2序列结合，产生多个三链DNA结构，并特异性地激活肿瘤细胞的凋亡。我们将使用细胞生长、克隆形成和凋亡测定来评估这些分子的功效。我们将研究三链体诱导的细胞凋亡中涉及的机制，重点是DNA损伤反应途径的组成部分，提供与凋亡途径的串扰，并建立所涉及的机制是否是独立的HER 2细胞功能。我们还将在无胸腺裸鼠模型中研究基因靶向细胞凋亡抑制HER 2阳性乳腺癌生长和转移的潜力。使用DNA结合分子在基因组水平上靶向HER 2基因以诱导三链体结构，为治疗HER 2阳性乳腺癌提供了一种新的治疗选择。这种方法提供了一种通过操纵细胞的DNA损伤反应机制来靶向HER 2的替代方法，因此代表了基因靶向药物的新范式。