MULTIPLEXED ISOFORM QUANTIFICATION IN HER2-POSITIVE BREAST CANCER

HER2 阳性乳腺癌的多重异构体定量

• 批准号: 10362550
• 负责人: Amy Elizabeth Herr
• 金额: $ 34.53万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-03 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10362550
• 关键词: Address; Automobile Driving; Binding; Biological; Biological Assay; Biological Markers; Biology; Biomedical Engineering; Biometry; Biopsy; Breast Cancer Cell; Breast Cancer Patient; Breast Cancer Treatment; Breast Cancer cell line; Breast biopsy; Cells; Chemistry; Classification; Clinical; Computational Biology; DNA; DNA Sequence Alteration; Detection; Development; Diagnosis; Dimerization; Drug Targeting; Drug resistance; ERBB2 gene; ERBB3 gene; Exhibits; Extracellular Domain; Fluorescence Resonance Energy Transfer; Fluorescent in Situ Hybridization; Genomics; Goals; Heterogeneity; Homo; In Situ Hybridization; Individual; Knowledge; Length; Life; Malignant Neoplasms; Mammary Gland Parenchyma; Maps; Measurement; Measures; Medicine; Membrane; Microfluidics; Molecular; Monitor; Mutation; Nature; Nuclear; Oncogenic; PIK3CA gene; Patients; Pertuzumab; Pharmaceutical Preparations; Play; Population Analysis; Precision therapeutics; Prognostic Marker; Protein Family; Protein Isoforms; Proteins; Proteomics; Radiation therapy; Recurrence; Research; Resistance; Resolution; Retinal blind spot; Role; Signal Transduction; Specificity; Surface; Survival Rate; Tissue Banks; Tissue Sample; Tissues; Trastuzumab; Variant; Western Blotting; base; biological heterogeneity; cancer cell; cancer drug resistance; clinically relevant; design; dimer; experience; fundamental research; improved; individualized medicine; malignant breast neoplasm; multimodality; mutant; neoplastic cell; news; next generation; novel therapeutics; oncology program; overexpression; patient oriented; precision medicine; protein complex; single cell analysis; stem; success; targeted cancer therapy; targeted treatment; therapy resistant; tool; tumor heterogeneity

While targeted therapy increases overall survival rates in HER2-positive breast cancer patients, most patients will experience recurrence due to resistance to initially successful therapy (trastuzumab-based). Accordingly, there is an unmet, patient-driven need to understand and circumvent breast cancer resistance, to even targeted therapies. At the cellular level, cell-to-cell variation (heterogeneity) is a hallmark of cancer. Perhaps surprisingly, molecular heterogeneity is also a hallmark of HER2+ breast cancer. Spanning the outer membrane of a cancer cell, the large protein HER2 displays an extracellular domain, which is the target of ‘targeted therapies’ (vs. chemo- or radiation therapies). These HER2+ breast cancer targeted therapies include the landmark drug Herceptin® (trastuzumab). But the HER2 protein manifests as a family of proteins (called protein isoforms), not just a single molecular form. Regrettably, numerous of these HER2 isoforms lack the extracellular domain of the full-length HER2 protein, making the cell non-responsive otherwise powerful anti- HER2 targeted therapies. These smaller HER2 isoforms are known as ‘truncated isoforms’, with a 95 kDa form ‘P95HER2’ being especially potent in drug resistance. Until our previous R01 research, the ability to discern full-length HER2 from the truncated P95HER2 isoform was not readily possible with same-cell resolution. Consequently, to advance our knowledge of resistance to anti-HER2 targeted therapies, we propose to build on our team’s capacity to precisely distinguish P95HER2 from other HER2 protein forms to scrutinize the role of P95HER2 in: (1) the potent, signal-activating HER2 dimers that reside on the surface of each breast cancer cell and (2) potentially ultra-resistant breast cancer cell subpopulations that exhibit both the P95HER2 protein isoform and the resistance-driving DNA mutation (PIK3CA). These are two cellular ‘modes’ (P95HER2 homo/heterodimers; co-expression of P95HER2 and PIK3CA mutation) that no other tools can directly and with high-specificity concurrently measure in minute tissue samples, down to single-cell resolution. Our clinical, biostatistics, and bioengineering team will conduct research to yield tools that can perform these isoform- involved multimodal assays in tissues and cells from HER2-positive breast cancer patient biopsies (Stanford Breast Tissue Bank), after performing early development on well-characterized breast cancer cell lines. The ability to directly measure the truncated HER2 isoforms and interaction modes in sparingly available breast biopsy tissues and with single-cell resolution should yield a tremendous advantage for understanding and then assessing the potential for drug resistance. These studies will allow us to profile the cellular and molecular heterogeneity of HER2 to advance understanding of persistent breast cancer resistance to anti-HER2 targeted treatment and, ultimately, to identify approaches to reduce or eliminate recurrence.

虽然靶向治疗增加了HER 2阳性乳腺癌患者的总生存率，但大多数患者 由于对最初成功的治疗（基于曲妥珠单抗）耐药而复发。因此，委员会认为， 有一个未满足的，病人驱动的需要，了解和规避乳腺癌耐药性，甚至 靶向治疗。在细胞水平，细胞间变异（异质性）是癌症的标志。也许 令人惊讶是，分子异质性也是HER 2+乳腺癌的标志。跨越外部 在癌细胞的细胞膜上，大蛋白HER 2展示细胞外结构域，其是癌细胞的靶点。 “靶向治疗”（相对于化疗或放疗）。这些HER 2+乳腺癌靶向治疗包括 标志性药物赫赛汀®（曲妥珠单抗）。但是HER 2蛋白表现为一个蛋白质家族（称为HER 2蛋白）。 蛋白质异构体），而不仅仅是单一的分子形式。令人遗憾的是，这些HER 2亚型中的许多缺乏HER 2基因。 全长HER 2蛋白的胞外结构域，使细胞无反应，否则强大的抗- HER 2靶向治疗。这些较小的HER 2亚型被称为“截短亚型”，具有95 kDa的形式， “P95 HER 2”在耐药性方面特别有效。在我们之前的R 01研究之前， 从截短的P95 HER 2同种型中分离全长HER 2不容易用相同的细胞分辨。 因此，为了提高我们对抗HER 2靶向治疗耐药性的认识，我们建议建立 我们的团队能够精确区分P95 HER 2与其他HER 2蛋白形式， P95 HER 2在：（1）位于每个乳腺癌表面的有效的信号激活HER 2二聚体 细胞和（2）表现出P95 HER 2蛋白的潜在超耐药乳腺癌细胞亚群 亚型和耐药驱动DNA突变（PIK 3CA）。这是两种细胞“模式”（P95 HER 2 同源/异源二聚体; P95 HER 2和PIK 3CA突变的共表达），没有其他工具可以直接和 在微小组织样本中同时测量高特异性，低至单细胞分辨率。我们的临床， 生物统计学和生物工程团队将进行研究，以产生可以执行这些亚型的工具- 涉及来自HER 2阳性乳腺癌患者活检组织和细胞的多模式测定（斯坦福大学 乳腺组织库），在对充分表征的乳腺癌细胞系进行早期开发后。的 能够直接测量少量乳腺癌中截短的HER 2亚型和相互作用模式 活检组织和单细胞分辨率应该产生巨大的优势， 评估潜在的抗药性。这些研究将使我们能够描绘出 HER 2异质性促进对乳腺癌抗HER 2持续耐药的理解 有针对性的治疗，并最终确定减少或消除复发的方法。