β-受体拮抗剂对曲妥珠单抗的增效作用及其机制研究

靶向Her2的治疗性抗体曲妥珠单抗用于治疗Her2阳性乳腺癌取得成功，但耐药成为制约其疗效的关键问题。申请人在开展国家自然基金青年项目时发现：β2肾上腺素能受体（β2-AR）表达水平与曲妥珠单抗疗效呈负相关。β2-AR信号激活诱导乳腺癌细胞对曲妥珠单抗产生抗性。基于此，我们推测阻断β-AR信号可能增强曲妥珠单抗抑瘤活性。β-受体拮抗剂临床应用多年，安全方便，价格低廉，如被证实可以提高曲妥珠单抗治疗效果，将有很大的临床实用价值。本研究拟通过体内外实验，结合临床资料回顾性和前瞻性研究，探讨β-受体拮抗剂协同增强曲妥珠单抗抑瘤效应的可行性；同时应用CRISPR文库和基因表达谱芯片在全基因组范围内筛选β-AR信号激活干扰曲妥珠单抗疗效过程中发挥关键作用的信号网络，并对其进行功能验证。明确适用β-AR拮抗剂+曲妥珠单抗联合治疗的患者的基因分型，为实现乳腺癌的个体化治疗提供理论依据。

Trastuzumab is a humanized monoclonal antibody targeting human epidermal growth factor receptor 2(Her2), which combined with chemotherapy drugs could significantly improve survival of patients. However, trastuzumab resistance severely limits its curative effect and clinical application. In our study supported by Natural Science Foundation of China, we found that the level of β2-adrenergic receptor (β2-AR) negatively correlated with the efficacy of trastuzumab and the β2-AR activation induced resistance of Her2 positive breast cancer cells to trastuzumab. Based on the above data, we propose inhibition of β2-AR activation could increase anti-tumor activity of trastuzumab. β-blocker has been widely used in clinic for its efficacy, safety and low costs. The clinical application value of β-blocker in breast carcinoma depends on the effect of β-blocker on improving the efficacy of trastuzumab. The aim of this study is to explore the feasibility of potentiating the anti-tumor response of trastuzumab by β-blocker, through in vivo/in vitro experiments and clinical research. In order to identify critical signaling pathways involving trastuzumab resistance induced by β-AR activation, we use Genome-Scale CRISPR Knock-Out (GeCKO) v2.0 pooled libraries and Human Gene Expression Microarray doing genome-wide screening experiments. Finally, these signaling pathways are verified with experiments. The study will clarify the genotype of the patients who are suitable to be treated with β-blocker + trastuzumab and improve the current paradigm of personalized Her2 positive breast cancer therapy.