GPER通过“barcode”磷酸化修饰调控β-arrestin/SH3-CPs信号介导肺腺癌EGFR-TKI原发耐药的机制研究

表皮生长因子受体酪氨酸激酶抑制剂(EGFR-TKI)治疗肺腺癌中，原发耐药占比20-30%，机制尚待阐明。我们首次发现G蛋白耦联雌激素受体(GPER)调控原发耐药克隆形成，通过表达、功能验证和生信分析提示这与募集β-抑制蛋白(β-arrestin)/SH3结构域包含蛋白(SH3-CPs)信号密切相关。我们提出：GPER可能通过“barcode”磷酸化修饰模式，在受体激酶(GRK)特异激活下，以β-arrestin为支架蛋白招募多种SH3-CPs，反式激活EGFR调节原发耐药特征。研究拟在细胞、小鼠层面模拟“原发耐药克隆获得竞争性优势”探索效应，从GRK/GPER磷酸化修饰、GPER/β-arrestin结合构型、β-arrestin/SH3-CPs作用区域、SH3-CPs招募特征阐明条码式信号传递机制，并在组织样本验证表达和预后。本项目有望为TKI原发耐药形成机制提供理论依据和应对思路。

Despite very frequent and often prolonged clinical response to EGFR tyrosine kinase inhibitors (EGFR-TKI), 20–30% of lung adenocarcinoma patients do not respond or respond for a very short time because of primary resistance. However, mechanisms underlying the primary TKI resistance are less understood. We found that G Protein-Coupled Receptor (GPER) play a vital role in formation of primary resistant clone. Our preliminary research revealed GPER may share a pathway by signaling to SRC Homology 3 domain-Containing Proteins (SH3-CPs) via agonist-dependent β-arrestin recruitment. We propose a hypothesis that GPER phospho-barcode mediates recruitment of SH3-CPs through β-arrestin, activated by a group of GPCR kinases (GRKs), leading to primary resistant to EGFR-TKI. In general, even a single type of GPER can initiate a broad range of signal transduction processes through β-arrestin engagement by scaffolding different SH3-CPs and downstream effectors. The current study was undertaken to demonstrate the ‘Progressive Competitive Advantage’ phenotypes in primary resistant clones mediated by GPER in vitro and vivo. GRK-mediated phosphorylation, specific conformation of ‘snuggly’ or ‘hanging’, functional outcomes of remote β-arrestin proline regions (PRs) and intrinsic efficacy and specificity of SH3 domain recruitment were explored to elucidate the mechanisms of signal transmission downstream of GPER activation. Prognostic outcome associated with GPER/β-arrestin/SH3-CPs signals were investigated in tissue specimens. These results will elicit future interest in determining the specificity and working mechanisms of β-arrestin/SH3-CPs -mediated GPER functions and unveil new converging elements that can aid in predicting and treating intrinsic resistance to EGFR-TKI.