Rab25 通过激活非小细胞肺癌中的β1 整合素/AKT/β-连环蛋白通路促进厄洛替尼耐药。

OBJECTIVES

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) has significant therapeutic efficacy in non-small-cell lung cancer (NSCLC) patients. However, acquired resistance is inevitable and limits the long-term efficacy of EGFR-TKI. Our study aimed to investigate the role of ras-associated binding protein 25 (Rab25) in mediating EGFR-TKI resistance in NSCLC.

MATERIALS AND METHODS

Rab25 expression in NSCLC patients was measured by immunohistochemical staining. Western blotting was used to analyse the expression of molecules in the Rab25, EGFR and Wnt signalling pathways. Lentiviral vectors were constructed to knock in and knock out Rab25. The biological function of Rab25 was demonstrated by cell-counting kit-8 and flow cytometry. The interaction between Rab25 and β1 integrin was confirmed by co-immunoprecipitation.

RESULTS

Rab25 overexpression induced erlotinib resistance, whereas Rab25 knockdown reversed this refractoriness in vitro and in vivo. Moreover, Rab25 interacts with β1 integrin and promotes its trafficking to the cytoplasmic membrane. The membrane-β1 integrin induced protein kinase B (AKT) phosphorylation and subsequently activated the Wnt/β-catenin signalling pathway, promoting cell proliferation. Furthermore, high Rab25 expression was associated with poor response to EGFR-TKI treatment in NSCLC patients.

CONCLUSIONS

Rab25 mediates erlotinib resistance by activating the β1 integrin/AKT/β-catenin signalling pathway. Rab25 may be a predictive biomarker and has potential therapeutic value in NSCLC patients with acquired resistance to EGFR-TKI.

目的

表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKI）在非小细胞肺癌（NSCLC）患者中具有显著的治疗效果。然而，获得性耐药是不可避免的，限制了 EGFR-TKI 的长期疗效。我们的研究旨在探讨 Ras 相关结合蛋白 25（Rab25）在介导 NSCLC 中 EGFR-TKI 耐药中的作用。

材料和方法

通过免疫组织化学染色测量 NSCLC 患者中 Rab25 的表达。使用 Western blot 分析 Rab25、EGFR 和 Wnt 信号通路中分子的表达。构建慢病毒载体以敲入和敲除 Rab25。通过细胞计数试剂盒-8 和流式细胞术证明 Rab25 的生物学功能。通过免疫共沉淀证实 Rab25 与 β1 整合素之间的相互作用。

结果

Rab25 过表达诱导厄洛替尼耐药，而 Rab25 敲低则在体外和体内逆转了这种耐药性。此外，Rab25 与 β1 整合素相互作用并促进其向细胞质膜转运。膜-β1 整合素诱导蛋白激酶 B（AKT）磷酸化，随后激活 Wnt/β-catenin 信号通路，促进细胞增殖。此外，Rab25 高表达与 NSCLC 患者对 EGFR-TKI 治疗反应不良相关。