AFAP1L2通过RAS/ERK信号通路促进胰腺癌细胞增殖和转移的机制研究

Mechanistic study of AFAP1L2 in promoting proliferation and metastasis of pancreatic cancer cells via the RAS/ERK signaling pathway

摘要:

背景与目的 胰腺癌恶性程度高、预后差，亟需寻找新的分子治疗靶点。肌动蛋白丝相关蛋白1相似蛋白2（AFAP1L2）在多种肿瘤中发挥促癌作用，但其在胰腺癌中的功能及分子机制尚未明确。本研究旨在探讨AFAP1L2在胰腺癌中的表达特征及其对肿瘤增殖与转移的调控机制。方法 基于生物信息学分析及Western blot检测AFAP1L2在胰腺癌组织与细胞中的表达，并分析其与患者预后的关系。通过shRNA沉默AFAP1L2表达，采用CCK-8、克隆形成、Transwell及划痕实验评估细胞增殖、侵袭与迁移能力；Western blot检测上皮-间充质转化及RAS/ERK信号通路相关蛋白变化；构建裸鼠皮下移植瘤模型验证体内作用。通过RAS-GTP检测及免疫共沉淀实验探讨其分子机制。结果 AFAP1L2在胰腺癌组织及细胞中高表达，且与患者生存期呈负相关。沉默AFAP1L2明显抑制胰腺癌细胞增殖、侵袭和迁移能力，并抑制裸鼠移植瘤生长。机制研究表明，AFAP1L2可与RASA1结合并抑制其GTP酶激活活性，导致RAS-GTP水平升高，激活RAS/ERK信号通路；而沉默AFAP1L2可恢复RASA1对RAS的负调控作用，降低ERK、MEK磷酸化水平，从而抑制肿瘤进展。结论 AFAP1L2通过结合并抑制RASA1活性，激活RAS/ERK信号通路，促进胰腺癌细胞增殖与转移，具有潜在分子治疗靶点价值。

Abstract:

Background and Aims Pancreatic cancer is highly malignant with poor prognosis, and effective molecular targets are still lacking. Actin filament-associated protein 1-like 2 (AFAP1L2) has been reported to promote tumor progression in multiple cancers; however, its role in pancreatic cancer remains unclear. This study aimed to investigate the expression profile and functional mechanism of AFAP1L2 in pancreatic cancer.Methods Bioinformatics analysis and Western blot were used to evaluate AFAP1L2 expression in pancreatic cancer tissues and cells, and its association with patient survival was analyzed. AFAP1L2 was silenced by shRNA, and cell proliferation, invasion, and migration were assessed using CCK-8, colony formation, Transwell, and wound healing assays. EMT markers and RAS/ERK pathway-related proteins were detected by Western blot. A nude mouse xenograft model was established to validate in vivo effects. RAS-GTP levels and co-immunoprecipitation assays were performed to explore the underlying mechanism.Results AFAP1L2 was highly expressed in pancreatic cancer tissues and cells and was negatively correlated with patient survival. Silencing AFAP1L2 significantly inhibited cell proliferation, invasion, and migration in vitro and suppressed tumor growth in vivo. Mechanistically, AFAP1L2 interacted with RASA1 and inhibited its GTPase-activating activity, leading to increased RAS-GTP levels and activation of the RAS/ERK pathway. Knockdown of AFAP1L2 restored RASA1-mediated negative regulation of RAS, decreased ERK and MEK phosphorylation, and attenuated malignant progression.Conclusion AFAP1L2 promotes proliferation and metastasis of pancreatic cancer cells by activating the RAS/ERK signaling pathway through inhibition of RASA1, suggesting its potential as a therapeutic target.