Objectives: To examine how the glucose transporter SLC2A1 influences the proliferation and migration of lung adenocarcinoma (LUAD) and explore the underlying molecular mechanisms.
Methods: We examined the differential expression of SLC2A1 between normal and LUAD tissues in the TCGA database and its prognostic implications. Immunohistochemistry was used to detect SLC2A1 protein levels in clinical samples of LUAD and adjacent tissues, and the association of SLC2A1 expression levels with clinicopathological features of the patients was analyzed. In PC9 cells with stable SLC2A1 overexpression or knockdown, the effects of SLC2A1 expression level on cell proliferation and migration were assessed using CCK-8 and Transwell assays, and the changes in expressions of ferroptosis- and autophagy-related proteins were measured; the occurrence of ferroptosis was confirmed using ROS and Fe2+ fluorescence staining.
Results: SLC2A1 expression was significantly higher in LUAD tumor tissues than in normal lung tissues (P<0.05) and was associated with worse pathological parameters and prognosis of the patients (P<0.05). In PC9 cells, SLC2A1 overexpression significantly promoted cell proliferation, invasion and migration, and SLC2A1 knockdown significanty increased cell death and inhibited cell invasion and proliferation. SLC2A1 knockdown caused obvious activation of cell ferroptosis, reduced GPX4 and xCT expressions, and increased intracellular levels of ROS and Fe2+. SLC2A1 knockdown also resulted in increased cell autophagy shown by increased LC3B expression, which could be reversed by treatement with 3-MA.
Conclusions: High SLC2A1 expression is correlated with poor prognosis of patients with LUAD, and inhibiting SLC2A1 can induce ferroptosis and autophagy of LUAD cells, suggesting the potential of SLC2A1 as a target for LUAD diagnosis and treatment.
目的: 探讨细胞能量代谢中的葡萄糖转运蛋白SLC2A1对肺腺癌增殖和迁移能力的影响及其分子机制。方法: 分析TCGA数据库中SLC2A1基因在肺腺癌正常组织和肿瘤组织中的表达差异及其对预后的影响。收集我院临床肺腺癌患者的肿瘤组织和癌旁配对组织,进行免疫组化染色,分析SLC2A1蛋白在肿瘤中的表达水平。验证肺腺癌肿瘤组织和癌旁组织中SLC2A1蛋白的表达差异,探讨该蛋白与患者临床病理特征之间的关系。体外构建稳定过表达和稳定干预SLC2A1基因的细胞系,通过Western blotting实验和qRT-PCR实验验证干预效果。采用CCK-8和Transwell实验体外验证细胞表型,明确其对肿瘤细胞增殖、迁移能力的影响。检测干预SLC2A1后细胞的铁死亡和细胞自噬相关蛋白的表达水平,并通过ROS荧光染色、Fe2+荧光染色明确铁死亡的发生过程。结果: 与正常肺组织相比,SLC2A1在肺腺癌肿瘤组织中高表达(P<0.05),且与肺腺癌患者的病理参数及不良预后相关(P<0.05)。与对照组相比,过表达SLC2A1,细胞中该基因上调(P<0.05),细胞增殖活性增加(P<0.05),细胞侵袭和迁移能力增强(P<0.05)。干预SLC2A1基因表达后,细胞死亡比例增加(P<0.05),侵袭和增殖能力均被抑制(P<0.05)。干预SLC2A1激活了铁死亡,GPX4、xCT等铁死亡指标表达下调,细胞内ROS累积,Fe2+增多(P<0.05)。同时检测到细胞自噬的发生,LC3B增加,且这一过程可被3-MA挽救。结论: SLC2A1在肿瘤组织中高表达且与不良预后有关。靶向抑制SLC2A1可以促进肺腺癌中的铁死亡和自噬发生,有望成为肺腺癌诊断和治疗的新潜在分子靶点。.
Keywords: autophagy; ferroptosis; glucose transporter 1; lung adenocarcinoma.