背景:随着转移性甲状腺乳头状癌的治疗变得越来越具有挑战性,免疫疗法已成为一个新的研究方向。肿瘤相关巨噬细胞(TAMs)影响发生,入侵,和肿瘤的转移。载脂蛋白E(APOE)可以调节巨噬细胞的极化变化,参与肿瘤微环境的重塑。然而,在甲状腺乳头状癌(PTC)中,APOE在调节TAMs极化和生物学功能中的作用尚不清楚,因为它充当双重生物标志物。
方法:我们使用免疫组织化学染色检测了PTC组织中APOE的表达。建立细胞共培养模型,其中将不同的表达APOE的K1细胞与THP-1衍生的M0巨噬细胞共培养。使用实时定量聚合酶链反应对巨噬细胞极化行为进行了深入分析,酶联免疫吸附测定,和西方印迹。随后,APOE调节的巨噬细胞对肿瘤细胞行为的影响,尤其是扩散,迁移,和入侵,使用IncuCyteZOOM系统进行了评估,流式细胞术,菌落形成,和划痕实验。最后,我们使用异种移植模型来证实APOE对PTC肿瘤发生的影响。
结果:肿瘤尺寸,舞台,淋巴结转移与PTC组织中APOE表达增加显著相关。K1细胞的增殖明显受限,迁移,当APOE表达沉默时,由PI3K/Akt/NF-κB信号轴介导的过程。此外,APOE是增强抗炎细胞因子IL-10和TGF-β1的关键促进剂。在PTC蜂窝模型中,APOE有助于THP-1衍生的巨噬细胞向M2表型极化的表型转变,主要通过IL-10的调节。此外,涉及无胸腺裸鼠的体内研究已证明APOE在肿瘤进展和诱导M2样TAM极化中的关键作用。
结论:我们的结果表明,APOE可以通过PI3K/Akt/NF-κB通路调节K1细胞炎症因子的表达,促进TAM从M0型向M2型极化转变。这些发现对于理解PTC发病机理的分子机制和开发治疗该疾病的免疫药物至关重要。
BACKGROUND: As metastatic papillary thyroid carcinoma becomes increasingly challenging to treat, immunotherapy has emerged as a new research direction. Tumor-associated macrophages (TAMs) influence the occurrence, invasion, and metastasis of tumors. Apolipoprotein E (APOE) can regulate the polarization changes of macrophages and participate in the remodeling of the tumor microenvironment. However, the role of APOE in regulating the polarization and biological functions of TAMs in papillary thyroid carcinoma (PTC) remains unclear, as it acts as a dual biomarker.
METHODS: We probed APOE expression in PTC tissues using immunohistochemical staining. A cell co-culture model was established where different APOE-expressing K1 cells were co-cultured with THP-1-derived M0 macrophages. An in-depth analysis of macrophage polarization behavior was performed using real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting. Subsequently, the impact of APOE-regulated macrophages on tumor cell behavior, especially proliferation, migration, and invasion, was evaluated utilizing IncuCyte ZOOM system, flow cytometry, colony formation, and scratch experiments. Finally, we used a xenograft model to confirm the effects of APOE on PTC tumorigenesis.
RESULTS: Tumor dimensions, stage, and lymphatic metastases were significantly associated with increased APOE expression in PTC tissues. K1 cells were markedly limited in their proliferation, migration, and invasion abilities when APOE expression was silenced, a process mediated by the PI3K/Akt/NF-κB signaling axis. Moreover, APOE is a key facilitator of the enhancement of the anti-inflammatory cytokines IL-10 and TGF-β1. In PTC cellular models, APOE contributed to the phenotypic shift of THP-1 derived macrophages towards an M2 phenotypic polarization, predominantly through the modulation of IL-10. Furthermore, in vivo studies involving athymic nude mice have demonstrated pivotal role of APOE in tumor progression and the induction of M2-like TAM polarization.
CONCLUSIONS: Our results elucidated that APOE could promote the shift of TAMs from M0-type to M2-type polarization by regulating inflammatory factors expressions in K1 cell through the PI3K/Akt/NF-κB pathway. These findings are crucial for understanding the molecular mechanisms underlying PTC pathogenesis and for developing immunological drugs to treat this disease.