肿瘤相关巨噬细胞（TAM）是肿瘤微环境中最丰富的免疫细胞，M2型TAM可以促进肿瘤生长、侵袭和血管生成，并抑制抗肿瘤免疫反应。据报道，血影蛋白β，非红细胞1（SPTBN1）可能会抑制Sptbn1/-小鼠肝脏中巨噬细胞的浸润，但肿瘤SPTBN1是否影响TAM极化仍不清楚。本研究探讨肿瘤细胞SPTBN1对肝癌和乳腺癌TAMs极化和迁移的影响及机制。通过分析肿瘤免疫数据库，我们发现SPTBN1与肿瘤微环境中巨噬细胞和骨髓源性抑制细胞（MDSC）的丰度呈负相关。通过逆转录定量实时 PCR 测定和细胞迁移测定，来自肝细胞癌细胞系 PLC/PRF/5、SNU449 和乳腺癌细胞系 MDA-MB 的培养基增强了巨噬细胞的迁移和 M2 极化。 231 具有 SPTBN1 抑制作用，可被 CXCL1 中和抗体 MAB275 逆转。同时，与M2巨噬细胞共培养时，PLC/PRF/5、SNU449和MDA-MB-231细胞的迁移和集落形成能力得到促进。我们还通过细胞质-核蛋白分离实验和 ChIP-qPCR 发现 SPTBN1 通过 p65 调节 CXCL1。我们的数据表明，肿瘤细胞 SPTBN1 通过抑制 p65 核定位来减少 CXCL1 的表达和分泌，从而抑制 TAM 的迁移和 M2 型极化。© 2023 Wiley periodicals LLC。

Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment, and the M2-type TAMs can promote tumor growth, invasion and angiogenesis, and suppress antitumor immune responses. It has been reported that spectrin beta, non-erythrocytic 1 (SPTBN1) may inhibit the infiltration of macrophages in Sptbn1+/-  mouse liver, but whether tumor SPTBN1 affects TAMs polarization remains unclear. This study investigated the effect and mechanism of tumor cell SPTBN1 on polarization and migration of TAMs in hepatoma and breast cancer. By analyzing tumor immune databases, we found a negative correlation between SPTBN1 and abundance of macrophages and myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment. By reverse transcription-quantitative real-time PCR assays and cell migration assays, the migration and M2 polarization of macrophages were enhanced by the culture medium from hepatocellular carcinoma cell line PLC/PRF/5, SNU449, and breast cancer cell line MDA-MB-231 with SPTBN1 suppression, which could be reversed by CXCL1 neutralizing antibody MAB275. Meanwhile, the ability of migration and colony formation of PLC/PRF/5, SNU449, and MDA-MB-231 cells were promoted when coculture with M2 macrophages. We also found that SPTBN1 regulated CXCL1 through p65 by cytoplasmic-nuclear protein isolation experiments and ChIP-qPCR. Our data suggest that tumor cell SPTBN1 inhibits migration and M2-type polarization of TAMs by reducing the expression and secretion of CXCL1 via inhibiting p65 nuclear localization.© 2023 Wiley Periodicals LLC.