APOC1, transcriptionally regulated by FOXM1, promotes M2 macrophage polarization and cervical cancer progression
Cervical cancer (CC) is a common malignant tumor in women. M2 macrophages are associated with tumor growth, metastasis, and immunosuppression. Apolipoprotein C1 (APOC1) has been confirmed as an oncogene in CC. However, the role and mechanism of APOC1 in CC progression and M2 macrophages remain to be elucidated. The effects of APOC1 on CC cell malignant phenotypes were examined by CCK-8, colony formation, wound healing, and transwell assays in vitro and mice transplant tumor model in vivo. M2 macrophage polarization was assessed by qRT-PCR and flow cytometry assays. The interaction between APOC1 and forkhead box M1 (FOXM1) was determined using chromatin immunoprecipitation (ChIP) and luciferase reporter assays. The expression of APOC1 and FOXM1 was upregulated in CC tissues and cells. Knockdown of APOC1 or FOXM1 resulted in the inhibition of cell proliferation, migration, invasion, and EMT. Moreover, the polarization of M2 macrophages was attenuated when APOC1 or FOXM1 was silenced. Mechanistically, FOXM1 transcriptionally activated APOC1 by binding to its promoter. Furthermore, overexpression of APOC1 reversed the inhibitory effects of FOXM1 knockdown on cell proliferation, metastasis, and M2 macrophage polarization. Additionally, the knockdown of APOC1 reduced tumor growth and M2 macrophage polarization in mice. FOXM1/APOC1 axis is involved in the progression of CC and the regulation of M2 macrophages polarization, bringing new hope to the treatment of CC.