[CCAAT/enhancer binding protein δ inhibits invasion and metastasis of liver cancer by regulating M1 type macrophages polarization].

Objective: To explore the regulation of macrophage polarization and its effects on liver cancer invasion, metastasis and apoptosis by CCAAT/enhancer binding protein δ (CEBPD). Methods: THP-1 stable transfected cells with knockdown CEBPD (shCEBPD) and negative control shNC were constructed by lentviral transfection technique. THP-1 transfected cells were induced into macrophages, lipopolysaccharide (LPS) and interferon γ(IFNγ) by phorbol 12-tetradecanoate 13-acetate (PMA), and then the polarized macrophages were further induced to M1 type. The quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect M1 type macrophage related interleukin 1β (IL-1β) genes, IL-6, tumor necrosis factor α (TNFα), and inducible nitric oxide synthase (iNOS) mRNA expression level. Flow cytometry was used to detect M1 macrophage-specific surface marker CD80 expression levels. M1-induced macrophages were co-cultured with liver cancer MHCC97H cells using Transwell non-contact small sized co-culture dishes. MHCC97H cells invasion and metastasis were detected by Transwell and scratch assay under co-culture conditions, and the MHCC97H cells apoptosis was detected by flow cytometry. Results: The mRNA expression levels of M1 macrophage marker genes iNOS, TNFα, IL-6 and IL-1β in THP-1 derived macrophages were decreased after CEBPD knockdown. M1 macrophage-specific surface marker CD80 expression levels were decreased (23.7% ± 2.1% and 62.5% ± 2.0%, t = 9.58, P < 0.05). THP-1 were co-cultured with MHCC97H in shCEBPD and shNC group, respectively. Compared with shNC group, the invasion [(158.0 ± 3.5) and (75.0 ± 4.5), t = 39.87, P < 0.01] and metastatic ability (54.6% ± 1.5% and 24.3% ± 1.0%, P < 0.01) of MHCC97H cells co-cultured in shCEBPD group were stronger and the apoptosis rate was reduced [(9.4% ± 1.0%) vs. (23.7% ± 1.2%), t = 12.68, P < 0.01]. Conclusion: CEBPD can inhibit the invasion and metastasis and increase the apoptosis by amplifying M1 type macrophages polarization in liver cancer cells.目的： 探讨CCAAT/增强子结合蛋白δ（CEBPD）对巨噬细胞极化的调控及通过巨噬细胞对肝癌细胞侵袭转移、凋亡的影响。 方法： 用慢病毒转染技术构建敲减CEBPD（shCEBPD）及阴性对照shNC的THP-1稳定转染细胞。用佛波醇12-十四酸酯13-乙酸酯（PMA）将转染后的THP-1细胞诱导为巨噬细胞，脂多糖（LPS）和干扰素γ（IFNγ）进一步将巨噬细胞向M1型极化诱导。实时荧光定量聚合酶链反应（qRT-PCR）检测M1型巨噬细胞相关基因白细胞介素1β（IL-1β）、IL-6、肿瘤坏死因子α（TNFα）及诱导型一氧化氮合酶（iNOS）的mRNA表达水平，流式细胞术检测M1型巨噬细胞特异表面标志物CD80表达水平。用Transwell非接触式共培养小皿将经M1型诱导后的巨噬细胞与肝癌MHCC97H细胞进行共培养。在共培养条件下，通过Transwell和划痕实验检测MHCC97H的侵袭转移能力，流式细胞术检测MHCC97H细胞的凋亡情况。组间数据比较采用t检验分析。 结果： 敲减CEBPD后，THP-1来源巨噬细胞中M1型巨噬细胞标志基因iNOS、TNFα、IL-6及IL-1β的mRNA表达水平降低，M1型巨噬细胞表面特异标志物CD80表达减少（23.7%±2.1%与62.5%±2.0%，t = 9.58，P < 0.05）。将shCEBPD组和shNC组的THP-1分别与MHCC97H进行共培养，与shNC组相比，shCEBPD组共培养的MHCC97H细胞侵袭能力[（158.0±3.5）个与（75.0±4.5）个，t = 39.87，P < 0.01]和转移能力（54.6%±1.5%与24.3%±1.0%，t = 61.42，P < 0.01）增强、凋亡率降低[（9.4%±1.0%）与（23.7%±1.2%），t = 12.68，P < 0.01]。 结论： CEBPD通过促进巨噬细胞M1型极化抑制肝癌侵袭转移，并增加肝癌细胞凋亡。.