Zhong N, Wang H, Zhao W, Sun Z, Geng B
The First Affiliated Hospital of Wannan Medical College, Internal Medicine-Oncology, Wuhu 241000, China.
The First Affiliated Hospital of Wannan Medical College, Department of respiratory and critical care medicine, Wuhu 241000, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2024 Sep 20;44(9):1704-1711. doi: 10.12122/j.issn.1673-4254.2024.09.10.
To investigate the mechanism of RNF7 for regulating myeloid-derived suppressor cells (MDSCs) in nonsmall cell lung cancer (NSCLC).
TIMER2.0 database and immunohistochemistry were used to analyze RNF7 expression level and its correlation with immune cell infiltration in non-small cell lung cancer. The impact of RNF7 expression levels on prognosis of lung cancer patients was analyzed using Kaplan-Meier survival analysis. CMT-167 cells with RNF7 overexpression or knockdown were inoculated subcutaneously in C57BL/6 mice, and the mice in RNF7 knockdown group were treated with anti-PD-1 or IgG isotype control 7 days after the inoculation. The tumor tissues were harvested after 30 days for tumor volume measurement, detection of S100A8+A9 and Gr-1 expressions with immunohistochemistry, and analysis of MDSC infiltration. Gene set enrichment analysis (GSEA) was performed to identify the potential pathways regulated by RNF7 in NSCLC. Western blotting and luciferase assays were used to assess the impact of RNF7 on the NF-κB signaling pathway. ELISA and RT-qPCR were used to measure chemokine (C-X-C motif) ligand 1 (CXCL1) expression.
RNF7 expression was significantly upregulated in NSCLC, and high RNF7 expression levels were associated with poor prognosis of the patients ( < 0.001). TIMER2.0 analysis revealed a positive correlation between RNF7 expression and MDSC infiltration ( < 0.001). GSEA suggested that RNF7 was enriched in the NF-κB signaling pathway. In NSCLC cells, RNF7 knockdown significantly inhibited NF-κB activation and reduced CXCL1 expression. In the tumor-bearing mice, RNF7 overexpression significantly increased MDSC infiltration in the tumor tissue, and RNF7 knockdown obviously reduced MDSC infiltration and enhanced the efficacy of anti-PD-1 therapy.
High expression of RNF7 in NSCLC cells promotes CXCL1 expression by activating the NF-κB signaling pathway, thus leading to the chemotactic recruitment of MDSCs, which contributes to tumor resistance to antiPD-1 therapy.
探讨RNF7调控非小细胞肺癌（NSCLC）中髓源性抑制细胞（MDSC）的机制。
利用TIMER2.0数据库和免疫组化分析RNF7在非小细胞肺癌中的表达水平及其与免疫细胞浸润的相关性。采用Kaplan-Meier生存分析评估RNF7表达水平对肺癌患者预后的影响。将过表达或敲低RNF7的CMT-167细胞皮下接种于C57BL/6小鼠，敲低RNF7组小鼠在接种后7天用抗PD-1或IgG同型对照进行处理。30天后收集肿瘤组织，测量肿瘤体积，用免疫组化检测S100A8+A9和Gr-1表达，并分析MDSC浸润情况。进行基因集富集分析（GSEA）以鉴定RNF7在NSCLC中调控的潜在通路。采用蛋白质免疫印迹法和荧光素酶报告基因检测评估RNF7对NF-κB信号通路的影响。采用酶联免疫吸附测定（ELISA）和逆转录定量聚合酶链反应（RT-qPCR）检测趋化因子（C-X-C基序）配体1（CXCL1）的表达。
RNF7在NSCLC中表达显著上调，高RNF7表达水平与患者预后不良相关（<0.001）。TIMER2.0分析显示RNF7表达与MDSC浸润呈正相关（<0.001）。GSEA提示RNF7在NF-κB信号通路中富集。在NSCLC细胞中，敲低RNF7显著抑制NF-κB激活并降低CXCL1表达。在荷瘤小鼠中，过表达RNF7显著增加肿瘤组织中MDSC浸润，敲低RNF7明显减少MDSC浸润并增强抗PD-1治疗效果。
NSCLC细胞中RNF7高表达通过激活NF-κB信号通路促进CXCL1表达，从而导致MDSC的趋化募集，这有助于肿瘤对抗PD-1治疗产生抗性。
