The bioinfomatics analysis of the M1 macrophage-related gene CXCL9 signature in cervical cancer

The expression and function of coexpression genes of M1 macrophage in cervical cancer have not been identified. And the CXCL9-expressing tumour-associated macrophage has been poorly reported in cervical cancer.
To clarify the regulatory gene network of M1 macrophage in cervical cancer, we downloaded gene expression profiles of cervical cancer patients in TCGA database to identify M1 macrophage coexpression genes. Then we constructed the protein–protein interaction networks by STRING database and performed functional enrichment analysis to investigate the biological effects of the coexpression genes. Next, we used multiple bioinformatics databases and experiments to overall investigate coexpression gene CXCL9, including western blot assay and immunohistochemistry assay, GeneMANIA, Kaplan-Meier Plotter, Xenashiny, TISCH2, ACLBI, HPA, TISIDB, GSCA and cBioPortal databases.
There were 77 positive coexpression genes and 5 negative coexpression genes in M1 macrophage. The coexpression genes in M1 macrophage participated in the production and function of chemokines and chemokine receptors. Especially, CXCL9 was positively correlated with M1 macrophage infiltration levels in cervical cancer. CXCL9 expression would significantly decrease and high CXCL9 levels were linked to good prognosis in the cervical cancer tumour patients, it manifestly expressed in blood immune cells, and was positively related to immune checkpoints. CXCL9 amplification was the most common type of mutation. The CXCL9 gene interaction network could regulate immune-related signalling pathways, and CXCL9 amplification was the most common mutation type in cervical cancer. Meanwhile, CXCL9 may had clinical significance for the drug response in cervical cancer, possibly mediating resistance to chemotherapy and targeted drug therapy.
Our findings may provide new insight into the M1 macrophage coexpression gene network and molecular mechanisms in cervical cancer, and indicated that M1 macrophage association gene CXCL9 may serve as a good prognostic gene and a potential therapeutic target for cervical cancer therapies.
Cervical cancer is a common gynaecological malignancy, investigating the precise gene expression regulation of M1 macrophage is crucial for understanding the changes in the immune microenvironment of cervical cancer. In our study, a total of 82 coexpression genes with M1 macrophages were identified, and these genes were involved in the production and biological processes of chemokines and chemokine receptors. Especially, the chemokine CXCL9 was positively correlated with M1 macrophage infiltration levels in cervical cancer. CXCL9 as a protective factor, it manifestly expressed in blood immune cells, and was positively related to immune checkpoints. CXCL9 amplification was the most common type of mutation. And CXCL9 expression could have an effect on the sensitivity of some chemicals or targeted drugs against cervical cancer. These findings may provide new insight into the M1 macrophage coexpression gene network and molecular mechanisms, and shed light on the role of CXCL9 in cervical cancer.

宫颈癌中M1巨噬细胞（M1 macrophage）共表达基因的表达模式与功能尚未明确，而表达CXCL9的肿瘤相关巨噬细胞（tumour-associated macrophage）在宫颈癌中的相关研究亦较为匮乏。
为明确宫颈癌中M1巨噬细胞的调控基因网络，本研究下载了TCGA数据库（The Cancer Genome Atlas）中宫颈癌患者的基因表达谱（gene expression profile），以筛选M1巨噬细胞共表达基因。随后通过STRING数据库构建蛋白质相互作用网络（protein–protein interaction network），并开展功能富集分析（functional enrichment analysis），以探究共表达基因的生物学效应。此外，本研究结合多组生物信息学数据库与实验手段，对共表达基因CXCL9进行了全面研究，涵盖蛋白质免疫印迹实验（western blot assay）、免疫组织化学实验（immunohistochemistry assay），以及GeneMANIA、Kaplan-Meier Plotter、Xenashiny、TISCH2、ACLBI、HPA、TISIDB、GSCA与cBioPortal数据库。
本研究共筛选得到77个M1巨噬细胞正共表达基因与5个负共表达基因。M1巨噬细胞的共表达基因参与趋化因子（chemokine）与趋化因子受体（chemokine receptor）的生成及功能调控过程。其中，CXCL9与宫颈癌中M1巨噬细胞的浸润水平呈显著正相关。宫颈癌患者体内CXCL9的表达水平显著降低，而高表达CXCL9与良好预后相关；CXCL9在血液免疫细胞中呈显著表达，且与免疫检查点（immune checkpoint）呈正相关。CXCL9基因扩增（amplification）是该基因最常见的突变类型。CXCL9基因的相互作用网络可调控免疫相关信号通路（signalling pathway），而CXCL9扩增亦是宫颈癌中最常见的基因突变类型。此外，CXCL9或对宫颈癌的药物应答具有临床指导意义，可能参与介导化疗（chemotherapy）与靶向药物治疗（targeted drug therapy）的耐药过程。
本研究结果可为宫颈癌中M1巨噬细胞共表达基因网络及分子机制研究提供新视角，同时提示M1巨噬细胞相关基因CXCL9可作为宫颈癌预后评估的潜在标志物及治疗靶点。
宫颈癌是常见的妇科恶性肿瘤（gynaecological malignancy），解析M1巨噬细胞的精准基因表达调控机制，对于理解宫颈癌免疫微环境（immune microenvironment）的变化至关重要。本研究共筛选得到82个与M1巨噬细胞相关的共表达基因，这些基因参与趋化因子与趋化因子受体的生成及生物学过程。其中，趋化因子CXCL9与宫颈癌中M1巨噬细胞的浸润水平呈显著正相关。CXCL9作为保护性因子，在血液免疫细胞中呈显著表达，且与免疫检查点呈正相关。CXCL9基因扩增是该基因最常见的突变类型，其表达水平可影响部分化疗药物及靶向药物对宫颈癌的敏感性。本研究结果可为M1巨噬细胞共表达基因网络及分子机制研究提供新视角，并阐明CXCL9在宫颈癌发生发展中的作用。