Huang Jing, Xu Yuting, Qi Shengnan, Zheng Qi, Cui Can, Liu Lei, Liu Fan
The First Clinical Medical College of Nanjing Medical University, Nanjing, 211166, China.
Department of Pathology, Affiliated Hospital of Nantong University, 20 Xisi Road, Chongchuan District, Nantong, 226001, China.
Discov Oncol. 2024 Jun 1;15(1):202. doi: 10.1007/s12672-024-01044-7.
Microfibril-associated protein 2 (MFAP2) is a protein presenting in the extracellular matrix that governs the activity of microfibrils through its interaction with fibrillin. While the involvement of MFAP2 in metabolic disorders has been documented, its expression and prognostic significance in triple-negative breast cancer (TNBC) remain unexplored.
We acquired datasets pertaining to breast cancer (BC) from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Next, a Venn diagram was used to identify the differentially expressed genes (DEGs). The DEGs were used to perform Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI), immune and survival analysis. The expressions of MFAP2, PD-1 and PD-L1 were examined by immunohistochemistry and western blot and their relationship with clinical pathological parameters were analyzed by clinical specimen samples from patients with TNBC. Tumor Immune Estimation Resource (TIMER, https://cistrome.shinyapps.io/timer/ ) was adopted to calculate the immune infiltration level of TNBC. The link between gene expression and tumor mutational burden (TMB) was described using Spearman's correlation analysis.
We identified 66 differentially expressed genes (DEGs) that were up-regulated. Among these DEGs, MFAP2 was found to be overexpressed in TNBC and was associated with a lower probability of survival. This finding was confirmed through the use of immunohistochemistry and western blot techniques. Additionally, MFAP2 was found to be related to various pathological parameters in TNBC patients. Mechanistically, gene set enrichment analysis (GSEA) revealed that MFAP2 primarily influenced cellular biological behavior in terms of epithelial mesenchymal transition, glycolysis, and apical junction. Notably, MFAP2 expression was positively correlated with the abundance of macrophages, while a negative correlation was observed with the abundance of B cells, CD4 + T cells, CD8 + T cells, neutrophils and dendritic cells through immune analysis. Furthermore, it was observed that MFAP2 displayed a negative correlation not only with tumor mutational burden (TMB), a recognized biomarker for PD-1/PD-L1 immunotherapy, but also with PD-L1 in samples of TNBC.
MFAP2 may be an important prognostic biomarker for TNBC, as well as a viable target for immunotherapy in this disease.
微原纤维相关蛋白2（MFAP2）是一种存在于细胞外基质中的蛋白质，它通过与原纤蛋白相互作用来调控微原纤维的活性。虽然已有文献记载MFAP2参与代谢紊乱，但其在三阴性乳腺癌（TNBC）中的表达及预后意义仍未得到探索。
我们从基因表达综合数据库（GEO）和癌症基因组图谱（TCGA）数据库中获取了与乳腺癌（BC）相关的数据集。接下来，使用维恩图来识别差异表达基因（DEG）。这些DEG用于进行基因本体论（GO）、京都基因与基因组百科全书（KEGG）、蛋白质-蛋白质相互作用（PPI）、免疫和生存分析。通过免疫组织化学和蛋白质印迹法检测MFAP2、PD-1和PD-L1的表达，并通过TNBC患者的临床标本样本分析它们与临床病理参数的关系。采用肿瘤免疫评估资源（TIMER，https://cistrome.shinyapps.io/timer/ ）来计算TNBC的免疫浸润水平。使用Spearman相关性分析来描述基因表达与肿瘤突变负荷（TMB）之间的联系。
我们鉴定出66个上调的差异表达基因（DEG）。在这些DEG中，发现MFAP2在TNBC中过表达，并且与较低的生存概率相关。这一发现通过免疫组织化学和蛋白质印迹技术得到了证实。此外，发现MFAP2与TNBC患者的各种病理参数有关。从机制上讲，基因集富集分析（GSEA）表明，MFAP2主要在上皮间质转化、糖酵解和顶端连接方面影响细胞生物学行为。值得注意的是，通过免疫分析发现MFAP2表达与巨噬细胞丰度呈正相关，而与B细胞、CD4 + T细胞、CD8 + T细胞、中性粒细胞和树突状细胞的丰度呈负相关。此外，观察到MFAP2不仅与肿瘤突变负荷（TMB，一种公认的PD-1/PD-L1免疫治疗生物标志物）呈负相关，而且与TNBC样本中的PD-L1也呈负相关。
MFAP2可能是TNBC的一个重要预后生物标志物，也是该疾病免疫治疗的一个可行靶点。
