图1 正常组织和SKCM中MMRN2的表达情况

Fig.1 MMRN2 expression in normal and cutaneous melanoma tissues. A: Differential gene expression analysis between tumor and normal tissues using data from GSE46517, GSE83583, and GSE4587 datasets. B: MMRN2 expression levels are significantly higher in metastatic cutaneous melanoma than in normal tissues. *P<0.05, **P<0.01 vs normal tissue; ***P<0.001 vs cutaneous melanoma.

图2 SKCM相关性基因和蛋白互作网络

Fig.2 Cutaneous melanoma-related genes and the protein-protein interaction network. A: Intersection analysis of genes associated with cutaneous melanoma using the GEPIA2.0 database. B: Protein-protein interaction (PPI) network constructed by retrieving 30 interacting molecules from the STRING database, resulting in 15 hub genes shared across analyses. C: Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the hub genes.

图3 MMRN2和SKCM的临床特征相关性

Fig.3 Association of MMRN2 expression levels with clinicopathological features of patients with cutaneous melanoma. A: Kaplan-Meier survival analysis of patients with cutaneous melanoma stratified by MMRN2 expression level. B: Correlations of MMRN2 expression level with pathological T stage, Breslow depth and melanoma ulceration in patients with cutaneous melanoma. *P<0.05.

图5 MMRN2在皮肤黑色素瘤中的免疫细胞浸润分析结果

Fig.5 Immune infiltration analysis of MMRN2 in cutaneous melanoma. A: Correlation lollipop chart between MMRN2 and immune infiltration matrix data in TCGA database. The results are visualized using the ggplot2 package. The 24 types of immune cells included aDC (activated DC), B cells, CD8 T cells, cytotoxic cells, DC, eosinophils, iDC (immature DC), macrophages, mast cells, neutrophils, NK CD56bright cells, NK CD56dim cells, NK cells, pDC (plasmacytoid DC), T cells, T helper cells, Tcm (T central memory), Tem (T effector memory), TFH (T follicular helper), Tgd (T gamma delta), Th1 cells, Th17 cells, Th2 cells, and TReg. B: Scatter plot of the correlation between MMRN2 expression level and iDC abundance. C: Scatter plot of correlations between MMRN2 and immune cells in cutaneous melanoma. D, E: Scatter plots of correlations between MMRN2 and tumor fibroblasts in cutaneous melanoma. F: Scatter plot of correlations between MMRN2 and endothelial cells in cutaneous melanoma. Data source: TIMER database, http://timer.comp-genomics.org/timer/

图6 MMRN2的免疫浸润分析

Fig.6 Immune infiltration analysis of MMRN2 in cutaneous melanoma. A: GSVA-based immune cell enrichment scores of MMRN2 in cutaneous melanoma. B: Immune infiltration profiles between high and low MMRN2 expression groups. #: FDR<0.05, *P<0.05, **P<0.01, ***P<0.001 vs low MMRN2 expression group.

图7 MMRN2和血管生成基因相关性分析

Fig.7 Correlation analysis of MMRN2 and angiogenesis-related genes. A: MMRN2 expression is positively correlated with the majority of angiogenesis-associated genes. B: MMRN2 expression level is strongly correlated with KCNJ8, SLCO2A1, NRP1 and COL3A1.

图8 敲低MMRN2抑制SKCM细胞的增殖、侵袭和迁移

Fig.8 Knockdown of MMRN2 suppresses proliferation, invasion, and migration of cutaneous melanoma cells. A: Western blotting of MMRN2 proteins. B: Colony formation assay for assessing cell proliferation. C: Transwell assay for assessing cell migration and invasion (Original magnification: ×10). D: Knockdown of MMRN2 impairs wound healing in B16 melanoma cells (×200). **P<0.01.

图9 敲低MMRN2能够改善小鼠病理特征并延长小鼠生存时间

Fig.9 Knockdown of MMRN2 attenuates pathological manifestations and extends survival of mice bearing cutaneous melanoma xenograft. A: HE staining of the liver, spleen, lung, and kidney of mice in MMRN2 knockdown group (×10). B: Kaplan-Meier curve. C: GM-CSF, CXCL9, and TGF-β1 expression levels measured by ELISA. ***P<0.001 vs NC group.