Comprehensive analysis of the protein phosphatase 2A regulatory subunit B56ε in pan-cancer and its role and mechanism in hepatocellular carcinoma

Figure 1 Analysis of B56ε expression levels and prognostic value in 33 types of cancers. A: B56ε expression profile in pan-cancer by the Tumor Immune Estimation Resource database; B: B56ε expression in pan-carcinoma was analyzed based on The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression databases; C: Relationship between B56ε expression and tumor survival in the Gene Expression Omnibus dataset; D: Prognostic value of B56ε in pan-cancer based on TCGA database. ^aP < 0.05; ^bP < 0.01; ^cP < 0.001. OS: Overall survival; CI: Confidence interval; HR: Hazard ratio; ACC: Adrenocortical carcinoma; BLCA: Bladder urothelial carcinoma; BRCA: Breast invasive carcinoma; CESC: Cervical squamous cell carcinoma; CHOL: Cholangiocarcinoma; COAD: Colon adenocarcinoma; DLBC: Lymphoid neoplasm diffuse large B cell lymphoma; ESCA: Esophageal carcinoma; GBM: Glioblastoma; HNSC: Head and neck squamous cell carcinoma; KICH: Kidney chromophobe; KIRP: Kidney renal papillary cell carcinoma; KIRC: Kidney clear cell carcinoma; LGG: Low-grade glioma; LIHC: The Cancer Genome Atlas-Liver hepatocellular carcinoma; LUAD: Lung adenocarcinoma; LUSC: Lung squamous cell carcinoma; MESO: Mesothelioma; OV: Ovarian serous cystadenoma; PAAD: Pancreatic adenocarcinoma; PCPG: Pheochromocytoma and paraganglioma; PRAD: Prostate adenocarcinoma; READ: Rectal adenocarcinoma; SARC: Sarcoma; SKCM: Skin cutaneous melanoma; STAD: Stomach adenocarcinoma; TGCT: Testicular germ cell tumor; THCA: Thyroid carcinoma; THYM: Thymic carcinoma; UCEC: Endometrial cancer; UCS: Uterine carcinosarcoma; UVM: Uveal melanoma.

Figure 2 Association analysis of B56ε expression with tumor mutations, somatic copy number alterations, and immunity in pan-cancer. A: Percentage of samples with B56ε mutation; B: Somatic copy number alterations by the Tumor Immune Estimation Resource database; C: Associations between B56ε expression and estimate score, immune score, and stromal score in different cancers; D: Correlation analysis between immune checkpoint genes and the expression of B56ε. ^aP < 0.05; ^bP < 0.01; ^cP < 0.001. sCNA: Somatic copy number alteration; ACC: Adrenocortical carcinoma; BLCA: Bladder urothelial carcinoma; BRCA: Breast invasive carcinoma; CESC: Cervical squamous cell carcinoma; CHOL: Cholangiocarcinoma; COAD: Colon adenocarcinoma; DLBC: Lymphoid neoplasm diffuse large B cell lymphoma; ESCA: Esophageal carcinoma; GBM: Glioblastoma; HNSC: Head and neck squamous cell carcinoma; KICH: Kidney chromophobe; KIRP: Kidney renal papillary cell carcinoma; KIRC: Kidney clear cell carcinoma; LGG: Low-grade glioma; LIHC: The Cancer Genome Atlas-Liver hepatocellular carcinoma; LUAD: Lung adenocarcinoma; LUSC: Lung squamous cell carcinoma; MESO: Mesothelioma; OV: Ovarian serous cystadenoma; PAAD: Pancreatic adenocarcinoma; PCPG: Pheochromocytoma and paraganglioma; PRAD: Prostate adenocarcinoma; READ: Rectal adenocarcinoma; SARC: Sarcoma; SKCM: Skin cutaneous melanoma; STAD: Stomach adenocarcinoma; TGCT: Testicular germ cell tumor; THCA: Thyroid carcinoma; THYM: Thymic carcinoma; UCEC: Endometrial cancer; UCS: Uterine carcinosarcoma; UVM: Uveal melanoma.

Figure 3 Expression and prognosis value of B56ε in hepatocellular carcinoma. A: Analysis of the B56ε expression difference between hepatocellular carcinoma (HCC) tissues and normal liver tissues in The Cancer Genome Atlas (TCGA); B: Pairwise difference comparison of B56ε expression level between HCC tissues and normal liver tissues in the TCGA database; C: TCGA combined with Genotype-Tissue Expression databases to analyze the expression of B56ε in HCC tissues and normal liver tissues; D: Gene Expression Profiling Interactive Analysis was utilized for analyzing the relationship between B56ε expression and HCC overall survival time; E: Expression of B56ε protein in normal liver tissue and HCC tissue by the Human Protein Atlas database. ^cP < 0.001. HCC: Hepatocellular carcinoma.

Figure 4 Correlation analysis of B56ε expression with immune subtype and immune cells. A: Analysis of B56ε expression in different immune subtypes of hepatocellular carcinoma (HCC); B: Differential expression of immune cells in the B56ε high and low expression groups; C: Correlation analysis between immune cells and the expression of B56ε; D: Analysis of differences in tumor microenvironment scores between groups with a high and low B56ε expression; E: Association of six common types of immune cells and B56ε expression in HCC by Tumor Immune Estimation Resource. ^aP < 0.05; ^bP < 0.01; ^cP < 0.001. aDC: Activate dendritic cell; iDC: Immature dendritic cell; NK: Natural killer; pDC: Plasmacytoid dendritic cell; TFH: Follicular helper T cell; Th: T helper; Treg: Regulatory T cell.

Figure 5 Correlation analysis of B56ε expression with immune checkpoint genes, human leukocyte antigen-associated genes and drug sensitivity. A: Correlation analysis between immune checkpoint genes and the expression of B56ε; B: Correlation analysis between human leukocyte antigen-associated genes and the expression of B56ε; C and D: Association between anticancer drug response and B56ε expression in the CellMiner database. ^aP < 0.05; ^bP < 0.01; ^cP < 0.001. HLA: Human leukocyte antigen; NS: Not significant.

Figure 6 Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses for samples with high and low B56ε expression. A: Gene Ontology enrichment analysis was performed on B56ε differential expression samples; B: Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway in the high B56ε expression group; C: KEGG signaling pathway in the low B56ε expression group. BP: Biological process; CC: Cellular component; MF: Molecular function.

Figure 7 Effects of B56ε downregulation on the proliferation, invasion, and migration of hepatocellular carcinoma cells. A: Quantitative polymerase chain reaction (qPCR) detected the expression of B56ε in human hepatocellular carcinoma (HCC) cell lines; B: qPCR and western blotting verified B56ε knockdown efficiency; C: Downregulation of B56ε expression on the proliferation of HCC cells was determined by the Cell Counting Kit-8 assay; D: Downregulation of B56ε expression on the proliferation of HCC cells was determined by the colony formation assay; E and F: Wound healing assay (E) and transwell assay (F) showed the ability of cells to invade and migrate after downregulation of B56ε. ^aP < 0.05; ^bP < 0.01; ^cP < 0.001. NC: Negative vector control; KD-1: B56ε knockdown vector 1; KD-2: B56ε knockdown vector 2; CCK-8: Cell Counting Kit-8.