Fig 1: High methylation levels in ccRCC promote the downregulation of SDHB. (A) Methylation levels of SDHB gene promoter was increased in ccRCC tissues based on the TCGA_KIRC data. The Beta value indicated the level of DNA methylation, and the P value was derived from independent sample two tailed t-test. The data were presented as mean ± SD. ****P < 0.0001. (B) The correlation between SDHB methylation levels and clinical parameters in the MEXPRESS database. (C) MSP analysis of SDHB gene promoter methylation in ACHN and 786-O cells following treatment with increasing dose of methylation inhibitor decitabine. Bisulphite-modified DNA was amplified with primer pair specific for unmethylated (U) and methylated (M) alleles. The data are representative of three independent experiments. (D) Western blotting results showed that SDHB protein level was gradually increased in ACHN and 786-O cells following treatment with increasing dose of methylation inhibitor decitabine. ß-actin was used as a loading control. The data are representative of three independent experiments.
Fig 2: SDHB is a potential prognostic marker for ccRCC patients. (A–E) SDHB mRNA and protein levels were gradually downregulated as T stage, AJCC stage and Fuhrman grade progressed. (F) SDHB mRNA level was negatively correlated with distant metastasis of ccRCC patients. (G, H) The Kaplan-Meier (KM) curves of overall survival and disease-free survival based on TCGA_KIRC data. ccRCC patients were divided into high/low expression groups according to SDHB mRNA level. (I–K) KM curves of overall survival based on TCGA_KIRC data. Advanced ccRCC patients were divided into high/low expression groups according to SDHB mRNA level. (L) Enrichment plot of gene expression signature for relapse (KAUFFMANN_MELANOMA_RELAPSE_UP) was obtained by GSEA according to SDHB mRNA levels. The ccRCC samples from TCGA_KIRC database were divided into high and low SDHB expression groups according to the median value of SDHB RNA-seq quantification results. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.
Fig 3: SDHB may suppress ccRCC tumorigenesis and development by inhibiting glycolysis. (A) Co-expression network of SDHB gene in ccRCC. Genes that were negatively correlated with SDHB were displayed in green, and genes that were positively correlated with SDHB were displayed in red. The darker the color, the stronger the correlation. (B) PPI network of SDHB-related DEGs. (C–E) Bubble chart according to GO (cellular component, molecular functions and biological processes) analyses of SDHB-related differentially expressed proteins. (F) KEGG pathway enrichment analysis of SDHB-related differentially expressed proteins. (G) Enrichment plot of gene expression signature for glycolysis (HALLMARK_GLYCOLYSIS). The ccRCC samples from TCGA_KIRC database were divided into high and low SDHB expression groups according to the median value of SDHB RNA-seq quantification results.
Fig 4: SDHB expression level is downregulated in ccRCC tissues. (A–C) Comparison of SDHB mRNA levels between adjacent normal tissues and ccRCC tissues based on GEO GSE53757 data (A), TCGA_KIRC data (B), and oncomine data (C), respectively. Oncomine data included Jones Renal (normal = 23; ccRCC = 32), Higgins Renal (normal = 3; ccRCC = 36), Beroukhim Renal (normal = 11; ccRCC = 32), Gumz Renal (normal = 10; ccRCC = 10), Lenbury kidney (normal = 9; ccRCC = 9). (D) Comparison of SDHB protein levels between adjacent normal tissues and ccRCC tissues based on CPTAC data. (E) Representative IHC figure of SDHB expression and scatter plot displaying the expression of SDHB in adjacent normal tissues and ccRCC tissues. P value was derived from independent sample two tailed t-test. The data were presented as mean ± SD. ****P < 0.0001.
Fig 5: SDHB overexpression inhibits glycolysis in ccRCC cells. (A) Glucose level in SDHB-overexpressing ACHN and 786-O cells. (B) Intracellular lactic acid level in SDHB-overexpressing ACHN and 786-O cells. P value was derived from independent sample two tailed t-test. The data were presented as mean ± SD. ****P < 0.0001. The data are representative of three independent experiments.
Supplier Page from Abcam for Anti-SDHB antibody [EPR10880]