Association between heat shock factor protein 4 methylation and colorectal cancer risk and potential molecular mechanisms: A bioinformatics study

Figure 1 Pan-cancer analysis of heat shock factor protein 4 methylation levels. A: Schematic representation of the distribution of eat shock factor protein 4 (HSF4) methylated CpG loci. B: Differential analysis of the β values of 19 CpG methylation loci of HSF4 in multiple malignancies. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001, and ^dP < 0.0001; ns: No significant difference.

Figure 2 Differential analysis of β values of 19 probes related to heat shock factor protein 4 methylation in colon adenocarcinoma and paracancerous tissues. The β values of all 19 probes were significantly increased in the tissues of colon adenocarcinoma (COAD) patients. Black is paracancerous tissue, and red is COAD tissue.

Figure 3 Correlation analysis of heat shock factor protein 4 expression and heat shock factor protein 4 methylation levels. The β values of all 19 probes exhibited a significant positive correlation with the expression of eat shock factor protein 4 (HSF4) mRNA. The x-axis is the β value of 19 probes, and y-axis is log₂ (TPM + 1) of HSF4 mRNA.

Figure 4 Correlation analysis of heat shock factor protein 4 methylation and prognosis of patients with colon adenocarcinoma. Kaplan Meier survival curves illustrating the survival of colon adenocarcinoma patients with high and low beta values for the 19 probes. The blue curve represents the cohort with low β values, and the red curve stands for the cohort with high β values.

Figure 5 Correlation analysis of heat shock factor protein 4 methylation and diagnosis in patients with colonic adenocarcinoma. A: Receiver operating characteristic (ROC) curves exhibiting the diagnostic value of 19 heat shock factor protein 4 (HSF4) methylation-associated probes in colon adenocarcinoma patients. B: Time-dependent ROC curves displaying the area under the curve of HSF4 methylation at 1, 3 and 5 years. AUC: Area under the curve; TPR: True positive rate; FPR: False positive rate.

Figure 6 Identification of heat shock factor protein 4 methylation-related genes and their enrichment analysis in colorectal cancer. A: Volcano plot showing genes positively and negatively associated with heat shock factor protein 4 (HSF4) methylation in colorectal cancer. B, C: Expression profiles of the top 50 genes ranked by absolute correlation coefficient of HSF4 methylation-related genes. B is the expression profile of genes positively associated with HSF4 methylation; C is the expression profile of genes negatively associated with HSF4 methylation. D: Bubble plots exhibiting the GO enrichment results of all HSF4 methylation-related genes. E: Possible pathways involved in HSF4 methylation-related genes obtained by Kyoto Encyclopedia of Genes and Genomes enrichment analysis. HSF4: Heat shock factor protein 4; BP: Biological process; CC: Cell component; MF: Molecular function; PD-L1: Programmed cell death-Ligand 1; PD-1: Programmed death 1; IL-17: Interleukin-17.

Figure 7 Protein-protein interaction network construction of heat shock factor protein 4 methylation positively associated genes. A: Protein-protein interaction (PPI) network of heat shock factor protein 4 methylation positively related genes constructed based on String database and MCODE algorithm. B: Top 20 genes in PPI network in terms of edge number. C: The top 10 clustering networks in terms of clustering scores obtained by the MCODE algorithm.

Figure 8 Protein-protein interaction network construction of heat shock factor protein 4 methylation negatively associated genes. A: Representative images of the protein-protein interaction (PPI) network of heat shock factor protein 4 methylation negatively associated genes. B: The bar chart displaying edge number of each gene in the PPI network. C: Gene composition and interactions of clustering networks obtained by the MCODE algorithm.

Figure 9 Diagrammatic representation of this study. CRC: Colorectal cancer; HSF4: Heat shock factor protein 4.