Fig. 6.

Integrated analysis of gene expression and DNA methylation changes in CNTexposed 16HBE cells. Analysis of gene expressions with significant differential methylation: (a) using genes with differentially methylated gene promoters after exposure to MWCNTs and (b) using genes with differentially methylated CpG sites after exposure to SWCNTs. log₂FC in mean gene expression are plotted against mean Δβ values of individual CpGs and gene promoter regions between CNT-exposed and control samples. Densities of values are plotted by using a color scale from light blue (low density) to red (high density). Gray lines indicate relative hypomethylation and hypermethylation (Δβ > 0.01 or Δβ < − 0.01) or relative increase and decrease (log₂FC > 0.2 or log₂FC < 0.2) in gene expression. In quadrant Q I, genes are relatively hypermethylated after CNT-exposure and show increased gene expression [(A) N = 0, (B) N= 6]; Q II, genes are relatively hypomethylated after CNT-exposure and show increased gene expression [(A) N= 568, (B) N = 43]; Q III, genes are relatively hypomethylated after CNT-exposure and show decreased gene expression [(A) N= 118, (B) N= 29]; Q IV, genes are relatively hypermethylated after CNT-exposure and show decreased gene expression [(A) N = 0, (B) N = 10]