Fig. 5
From: Ambient fine particulate matter inhibits 15-lipoxygenases to promote lung carcinogenesis
15-LOX1 is partially silenced by promoter methylation in human lung carcinogenic cells. a and (b) Downregulation of 15-LOX1 and 15-LOX2 by PM2.5 or NNK. Bet1A and NCI-H23 cells were treated with PM2.5 or NNK for 28 days. Total protein and RNA were extracted for (a) Western-blot and (b) real-time PCR assay (n = 3, **p < 0.01when compared each PM2.5- or NNK-treated condition with the control cells). c MassArray for methylation assay. One CpG island was found in 15-LOX1 promotor region. CpGs within the 15-LOX1 locus were hypermethylated in lung cancer cell NCI-H23 as compared with normal lung epithelial cell Bet1A. More denser methylation was also observed in some points of PM2.5 and NNK-treated NCI-H23 cells than NCI-H23 control cells as indicated with the arrow