The AHR Pathway And Its Potential Role In The Regulation Of The 15 kDa Selenoprotein

Several selenoproteins, including the 15kDa selenoprotein (Sep15), are thought to have roles in both cancer prevention and promotion. Sep15 belongs to the group of stress-related selenoproteins, and though its functional role continues to be elucidated, this oxidoreductase resides in the ER and is thought to be involved in reduction or isomerization of disulfide bonds. Little is known about factors regulating Sep15 expression. Our preliminary analyses indicated that some dietary polyphenols decreased Sep15 mRNA expression in human colon cancer HT29 cells. Because many of these flavonoids are known to affect Arylhydrocarbon Receptor (AHR) and/or NRF2-regulatory pathways, expression of AHR and NRF2-related genes are being investigated in Sep15-deficient and -sufficient HT29 colon cancer cells to elucidate the potential regulatory mechanisms of Sep15. Analysis of previously published microarray data indicated that mRNA expression of AHR-pathway-related genes was significantly changed in HT29 cells lacking Se...