BACKGROUND: The KEAP1-Nrf2 antioxidant signaling pathway is important in protecting liver from various insults. However,little is known about the expression of Nrf2-related genes in human liver in different diseases.METHODS: This study utilized normal donor liver tissues(n=35), samples from patients with hepatocellular carcinoma(HCC, n=24), HBV-related cirrhosis(n=27), alcoholic cirrhosis(n=5) and end-stage liver disease(n=13). All of the liver tissues were from the Oriental Liver Transplant Center, Beijing,China. The expressions of Nrf2 and Nrf2-related genes, including its negative regulator Kelch-like ECH-associated protein 1(KEAP1), its targeted gene NAD(P)H-quinone oxidoreductase 1(NQO1), glutamate-cysteine ligase catalytic subunit(GCLC) and modified subunit(GCLM), heme oxygenase 1(HO-1) and peroxiredoxin-1(PRDX1) were evaluated. RESULTS: The expression of Nrf2 was decreased in HCC, increased in alcoholic cirrhosis and end-stage liver disease. The expression of KEAP1 was increased in all of the liver samples.The most notable finding was the increased expression of NQO1 in HCC(18-fold), alcoholic cirrhosis(6-fold), endstage liver disease(5-fold) and HBV-related cirrhosis(3-fold).Peri-HCC also had 4-fold higher NQO1 m RNA as compared to the normal livers. GCLC m RNA levels were lower only in HCC, as compared to the normal livers and peri-HCC tissues.GCLM m RNA levels were higher in HBV-related cirrhosis and end-stage liver disease. HO-1 m RNA levels were increased in all liver tissues except for HCC. Peri-HCC had higher PRDX1 m RNA levels compared with HCC and normal livers.CONCLUSION: Nrf2 and Nrf2-related genes are aberrantly expressed in the liver in different diseases and the increase of NQO1 was the most notable finding, especially in HCC.
Ming-Liang ChengYuan-Fu LuHong ChenZhong-Yang ShenJie Liu