Decreased PADI4 mRNA association with global hypomethylation in hepatocellular carcinoma during HBV exposure.
To gain insight into the role of peptidylarginine deiminase type 4 (PADI4), we determined the relationship between PADI4 mRNA and global hypomethylation during HBV exposure in hepatocarcinogenesis. We analyzed Line-1 methylation by MSP, and CD133 mRNA by real-time PCR in 74 HCC. The HCC cancer lines (7721, Huh7, and Hep-G2) were treated with 5-Aza-CdR and TSA. PADI4 mRNA were lower in HCC tissues (Mean(-∆Ct) = 1.41) than that in Non-Hcc tissues (Mean(-∆Ct) = 3.10). Expression of PADI4 was elevated in only 20 (27 %) of the 74 HCC patients but decreased in 54 (73 %) of the patients. The declined PADI4 mRNA was significantly associated with Line-1 demethylation in HCC patients. PADI4 mRNA were lower in HCC patients with Line-1 ∆MI <-0.15 (Mean(-∆∆Ct) = -2.66) than those with Line-1 ∆MI >= -0.15 (Mean(-∆∆Ct) = -1.02). The results suggested that HCC showing hypomethylation of Line-1 is considered to be silencing PADI4 mRNA. And the lower PADI4 mRNA was also found in HCC patients with HBV >= 10(5) (copy/ml) than those with HBV < 10(5) (copy/ml). After treated by 5-Aza-CdR and TSA, we found that PADI4 mRNA induced significantly by TSA in Huh7 and Hep-G2 cells, but not in 7721 cells. Meanwhile, PADI4 mRNA induced by the combination of 5-Aza-CdR and TSA in HCC cells, and it could no effect for exposure to 5-Aza-CdR alone. The results suggested that decreased PADI4 mRNA is associated with global hypomethylation in HCC during HBV exposure.
Tumor Immunology and Gene Therapy Center, Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, Shanghai, China.
Changsong
C
Zhang
Lieying
L
Fan
Tingting
T
Fan
Dong
D
Wu
Lu
L
Gao
Yang
Y
Ling
Jing
J
Zhu
Rong
R
Li
Lixin
L
Wei
D000328:Adult; D000368:Aged; D001374:Azacitidine / Q000031:analogs & derivatives; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology / Q000821:virology; D045744:Cell Line, Tumor; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D000077209:Decitabine; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D006509:Hepatitis B / Q000821:virology; D006515:Hepatitis B virus / Q000502:physiology; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D054884:Host-Pathogen Interactions; D006801:Humans; D006867:Hydrolases / Q000235:genetics* / Q000378:metabolism; D006877:Hydroxamic Acids / Q000494:pharmacology; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology / Q000821:virology; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008297:Male; D008875:Middle Aged; D000080002:Protein-Arginine Deiminase Type 4; D000076342:Protein-Arginine Deiminases; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis
D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D012333:RNA, Messenger; C012589:trichostatin A; D000077209:Decitabine; D015254:DNA Modification Methylases; D006867:Hydrolases; C000629235:PADI4 protein, human; D000080002:Protein-Arginine Deiminase Type 4; D000076342:Protein-Arginine Deiminases; D001374:Azacitidine