Xia WANG, Jun YAN. Effect of HBx-mediated RXR alpha repression on DNMT3a in hepatocellular carcinoma and underlying mechanism[J]. Journal of Third Military Medical University, 2017, 39(24): 2374-2379.
DOI:
Xia WANG, Jun YAN. Effect of HBx-mediated RXR alpha repression on DNMT3a in hepatocellular carcinoma and underlying mechanism[J]. Journal of Third Military Medical University, 2017, 39(24): 2374-2379. DOI: 10.16016/j.1000-5404.201709085.
Effect of HBx-mediated RXR alpha repression on DNMT3a in hepatocellular carcinoma and underlying mechanism
To explore the role and mechanism of retinoic acid receptor alpha (RXRα) in the regulation of DNA methyltransferases 3a (DNMT3a) expression induced by hepatitis B virus X protein (HBx) in hepatocellular carcinoma.
Methods
2
The gene and protein expression levels of DNMT3a and RXRα were detected by RT-PCR and Western blot assay respectively in normal liver tissues of 12 healthy individual
and HBV positive hepatocellular carcinoma and paired paracancerous tissues of 56 patients. The expression of DNMT3a was measured after HBx gene and/or RXRα gene were transfected in SMMC-7721 cells. The MKK/MEK blocker PD98059 and p38 MAPK blocker SB203580 were added to observe the role of signal pathways in the regulation of RXRα in SMMC-7721 cells transfected with HBx gene.
Results
2
Compared with normal liver tissues
the expression of DNMT3a at mRNA and protein levels was significantly increased in hepatocellular carcinoma tissues and adjacent tissues (
P
<
0.01)
but the levels of RXRα were significantly decreased (
P
<
0.01). Overexpression of HBx gene inhibited the level of RXRα protein and raised the level of DNMT3a protein
while RXRα co-transfected with HBx decreased the expression of DNMT3a induced by HBx (
P
<
0.01). MKK/MEK inhibitor PD98059 and p38 MAPK inhibitor SB203580 both significantly increased the expression of RXRα which was down-regulated by HBx gene (
P
<
0.01).
Conclusion
2
HBx encoded by HBV genome may reduce the expression of RXRα and increase the content of DNMT3a through the MAPK signaling pathway.
关键词
Keywords
references
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