Background:
Smad3 is a pivotal intracellular mediator for participating in the activation of multiple immune
signal pathway.
Objective:
The epigenetic regulation mechanism of the positive immune factor Smad3 in cervical cancer remains
unknown. Therefore, the epigenetic regulation on Smad3 is investigated in this study.
Methods:
The methylation status of SMAD3 was detected by Methylation-specific PCR (MS-PCR) and Quantitative
Methylation-specific PCR (MS-qPCR) in cervical cancer tissues and cell lines. The underlying molecular mechanisms of
SUV39H1-DNMT1-Smad3 regulation was elucidated using cervical cancer cell lines containing siRNA or/and overexpression system. Confirmation of the regulation of DNMT1 by SUV39H1 used Chromatin immunoprecipitation-qPCR
(ChIP-qPCR). The statistical methods used for comparing samples between groups were paired t tests and one-way
ANOVAs.
Results:
H3K9me3 protein which regulated by SUV39H1 directly interacts with the DNMT1 promoter region to regulate
its expression in cervical cancer cells, resulting in the reduce expression of the downstream target gene DNMT1. In
addition, DNMT1 mediates the epigenetic modulation of the SMAD3 gene by directly binding to its promoter region. The
depletion of DNMT1 effectively restores the expression of Smad3 in vitro. Moreover, in an in vivo assay, the expression
profile of SUV39H1-DNMT1 was found to correlate with Smad3 expression in accordance with the expression at the
cellular level. Notably, the promoter region of SMAD3 was hypermethylated in cervical cancer tissues, and this
hypermethylation inhibits the subsequent gene expression.
Conclusion:
These results indicate that SUV39H1-DNMT1 is a crucial Smad3 regulatory axis in cervical cancer.
SUV39H1-DNMT1 axis may provide a potential therapeutic target for the treatment of cervical cancer.
Quantitative Multiplex Methylation-Specific PCR Analysis Doubles Detection of Tumor Cells in Breast Ductal Fluid
