Oral Contraceptive Use May Modulate Global Genomic DNA Methylation and Promoter Methylation of APC1 and ESR1.

Background

There are challenging reports in the public health sphere regarding associations between oral contraceptive (OC) use and cancer risk.

Methods

To evaluate possible effects of OCs on cancer susceptibility, we quantified of global 5-methyl cytosine (5-mC) levels and assessed methylation patterns of CpG islands of two key tumor suppressor genes, APC1 and ESR1, in serum of users by enzyme-linked immunosorbent assay and methylation specific PCR methods, respectively.

Results

Our results indicated that OCs significantly decrease the level of global DNA methylation in users relative to control non-users. However, our data revealed no significant differences between CpG island methylation patterns for ESR1 and APC1 in healthy control and OC-treated women. However, we did find a trend for hypermethylation of both tumor suppressor genes in OC users.

Conclusion

Our data suggest that the level of 5-mC but not individual CpG island patterns is significantly influenced by OCs in our cross-section of adult users.