Evaluation of candidate methylation markers to detect cervical neoplasia

Abstract Objective. Studies of cervical cancer and its immediate precursor, cervical intraepithelial neoplasia 3 (CIN3), have identified genes that often show aberrant DNA methylation and therefore represent candidate early detection markers. We used quantitative PCR assays to evaluate methylation in five candidate genes (TNFRSF10C, DAPK1, SOCS3, HS3ST2 and CDH1) previously demonstrated as methylated in cervical cancer. Methods. In this analysis, we performed methylation assays for the five candidate genes in 45 invasive cervical cancers, 12 histologically normal cervical specimens, and 23 liquid-based cervical cytology specimens confirmed by expert review as unequivocal demonstrating cytologic high-grade squamous intraepithelial lesions, thus representing the counterparts of histologic CIN3. Results. We found hypermethylation of HS3ST2 in 93% of cancer tissues and 70% of cytology specimens interpreted as CIN3; hypermethylation of CDH1 was found in 89% of cancers and 26% of CIN3 cytology specimens. Methylation of either HS3ST2 or CDH1 was observed in 100% of cervical cancer tissues and 83% of CIN3 cytology specimens. None of the five genes showed detectable methylation in normal cervical tissues. Conclusion. Our data support further evaluation of HS3ST2 and CDH1 methylation as potential markers of cervical cancer and its precursor lesions.