GLAD-PCR assay of DNA methylation sites in regulatory regions of some tumor-suppressor genes in breast cancer

Hypermethylation of the RCGY sites is shown for many cancer diseases. Such aberrant methylation, suppressing the gene activity, occurs at early stages of carcinogenesis. Recently, using GLAD-PCR assay, we have detected aberrantly methylated RCGY sites, which can be considered to be epigenetic markers of colorectal, lung, and gastric cancers. In breast cancer, methylation of the regulatory regions of ALX4, BMP2, CCND2, CDH13, CDX1, FOXA1, GALR1, GATA5, GREM1, HIC1, HMX2, HS3ST2, HOXCIO, ICAM5, LAMA1, RARB, RASSF1A, RUNX3, RXRG, RYR2, SFRP2, SOX17, TERT, and ZNF613 tumor-suppressor genes is reported. In the present work, we determined aberrantly methylated RCGY sites in the regulatory regions of these genes in DNA preparations from breast cancer tissues. The study of DNA samples from 30 tumor and 22 normal mammary tissue samples demonstrates a high diagnostic potential of selected R(5mC)GY sites in regulatory regions of CCND2, BMP2, GALR1, SOX17, HMX2, and HS3ST2 genes with total index of sensitivity and specificity for R(5mC)GY detection in tumor DNA 90.0 % and 100.0 %, respectively.