Figure 4.

Progression to malignancy is associated with DNA hypermethylation at several gene loci. MSP analysis of CCND2, RASSF1A, SFRP1, p57, MGMT, and THBS1 in the cells indicated using primer sets listed in Table 1 that specifically amplify either methylated (m) or unmethylated (u) DNA. Positive (+) and (-) controls for the methylated product, as well as a H₂O negative control, were included in all experiments. All MSP experiments were performed on at least two independent cell populations. The data presented for the SFRP1-exon1 MSP are from two different experiments. Analysis of the primary cells (HMEC, vHMEC, vector, ras, and ras0.5) and the cell lines (184A1, MCF10A, MCF7, and MDA231) was done separately and merged. The data presented for all the other genes were obtained in the same experiment. Replicate experiments are available online in Additional file 2.