FIG. 4.

RCAN1.4 intron 1 is hypermethylated in tumor PTC vs. paired normal tissue samples. Paired thyroid cancer normal and tumor samples were analyzed for RCAN1.4 methylation of intron 1. (A) Qualitative methylation-specific PCR was performed to assess methylation of intron 1 (both regions) in 14 PTC normal and tumor paired samples with adequate DNA with results suggesting relatively higher methylated: unmethylated DNA in tumor samples. (B) Quantitative capture of methylated DNA by MBD2 at RCAN1.4 intron 1 for all 18 pairs confirmed higher levels of methylation in both regions 2 and 3 in thyroid cancer samples. Paired Student t-test was used for statistical analysis; p < 0.05 is significant. N, normal; PTC, papillary thyroid cancer; T, tumor.