THRB is hypermethylated in DTC. A, Representative results of THRB promoter methylation in cancer and normal thyroid tissue. The amounts of methylated (M) or unmethylated (U) THRB promoter from bisulfite-treated genomic DNA of each tissue were determined by specific PCR analysis. B, The ratio of methylated to unmethylated THRB promoter from normal (n = 7) and cancer tissues (n = 18). The data are presented as medians and analyzed by the Mann-Whitney U test. C, The relative THRB methylation ratios of normal and DTC tissues according to lower (n = 10) and higher (n = 8) tumor (T) staging. The relative THRB methylation ratios of normal and DTC tissues are shown according to lymph node (N) staging [the absence (n = 9) or presence (n = 9) of lymph node (N) metastasis]. The relative ratio of methylated and unmethylated THRB in different groups was evaluated by examining the P value for trend via linear regression analysis. D, Representative results of Western blot analysis of TRβ and GAPDH as the loading control in normal and cancer tissues. E, Quantification of relative protein expression of TRβ after normalization via use of GAPDH as the loading control. The data are presented as medians and analyzed by the Mann-Whitney U test.