SPRY2 is DNA hypermethylated, and its expression is repressed but can be reactivated by treatment with a demethylating agent in human B-cell lymphoma lines. (A) SPRY2 expression normalized to GAPDH expression was assessed by quantitative PCR in human tonsil B cells (B-cell sort), EBV-immortalized PBL, and a panel of human B-cell lymphoma lines. N.D. indicates not detected. DNA methylation status for sorted B cells, PBLs, and each tumor cell line was assessed by MSP. The top and bottom bands correspond to PCR products amplified by primers specific for methylated (M) or unmethylated (U) CpG sites after bisulfite conversion. (B) GBS of a CpG-rich region located between −163 and +25 in the SPRY2 promoter in human tonsil B cells (B-cell sort) and human B-cell lines Nalm-6, 2F7, P3HR1, and BL41. Each row represents the sequence of an individual clone. ○ represents unmethylated CpG sites; ●, methylated CpG sites. (C) SPRY2 expression normalized to GAPDH expression was assayed in triplicate by quantitative PCR without and with 5-aza-dC and/or 100 nm TSA treatment.