Summary of Pyro-Q-CpG findings. Illustrated are the summary findings by Pyro-Q-CpG analysis of U2OS cells in vitro without treatment (control) and with 1 μM decitabine treatment (treated). The illustration also summarizes Pyro-Q-CpG findings in control U2OS xenograft tumors (Xeno-1, Xeno-2, and Xeno-3), and 2.5 mg/kg decitabine treated U2OS xenograft tumors (Xeno-4, Xeno-5, and Xeno-6). DNA from NHOst (normal low-passage human osteoblasts) was also analyzed for experiment control. DNAs from early embryonic DNA (Emb-DNA) and universally methylated DNA (Met-DNA) were used for negative and positive control respectively. CpG-islands are denoted by grey rectangles relative to the gene start site. The region further enlarged below corresponds to each tested CpG sequence. The tick marks denotes the individual CpG dinucleotides. The transcription start site is indicated by a directional arrow with the base pair numbers annotated for each tested sequence. The extent of methylation is represented by the scale bar (bottom right). GADD45A, PAWR, and PDCD5, had a high level of methylation before decitabine treatment while HSPA9B had an intermediate level of methylation before treatment. In all cases the methylation was decreased significantly (p < 0.001) as a result of decitabine treatment. The detailed results for all genes are shown in [Additional file 4].