Fig. 1
DCC promoter methylation and 18q LOH analyses. (a) Schematic representation of the location of the three LOH probes and DCC gene promoter regions in chromosome 18. The red line denotes the DCC gene. Gray and black squares represent the untranslated and the coding exon 1 regions, respectively; arrows on the squares indicate transcriptional starting sites; vertical lines indicate CpG sites; white diamonds represent the restriction sites for HhaI; thick horizontal lines depict the locations of COBRA products; arrows on the thick horizontal lines denote COBRA primers. (b) Representative results of COBRA of DCC. Arrows indicate methylated alleles; M denotes methylation; U denotes unmethylation; Mc denotes the methylated control; SM denotes the size marker. (c) Results of DCC methylation as a continuous variable. In the box plot diagrams, the horizontal line within each box represents the median, the limits of each box represent the interquartile ranges, and the whiskers are the maximum and minimum values. Each green bar represents the mean. NM denotes normal mucosa. T denotes tumor. (d) The frequency of methylation-positivity of cancer and normal tissues according to different thresholds. (e) DCC mRNA expression levels and methylation status in 10 gastric cancer cell lines and a human lung fibroblast cell line. DCC mRNA expression is observed (lower ΔCT) in GCIY and NHLH cell lines. DW denotes distilled water