Fig. 4.

RUNX1t1 and gastric cancer. a RUNX1t1 expression was evaluated by immunohistochemistry in 64 human gastric cancer samples, and staining was classified by comparison to the expression in the normal mucosa (left panel). Thirty-eight percent of the cases showed reduced expression of nuclear RUNX1t1 (Tumor 1–3) in comparison to staining in the normal epithelium. b In 10 gastric tumors with reduced RUNX1t1, RNA levels were examined for C/EBPβ expression by qPCR. Only 3 out of 10 cases showed higher C/EBPβ expression as compared to WT. c The methylation status of the RUNX1t1 promoter was evaluated by methylation-specific PCR. Bisulfite treatment of tumor DNA converts unmethylated but not methylated cytosines to uracil, and subsequent methylation-specific PCR detects either methylated (M) or unmethylated (U) DNA. Fifty percent of the analyzed human gastric cancer cases (rows a-b, columns 1–5) present RUNX1t1 promoter hypermethylation. An increase in the methylation status is considered when the PCR product with methylation-specific primers is more intense than the one produced by non-methylated specific primers. d Ectopic expression of RUNX1t1 in MKN28 and MKN45 gastric cancer cell lines reduces gastric cancer cell proliferation as measured by BrdU incorporation assay. S-phase percentages are indicated in the FACS plots