Methylation of PTCH1a gene in a subset of gastric cancers

Figure 4 Correlation of PTCH1 mRNA and protein expression with methylation of PTCH1a TRR. Expression of PTCH1 genes, as well as methylation of PTCH1a TRR are displayed in four representative gastric cancer tissue samples (#3, #5, #7 and #10). PTCH1 protein expression was detected by immunohistochemical staining (original magnification, × 100). Methylation of PTCH1a TRR was detected by MSP. The RQ value of PTCH1 gene mRNA expression was calculated in comparison with a calibrator (the expression level of pooled adjacent normal tissue samples). The well-differentiated tissue sample #3 and the poorly differentiated tissue sample #5 showed non-methylated products by MSP, positive expression of PTCH1 protein, and higher RQ value of PTCH1 mRNA expression. The well-differentiated tissue sample #7 and poorly differentiated tissue sample #10 showed methylated products by MSP, negative expression of PTCH1 protein, and lower RQ value of PTCH1 mRNA expression.