ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of Runx3 gene CpG island methylation in the development of human gastric carcinoma.</p><p><b>METHODS</b>A total of 150 tumor specimens from patients with gastric carcinoma and 50 normal tissue specimens were selected. Methylation specific PCR (MSP) and pyrosequencing (PS) were used to detect the methylation status of Runx3 gene promoter.</p><p><b>RESULTS</b>Compared to normal tissue samples, a significant increase of CpG island methylation status of Runx3 gene was observed in gastric carcinomas (MSP: 67.3% vs. 40.0%, P = 0.002; PS: 76.0% vs. 30.0%, P < 0.01). Runx3 gene methylation was only related to tumor size (P < 0.05) based on MSP analysis. PS test however showed that the extent of methylation of Runx3 gene was related to the tumor size (P = 0.004), Lauren's classification (P = 0.043), depth of invasion (P < 0.01), lymph node metastasis (P = 0.021) and TNM staging (P = 0.045).</p><p><b>CONCLUSIONS</b>Methylation status of Runx3 gene detectable by PS is closely correlated with clinicopathological parameters of gastric carcinoma, including tumor size, Lauren's classification, depth of invasion, lymph node metastasis and TNM staging. PS is more sensitive than MSP in the detection of Runx3 gene methylation, which may serve as an important marker for early diagnosis and treatment of gastric carcinoma.</p>