Objective:To probe into the relationships between PTEN gene expression,the promoter methylation and gastric cancer and its clinical pathological specific features.Methods:We analyzed the PTEN gene promoter methylation and mRNA expression status in gastric cancer tissues and its adjacent normal tissues by methylation specific PCR(MSP) and reverse transcription-polymerase chain reaction(RT-PCR) techniques.Results:PTEN promoters in 48.2%(27/56) gastric cancer tissues and 3.6(2/56) adjacent normal tissues were methylated and the PTEN promoter methylation rate in carcinoma tissues was obviously higher(P < 0.05).Of the 2 cases where the adjacent gastric tissues were methylated,the gastric cancer tissues were both methylated.Of the 29 gastric cancers with lymph node metastasis,19 had their PTEN gene promoters methylated and the PTEN gene promoter methylation in cases with lymph node metastasis was obviously higher than that without lymph node metastasis(P < 0.05).RT-PCR result showed that no expression of PTEN mRNA existed in any of the methylated gastric cancer tissues.Conclusion:The expression loss of PTEN gene mRNA in gastric cancers is related to their promoter methylation and might be one of the reasons for the generation,development and metastasis of gastric cancers. Objective: To probe into the relationships between PTEN gene expression, the promoter methylation and gastric cancer and its clinical pathological specific features. Methods: We analyzed the PTEN gene promoter methylation and mRNA expression status in gastric cancer tissues and its adjacent normal tissues by methylation specific PCR (MSP) and reverse transcription-polymerase chain reaction (RT-PCR) techniques. Results: PTEN promoters in 48.2% (27/56) gastric cancer tissues and 3.6 (2/56) adjacent normal tissues were methylated and the PTEN promoter methylation rate in carcinoma tissues was obviously higher (P <0.05) .Of the 2 cases where the adjacent gastric tissues were methylated, the gastric cancer tissues were both methylated. Of the 29 gastric cancers with lymph node metastasis, 19 had their PTEN gene promoters methylated and the the PTEN gene promoter methylation in cases with lymph node metastasis was obviously higher than that without lymph node metastasis (P <0.05). RT-PCR result showed that no expression of PTEN mRNA existed in any of the methylated gastric cancer tissues. Confluence: The expression loss of PTEN gene is related to their promoter methylation and might be one of the reasons for the generation, development and metastasis of gastric cancers.