Study On The Mutation And Methylation Of Pten Gene In Hazakh's Esophageal Carcinomas

Objective: To detect the frequency of mutation and methylation of PTEN gene in esophageal carcinomas and normal esophageal mucosas of Kazakh in Xinjiang. To approach the relationship and significance between PTEN gene mutation and methylation in esophageal carcinomas.Methods: We detected the PTEN gene mutation by PCR-SSCP in 125 esophageal carcinomas and 78 normal esophageal mucosas; we also analyzed the PTEN gene methylation by MALDI-TOF MS in 105 esophageal carcinomas and 72 normal esophageal mucosas. Analysis the difference in esophageal carcinomas with gender and age, clinical staging, pathologic grading respectively. All data were analyzed by using the SPSS 13.0 software.Results: 1. Results of PTEN gene mutation: (1) The frequency of PTEN gene mutation in esophageal carcinomas is 4 %( 5/125), which lie in the exon 5(1/125) and exon 8(4/125), exon 6 and exon 7 were found nothing. 78 normal esophageal mucous were detected no mutation of exon5-8. (2)5 HPV-associated esophageal carcinomas of Kazakh were in moderate-differentiated(2/56) and poor-differentiated(3/35) esophageal squamous cell carcinomas (P>0.05). All of these patients are male over 50 years old. 2. Results of PTEN gene methylation: (1)The PTEN gene methylation level(CpG sites+ average methylation rate)was higher in 105 esophageal carcinomas than in 72 normal esophageal mucosas of Kazakh. The average methylation rate of PTEN gene in esophageal carcinomas and normal mucosas were 9.19% and 6.28% (P<0.05). The methylation level of PTEN gene in different gender and age, clinical staging, pathologic grading has no difference(P>0.05). (2) PTEN₀01 methylation level in 99 esophageal carcinomas and PTEN₀03 methylation level in 87 esophageal carcinomas were higher than in 67 normal esophageal mucosas of Kazakh. The average methylation rate of PTEN₀01 and PTEN₀03 in esophageal carcinomas and normal mucosas were 7.02% and 5.23% (P<0.05), 11.36% and 7.34% (P<0.05) respectively. The methylation level of PTEN₀01 in different clinical staging, pathologic grading has no difference(P>0.05);The average methylation rate of PTEN₀03 in different pathologic grading has no difference(P>0.05)but has difference in the metastasis of lymph (P<0.05)(.3)The methylation level of PTEN₀01 CpG₁1.12 and PTEN₀03 CpG₁ were obviously higher in esophageal carcinomas than in normal mucosas, but have no difference with pathologic grading and metastasis of lymph(P>0.05)Conclusions (1) PTEN gene mutation are not frequent in esophageal carcinomas, PTEN mutation may be related to the development of HPV-associated esophageal carcinomas of Kazakh; (2) PTEN gene methylation haveconnection with the development of esophageal carcinomas , PTEN₀01 may be related to the metastasis of lymph.