title: Infrequent hypermethylation of the PTEN gene in Korean non-small-cell lung cancers.
abstract: CpG islands (CGIs) hypermethylation is implicated in the pathogenesis of many cancers, including lung cancer. The phosphate and tension homolog (PTEN) is a tumor suppressor that controls a variety of biological processes including cell proliferation, growth, migration, and death. The defects in PTEN regulation have a profound impact on carcinogenesis. Herein, we have examined the methylation status of the human PTEN gene in 137 primary non-small-cell lung cancers (NSCLCs) by using a methylation-specific PCR and correlated the results with clinicopathological features. Promoter methylation of the PTEN gene was observed in 5.1%, 2.9%, and 0.0% of three different CpG regions, which were localized at -1460 to -1263, -984 to -848, and -300 to -128 nucleotides upstream of the translation start site, respectively. Reverse transcription-PCR and immunohistochemical analysis showed the methylation of the CGI region at -984 to -848 correlated more accurately with PTEN expression. In addition, no significant correlation was found between PTEN methylation and clinicopathological factors, including the survival rates. These findings suggest that promoter methylation is not an important mechanism for PTEN deregulation in NSCLCs from Koreans.
authors.affiliation: Department of Anatomy, School of Medicine, Kyungpook National University, Daegu, Korea.
authors.forename: Dong Sun
authors.initials: DS
authors.lastname: Kim
authors.forename: Su Man
authors.initials: SM
authors.lastname: Lee
authors.forename: Ghil Suk
authors.initials: GS
authors.lastname: Yoon
authors.forename: Jin Eun
authors.initials: JE
authors.lastname: Choi
authors.forename: Jae Yong
authors.initials: JY
authors.lastname: Park
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics*; D018899:CpG Islands; D019175:DNA Methylation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007723:Korea; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D051059:PTEN Phosphohydrolase / Q000032:analysis / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human