title: DNA hypermethylation status of multiple genes in soft tissue sarcomas.
abstract: The aberrant methylation of promoter CpG islands is known to be a major inactivation mechanism of tumor-related genes. To determine the clinicopathological significance of gene promoter methylation in soft tissue sarcomas, we examined the promoter methylation status of 10 tumor-related genes in 65 soft tissue sarcomas and 19 adjacent non-neoplastic tissues by methylation-specific PCR. The methylation frequencies of tumor-related genes tested in soft tissue sarcomas were 17 (26%) for RASSF1A, 11 (17%) for DAP kinase, 10 (15%) for MGMT, nine (14%) for GSTP1, eight (12%) for PTEN, six (9%) for p16 and hMLH1, five (8%) for hMSH2, two (3%) for p14, and one (2%) for RB. Promoter methylation of these genes was not recognized in non-neoplastic tissues. All those cases of soft tissue sarcoma that had MGMT methylation, with the exception of one case of malignant peripheral nerve sheath tumor, showed large tumor size (> or = 10 cm) or recurrence. Moreover, eight of 10 cases with MGMT methylation revealed high American Joint Committee on Cancer stage. Seven of 10 cases (70%) with MGMT methylation showed a loss of MGMT expression by immunohistochemistry. In addition, MGMT methylation status had a statistically significant correlation with a loss of MGMT expression (P=0.014). In conclusion, although methylation of tumor-related genes was a relatively rare event in soft tissue sarcomas, methylation was tumor-specific. Of 10 tumor-related genes, cases with MGMT methylation had a tendency to be aggressive behavior. Moreover, MGMT methylation was closely associated with a loss of MGMT expression. Although our findings need to be extending to a large series, promoter methylation of tumor-related genes is likely to have an association with the pathogenesis of soft tissue sarcomas. Furthermore, MGMT methylation may be associated with tumor aggressiveness and the inactivation of MGMT gene.
authors.affiliation: Department of Anatomic Pathology, Pathological Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kawaguchi
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Saito
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Tomonari
authors.initials: T
authors.lastname: Takahira
authors.forename: Chikashi
authors.initials: C
authors.lastname: Kobayashi
authors.forename: Sadafumi
authors.initials: S
authors.lastname: Tamiya
authors.forename: Naomi
authors.initials: N
authors.lastname: Tateishi
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
authors.forename: Masazumi
authors.initials: M
authors.lastname: Tsuneyoshi
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051017:Apoptosis Regulatory Proteins; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics; D019175:DNA Methylation; D064550:Death-Associated Protein Kinases; D005260:Female; D051549:Glutathione S-Transferase pi / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D019853:O(6)-Methylguanine-DNA Methyltransferase / Q000032:analysis / Q000235:genetics; D051059:PTEN Phosphohydrolase / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic / Q000235:genetics; D016160:Retinoblastoma Protein / Q000235:genetics; D012509:Sarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D019941:Cyclin-Dependent Kinase Inhibitor p16; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C411762:RASSF1 protein, human; D016160:Retinoblastoma Protein; D025521:Tumor Suppressor Proteins; D019853:O(6)-Methylguanine-DNA Methyltransferase; D051549:Glutathione S-Transferase pi; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein