| Autor: |
Noh BJ; Department of Pathology, School of Medicine, Kyung Hee University Hospital, Seoul 02447, Republic of Korea., Sung JY; Department of Pathology, School of Medicine, Kyung Hee University Hospital, Seoul 02447, Republic of Korea., Kim YW; Department of Pathology, School of Medicine, Kyung Hee University Hospital, Seoul 02447, Republic of Korea., Araujo ES; Laboratory of Orthopedic Pathology, Central Army Hospital, Buenos Aires C1426BOR, Argentina., Kalil RK; Molecular Pathology Division, SARAH Network of Rehabilitation Hospitals, Brasilia 70335-901, Brazil., Jung WW; Department of Biomedical Laboratory Science, College of Health Science, Korea University, Seoul 02708, Republic of Korea., Kim HS; Department of Biomedical Laboratory Science, College of Health Sciences, Cheongju University, Chungcheongbuk 28503 Republic of Korea., Park YK; Department of Pathology, School of Medicine, Kyung Hee University Hospital, Seoul 02447, Republic of Korea. |
| Abstrakt: |
The objective of the present study was to determine whether guanine nucleotide-binding protein α stimulating ( GNAS ) gene expression correlates with pathognomonic signs by analyzing the mutations, methylation status and G-protein α subunit (G sα ) expression of GNAS in Ewing sarcoma (ES). Formalin-fixed paraffin-embedded tissue samples from 77 patients with primary ES were obtained in South Korea, Argentina and Brazil, and were studied via methylation chip assay and direct sequencing of the GNAS gene and immunohistochemical analysis of G sα . The mutation and methylation statuses of the GNAS gene were examined. Immunohistochemical results were measured with respect to proportion and staining intensity. The results revealed that GNAS genes in ES tumor samples were less methylated compared with normal controls. No mutations were detected at exons 8 or 9 of the GNAS locus complex on chromosome 20q13.3, indicating that the pathogenesis of ES was not associated with GNAS mutation. G sα expression correlated well with the methylation status of the GNAS gene. Notably, high G sα expression was detected more frequently in samples from living patients than from decedents, although this was not statistically significant (P=0.055). In conclusion, GNAS mutation is not associated with the pathogenesis of ES tumors. This finding may be used to differentiate ES tumors from metastatic bone lesions with morphological similarity to ES tumors. Analysis of the methylation status of the GNAS gene and immunohistochemical G sα expression suggests that hypermethylated GNAS (low G sα expression) in ES may be associated with unfavorable progression with a non-significant trend. |
