Analysis of microsatellite instability and loss of heterozygosity in thymoma
- Author:
Ming-Hai SHAO
1
Author Information
1. Department of Radiotherapy
- Publication Type:Journal Article
- Keywords:
Immunohistochemistry;
Loss of heterozygosity;
Microsatellite instability;
Polymorphism, single nucleotide;
Thymoma
- From:
Tumor
2008;28(1):57-60
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate the frequency of microsatellite instability (MSI) and loss of heterozygosity (LOH) in thymoma and its relationship with clinicopathological parameters. Methods: We selected 5 microsatellite polymorphism markers and extracted DNA from 28 specimens of paired thymomas/normal tissues. MSI and LOH in the specimens of thymomas and relevant pericancerous tissues were detected by polymerase chain reaction (PCR) followed by 6% polyacrylamide gel electrophoresis (PAGE) with silver staining. SP immunohistochemical method was used to assess the expressions of epithelial growth factor receptor (EGFR), p53, Bcl-2, and Ki-67 proteins in thymoma. Results: MSI or LOH was detected in 11 out of 28 thymoma tissues. The frequency of MSI was 21.4% (6/28), 10.7% (3/28), 14.3% (4/28), 10.7% (3/ 28), and 0% (0/28) at loci of D6S1708, TP53, DM, D11S988, and D8S136. LOH at D6S1708 (5/6) was a common genetic alteration. DM had only MSI alteration and D11S988 had only LOH alteration. There was no significant association between MSI and LOH with age, sex, with or without myasthenia gravis (MG), histological classification, clinical staging, and immunohistochemical staining (EGFR, p53, Bcl-2, and Ki-67 proteins) (P > 0.05). Conclusion: D6S1708, TP53, DM, and D11S988 are sensitive loci for studying microsatellite DNA imbalance in thymoma. Microsatellite DNA imbalance may play a certain role in occurrence and develoyment of thymoma, and the relationship between MSI or LOH and clinicopathological features of thymoma needs further investigation.
