[Expression of PTEN, matrix metaloproteinases 2 and 9 in thymomas].

Objective To evaluate the expression of PTEN, MMP-2 and MMP-9 in thymomas and their correlation with clinical significance. Methods Immunohistochemical S-P assay was used to detect the expression of PTEN, MMP-2 and MMP-9 in 45 thymomas and 16 non-neoplastic thymuses. Results The positive rate of PTEN, MMP-2 and MMP-9 expression in 45 thymomas were 53.5% , 48.9% and 62.2%, respectively. There were significant differences between non-neoplastic thymus and thymomas （ P 〈 0. 05 ）. The expression of PTEN, MMP-2 correlated with histological type （P 〈 0.05 ） and different clinical stage of the thymoma （P 〈0.01 ）. The expression of MMP-9 was not correlated with histological type and different clinical stages of thymoma （ P 〉 0.05 ）. Conclusion PTEN, MMP-2 and MMP-9 may play an important role in the occurrence and development of thymoma. The expression of PTEN and MMP-2 correlates with the malignance and the aggression of thymoma. Key words: Thymoma;  PTEN gene ;  MMP-2 ;  MMP-9