[Aberrant methylation of NF2, TIMP-3 and THBS1 genes and their diagnostic values in meningiomas].

OBJECTIVE

To explore the functions of NF2, TIMP-3 and THBS1 genes in the tumorigenesis or progression of meningiomas and analyze the values of these genes in early diagnosis, therapy and prognostic evaluation in meningiomas.

METHODS

A total of 66 cases with histological sections of meningiomas, including solitary (SMs, n = 30) and multiple meningiomas (MMs, n = 36), were retrieved from our departmental archives. All cases were regrouped as benign, atypical and anaplastic (malignant) by hematoxylin & eosin staining according to the recently published WHO classification of nervous system tumors. Genomic DNA was extracted from tumor sections and methylation-specific polymerase chain reaction (MSP) performed to detect the CpG methylation status. Normal brain tissue was used as the control group. And then the differences of methylation rate between SMs and MMs tissues and among different subgroups were analyzed by statistical analyses.

RESULTS

The results of methylation in different types of meningiomas demonstrated that the rates of NF2, TIMP-3 and THBS1 methylation were 26.7% (8/30), 16.7% (5/30) and 36.7% (11/30) in 30 SMs tissues and 30.6% (11/36), 22.2% (8/36) and 22.2% (8/36) in 36 MMs tissues respectively. But no aberrant methylation of NF2, TIMP-3 and THBS1 genes was found in normal brain tissue. No significant differences in three types of gene methylation rates existed between SMs and MMs in the I-III grade meningiomas. Nevertheless, there was great difference between grades I, II and III in SMs and MMs while no significant difference was found between grades II and III.

CONCLUSION

The methylation of NF2, TIMP-3 and THBS1 is correlated with the tumorigenesis of meningiomas (grade II and III). As an important pathogenetic cause of meningiomas, it may be used as a clinical tool for an early diagnosis of meningiomas.