Relationship between expression of MeCP2 and prognosis of patients treated by microsurgery in glioma

Background  Methyl-CpG-binding protein 2 (MeCP2) plays an important role in gene transcription regulation. Studies have shown that MeCP2 may be a new therapeutic target in glioma, but the relationship between its expression in glioma and the prognosis of patients is still unclear.

Objective To explore the relationship between the expression of MeCP2 and clinical prognosis of patients treated by microsurgery in glioma.

Methods A total of 96 glioma patients with complete clinicopathological data who underwent surgical treatment from January 2016 to October 2018 were collected from Department of Neurosurgery, the Second People’s Hospital of Guiyang. The expression level of MeCP2 in tumor tissue and normal tissue were detected by immunohistochemical method and the survival of patients was followed up. The Kaplan-Meier method was used for survival analysis. Univariate and multivariate Cox regression analysis were used to identify the expression level of MeCP2 and related clinicopathological factors with patients survival prognosis.

Results All the 96 patients were followed up, including 51 males and 45 females, aged from 7 to 79 years, with an average age of (44.9 ± 18.3) years. Immunohistochemical staining indicated that the positive rate of MeCP2 expression in glioma was significantly higher than those in normal brain tissues (75.0% vs 30.0%, P<0.05). The positive rate of MeCP2 expression in WHO Ⅰ-Ⅳ grade glioma tissues were 20.0%, 66.7%, 75.0%, 90.6% (1/5, 18/27, 24/32, 29/32), respectively. The positive expression rate of MeCP2 in high-grade gliomas (WHO grade Ⅲ and Ⅳ) was significantly higher than that in low-grade gliomas (WHO grade Ⅰ and Ⅱ)(P<0.05). Moreover, 70 patients had tumor recurrence and 59 patients died. The median PFS and OS were (10.7 ± 1.7) months and (24.1 ± 2.9) months, respectively. Kaplan-Meier survival analysis showed that the median PFS and OS in the high expression group of MeCP2 were significantly lower than those in the low expression group (PFS: 15.6 ± 1.8 months vs 28.0 ± 2.6 months, P=0.026; OS: 16.1 ± 2.0 months vs 28.3 ± 5.8 months, P=0.022). Cox analysis suggested that high expression of MeCP2 (HR: 1.705, 95% CI: 1.019-2.854), multiple tumors (HR: 2.727, 95% CI: 1.453-5.120), surgery alone (HR: 1.704, 95% CI: 1.015-2.861) and high pathological grade (WHO grade Ⅲ-Ⅳ) (HR: 3.294, 95% CI: 2.317-4.683) were independently associated with poor prognosis of glioma patients.

Conclusion MeCP2 is up-regulated in patients undergoing glioma surgery, and the high expression level of MeCP2 is related to the poor prognosis of glioma patients after surgery.