Expression and clinical significance of microchromosome maintenance protein 10 in thalamic gliomas

Abstract

Objective To investigate the expression of microchromosome maintenance protein 10(MCM10) in thalamic gliomas and its prognostic value. Methods A retrospective analysis was conducted on the clinical data of 48 patients with thalamic glioma who underwent tumor resection at Neurosurgery Department of Beijing Tiantan Hospital, Capital Medical University from September 2016 to September 2017. At 1 week post operation, the degree of tumor resection was determined according to cranial MRI. After discharge, all patients underwent follow-up by outpatient clinic visits or telephone, which included reexamination of skull enhanced MRI and assessment of Karnofsky performance scale(KPS) score. All tumor tissues were reserved during operation for immunohistochemical staining analysis of MCM10. According to the positive rate of MCM10 expression and comprehensive score of staining intensity, the lower expression of MCM10 was decided as less than 6 points, and the higher expression of MCM10 as at least 6 points. The expression of MCM10 in different grade thalamic gliomas was analyzed. We then compared the clinical data of MCM10 low expression group and high expression group. The survival of two groups was further analyzed using Kaplan-Meier method. Finally, the univariate and multivariate Cox regression analysis methods were used to determine whether MCM10 was an independent risk factor affecting the total survival of thalamic glioma patients. Results In 48 patients, 1 week after surgery, the cranial MRI showed that total resection was achieved in 13 cases (27.1%), near-total resection in 29 cases (60.4%) and partial resection in 6 cases (12.5%). The median follow-up time was 22.6 months (0.3-34.2 months) in 48 patients. Three months after surgery, the median KPS score was 60 points(0-100 points). By the end of the follow-up period, 31 of the 48 patients survived and 17 died. The results of immunohistochemistry showed that the tumor tissue in 48 patients expressed MCM10, of which 23 (47.9%) were low expression and 25 (52.1%) were high expression. Immunohistochemistry analysis in the 48 patients of thalamic gliomas with various World Health Organization (WHO) grades showed that MCM10 had the lowest staining points (3.7±1.2) in grade Ⅰ glioma, middle-level in grade Ⅱ (5.8±2.3) and grade Ⅲ(7.5±3.5), and the highest in grade Ⅳ (7.9±2.8). The difference between groups was statistically significant (P=0.021). The differences in age, sex, WHO grade, preoperative KPS score and postoperative recurrence of MCM10 high expression group and low expression group were not statistically significant (all P>0.05). The survival rate and KPS score improvement were significantly higher in the patients of MCM10 low expression group than those in the high expression group (both P<0.05). The results of univariate and multivariate Cox regression analysis showed that MCM10 high expression was one of the independent risk factors affecting the outcome of patients with thalamic glioma (HR=0.129, 95% CI: 0.024-0.685, P=0.016). Conclusions MCM10 is expressed in thalamic glioma with the lowest level in WHO Ⅰ grade tumor and the highest in grade Ⅳ. Longer survival is associated with low expression of MCM10, which can be used as an indicator of the prognosis judgment of thalamic glioma. Key words: Thalamus; Glioma; Prognosis; Microchromosome maintenance protein 10