Methylation of RasGRF1 in brain tissues of patients with refractory epilepsy

• 1、Neurology Department, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China

Abstract：Purpose: The mechanisms of refractory epilepsy have not completely understood yet. Previous study found that RasGRF1 significantly decreased in the brain of patients with intractable epilepsy, however, the regulatory mechanism of its expression has not yet clear. This paper focus on the methylation of the promoter of RasGRF1 in brain tissue of patients with epilepsy and its effect on the expression of downstream p-ERK. Methods: Methylation-specific PCR (MS-PCR) were used to analyze 30 samples of brain tissue of patients with intractable epilepsy and 20 samples of control group. Promoter methylation rates were compared. Expression of RasGRF1 and p-ERK were detected by immunoblotting. Comparison was conducted among RasGRF1 methylation group, the non methylation group of patient and control group. Results: Among 30 brain tissue samples of refractory epilepsy group, 8 samples showed RasGRF1 promoter methylation (27%), while no methylation was detected in the control group, the the difference was statistically significant (P<0.05). Expression of RasGRF1 in patient group was significantly decreased, which was the lowest in methylation group of patient; p-ERK1/2 expression was significantly lower in control group. Although the expression of p-ERK1/2 was lower in methylation group of patient, however, there was no significant difference compared with non methylation group of patient. Conclusion: RasGRF1 promoter methylation was significantly increased in brain tissues of patients with refractory epilepsy, and led to further reduced expression of RasGRF1 in part of patients, which may be a protective feedback mechanism of the brain.

Keywords： Epilepsy Methylation RasGRF1