CHN2 Promoter Methylation Change May Be Associated With Methamphetamine Dependence

Background: Methamphetamine (MA) abuse is becoming increasingly serious in China. The mechanism of MA dependence remains unclear. CHN2 gene encodes chimeric protein-2 that regulate axonal pruning via the Rac-GTPase system and play a pivotal role in the formation of nervous circuits. Genetic studies suggest that the polymorphism of the CHN2 gene was related to substance dependence.

Aims: The aim of this study was to investigate the association between the methylation of CHN2 gene promoter with MA dependence.

Methods: According to SCID-I (Structured Clinical Interview for DSM-IV Axis I Disorders, SCID-I) used for investigating MA dependence, 224 male MA addicts were recruited into the case group. In addition, 109 healthy men were recruited into the control group. Blood samples were collected with the purpose of detecting the methylation levels of CHN2 gene promoter by methylight qPCR. The association between the methylation of CHN2 gene promoter with MA dependence was analyzed.

Results: The mean (sd) methylation levels of CHN2 gene promoter in the case group were significantly higher than in the control group, which were 2795.55 (733.19) and 1026.73 (698.73), respectively, showing significant differences between the two groups (t=21.25, p<0.001). Pearson analysis showed no significant correlation between the methylation levels of CHN2 promoter and other factors (the age of initial MA use, the duration of MA use, combination with K powder, tobacco and alcohol).

Conclusions: The abnormal methylation of CHN2 gene promoter was significantly correlated with MA dependence.