HDAC1 and glioma: In C6 glioma cells, experiments using valproic acid showed that changes in the expression of the melatonin receptor gene MTNR1A (coding for receptor MT1) were accompanied by alterations in the mRNA levels of methyl CpG binding protein 2 (MeCP2) and of histone deacetylases, HDAC1, 2 and 3 [44], indicating that both the DNA methylation pattern and chromatin remodeling via histone deacetylation may be associated with changes in MT1 expression.