Robens Barbara K, Gembé Eva, Fassunke Jana, Becker Albert J, Schoch Susanne, Grote Alexander
Dept. of Neuropathology/Section for Translational Epilepsy Research, Germany.
Dept. of Pathology, University Clinic of Cologne, Germany.
Life Sci. 2016 Jun 15;155:70-5. doi: 10.1016/j.lfs.2016.01.049. Epub 2016 Apr 30.
Chronic epilepsy associated gangliogliomas (GGs) represent tumors composed of irregularly distributed, often dysmorphic, neurons and neoplastic astroglia. The pathogenesis of GGs is largely unknown. Low-density lipoprotein receptor-related protein 12 (LRP12) is critical for brain development and involved in tumorigenesis of non-cerebral neoplasms.
Here, we have examined a potential role of LRP12 in the pathogenesis of GGs by a combination of mRNA quantification and molecular-biological in vitro assays.
We observed a significant increase of the single nucleotide polymorphism (SNP) rs9694676 C-allele, located in the LRP12 promoter, in GGs compared to normal control individuals. C-allele expression is correlated with abundant seizure frequency. Expression of LRP12 was lower in GGs than in control brain. In luciferase assays, the C-allele of rs9694676 decreases both, the basal LRP12 core promoter activity and the stimulatory effect of the transcription factor (TF) STAT5a.
Accumulation of functional promoter-associated allelic variants with impact on the transcriptional regulation of LRP12 provides a new pathomechanism for GGs, i.e. highly differentiated epileptogenic brain tumors.
慢性癫痫相关神经节胶质瘤(GGs)是由分布不规则、常呈发育异常的神经元和肿瘤性星形胶质细胞组成的肿瘤。GGs的发病机制在很大程度上尚不清楚。低密度脂蛋白受体相关蛋白12(LRP12)对脑发育至关重要,并参与非脑肿瘤的肿瘤发生过程。
在此,我们通过mRNA定量和分子生物学体外试验相结合的方法,研究了LRP12在GGs发病机制中的潜在作用。
我们观察到,与正常对照个体相比,位于LRP12启动子区的单核苷酸多态性(SNP)rs9694676的C等位基因在GGs中显著增加。C等位基因表达与癫痫发作频率高相关。GGs中LRP12的表达低于对照脑。在荧光素酶试验中,rs9694676的C等位基因降低了基础LRP12核心启动子活性以及转录因子(TF)STAT5a的刺激作用。
功能性启动子相关等位基因变异的积累对LRP12转录调控产生影响,为GGs(即高度分化的致痫性脑肿瘤)提供了一种新的发病机制。