The Treatment Strategy And Molecular Mechanism Of Cystic Vestibular Schwannoma

Purpose: Vestibular schwannoma?VS?is one of the most common intracranial tumors in the lateral skull base that arises from Schwann cells of the vestibular nerve.VS is classified as cystic vestibular schwannoma?CVS?and solid vestibular schwannoma?SVS?according to imaging features.We carried out this study on both the clinical charecters and molecular biology: we focused on the classification of CVS,and illustrated the relationship between the treatment strategy and postoperative outcomes;at the same time,we explored the molecular mechanism of microRNAs?miRNAs?and their target genes in cystic change of vestibular schwannoma.Methods: We collected the retrospective clinical information of 188 patients diagnosed with CVS from January,2009 to December,2015.These patients were grouped as Type A and Type B according to magnetic Resonance Imaging?MRI?.The general information was collected,and the postoperative outcomes were compared between the two groups.In the study of molecular biology,we grouped the patients as CVS and SVS,and screened the differential miRNAs by high-throughput sequencing.Then we used quantitative reverse transcription polymerase chain reaction?qRT-PCR?to validate the differences in miRNA profiles between CVS and SVS.Results: The total resection rate of patients with Type A CVS was much higher than that of patients with Type B?86.1% vs 72.5%,p = 0.021?.And the short-term facial nerve function was better in Type A group compared with Type B group?p = 0.012?.The postoperative facial nerve function was negatively correlated with tumor size.There was no significant difference between the two groups in anatomical preservation rate of facial nerve,long-term facial nerve function and postoperative complications.The results of miRNA high-throughput sequencing indicated that chr19₃4670,a newly identified miRNA,was downregulated in CVS compared with SVS.TGF? was identified as its target gene by bioinformatics tools as well as luciferase reporter analysis,and its expression level was higher in CVS compared with SVS.Upregulation of chr19₃4670 inhibited the proliferation of VS primary cells by suppressing the expression of TGF? through MAPK pathway.The rescue experiments further confirmd the inhibitory effect of chr19₃4670 on VS cell proliferation and the targeted relationship between chr19₃4670 and TGF?.Conclusion: The total resction rate was higher in patients of Type A group,and the short-term facial nerve function was better in the Type A group as well.In addition,the postoperative facial nerve function was negatively correlated with tumor size.chr19₃4670 inhibited the proliferation of VS cells by suppressing the expression of its target gene,TGF?,through MAPK pathway.