The Study Of LncRNA LINC00899 Aggravates The Biological Behaviour Of Spinal Ependymomas Though FoxO Signaling Pathway Via RBL2

Ependymomas,the most common primary intra-medullary spinal cord tumor in adults,accounts for 30% to 45% of all intramedullary tumors.Ependymomas are originated from the ependymal lining of the ventricular system or spinal canal,which may arise from anywhere along the ventricular system and spinal cord.Although there is a long history of subclassifying ependymoma in histology,there is little treatment stratification for ependymoma and the long-term prognosis for patients with ependymoma remains barely understood.Nowadays,as a major class of regulatory molecules,Long non-coding RNA(LncRNA)have involved in a broad range of biological processes and complex diseases.More recently,researchers have managed to understand the connections between LncRNA and diseases,and LncRNA dysfunctions are connected with a broad range of diseases which includes cancers,cardiovascular diseases and neurode-generation diseases.This study is aimed to clarify the potential role of LncRNA LINC00899 in biological behaviour of spinal ependymoma cells through the FoxO pathway via RBL2.Spinal ependymoma related chip data(GSE50161 and GSE66354)was initially downloaded and differentially expressed LncRNAs were screened out.Fifty-eight cases of spinal ependymoma and some normal ependymal tissues were collected.The effects of LINC00899 and RBL2 on the spinal ependymoma cell were determined using the third generation spinal ependymoma cells andtransfection with LINC00899 vector,siRNA-LINC00899 and siRNA-RBL2.The expression of LINC00899,pathway and cell proliferation-and apoptosis-related factors was determined.Finally,we also detected cell proliferation,migration,invasion,cycle and apoptosis after transfection.Our results showed that LINC00899 was up-regulated in spinal ependymoma and RBL2 was confirmed as a target gene of LINC00899 and found to be involved in regulation of FoxO pathway.LINC00899 expression increased in spinal ependymoma tissues whereas RBL2 expression decreased.Moreover,we found that siRNA-LINC00899 could elevate RBL2,p21,p27 and Bax levels,decrease FoxO,Bcl-2,Vimentin,Annexin levels,reduced cell proliferation,migration and invasion and enhanced apoptosis.Taken together,our study suggests that down-regulated LINC00899 exerts anti-oncogenic effects on spinal ependymoma via RBL2-dependent FoxO,which provides a novel therapeutic target for the treatment of spinal ependymomas.