Hsa_Circ_034367 Regulates the Progression of Shh-Type Medulloblastoma Through the Has-Mir-17-3p/Dicer1 Axis

Yafei Wang

Shanghai Jiao Tong University, China

Biography :

Yafei Wang, M.D., studied Pediatric Neurosurgery at Xinhua Hospital, Shanghai Jiao Tong University.Chenran Zhang, M.D., Associate Chief Physician, Master’s Advisor, is a member of the American Association of NeuroSur­geons (AANS) and the International Association of Pediatric Neurosurgery (ISPN).

Abstract :

Background: Medulloblastoma is the most common malignant brain tumor in children, but its pathogenesis is unknown and there is a lack of early diagnostic markers or effective thera­peutic targets. circRNA is a class of endogenous non-coding Rnas that regulate gene expres­sion in eukaryotes. Hsa_circ_034367 is a newly discovered circRNA highly expressed in SHH-type medulloblastoma. The role and mechanism of CircRNA in SHH-type medulloblastoma remain to be further elucidated.

Methods: After ethical approval, several samples of medulloblastoma were obtained in our hospital, and adjacent tissues were obtained at the same time. By whole transcriptome se­quencing and bioinformatics analysis, circRNA with high expression was screened. The ex­pression pattern of hsa_circ_034367 in medulloblastoma was detected by Sanger sequencing and Northern blots. Real-time fluorescence quantitative PCR was used to detect the expres­sion of hsa_circ_034367, has-miR-17-3p and DICER1. Lentivirus-infected medulloblastoma cell lines daoy and uw228 were constructed, and cell proliferation, migration, invasion and apoptosis were detected by MTT assay, colony formation assay, transwell assay, Celltier-GLO fluorescence cell viability assay and flow cytometry. In addition, the interaction between hsa_ circ_034367, has-miR-17-3p and DICER1 was examined by dual luciferase reporting assay and RNA drop-down assay. DICER1 protein expression was detected by Western blot. To in­vestigate the role of hsa_circ_034367 in the growth of medulloblastoma tumors in vivo by Patient-derived tumor xenograft (PDX) model.

Results: Hsa_circ_034367 was overexpressed in medulloblastoma tissues and cells, and its silence could inhibit the proliferation, migration and invasion of medulloblastoma and accel­erate cell apoptosis. Has-miR-17-3p can be wiped by hsa_circ_034367 sponge, and its over­expression can inhibit the progression of medulloblastoma. Further experiments showed that the has-miR-17-3p inhibitor reversed the negative regulation of hsa_circ_034367 knockdown on medulloblastoma cell progression. In addition, DICER1 is the target of has-miR-17-3p, and its downregulation can inhibit the progression of medulloblastoma cells. Overexpression of DICER1 reversed the inhibitory effect of has-miR-17-3p on the progression of medulloblasto­ma cells. Animal experiments showed that hsa_circ_034367 gene knockout can effectively inhibit cell apoptosis.

Conclusion: hsa_circ_034367 and DICER1 can inhibit medulloblastoma tumor growth. These data suggest that circRNA is a potential target for controlling the proliferation of SHH-type medulloblastoma.