Mechanisms Of LncRNA HULC Overexpression Promoting Vasculogenic Mimicry And Epithelial-Mesenchymal Transition Of Glioblastoma Cells

Background and purpose:Glioblastoma?GBM?is the most common type of primary malignant tumor of the human brain with a high degree of malignancy and a generally poor prognosis.Traditional treatment methods based on surgery,radiotherapy and chemotherapy are ineffective and difficult to significantly extend the median survival time of patients^[1].The rapid growth of glioblastoma cells in the skull depends on abundant blood supply inside tumor tissue.The full exchange of nutrients and metabolites provides the motive force for proliferation and invasion of tumor cells.Studies have shown that vasculogenic mimicry?VM?exists in glioblastoma,which means a vascular-like structure formed by tumor cells rather than vascular endothelial cells,guaranteeing blood supply inside tumor tissue^[2].Tumor cells involved in vasculogenic mimicry also have epithelial-mesenchymal transition?EMT?tendency,with reduced epithelial characteristics and increased mesenchymal characteristics.Therefore,tumor cells lose their polarity and increase their mobility while weakening cell adhesion,leading to invasion^[3].In recent years,many studies have focused on the role of long non-coding RNA?lnc RNA?in tumorigenesis and development.Lnc RNA HULC?highly up-regulated in liver cancer?,initially detected in liver cancer,is also abnormally expressed in glioblastoma.In view of the carcinogenic effect of lnc RNA HULC in liver cancer,we believed that it also plays a role in promoting tumor growth and metastasis in glioblastoma.We speculated that lnc RNA HULC can promote the vasculogenic mimicry and epithelial-mesenchymal transition of glioblastoma cells,thereby promoting proliferation and invasion of glioblastoma.Therefore,in this experiment,we attempted to investigate whether lnc RNA HULC promoted vasculogenic mimicry and epithelial-mesenchymal transition of glioblastoma cells through a series of cell function experiments and molecular mechanism experiments with SHG44 and U87 glioblastoma cell lines.Methods:1.Human brain glioblastoma cell lines SHG44 and U87 were cultured,then lentiviral packaging and stable strains were constructed to obtain stably transfected lnc RNA HULC overexpressing cell lines and control cell lines transfected with blank vectors;2.The ability of cells to generate mimic vessels was tested by VM experiments.;3.The transcription levels of RNA?lnc RNA HULC,Snail,Slug,E-cadherin,N-cadherin,Vimentin,MMP2 and MMP9?in cells were detected by q RT-PCR;4.The expression levels of proteins?Snail,Slug,E-cadherin,N-cadherin,Vimentin,MMP2 and MMP9?in cells were detected by Western blot.Results:1.The results of VM experiments showed that the number and integrity of mimic vascular structures in the lnc RNA HULC overexpression group were higher,suggesting that lnc RNA HULC promotes VM in glioblastoma cells;2.The q RT-PCR results showed that the expression of lnc RNA HULC in the overexpression group cells increased significantly,suggesting that the lnc RNA HULC overexpression cell line was successfully constructed.The m RNA transcription levels of transcription factors?Snail,Slug?,interstitial markers?N-cadherin,Vimentin?,and matrix metalloproteinases?MMP2,MMP9?increased and the m RNA transcription levels of epithelial markers?E-cadherin?decreased,suggesting that lnc RNA HULC promotes EMT in glioblastoma cells;3.The Western blot results showed that the protein expression levels of transcription factors?Snail,Slug?,interstitial markers?N-cadherin,Vimentin?,and matrix metalloproteinases?MMP2,MMP9?increased and the protein expression levels of epithelial markers?E-cadherin?decreased,suggesting that lnc RNA HULC promotes EMT in glioblastoma cells;Conclusion:Lnc RNA HULC promotes VM and EMT of glioblastoma cells.