RNA-Binding Protein UNR Promotes Glioma Cell Migration and Regulates the Expression of Ribosomal Protein L9

Abstract

Objective To investigate the role of RNA binding protein─upstream-of-N-Ras (UNR) in the development of glioma and its molecular mechanism.Methods First, bioinformatics analysis of CGGA database was performed to detect UNR expression level and prognosis of patients with glioma. Western blot and real-time PCR were used to detect UNR expression level in glioma cell lines and tissues. Next, UNR siRNAs were transfected in glioma cells, and MTS assay and scratch wound-healing assay were used to detect changes in cell proliferation and migration. Then, the candidate UNR target mRNAs were identified by analyzing the sequencing data of UNR iCLIP-seq, RNA sequencing and ribosome profiling databases of human melanoma. RNA immunoprecipitation and biotin pull-down assays were used to identify the UNR target mRNAs in glioma cells. Finally, western blot was used to detect the effect of UNR knockdown on ribosomal protein L9 (RPL9) and RPL9 protein expression level in glioma cell lines. RPL9 siRNA was transfected in A172 and T98G and the expression of vimentin in the cells was detected with western blot.Results Bioinformatics analysis showed that UNR mRNA expression level was significantly higher in high-grade glioma [Grade 2 (n=126), Grade 3 (n=51), Grade 4 (n=128), P<0.001]. UNR high expression levels were associated with poor prognosis (P=0.0177). UNR had high expression level in glioma cell lines and patient samples compared with normal cell lines and normal brain samples (P<0.01). Knockdown of UNR inhibited glioma cells migration (P<0.05), but did not inhibit glioma cells growth in three glioma cell lines. UNR binded the 3' untranslated region (UTR) of PTEN and RPL9 mRNAs. RPL9 protein was significantly highly expressed in most glioma cell lines (n=9) and knockdown of UNR resulted in a downregulation of RPL9 protein expression. Epithelial-mesenchymal transition (EMT)-related marker─vimentin was positively regulated by RPL9.Conclusions UNR could bind to the 3'UTR of PTEN and RPL9 in glioma cell lines, therefore promoting glioma cell migration and regulating the expression of RPL9. Here, we establish a link between UNR and RPL9 protein, which will provide new ideas for the further study of glioma.

Identification of Key Genes and Signaling Pathways Associated with the Progression of Glioblastoma multiform

“…In pathway enrichment analysis for up regulated genes was performed. Enriched genes such as SOD2 [68], RPS11 [69], RPL9 [70], MYC (MYC proto-oncogene, bHLH transcription factor) [71], SEC61G [72], BIRC5 [73], NEK2 [74], CDK2 [75], AURKB (aurora kinase B) [76], RPS3 [77], MGP (matrix Gla protein) [78], AEBP1 [79], CTHRC1 [80], COL1A1 [81], COL3A1 [82], TNC (tenascin C) [83], POSTN (periostin) [84], IGFBP2 [85], IGFBP3 [86], IGFBP4 [87], SRPX2 [88], LAMB1 [89], ESM1 [90], TGFBI (transforming growth factor beta induced) [91], ITGA5 [92], RAP1B [93], CAV1 [94], HMOX1 [95] and LOX (lysyl oxidase) [96] were linked with progression of GBM. GPX7 was important for advancement of gastric cancer [97], but this gene was identified first time in GBM and may be liable for progression of GBM.…”

The role of CSDE1 in translational reprogramming and human diseases

“…The CSDE1 mRNA expression level was also higher in grade IV glioma than it was in grade II and III patients (P < 0.001) according to the data released by the Chinese Glioma Genome Atlas (CGGA). In addition, higher CSDE1 expression was correlated with poorer survival in glioma patients (P = 0.0177) [16]. Another recent investigation revealed that low CSDE1 expression was significantly associated with poor outcome in low-grade resected PDAC patients [20].…”

“…Oncogene [16] Breast cancer Oncogene [17] PCCs &PGLs Tumor suppressor [18] Oral squamous cell carcinoma Tumor suppressor [19] Pancreatic ductal adenocarcinoma Prognostic biomarker [20] Epithelial ovarian cancer Platinum resistance gene [21] Other diseases…”

“…As a treatment, downregulating CSDE1 increased the camptothecin response in CRC-derived cell lines and CRC patients [80]. High expression of CSDE1 was associated with poor prognosis in glioma and pancreatic ductal adenocarcinoma (PDAC) [16]. CSDE1 expression was also significantly higher in glioma cells and tissues than it was in normal human astrocytes and brain tissues.…”

Coordinated post-transcriptional control of oncogene-induced senescence by UNR/CSDE1

“…VIM, RAC1) (Wurth et al, 2016). While the oncogenic potential of CSDE1 has been observed in multiple other tumors (Fang et al, 2005; Liu et al, 2020; Martinez-Useros et al, 2019; Tian et al, 2018), loss of function CSDE1 mutations have been detected in neuroendocrine tumors, suggesting tumor suppressive roles (Fishbein et al, 2017). Intrigued by context-specific functions of CSDE1 in cancer, we noticed that this RBP could bind SASP factor mRNAs in melanoma, although such binding did not have functional consequences in this system (Wurth et al, 2016).…”