RESUMO
BACKGROUND: Increasing evidences have reported the critical roles of circular RNA (circRNA) in gliomas. Whereas, the role of circXRCC5 in glioma and its underlying molecular mechanism has not been reported. METHODS: The RNA transcripts and protein levels were detected using qRT-PCR, immunohistochemistry (IHC) and in situ hybridization (ISH) assays. Cell proliferation was characterized by CCK-8 and clone formation assays. The formation of NLRP3-inflammasomes was identified using immunofluorescence (IF) and Western blot assays. The cytokines were determined using immunosorbent assay (ELISA) and Western blot assays. The molecular interactions were validated using RIP and pull-down assays. RESULTS: circXRCC5 was over-expressed in glioma and positively related to the shorter survival rate, advanced TNM stage and larger tumor volume. circXRCC5 knockdown inhibited cell proliferation and NLRP3-mediated inflammasome activation of glioma cells. Subsequently, we found that circXRCC5 maintained mRNA stability of CLC3 by binding to IGF2BP2. Furthermore, CLC3 accelerated SGK1 expression via PI3K/PDK1/AKT pathway. The rescue experiments showed that both overexpression of CLC3 or SGK1 dramatically alleviated circXRCC5 knockdown-induced inhibition of cell proliferation and NLRP3-mediated inflammasome activation of glioma cells. In vivo, our study proved that circXRCC5 accelerated glioma growth by regulating CLC3/SGK1 axis. CONCLUSION: Our data concluded that circXRCC5 formed a complex with IGF2BP2 to regulate inflammasome activation and tumor growth via CLC3/SGK1 axis.
Assuntos
Glioma , RNA Circular , Humanos , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Glioma/metabolismo , Inflamassomos/metabolismo , Autoantígeno Ku/genética , Autoantígeno Ku/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , RNA Circular/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
Circular RNAs (circRNAs), forming a covalently closed loop, are identified as a special subgroup of non-coding RNAs. Herein, we investigated the function and underlying mechanism of circXRCC5, generated from the XRCC5 gene, in glioma progression. Bioinformatics analysis was employed to determine the genomic information of circXRCC5 derived from XRCC5 pre-mRNA. Quantitative real-time PCR was conducted to examine the expression of circXRCC5 in glioma tissues and cells. Stable knockdown of circXRCC5 in U87 and U251 cells was established to assess its' biological functions. Cell Counting Kit-8, EdU incorporation, flow cytometry and transwell assay were performed to evaluate cell proliferation, apoptosis, migration and invasion, respectively. The circRNA-miRNA-mRNA regulatory network was verified using luciferase reporter assay and RNA immunoprecipitation. The samples were subjected to CHIP to ascertain the transcriptional regulation of XRCC5 at the promoter region of CLC3. Up-regulation of circXRCC5 was observed in glioma tissues and cell lines, and indicated poor prognosis of glioma patients. Knockdown of circXRCC5 suppressed cell proliferation, migration and invasion, while facilitated apoptosis. Mechanistically, circXRCC5 acted as a molecular sponge for miR-490-3p in a sequence-specific manner. There was a reciprocal negative feedback between circXRCC5 and miR-490-3p in an Argonaute2-dependent manner. Moreover, circXRCC5 acted as a sponge of miR-490-3p to regulate the expression of downstream target gene XRCC5, thus activating the transcription of CLC3, which fostered the progression of glioma. Collectively, circXRCC5 promoted glioma progression via the miR-490-3p/XRCC5/CLC3 ceRNA network, providing a novel prognostic biomarker and a prospective target for glioma treatment.
Assuntos
Glioma , MicroRNAs , RNA Circular , Biomarcadores , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Humanos , Autoantígeno Ku/genética , Autoantígeno Ku/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Estudos Prospectivos , RNA Circular/genéticaRESUMO
N6-methyladenosine (m6A) is the most common form of messenger RNA (mRNA) modification. An increasing number of studies have proven that m6A RNA methylation regulators are overexpressed in many cancers and participate in the development of cancer through the dynamic regulation of m6A RNA methylation regulators. However, the prognostic role of m6A RNA methylation regulators in bladder cancer (BC) is poorly understood. In the present study, we downloaded the mRNA expression data from The Cancer Genome Atlas (TCGA) database and the corresponding clinical and prognostic information. The relationship between m6A RNA methylation regulators and clinicopathological variables of BC patients was assessed by the Kolmogorov-Smirnov test. The expression of the m6A RNA methylation regulators was differentially associated with different clinicopathological variables of BC patients. The least absolute shrinkage and selection operator (LASSO) Cox regression model was then applied to identify three m6A RNA methylation regulators. The risk signature was constructed as follows: 0.164FTO - (0.081YTHDC1+0.032WTAP). Based on the risk signature, the risk score of each patient was calculated, and the patients were divided into a high-risk group and a low-risk group. The overall survival (OS) rate of the high-risk group was significantly lower than that of the low-risk group. The risk signature was not only an independent prognostic marker for BC patients but also a predictor of clinicopathological variables. In conclusion, m6A RNA methylation regulators can participate in the malignant progression of BC, and a risk signature with three selected m6A RNA methylation regulators may be a promising prognostic biomarker to guide personalized treatment for BC patients.
