RESUMO
Despite progress in conventional treatment for glioblastoma (GBM), the prognosis remains poor due to high tumor recurrence. Therefore, identification of new molecular mechanisms is a pressing need for betterment of GBM patient outcomes. qRT-PCR was used to determine BDNF-AS expression in GBM cells. CCK-8, EdU incorporation, and caspase-3 activity assays were employed to analyze biological functions of BDNF-AS. RIP and RNA pull-down were conducted to detect the interactions among BDNF-AS, ADAR, and p53. Actinomycin D was utilized to examine the stability of p53 mRNA. ChIP and luciferase reporter assays were performed to detect transcriptional activation of BDNF-AS by p53. We found that BDNF-AS was significantly downregulated in GBM cell lines, and its overexpression inhibited GBM cell growth, and promoted apoptosis. Importantly, we illustrated that BDNF-AS coupled with ADAR protein to potentiate stability of p53 mRNA and thus upregulate p53. Interestingly, we further identified p53 as a transcription factor of BDNF-AS, activating transcription of BNDF-AS. This study firstly demonstrated that BDNF-AS acted as a tumor suppressor in GBM and the positive feedback circuit of BDNF-AS/ADAR/p53 served an important mechanism to control GBM proliferation. Targeting this auto-regulatory loop may provide a potential therapeutic strategy for GBM patients.
Assuntos
Adenosina Desaminase/metabolismo , Proliferação de Células/fisiologia , Glioblastoma/metabolismo , RNA Longo não Codificante/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Estabilidade de RNA , RNA Longo não Codificante/genética , RNA Mensageiro/metabolismo , Transcrição Gênica/fisiologia , Proteína Supressora de Tumor p53/genéticaRESUMO
As the most fatal disease in human central nerve system, glioblastoma has attracted increasing attention. Unfortunately, the prognosis for patients with glioblastoma still quite unfavorable. Recent years, circular RNAs (circRNAs) have been identified to be associated with carcinogenesis due to their abnormal expression. However, the detailed molecular mechanism of circRNAs in regulating cancer progression is still unclear. This study focused on the potential mechanism of circ-PITX1 in glioblastoma. Herein, circ-PITX1 was found to be upregulated in glioblastoma and could mediate glioblastoma tissues and cell lines. Functionally, downregulation of circ-PITX1 hampered cell proliferation and accelerated cell apoptosis. Through mechanism investigation, we identified the cytoplasmic localization of circ-PITX1 and its molecular sponge role. The interactions between circ-PITX1 and miR-379-5p as well as between miR-379-5p and MAP3K2 were demonstrated. Thus, we confirmed that circ-PITX1 exerted as a competing endogenous RNA (ceRNA) in glioblastoma by sponging miR-379-5p to elevate MAP3K2 expression. Rescue assays demonstrated that MAP3K2 rescued the proliferation and apoptosis mediated by the silencing of circ-PITX1. Collectively, our study elucidated a novel molecular pathway and its functions in glioblastoma.
Assuntos
Progressão da Doença , Glioblastoma/genética , Glioblastoma/patologia , MAP Quinase Quinase Quinase 2/metabolismo , MicroRNAs/genética , Fatores de Transcrição Box Pareados/genética , RNA Circular/genética , Apoptose/genética , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Fatores de Transcrição Box Pareados/deficiência , Regulação para CimaRESUMO
In this study, in-depth observation and investigation of blood-brain barrier permeability and neuroprotective effect of Trichosanthes kirilowii cassia twig particles on rats with cerebral ischemia-reperfusion injury were performed. Focal cerebral ischemia-reperfusion injury model was established by middle cerebral artery occlusion method, reperfusion was implemented 2 hours after ischemia; qualitative analysis and investigation of trichosanthes kirilowii cassia twig particles in plasma, brain tissue and cerebrospinal fluid in normal and middle cerebral artery occlusion (MCAO) rats were done by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS); changes in neurological deficits, cerebral infarction stereometry, blood-brain barrier permeability and histopathological changes of MCAO model rats were observed. Qualitative analysis by HPLC-MS/MS results showed that ingredients, paeoniflorin, albiflorin, liquiritin in Trichosanthes kirilowii cassia twig particles can reach the brain through the blood-brain barrier. In the model group, glycyrrhizin and glycyrrhizic acid can be detected in brain tissue or cerebrospinal fluid. In addition, Trichosanthes kirilowii cassia twig particles can significantly lower neurological deficits of rats in middle cerebral artery occlusion model, reduce the Evans blue penetration, contract infarct size, and reduce pathological tissue injury of cerebral ischemia reperfusion. The ingredients of Trichosanthes kirilowii cassia twig particles can reach the brain tissue through the blood-brain barrier and play a role in neuroprotection of rats with cerebral ischemia-reperfusion injury, which has important research significance and brings scientific experimental, theoretical basis for clinical drug use.
