Dataset Information

Bmi-1 promotes glioma angiogenesis by activating NF-?B signaling.

ABSTRACT: Angiogenesis in glioma is associated with the poor prognosis of the disease and closely correlates with the highly invasive phenotype of glioma cells, which represents the most challenging impediment against the currently glioma treatments. Bmi-1, an onco-protein, has been implicated in the progression of various human cancers, including gliomas, whereas its role in glioma angiogenesis remains unclear. Our current study examined the effects of Bmi-1 on glioma angiogenesis in vitro as well as in vivo. We found that overexpression of Bmi-1 enhanced, whereas knockdown of Bmi-1 diminished, the capability of glioma cells to induce tubule formation and migration of endothelial cells and neovascularization in chicken chorioallantoic membrane. In vivo, Bmi-1 overexpression and knockdown, respectively, promoted and inhibited angiogenesis in orthotopically transplanted human gliomas. Furthermore, NF-?B activity and VEGF-C expression was induced by Bmi-1 overexpression, whereas Bmi-1 knockdown attenuated NF-?B signaling and decreased VEGF-C expression. Additionally suppression of NF-?B activity using a specific chemical inhibitor abrogated the NF-?B activation and the pro-angiogenic activities of glioma cells. Together, our data suggest that Bmi-1 plays an important role in glioma angiogenesis and therefore could represent a potential target for anti-angiogenic therapy against the disease.

SUBMITTER: Jiang L

PROVIDER: S-EPMC3561301 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Bmi-1 promotes glioma angiogenesis by activating NF-κB signaling.

Jiang Lili L Song Libing L Wu Jueheng J Yang Yi Y Zhu Xun X Hu Bo B Cheng Shi-Yuan SY Li Mengfeng M

PloS one 20130131 1

Angiogenesis in glioma is associated with the poor prognosis of the disease and closely correlates with the highly invasive phenotype of glioma cells, which represents the most challenging impediment against the currently glioma treatments. Bmi-1, an onco-protein, has been implicated in the progression of various human cancers, including gliomas, whereas its role in glioma angiogenesis remains unclear. Our current study examined the effects of Bmi-1 on glioma angiogenesis in vitro as well as in ...[more]

PMID: 23383216

Similar Datasets

Project description:BackgroundThe prognosis of human glioma is poor, and the highly invasive nature of the disease represents a major impediment to current therapeutic modalities. The oncoprotein B-cell-specific Moloney murine leukemia virus integration site 1 protein (Bmi-1) has been linked to the development and progression of glioma; however, the biological role of Bmi-1 in the invasion of glioma remains unclear.MethodsA172 and LN229 glioma cells were engineered to overexpress Bmi-1 via stable transfection or to be silenced for Bmi-1 expression using RNA interfering method. Migration and invasiveness of the engineered cells were assessed using wound healing assay, Transwell migration assay, Transwell matrix penetration assay and 3-D spheroid invasion assay. MMP-9 expression and activity were measured using real-time PCR, ELISA and the gelatin zymography methods. Expression of NF-kappaB target genes was quantified using real-time PCR. NF-kappaB transcriptional activity was assessed using an NF-kappaB luciferase reporter system. Expression of Bmi-1 and MMP-9 in clinical specimens was analyzed using immunohistochemical assay.ResultsEctopic overexpression of Bmi-1 dramatically increased, whereas knockdown of endogenous Bmi-1 reduced, the invasiveness and migration of glioma cells. NF-kappaB transcriptional activity and MMP-9 expression and activity were significantly increased in Bmi-1-overexpressing but reduced in Bmi-1-silenced cells. The reporter luciferase activity driven by MMP-9 promoter in Bmi-1-overexpressing cells was dependent on the presence of a functional NF-kappaB binding site, and blockade of NF-kappaB signaling inhibited the upregulation of MMP-9 in Bmi-1 overexpressing cells. Furthermore, expression of Bmi-1 correlated with NF-kappaB nuclear translocation as well as MMP-9 expression in clinical glioma samples.ConclusionsBmi-1 may play an important role in the development of aggressive phenotype of glioma via activating the NF-kappaB/MMP-9 pathway and therefore might represent a novel therapeutic target for glioma.

Project description:BackgroundGlioma is the most frequent and lethal primary brain malignancy. Amounting evidence has highlighted the importance of exosomal microRNAs (miRNAs or miRs) in this malignancy. This study aimed to investigate the regulatory role of exosomal miR-148a-3p in glioma.MethodsBioinformatics analysis was firstly used to predict the target genes of miR-148a-3p. Exosomes were then extracted from normal human astrocytes and glioma cells. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to determine the expression patterns of miR-148a-3p and ERBB receptor feedback inhibitor 1 (ERRFI1). Dual-luciferase reporter gene assay was applied to verify the direct binding between miR-148a-3p and ERRFI1. Cell counting kit-8 and tube formation assays were further conducted to assess the proliferation and angiogenic properties of human umbilical vein endothelial cells (HUVECs) in the co-culture system with exosomes. Lastly, glioma tumor models were established in BALB/c nude mice to study the role of exosomal miR-148a-3p in vivo.ResultsmiR-148a-3p was highly expressed, while ERRFI1 was poorly expressed in glioma. miR-148a-3p was found to be enriched in glioma cells-derived exosomes and could be transferred to HUVECs via exosomes to promote their proliferation and angiogenesis. ERRFI1 was identified as a target gene of miR-148a-3p. In addition, miR-148a-3p activated the epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase (MAPK) signaling pathway by inhibiting ERRFI1. In the co-culture system, our data demonstrated that glioma cells-derived exosomal miR-148a-3p down-regulated ERRFI1 and activated the EGFR/MAPK signaling pathway, so as to promote cell proliferation and angiogenesis. In vivo experimentation further demonstrated that this mechanism was responsible for the promotive role of exosomal miR-148a-3p in tumorigenesis and angiogenesis.ConclusionTaken together, glioma-derived exosomal miR-148a-3p promoted tumor angiogenesis through activation of the EGFR/MAPK signaling pathway by ERRFI1 inhibition.

Project description:Objective:Breast cancer has become the most common malignancy among women worldwide; therefore, novel diagnostic and prognostic markers and therapeutic targets are urgently required. NF-?B signaling plays a pivotal role in enhancing breast cancer malignant phenotypes, especially cancer invasion and metastasis, which is the main cause of death in cancer patients. TNIP2, an important inhibitor of the NF-?B pathway, is known to involve a negative feedback loop of the NF-?B signaling cascade and to regulate tumor aggressiveness in various cancer types. However, the mRNA level of TNIP2 is barely altered in breast cancer; thus, the mechanism that regulates TNIP2 in breast cancer still needs to be elucidated. Methods:We analyzed the expression and prognosis of miR-423 in a TCGA BRCA miRNA cohort and in clinical specimens. We detected the invasive capacity through a Matrigel-coated Transwell penetration assay, a three-dimensional (3D) spheroid invasion assay and a wound healing assay. Then, we applied luciferase assays, real-time PCR assays and Western blotting to further study the mechanism. Results:In this study, analysis of the TCGA BRCA miRNA cohort and clinical specimens demonstrated that miR-423 was upregulated in human breast cancers and was positively correlated with clinical stage, poor overall survival and metastasis classification. Moreover, the invasiveness of breast cancer cells was enhanced by ectopic expression of miR-423 and inhibited by miR-423 downregulation. Mechanistically, upregulation of miR-423 led to activation of the NF-?B signaling pathway and elevated expression of snail and twist, while repression of miR-423 inhibited this pathway. Furthermore, the results indicated that TNIP2 is a target gene of miR-423, and suppression of TNIP2 resulted in increased invasiveness in miR-423-silenced cells. Conclusion:Our results suggest that miR-423 is a crucial factor that enhances breast cancer cell invasion through the NF-?B signaling pathway and shed light on miR-423 as a promising prognostic and therapeutic marker for metastatic breast cancer.

Dataset Information

Bmi-1 promotes glioma angiogenesis by activating NF-?B signaling.

Publications

Bmi-1 promotes glioma angiogenesis by activating NF-κB signaling.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets