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Sipos TC, Kövecsi A, Kocsis L, Nagy-Bota M, Pap Z. Evaluation of Microvascular Density in Glioblastomas in Relation to p53 and Ki67 Immunoexpression. Int J Mol Sci 2024; 25:6810. [PMID: 38928515 PMCID: PMC11204252 DOI: 10.3390/ijms25126810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 06/16/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
Glioblastoma is the most aggressive tumor in the central nervous system, with a survival rate of less than 15 months despite multimodal therapy. Tumor recurrence frequently occurs after removal. Tumoral angiogenesis, the formation of neovessels, has a positive impact on tumor progression and invasion, although there are controversial results in the specialized literature regarding its impact on survival. This study aims to correlate the immunoexpression of angiogenesis markers (CD34, CD105) with the proliferation index Ki67 and p53 in primary and secondary glioblastomas. This retrospective study included 54 patients diagnosed with glioblastoma at the Pathology Department of County Emergency Clinical Hospital Târgu Mureș. Microvascular density was determined using CD34 and CD105 antibodies, and the results were correlated with the immunoexpression of p53, IDH1, ATRX and Ki67. The number of neoformed blood vessels varied among cases, characterized by different shapes and calibers, with endothelial cells showing modified morphology and moderate to marked pleomorphism. Neovessels with a glomeruloid aspect, associated with intense positivity for CD34 or CD105 in endothelial cells, were observed, characteristic of glioblastomas. Mean microvascular density values were higher for the CD34 marker in all cases, though there were no statistically significant differences compared to CD105. Mutant IDH1 and ATRX glioblastomas, wild-type p53 glioblastomas, and those with a Ki67 index above 20% showed a more abundant microvascular density, with statistical correlations not reaching significance. This study highlighted a variety of percentage intervals of microvascular density in primary and secondary glioblastomas using immunohistochemical markers CD34 and CD105, respectively, with no statistically significant correlation between evaluated microvascular density and p53 or Ki67.
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Affiliation(s)
- Tamás-Csaba Sipos
- Department of Anatomy and Embryology, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 540142 Târgu Mures, Romania; (T.-C.S.)
- Doctoral School of Medicine and Pharmacy, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, 540142 Targu Mures, Romania
- Pathology Department, County Emergency Clinical Hospital of Târgu Mureș, 540136 Târgu Mureș, Romania
| | - Attila Kövecsi
- Pathology Department, County Emergency Clinical Hospital of Târgu Mureș, 540136 Târgu Mureș, Romania
- Pathology Department, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 540142 Târgu Mures, Romania
| | - Lóránd Kocsis
- Department of Anatomy and Embryology, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 540142 Târgu Mures, Romania; (T.-C.S.)
- Doctoral School of Medicine and Pharmacy, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, 540142 Targu Mures, Romania
| | - Monica Nagy-Bota
- Department of Anatomy and Embryology, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 540142 Târgu Mures, Romania; (T.-C.S.)
| | - Zsuzsánna Pap
- Department of Anatomy and Embryology, “George Emil Palade” University of Medicine, Pharmacy, Sciences and Technology of Târgu Mures, 540142 Târgu Mures, Romania; (T.-C.S.)
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The Mutually Mediated Chloride Intracellular Channel Protein 1 (CLIC1) Relationship between Malignant Cells and Tumor Blood Vessel Endothelium Exhibits a Significant Impact on Tumor Angiogenesis, Progression, and Metastasis in Clear Cell Renal Cell Carcinoma (ccRCC). Cancers (Basel) 2022; 14:cancers14235981. [PMID: 36497464 PMCID: PMC9740861 DOI: 10.3390/cancers14235981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/24/2022] [Accepted: 11/29/2022] [Indexed: 12/07/2022] Open
Abstract
Background: Overexpression of chloride intracellular channel protein 1 (CLIC1) in tumor cells has been confirmed, but it has received less attention in the tumor blood vessel endothelium. Aim: The assessment of CLIC1 expression in ccRCC tumor blood vessels and its relationship with TNM parameters and tumor cell CLIC1 expression. Methods: CLIC1 immunostaining in ccRCC was evaluated in 50 cases in both malignant cells and tumor blood vessels (CLIC1 microvessel density-CLIC1-MVD) and was correlated with TNM staging parameters. Results: CLIC1-MVD was observed in approximately 65% of cases, and CLIC1 co-localization in both tumor and endothelial cells was observed in 59% of cases. ccRCC was classified into four groups (Classes 0−3) based on the percentage of positive tumor cells, with each group including sub-groups defined by CLIC1 expression in the endothelium. Class 3 (60−100% positive tumor cells) had the highest CLIC1-MVD, with an impact on T and M parameters (p value = 0.007 for T, and p value = 0.006 for M). For cases with CLIC1 intracellular translocation, there was a strong correlation between CLIC1-MVD and M (p value < 0.001). Conclusions: Co-expression of ccRCC tumor and endothelial cells promotes tumor progression and metastasis and should be investigated further as a potential therapeutic target for ccRCC and other human malignancies.
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Li L, Zhong L, Tang C, Gan L, Mo T, Na J, He J, Huang Y. CD105: tumor diagnosis, prognostic marker and future tumor therapeutic target. Clin Transl Oncol 2022; 24:1447-1458. [PMID: 35165838 DOI: 10.1007/s12094-022-02792-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/21/2022] [Indexed: 02/06/2023]
Abstract
Cancer is one of the diseases with the highest morbidity and mortality rates worldwide, and its therapeutic options are inadequate. The endothelial glycoprotein, also known as CD105, is a type I transmembrane glycoprotein located on the surface of the cell membranes and it is one of the transforming growth factor-β (TGF-β) receptor complexes. It regulates the responses associated with binding to transforming growth factor β1 egg (Activin-A), bone morphogenetic protein 2 (BMP-2), and bone morphogenetic protein 7 (BMP-7). Additionally, it is involved in the regulation of angiogenesis. This glycoprotein is indispensable in the treatment of tumor angiogenesis, and it also plays a leading role in tumor angiogenesis therapy. Therefore, CD105 is considered to be a novel therapeutic target. In this study, we explored the significance of CD105 in the diagnosis, treatment and prognosis of various tumors, and provided evidence for the effect and mechanism of CD105 on tumors.
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Affiliation(s)
- Lan Li
- National Center for International Research of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-Targeting Theranostics, Guangxi Medical University, Nanning, 530021, Guangxi, China
- Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Liping Zhong
- National Center for International Research of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-Targeting Theranostics, Guangxi Medical University, Nanning, 530021, Guangxi, China
- Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Chao Tang
- National Center for International Research of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-Targeting Theranostics, Guangxi Medical University, Nanning, 530021, Guangxi, China
- Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Lu Gan
- National Center for International Research of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-Targeting Theranostics, Guangxi Medical University, Nanning, 530021, Guangxi, China
- Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Tong Mo
- National Center for International Research of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-Targeting Theranostics, Guangxi Medical University, Nanning, 530021, Guangxi, China
- Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Jintong Na
- National Center for International Research of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-Targeting Theranostics, Guangxi Medical University, Nanning, 530021, Guangxi, China
- Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Jian He
- National Center for International Research of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-Targeting Theranostics, Guangxi Medical University, Nanning, 530021, Guangxi, China
- Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Yong Huang
- National Center for International Research of Bio-Targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-Targeting Theranostics, Guangxi Medical University, Nanning, 530021, Guangxi, China.
- Guangxi Medical University, Nanning, 530021, Guangxi, China.
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The histological representativeness of glioblastoma tissue samples. Acta Neurochir (Wien) 2021; 163:1911-1920. [PMID: 33085022 PMCID: PMC8195928 DOI: 10.1007/s00701-020-04608-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 10/05/2020] [Indexed: 02/08/2023]
Abstract
Background Glioblastomas (GBMs) are known for having a vastly heterogenous histopathology. Several studies have shown that GBMs can be histologically undergraded due to sampling errors of small tissue samples. We sought to explore to what extent histological features in GBMs are dependent on the amount of viable tissue on routine slides from both biopsied and resected tumors. Methods In 106 newly diagnosed GBM patients, we investigated associations between the presence or degree of 24 histopathological and two immunohistochemical features and the tissue amount on hematoxylin-eosin (HE) slides. The amount of viable tissue was semiquantitatively categorized as “sparse,” “medium,” or “substantial” for each case. Tissue amount was also assessed for associations with MRI volumetrics and the type of surgical procedure. Results About half (46%) of the assessed histological and immunohistochemical features were significantly associated with tissue amount. The significant features were less present or of a lesser degree when the tissue amount was smaller. Among the significant features were most of the features relevant for diffuse astrocytic tumor grading, i.e., small necroses, palisades, microvascular proliferation, atypia, mitotic count, and Ki-67/MIB-1 proliferative index (PI). Conclusion A substantial proportion of the assessed histological features were at risk of being underrepresented when the amount of viable tissue on HE slides was limited. Most of the grading features were dependent on tissue amount, which underlines the importance of considering sampling errors in diffuse astrocytic tumor grading. Our findings also highlight the importance of adequate tissue collection to increase the quality of diagnostics and histological research.
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Mikkelsen VE, Dai HY, Stensjøen AL, Berntsen EM, Salvesen Ø, Solheim O, Torp SH. MGMT Promoter Methylation Status Is Not Related to Histological or Radiological Features in IDH Wild-type Glioblastomas. J Neuropathol Exp Neurol 2021; 79:855-862. [PMID: 32688383 DOI: 10.1093/jnen/nlaa060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/25/2020] [Accepted: 06/03/2020] [Indexed: 11/15/2022] Open
Abstract
O6-methylguanine DNA methyltransferase (MGMT) promoter methylation is an important favorable predictive marker in patients with glioblastoma (GBM). We hypothesized that MGMT status could be a surrogate marker of pretreatment tumor biology observed as histopathological and radiological features. Apart from some radiological studies aiming to noninvasively predict the MGMT status, few studies have investigated relationships between MGMT status and phenotypical tumor biology. We have therefore aimed to investigate such relationships in 85 isocitrate dehydrogenase (IDH) wild-type GBMs. MGMT status was determined by methylation-specific PCR and was assessed for associations with 22 histopathological features, immunohistochemical proliferative index and microvessel density measurements, conventional magnetic resonance imaging characteristics, preoperative speed of tumor growth, and overall survival. None of the investigated histological or radiological features were significantly associated with MGMT status. Methylated MGMT status was a significant independent predictor of improved overall survival. In conclusion, our results suggest that MGMT status is not related to the pretreatment phenotypical biology in IDH wild-type GBMs. Furthermore, our findings suggest the survival benefit of MGMT methylated GBMs is not due to an inherently less aggressive tumor biology, and that conventional magnetic resonance imaging features cannot be used to noninvasively predict the MGMT status.
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Affiliation(s)
- Vilde Elisabeth Mikkelsen
- From the Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, NTNU-Norwegian University of Science and Technology
| | - Hong Yan Dai
- Department of Pathology, St Olav's University Hospital
| | - Anne Line Stensjøen
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU-Norwegian University of Science and Technology
| | - Erik Magnus Berntsen
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU-Norwegian University of Science and Technology.,Department of Radiology and Nuclear Medicine, St. Olav's University Hospital
| | | | - Ole Solheim
- Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU-Norwegian University of Science and Technology.,Department of Neurosurgery, St. Olav's University Hospital, Trondheim, Norway
| | - Sverre Helge Torp
- From the Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, NTNU-Norwegian University of Science and Technology.,Department of Pathology, St Olav's University Hospital
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Radiological evaluation of ex novo high grade glioma: velocity of diametric expansion and acceleration time study. Radiol Oncol 2020; 55:26-34. [PMID: 33885243 PMCID: PMC7877266 DOI: 10.2478/raon-2020-0071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/16/2020] [Indexed: 12/03/2022] Open
Abstract
Background One of the greatest neuro-oncological concern remains the lack of knowledge about the etiopathogenesis and physiopathology of gliomas. Several studies reported a strict correlation between radiological features and biological behaviour of gliomas; in this way the velocity of diametric expansion (VDE) correlate with lower grade glioma aggressiveness. However, there are no the same strong evidences for high grade gliomas (HGG) because of the lack of several preoperative MRI. Patients and methods We describe a series of 4 patients affected by HGG followed from 2014 to January 2019. Two patients are male and two female; two had a pathological diagnosis of glioblastoma (GBM), one of anaplastic astrocytoma (AA) and one had a neuroradiological diagnosis of GBM. The VDE and the acceleration time (AT) was calculated for fluid attenuated inversion recovery (FLAIR) volume and for the enhancing nodule (EN). Every patients underwent sequential MRI study along a mean period of 413 days. Results Mean VDE evaluated on FLAIR volume was 39.91 mm/year. Mean percentage ratio between peak values and mean value of acceleration was 282.7%. Median appearance time of EN after first MRI scan was 432 days. Mean VDE was 45.02 mm/year. Mean percentage ratio between peak values and mean value of acceleration was 257.52%. Conclusions To our knowledge, this is the first report on VDE and acceleration growth in HGG confirming their strong aggressiveness. In a case in which we need to repeat an MRI, time between consecutive scans should be reduced to a maximum of 15–20 days and surgery should be executed as soon as possible.
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Liang T, Zhou X, Li P, You G, Wang F, Wang P, Feng E. DZIP3 is a key factor to stratify IDH1 wild-type lower-grade gliomas. Aging (Albany NY) 2020; 12:24995-25004. [PMID: 33229627 PMCID: PMC7803555 DOI: 10.18632/aging.103817] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 07/16/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Malignant glioma is the most common form of primary malignant brain cancer. Heterogeneity is the hallmark of glioma. DAZ-interacting zinc finger 3 (DZIP3), acts as an RNA-binding RING-type ubiquitin ligase; however, its function in glioma is yet unclear. RESULTS The DZIP3 expression was related to the World Health Organization (WHO) grade and isocitrate dehydrogenase 1(IDH1) status, as well as the clinical outcome. Malignant cases exhibit lower DZIP3 expression. DZIP3 was an independent predictive factor of good prognosis in all grade and lower grade gliomas (p < 0.0001). Gene enrichment analysis and immunohistochemistry indicated that DZIP3 affected the biological behavior of glioma through the angiogenesis pathway. Moreover, based on DZIP3 expression, IDH1 wild-type lower-grade gliomas could be divided into two groups with different survival time. CONCLUSION In conclusion, the loss of DZIP3 may be involved in the mechanism of angiogenesis in the invasive biological process of glioma. These findings laid an understanding of DZIP3-specific clinical features in glioma. METHODS A total of 325 glioma patients from the Chinese Glioma Genome Atlas (CGGA) RNA-seq cohort comprised the training cohort, while 265 patients from the GSE 16011 array cohort formed the validation cohort. The mRNA expression of DZIP3 and clinical characteristics was assessed. DZIP3 protein expression and microvessel density (MVD) were evaluated by immunohistochemistry (IHC).
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Affiliation(s)
- Tingyu Liang
- Department of Neurosurgery, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Xingang Zhou
- Department of Pathology, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Peiliang Li
- Department of Neurosurgery, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Gan You
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
| | - Fang Wang
- Department of Neurosurgery, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Peng Wang
- Department of Pathology, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Enshan Feng
- Department of Neurosurgery, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
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Xu CH, Liu Y, Xiao LM, Chen LK, Zheng SY, Zeng EM, Li DH, Li YP. Silencing microRNA-221/222 cluster suppresses glioblastoma angiogenesis by suppressor of cytokine signaling-3-dependent JAK/STAT pathway. J Cell Physiol 2019; 234:22272-22284. [PMID: 31106423 DOI: 10.1002/jcp.28794] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 04/17/2019] [Accepted: 04/22/2019] [Indexed: 12/13/2022]
Abstract
Angiogenesis is a major pathologic characteristic of glioblastoma, which is one aggressive primary brain tumor. MicroRNA-221/222 (miR-221/222) cluster has been previously reported to function importantly in malignant glioma biological process. The current study aims at evaluating the effects of miR-221/222 cluster on angiogenesis of glioblastoma cells. Microarray data were analyzed to select glioblastoma-associated differentially expressed genes, and dual-luciferase reporter assay was performed to assess targeting correlation between miR-221/222 cluster and suppressor of cytokine signaling-3 (SOCS3). Subsequently, the expression patterns of miR-221 and miR-222 in glioblastoma cells were identified. miR-221 and miR-222 were overexpressed or silenced in glioblastoma cells to identify the effect of miR-221/222 cluster in cell invasion, migration, proliferation, and angiogenesis. To define downstream pathway of miR-221/222 cluster or SOCS3 in glioblastoma, levels of Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway-related proteins were assessed. Additionally, the functions of miR-221/222 on glioblastoma cell angiogenesis were measured in vivo with microvessel density assayed. miR-221 and miR-222 were expressed at a high level and SOCS3 was at a low level in glioblastoma. Downregulation of the miR-221/222 cluster diminished the invasion, migration, proliferation, and angiogenesis with reduced protein levels of matrix metalloproteinase-2 (MMP-2), MMP-9, and vascular endothelial growth factor in glioblastoma cells. Also, silencing miR-221/222 cluster reduced p-JAK2/JAK2 and p-STAT3/STAT3. Consistently, the inhibitory role of silencing miR-221/222 cluster on tumorigenesis of glioblastoma cells was confirmed in vivo. Collectively, the inhibition of miR-221/222 cluster could attenuate the glioblastoma angiogenesis through inactivation of the JAK/STAT pathway by upregulating SOCS3.
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Affiliation(s)
- Chun-Hua Xu
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, P.R. China
| | - Yue Liu
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, P.R. China
| | - Li-Min Xiao
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, P.R. China
| | - Li-Ke Chen
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, P.R. China
| | - Su-Yue Zheng
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, P.R. China
| | - Er-Ming Zeng
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, P.R. China
| | - Dong-Hai Li
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, P.R. China
| | - You-Ping Li
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, P.R. China
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CircSMARCA5 Regulates VEGFA mRNA Splicing and Angiogenesis in Glioblastoma Multiforme Through the Binding of SRSF1. Cancers (Basel) 2019; 11:cancers11020194. [PMID: 30736462 PMCID: PMC6406760 DOI: 10.3390/cancers11020194] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 01/24/2019] [Accepted: 02/06/2019] [Indexed: 02/06/2023] Open
Abstract
Circular RNAs are a large group of RNAs whose cellular functions are still being investigated. We recently proposed that circSMARCA5 acts as sponge for the splicing factor Serine and Arginine Rich Splicing Factor 1 (SRSF1) in glioblastoma multiforme (GBM). After demonstrating by RNA immunoprecipitation a physical interaction between SRFS1 and circSMARCA5, we assayed by real-time PCR in a cohort of 31 GBM biopsies and 20 unaffected brain parenchyma controls (UC) the expression of total, pro-angiogenic (Iso8a) and anti-angiogenic (Iso8b) mRNA isoforms of Vascular Endothelial Growth Factor A (VEGFA), a known splicing target of SRSF1. The Iso8a to Iso8b ratio: (i) increased in GBM biopsies with respect to UC (p-value < 0.00001); (ii) negatively correlated with the expression of circSMARCA5 (r-value = −0.46, p-value = 0.006); (iii) decreased in U87-MG overexpressing circSMARCA5 with respect to negative control (p-value = 0.0055). Blood vascular microvessel density, estimated within the same biopsies, negatively correlated with the expression of circSMARCA5 (r-value = −0.59, p-value = 0.00001), while positively correlated with that of SRSF1 (r-value = 0.38, p-value = 0.00663) and the Iso8a to Iso8b ratio (r-value = 0.41, p-value = 0.0259). Kaplan-Meier survival analysis showed that GBM patients with low circSMARCA5 expression had lower overall and progression free survival rates than those with higher circSMARCA5 expression (p-values = 0.033, 0.012, respectively). Our data convincingly suggest that circSMARCA5 is an upstream regulator of pro- to anti-angiogenic VEGFA isoforms ratio within GBM cells and a highly promising GBM prognostic and prospective anti-angiogenic molecule.
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