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Li Q, Liu X, Mao J, Liu S, Hou B, Li K, Fang D. RRAGB-mediated suppression of PI3K/AKT exerts anti-cancer role in glioblastoma. Biochem Biophys Res Commun 2023; 676:149-157. [PMID: 37517217 DOI: 10.1016/j.bbrc.2023.07.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/12/2023] [Accepted: 07/14/2023] [Indexed: 08/01/2023]
Abstract
Glioblastoma (GBM) has a high degree of invasiveness, which is largely attributed to the invalidation of current therapy and the unclear tumor growth mechanism. Ras related GTP binding B (RRAGB) is a family member of the Ras-homologous GTPases. The effect of RRAGB on tumor growth has been recognized, but its influences on GBM progression are ill-defined. Here, in our research, a significantly decreased expression of RRAGB in GBM tissues by using TCGA databases and glioma samples is observed. According to Kaplan-Meier (KM) analysis, RRAGB low expression leads to a significant decrease of overall survival rate of patients, and is associated with the classification of WHO grade, histological type and age increase. Functional enrichment analysis reveals that the pathway of enrichment includes cell cycle arrest, extracellular matrix (ECM) processes and PI3K/AKT signal. Thereafter, our cell experiments confirm an obvious decrease of RRAGB in several GBM cell lines. It should be noted that RRAGB promotion strongly reduces the proliferation, migration and invasion of GBM cells and induces cell cycle arrest in G0/G1 phase. RRAGB up-regulation significantly decreases the expression of PI3K, phosphorylated AKT, mTOR and S6K in GBM cell lines. Surprisingly, we further find that RRAGB-restrained proliferative, migratory and invasive properties of GBM cells are markedly offset after promoting AKT activation, accompanied with restored phosphorylation of mTOR and S6K, elucidating that AKT signaling blockage is partially indispensable for RRAGB to play its anti-cancer role in GBM. Animal studies confirmed that RRAGB over-expression obviously inhibits the tumor growth both in the xenograft and orthotopic mouse glioma models, along with improved overall survival rates. In short, we provide evidence that RRAGB is a potential therapeutic target and prognostic marker for GBM treatment.
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Affiliation(s)
- Qinggang Li
- Department of Neurosurgery, Peking University People's Hospital, No. 11, Xizhimen South Street, Xicheng District, Beijing, 100044, China; Department of Neurosurgery, Beijing Beiya Orthopedic Hospital, No. 20, Haotian North Street, Fangshan District, Beijing, 102445, China
| | - Xiaonan Liu
- Sanmenxia Key Laboratory of Neurotumor Diagnosis and Treatment, Department of Neurosurgery, Sanmenxia Central Hospital, 472000, Sanmenxia, Henan, China
| | - Jian Mao
- Sanmenxia Key Laboratory of Neurotumor Diagnosis and Treatment, Department of Neurosurgery, Sanmenxia Central Hospital, 472000, Sanmenxia, Henan, China
| | - Shimin Liu
- Sanmenxia Key Laboratory of Neurotumor Diagnosis and Treatment, Department of Neurosurgery, Sanmenxia Central Hospital, 472000, Sanmenxia, Henan, China
| | - Baosen Hou
- Sanmenxia Key Laboratory of Neurotumor Diagnosis and Treatment, Department of Neurosurgery, Sanmenxia Central Hospital, 472000, Sanmenxia, Henan, China
| | - Kaiyan Li
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, 471000, China
| | - Dandong Fang
- Sanmenxia Key Laboratory of Neurotumor Diagnosis and Treatment, Department of Neurosurgery, Sanmenxia Central Hospital, 472000, Sanmenxia, Henan, China.
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Li X, Wang J, Lin W, Yuan Q, Lu Y, Wang H, Chen Y, Chen L, Dai P, Long H, Li X. circEXOC6B interacting with RRAGB, an mTORC1 activator, inhibits the progression of colorectal cancer by antagonizing the HIF1A-RRAGB-mTORC1 positive feedback loop. Mol Cancer 2022; 21:135. [PMID: 35739524 PMCID: PMC9219196 DOI: 10.1186/s12943-022-01600-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Background In recent years, an increasing number of studies have indicated that circular RNA plays crucial roles in regulating tumor development and chemoresistance. Using two high-throughput RNA sequence datasets, we previously found that circEXOC6B was downregulated in colon cancer. However, its role and mechanism in colorectal cancer (CRC) remained unknown. Methods Real-time quantitative PCR was used to examine the expression of circEXOC6B in CRC tissues. In vivo and in vitro functional experiments were performed to determine the suppressor role of circEXOC6B in CRC progression. RNA pull-down, mass spectrometry, RNA-binding protein immunoprecipitation, co-immunoprecipitation, fluorescence in situ hybridization, and immunofluorescence were applied to investigate the possible mechanisms connecting circEXOC6B to CRC growth and 5-fluorouracil-induced apoptosis. Chromatin immunoprecipitation, dual-luciferase assay, western blot, and immunohistochemistry were used to explore the mechanisms underlying the HIF1A regulation of RRAGB transcription. Results circEXOC6B was downregulated in CRC tissues, and its lower expression was associated with poor prognosis of patients. Functional experiments showed that circEXOC6B inhibited growth and increased the 5-fluorouracil-induced apoptosis of CRC cells in vitro and in vivo. Mechanistically, circEXOC6B inhibited the heterodimer formation of RRAGB by binding to it, thereby suppressing the mTORC1 pathway and HIF1A level. In addition, HIF1A upregulated the transcription of RRAGB by binding to its promoter region. Altogether, the results demonstrated that a HIF1A-RRAGB-mTORC1 positive feedback loop drives tumor progression in CRC, which could be interrupted by circEXOC6B. Conclusions circEXOC6B inhibits the progression of CRC and enhances the chemosensitivity of CRC cells to 5-fluorouracil by antagonizing the HIF1A-RRAGB-mTORC1 positive feedback loop. circEXOC6B is a possible therapeutic target for CRC treatment. Supplementary Information The online version contains supplementary material available at 10.1186/s12943-022-01600-1.
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Affiliation(s)
- Xiaomin Li
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Jianjun Wang
- Department of Histology and Embryology, Wannan Medical College, Wuhu, 241002, Anhui Province, China
| | - Weihao Lin
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Qinzi Yuan
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Yanxia Lu
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Haowei Wang
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Yujia Chen
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Lixia Chen
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Peiling Dai
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Huaicheng Long
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China
| | - Xuenong Li
- Guangdong Province Key Laboratory of Molecular Tumor Pathology, Department of Pathology, Southern Medical University, Guangzhou, 510515, Guangdong Province, China. .,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China.
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Xiao J, Liu Q, Wu W, Yuan Y, Zhou J, Shi J, Zhou S. Elevated Ras related GTP binding B ( RRAGB) expression predicts poor overall survival and constructs a prognostic nomogram for colon adenocarcinoma. Bioengineered 2021; 12:4620-4632. [PMID: 34320917 PMCID: PMC8806650 DOI: 10.1080/21655979.2021.1956402] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Currently, no articles have explored the roles of RRAGB gene in the occurrence and development of cancer. By means of The Cancer Genome Atlas (TCGA) data mining, we found that this gene might be a novel prognostic predictor for colon adenocarcinoma (COAD). Hence, this article was carried out to explore its roles in COAD and associations with immunity. RRAGB single-gene expression matrix and corresponding clinical information were extracted from TCGA database. Univariate/multivariate cox regression analyses and gene set enrichment analysis (GSEA) were utilized to identify independent prognostic factors and RRAGB related pathways, respectively. Relationships between RRAGB and immunity were also analyzed. Boxplot and K-M survival analysis indicated that RRAGB was not only differently expressed in COAD (P < 0.05), but also significantly associated with overall survival (OS; P < 0.05). Univariate and multivariate Cox hazard regression analyses indicated that RRAGB could serve as an independent prognostic factor for COAD (both P < 0.05). GSEA identified five signaling pathways significantly enriched in the high-RRAGB expression phenotype. Moreover, a RRAGB-based nomogram was successfully constructed and displayed a satisfactory performance. In addition, RRAGB expression was found to be significantly associated with microsatellite instability (MSI), tumor mutational burden (TMB) and immunity. Our results revealed that RRAGB could be a prognostic biomarker for COAD in terms of OS and markedly related to MSI, TMB, and immunity. We also constructed an RRAGB-based nomogram with a satisfactory performance. Further researches should be carried out to validate our findings.
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Affiliation(s)
- Jianjia Xiao
- Department of General Surgery, Taizhou Hospital of Traditional Chinese Medicine, Taizhou, Jiangsu Province, China
| | - Qingqing Liu
- Department of Gastroenterology, Affiliated Hospital NO.2 Of Nantong University, Nantong, Jiangsu Province, China
| | - Weijie Wu
- Department of Orthopedics, The Sixth People's Hospital of Nantong, Medical College of Nantong University, Nantong, Jiangsu Province, China
| | - Ying Yuan
- Department of Geriatrics, Taizhou Second People's Hospital, Taizhou, Jiangsu Province, China
| | - Jie Zhou
- Department of General Surgery, Taizhou Hospital of Traditional Chinese Medicine, Taizhou, Jiangsu Province, China
| | - Jieyu Shi
- Department of Neurology, Taizhou Hospital of Traditional Chinese Medicine, Taizhou, Jiangsu Province, China
| | - Shaorong Zhou
- Department of General Surgery, Taizhou Hospital of Traditional Chinese Medicine, Taizhou, Jiangsu Province, China
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