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P4HA2 Promotes Epithelial-to-Mesenchymal Transition and Glioma Malignancy through the Collagen-Dependent PI3K/AKT Pathway. JOURNAL OF ONCOLOGY 2021; 2021:1406853. [PMID: 34434233 PMCID: PMC8382519 DOI: 10.1155/2021/1406853] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 06/21/2021] [Accepted: 08/03/2021] [Indexed: 01/15/2023]
Abstract
Prolyl-4-hydroxylase subunit 2 (P4HA2) is a member of collagen modification enzymes involved in the remodeling of the extracellular matrix (ECM). Mounting evidence has suggested that deregulation of P4HA2 is common in cancer. However, the role of P4HA2 in glioma remains unknown. The present study aimed to elucidate the expression pattern, oncogenic functions, and molecular mechanisms of P4HA2 in glioblastoma cells. The TCGA datasets and paraffin samples were used for examining the expressions of P4HA2. P4HA2-specific lentivirus was generated to assess its oncogenic functions. A P4HA2 enzyme inhibitor (DHB) and an AKT agonist (SC79) were utilized to study the mechanisms. As a result, we demonstrated that P4HA2 is overexpressed in glioma and inversely correlates with patient survival. Knockdown of P4HA2 inhibited proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) like phenotype of glioma cells in vitro and suppressed tumor xenograft growth in vivo. Mechanistically, expressions of a series of collagen genes and of phosphorylated PI3K/AKT were downregulated by either P4HA2 silencing or inhibition of its prolyl hydroxylase. Finally, the inhibitory effects on the migration, invasion, and EMT-related molecules by P4HA2 knockdown were reversed by AKT activation with SC79. Our findings for the first time reveal that P4HA2 acts as an oncogenic molecule in glioma malignancy by regulating the expressions of collagens and the downstream PI3K/AKT signaling pathway.
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Cui Y, Wang Q, Lin J, Zhang L, Zhang C, Chen H, Qian J, Luo C. miRNA-193a-3p Regulates the AKT2 Pathway to Inhibit the Growth and Promote the Apoptosis of Glioma Cells by Targeting ALKBH5. Front Oncol 2021; 11:600451. [PMID: 33968717 PMCID: PMC8103841 DOI: 10.3389/fonc.2021.600451] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 03/30/2021] [Indexed: 12/21/2022] Open
Abstract
Emerging evidence indicates that microRNA (miR)-193a-3p is involved in the tumor progression of various cancers. However, the biological functions and precise molecular mechanisms of miR-193a-3p in gliomas have not been well documented. Accordingly, this study focused on the tumor suppressor role and molecular mechanisms of miR-193a-3p in glioma cells. miR-193a-3p expression was determined by qRT-PCR in glioma tissues and cell lines. U251 and U87 glioma cells were transfected with a miR-193a-3p mimic. The effects of miR-193a-3p on cell growth and apoptosis were investigated using MTT, colony-forming, and flow cytometry assays. Overexpression of miR-193a-3p in U87 cells also significantly suppressed tumorigenicity and induced apoptosis in the xenograft mouse model. Luciferase assays were conducted to determine if ALKBH5 is a direct target of miR-193a-3p in glioma cells. Immunoprecipitation was used to explore the interaction between ALKBH5 and RAC-serine/threonine-protein kinase 2 (AKT2) in glioma cells. miR-193a-3p was downregulated in glioma tissues and cell lines. miR-193a-3p treatment suppressed proliferation and promoted apoptosis in both U251 and U87 cells. Bioinformatics analysis and luciferase reporter assay identified a novel miR-193a-3p target, ALKBH5. Notably, the antitumor effect of miR-193a-3p transfection in glioma cells may be due to the miR-193a-3p–induced inhibition of AKT2 expression caused by the suppression of ALKBH5 expression. Furthermore, immunoprecipitation indicated that ALKBH5 physically interacted with AKT2 through an RNA-independent mechanism in glioma cells. miR-193a-3p directly targets ALKBH5 to inhibit the growth and promote the apoptosis of glioma cells by suppressing the AKT2 pathway both in vitro and in vivo, and the physical interaction between ALKBH5 and AKT2 is essential for suppressing cell apoptosis by upregulating miR-193a-3p in glioma cells. Our study revealed that the antitumor effects of miR-193a-3p on glioma cells is due to ALKBH5 mediation of the AKT2-induced intrinsic apoptosis signaling pathway.
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Affiliation(s)
- Yong Cui
- Department of Neurosurgery, Third Affiliated Hospital of Naval Medical University, Shanghai, China.,Department of Neurosurgery, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Qi Wang
- Department of Neurosurgery, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jing Lin
- Department of Neurosurgery, Changzheng Hospital of Naval Medical University, Shanghai, China
| | - Lei Zhang
- Department of Neurosurgery, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Chi Zhang
- Department of Neurosurgery, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Huairui Chen
- Department of Neurosurgery, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jun Qian
- Department of Neurosurgery, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, China
| | - Chun Luo
- Department of Neurosurgery, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, China
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Targeted Delivery of Nanoparticulate Cytochrome C into Glioma Cells Through the Proton-Coupled Folate Transporter. Biomolecules 2019; 9:biom9040154. [PMID: 31003476 PMCID: PMC6523331 DOI: 10.3390/biom9040154] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/11/2019] [Accepted: 04/15/2019] [Indexed: 01/14/2023] Open
Abstract
In this study, we identified the proton-coupled folate transporter (PCFT) as a route for targeted delivery of drugs to some gliomas. Using the techniques of confocal imaging, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and small interfering (siRNA) knockdown against the PCFT, we demonstrated that Gl261 and A172 glioma cells, but not U87 and primary cultured astrocytes, express the PCFT, which provides selective internalization of folic acid (FA)-conjugated cytochrome c-containing nanoparticles (FA-Cyt c NPs), followed by cell death. The FA-Cyt c NPs (100 µg/mL), had no cytotoxic effects in astrocytes but caused death in glioma cells, according to their level of expression of PCFT. Whole-cell patch clamp recording revealed FA-induced membrane currents in FA-Cyt c NPs-sensitive gliomas, that were reduced by siRNA PCFT knockdown in a similar manner as by application of FA-Cyt c NPs, indicating that the PCFT is a route for internalization of FA-conjugated NPs in these glioma cells. Analysis of human glioblastoma specimens revealed that at least 25% of glioblastomas express elevated level of either PCFT or folate receptor (FOLR1). We conclude that the PCFT provides a mechanism for targeted delivery of drugs to some gliomas as a starting point for the development of efficient methods for treating gliomas with high expression of PCFT and/or FOLR1.
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Down-regulation of ABCE1 inhibits temozolomide resistance in glioma through the PI3K/Akt/NF-κB signaling pathway. Biosci Rep 2018; 38:BSR20181711. [PMID: 30455394 PMCID: PMC6294624 DOI: 10.1042/bsr20181711] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/04/2018] [Accepted: 11/16/2018] [Indexed: 02/07/2023] Open
Abstract
The ATP binding cassette (ABC) E1 (ABCE1), a member of the ABC family, was originally described as the RNase L inhibitor. Through forming a heterodimer with RNase L, ABCE1 participates in the negative regulation of the 2-5A/RNase L system and thus mediates a wide range of biological functions. Recent evidence has shown the new roles of ABCE1 in tumorigenesis. However, there have been no investigations on the specific effect of ABCE1 on glioma. In the present study, we examined the expression pattern and possible role of ABCE1 in glioma. Our study demonstrated that ABCE1 was up-regulated in glioma tissues and cell lines. Down-regulation of ABCE1 inhibited temozolomide (TMZ) resistance of glioma cells in vitro and in vivo In addition, we found that the PI3K/Akt/NF-κB pathway was involved in ABCE1-mediated chemoresistance of glioma cells. Taken together, our study suggested ABCE1 as a promising target for glioma chemotherapy.
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Lin J, Ji A, Qiu G, Feng H, Li J, Li S, Zou Y, Cui Y, Song C, He H, Lu Y. FBW7 is associated with prognosis, inhibits malignancies and enhances temozolomide sensitivity in glioblastoma cells. Cancer Sci 2018; 109:1001-1011. [PMID: 29427543 PMCID: PMC5891203 DOI: 10.1111/cas.13528] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/20/2018] [Accepted: 01/24/2018] [Indexed: 12/18/2022] Open
Abstract
F‐box and WD repeat domain‐containing 7 (FBW7) is a SCF‐type E3 ubiquitin ligase targeting a multitude of oncoproteins for degradation. Acting as one of the most important tumor suppressors, it is frequently inactivated in various tumors. In this study we aimed to evaluate the relationship of FBW7 with glioma pathology and prognosis, and examine its effect in glioma malignancies and temozolomide (TMZ)‐based therapy. Clinical tissues and TCGA database analysis revealed that FBW7 expression was correlated inversely with glioma histology and positively with patient survival time. Lentivirus transfection‐induced FBW7 overexpression significantly suppressed proliferation, invasion and migration of U251 and U373 cells, whereas knockdown of FBW7 by targeted shRNA promoted proliferation, invasion and migration of glioma cells. Most importantly, the expression level of FBW7 was found to affect the 50% inhibitory concentration (IC50) of U251 and the TMZ‐resistant variant. Combining TMZ with FBW7 overexpression notably increased the cytotoxicity compared to TMZ treatment alone, which was conversely attenuated by FBW7 knockdown. Moreover, flow cytometry (FC) analysis showed overexpression of FBW7, TMZ or the combination‐increased proportion of G2/M arrest and the apoptotic rate, whereas FBW7 inhibition reduced G2/M arrest and apoptosis in U251 cells. Finally, mechanistic study found that FBW7 overexpression downregulated Aurora B, Mcl1 and Notch1 levels in a time‐dependent pattern and this expressional suppression was independent of TMZ. These findings collectively demonstrate the critical role of FBW7 as a prognostic factor and a potential target to overcome chemoresistance of glioblastoma.
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Affiliation(s)
- Jing Lin
- Department of Neurosurgery, The 452 Hospital of Western Air Force, Chengdu, China
| | - Aihui Ji
- Department of Rehabilitation Medicine, Shandong Provincial Western Hospital, Jinan, China
| | - Guanzhong Qiu
- Department of Neurosurgery, General Hospital of Jinan Military Command, Jinan, China
| | - Huaizhi Feng
- Department of Nutrition, The 452 Hospital of Western Air Force, Chengdu, China
| | - Jian Li
- Department of Urology, The 452 Hospital of Western Air Force, Chengdu, China
| | - Shuo Li
- Department of Nutrition, The 452 Hospital of Western Air Force, Chengdu, China
| | - Yongxiang Zou
- Department of Neurosurgery, The 463 Hospital of People's Liberty Army, Shenyang, China
| | - Yong Cui
- Department of Neurosurgery, The 411 Hospital of People's Liberty Army, Shanghai, China
| | - Chaoli Song
- Department of Neurosurgery, The 452 Hospital of Western Air Force, Chengdu, China
| | - Hua He
- Department of Rehabilitation Medicine, Shandong Provincial Western Hospital, Jinan, China.,State key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Beijing, China
| | - Yicheng Lu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
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Othman N, Nagoor NH. miR-608 regulates apoptosis in human lung adenocarcinoma via regulation of AKT2. Int J Oncol 2017; 51:1757-1764. [PMID: 29075783 DOI: 10.3892/ijo.2017.4174] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/05/2017] [Indexed: 11/06/2022] Open
Abstract
Lung cancer remains a major health problem with a low 5-year survival rate of patients. Recent studies have shown that dysregulation of microRNAs (miRNAs) are prevalent in lung cancer and these aberrations play a significant role in the progression of tumour progression. In the present study, bioinformatics analyses was employed to predict potential miR-608 targets, which are associated with signaling pathways involved in cancer. Luciferase reporter assay identified AKT2 as a novel target of miR-608, and suppression of its protein levels was validated through western blot analysis. Zebrafish embryos were microinjected with cells transfected with miR-608 to elucidate the role of miR-608 in vivo, and immunostained with antibodies to detect activated caspase-3. We present the first evidence that miR-608 behaves as a tumour suppressor in A549 and SK-LU-1 cells through the regulation of AKT2, suggesting that selective targeting of AKT2 via miR-608 may be developed as a potential therapeutic strategy for miRNA-based non-small cell lung cancer (NSCLC) therapy.
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Affiliation(s)
- Norahayu Othman
- Institute of Biological Sciences (Genetics and Molecular Biology), Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Noor Hasima Nagoor
- Institute of Biological Sciences (Genetics and Molecular Biology), Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Ding Z, Xu F, Li G, Tang J, Tang Z, Jiang P, Wu H. Knockdown of Akt2 expression by shRNA inhibits proliferation, enhances apoptosis, and increases chemosensitivity to paclitaxel in human colorectal cancer cells. Cell Biochem Biophys 2016; 71:383-8. [PMID: 25134663 DOI: 10.1007/s12013-014-0209-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Akt2 overexpression correlates with chemoresistance of colorectal cancer (CRC). However, the cellular functions and precise signals elicited by Akt2 in LSCC have not been elucidated. Here, we transfected a CRC cell line HCT116 with Akt-2 targeted shRNA in order to establish a cell line with Akt2 knockdown. In vitro experiments showed that knockdown Akt2 in HCT116 cells was associated with decrease in cell proliferation as well as enhanced cell apoptosis. Furthermore, our results demonstrated that Akt2 knockdown correlated with elevated chemosensitivity of HCT116 cells to paclitaxel. Importantly, we found that knockdown of AKt2 resulted in downregulation of MDR-1 and MRP-1. Our findings may lead to a better understanding of the biological effect of Akt2 and may provide mechanistic insights for developing potential therapeutic strategies targeting AKt2.
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Affiliation(s)
- Zhongyang Ding
- Department of Surgery, Nanjing Medical University affiliated Wuxi People's Hospital, Wuxi, 214023, China
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Zhang C, Zhu Q, He H, Jiang L, Qiang Q, Hu L, Hu G, Jiang Y, Ding X, Lu Y. RIZ1: a potential tumor suppressor in glioma. BMC Cancer 2015; 15:990. [PMID: 26690953 PMCID: PMC4685634 DOI: 10.1186/s12885-015-2023-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 12/16/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Retinoblastoma protein-interacting zinc-finger gene 1 (RIZ1) displays strong tumor suppressive activities, and its expression is often silenced in many types of human tumors. However, the relationship between RIZ1 expression and glioma prognosis remains unclear. METHODS The dysregulation of RIZ1 was evaluated using real-time polymerase chain reaction, western blot, and immunohistochemical analysis of gliomas from 51 patients. Correlation analysis was performed to examine relationships between RIZ1 immunoreactivity, clinicopathological features, and patient prognosis. Also, human malignant glioma U87 and U251 cell lines were stably transduced with ectogenic RIZ1 using a lentiviral vector to investigate the effects of induced expression of RIZ1 on cell proliferation, cell cycle, and apoptosis. RESULTS Real-time polymerase chain reaction and western blot analysis showed that RIZ1 was downregulated in high-grade gliomas compared with low-grade gliomas and normal brain tissue. Immunohistochemistry showed less RIZ1 labeling in high-grade gliomas than in low-grade gliomas. There was a negative correlation between RIZ1 and Ki-67 immunoreactivity. Clinicopathological evaluation revealed that RIZ1 expression was negatively correlated with tumor grade and patient age. Kaplan-Meier survival analysis showed a positive correlation between RIZ1 immunoreactivity level and progression-free and overall survival times. Multivariate analysis showed that high RIZ1 expression was an independent prognostic factor for patients with gliomas. Induced expression of RIZ1 in U87 and U251 cells reduced cell proliferation and increased apoptosis, and cell cycle analysis revealed that a majority of cells were arrested at G2-M. Moreover, transfection with a RIZ1 expression vector increased p53 and caspase-3 expression and decreased p-IKBα and p-AKT protein levels, suggesting that RIZ1 may stimulate p53-mediated apoptosis and inhibit p-IKBα and p-AKT signaling pathways. CONCLUSIONS Our results suggest that high RIZ1 labeling is indicative of lower grades of gliomas and is associated with better progression-free and overall survival rates. Therefore, RIZ1 may be a promising therapeutic target for patients with gliomas.
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Affiliation(s)
- Chenran Zhang
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
| | - Qiubei Zhu
- Department of Otolaryngology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
| | - Hua He
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
| | - Lei Jiang
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
| | - Qiang Qiang
- Department of Neurology, Huadong Hospital, Fudan University, Shanghai, 200040, China.
| | - Liuhua Hu
- Department of Cardiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China.
| | - Guohan Hu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
| | - Ying Jiang
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
| | - Xuehua Ding
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
| | - Yicheng Lu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
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Cui Y, Lin J, Zuo J, Zhang L, Dong Y, Hu G, Luo C, Chen J, Lu Y. AKT2-knockdown suppressed viability with enhanced apoptosis, and attenuated chemoresistance to temozolomide of human glioblastoma cells in vitro and in vivo. Onco Targets Ther 2015; 8:1681-90. [PMID: 26185456 PMCID: PMC4501163 DOI: 10.2147/ott.s83795] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The AKT2 kinase (protein kinase Bβ) is overexpressed in high-grade gliomas. Upregulation of the AKT2 gene has been previously observed in glioblastoma patients suffering from chemotherapy failure and tumor progress. In this study, we aimed to evaluate the effect of AKT2 on viability and chemoresistance in the human glioblastoma cell line U251. The U251 cell line was stably transfected with short hairpin RNA (shRNA) targeting AKT2. U251 cells underexpressing AKT2 were then examined for viability with temozolomide (TMZ) treatment, and tested for cell apoptosis both in vitro and in tumor-implanted mice. Next, expressions of several chemoresistance-related molecules were measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and western blot analysis. The results showed that the 50% inhibitory concentration (IC50) of AKT2 shRNA-transfected cells was significantly lower compared with Lenti-GFP-transfected and nontransfected controls and that the tumor growth of the AKT2-shRNA and TMZ combined-treated mice was obviously suppressed in either mass or volume. Concomitantly, the apoptosis of TMZ-treated tumor cells was significantly enhanced after knockdown of AKT2, as measured by flow cytometry and in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. Furthermore, AKT2-inhibition in TMZ-treated glioblastoma U251 cells upregulated apoptotic effector caspase-3, whereas it downregulated antiapoptotic protein Bcl-2, DNA repairing protein MGMT, and drug efflux pump protein MRP1. Our study identified AKT2 as an important gene in presenting chemoresistance in glioblastoma, and a potential target to potentiate the clinical effect of chemotherapy in glioma treatment.
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Affiliation(s)
- Yong Cui
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Jing Lin
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Jianling Zuo
- Department of Neurosurgery, First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Lei Zhang
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Yan Dong
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Guohan Hu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Chun Luo
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Juxiang Chen
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
| | - Yicheng Lu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China
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let-7b and let-7c are determinants of intrinsic chemoresistance in renal cell carcinoma. World J Surg Oncol 2015; 13:175. [PMID: 25951903 PMCID: PMC4426556 DOI: 10.1186/s12957-015-0596-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 04/24/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Renal cell carcinoma (RCC) is characterized by inherent resistance to chemotherapy. Earlier studies demonstrated that microRNAs (miRNAs) might be involved in the chemosensitivity of cancers. MicroRNA let-7, a putative tumor suppressor, is dysregulated in many cancers. Our study aims to investigate the exact role of let-7 in chemotherapy sensitivity of 5-fluorouracil (5-FU) in RCC. METHODS The clinical significance of let-7b and let-7c expression in surgically resected specimens was assessed by qRT-PCR. Cell proliferation assay and colony formation assay were used to assess the survival of 786-O cells treated with let-7b or let-7c combined with 5-FU. Western blot was used to detect the expression of Akt2 and caspase-7. Luciferase assay was used to detect the direct binding of let-7b and let-7c to the 3'-untranslated region (UTR) of Akt2. RESULTS Expression of let-7b and let-7c was significantly decreased in 32 paired clear cell renal cell carcinoma tissue specimens and the dysregulation of let-7b was associated with pathological grade. Transfection of let-7b or let-7c combined with 5-FU inhibited proliferation and potentiated the antitumor efficacies of 5-FU at tolerated concentration. let-7b and let-7c suppressed the luciferase activity of reporter plasmid containing the 3'-UTR of Akt2. Overexpression of let-7b and let-7c reduced Akt2 expression, and Akt2 inhibition enhanced the sensitivity to 5-FU by affecting apoptotic pathway. CONCLUSIONS Expression of let-7b and let-7c was frequently decreased in clear cell renal cell carcinoma tissues. The dysregulation of let-7b and let-7c may be involved in chemoresistance of RCC cells to 5-FU by down-regulating Akt2.
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11
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Hu B, Emdad L, Bacolod MD, Kegelman TP, Shen XN, Alzubi MA, Das SK, Sarkar D, Fisher PB. Astrocyte elevated gene-1 interacts with Akt isoform 2 to control glioma growth, survival, and pathogenesis. Cancer Res 2014; 74:7321-32. [PMID: 25304263 DOI: 10.1158/0008-5472.can-13-2978] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The oncogene astrocyte elevated gene-1 (AEG-1; MTDH) is highly expressed in glioblastoma multiforme (GBM) and many other types of cancer, where it activates multiple signaling pathways that drive proliferation, invasion, angiogenesis, chemoresistance, radioresistance, and metastasis. AEG-1 activates the Akt signaling pathway and Akt and c-Myc are positive regulators of AEG-1 transcription, generating a positive feedback loop between AEG-1 and Akt in regulating tumorigenesis. Here, we describe in GBM cells a direct interaction between an internal domain of AEG-1 and the PH domain of Akt2, a major driver in GBM. Expression and interaction of AEG-1 and Akt2 are elevated in GBM and contribute to tumor cell survival, proliferation, and invasion. Clinically, in silico gene expression and immunohistochemical analyses of patient specimens showed that AEG-1 and Akt2 expression correlated with GBM progression and reduced patient survival. AEG-1-Akt2 interaction prolonged stabilization of Akt2 phosphorylation at S474, regulating downstream signaling cascades that enable cell proliferation and survival. Disrupting AEG-1-Akt2 interaction by competitive binding of the Akt2-PH domain led to reduced cell viability and invasion. When combined with AEG-1 silencing, conditional expression of Akt2-PH markedly increased survival in an orthotopic mouse model of human GBM. Our study uncovers a novel molecular mechanism by which AEG-1 augments glioma progression and offers a rationale to block AEG-1-Akt2 signaling function as a novel GBM treatment.
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Affiliation(s)
- Bin Hu
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia
| | - Luni Emdad
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia. VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, Virginia. VCU Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, Virginia
| | - Manny D Bacolod
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia. VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, Virginia
| | - Timothy P Kegelman
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia
| | - Xue-Ning Shen
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia
| | - Mohammad A Alzubi
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia
| | - Swadesh K Das
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia. VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, Virginia
| | - Devanand Sarkar
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia. VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, Virginia. VCU Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, Virginia
| | - Paul B Fisher
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, Virginia. VCU Institute of Molecular Medicine, Virginia Commonwealth University, School of Medicine, Richmond, Virginia. VCU Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, Virginia.
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12
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Kang W, Tong JHM, Lung RWM, Dong Y, Yang W, Pan Y, Lau KM, Yu J, Cheng AS, To KF. let-7b/g silencing activates AKT signaling to promote gastric carcinogenesis. J Transl Med 2014; 12:281. [PMID: 25288334 PMCID: PMC4196013 DOI: 10.1186/s12967-014-0281-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 09/24/2014] [Indexed: 12/13/2022] Open
Abstract
Background Aberrant AKT activation contributes to gastric cancer cell survival and chemotherapy resistance, however its regulation is poorly understood. microRNAs have been established to be important regulators in gastric carcinogenesis. Here, we showed the functional role and putative target of let-7b and let-7g (let-7b/g) in gastric carcinogenesis. Methods The expression of let-7b/g in gastric cancer cell lines and primary tumors were evaluated by miRNA qRT-PCR. The putative target gene of let-7b/g was explored by TargetScan followed by further validation. Functional analyses including MTT proliferation, monolayer colony formation, cell invasion assays and in vivo study were performed in both ectopic expression and knockdown approaches. Results let-7b/g was found down-regulated in gastric cancer and its downregulation was associated with poor survival and correlated with lymph node metastasis. let-7b/g inhibited AKT2 expression by directly binding to its 3’UTR, reduced p-AKT (S473) activation and suppressed expression of the downstream effector pS6. AKT2 mRNA expression showed negative correlation with the expression of let-7b/g in primary tumors. Short interfering RNA (siRNA) mediated knockdown of AKT2 phenocopied the tumor-suppressive effects of let-7b/g. Moreover, AKT2 re-expression partly abrogated the growth-inhibitory effect of let-7b/g. Conclusion In conclusion, our findings reveal decreased let-7b/g contributes to aberrant AKT activation in gastric tumorigenesis and provide a potential therapeutic strategy for gastric cancer. Electronic supplementary material The online version of this article (doi:10.1186/s12967-014-0281-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Ka Fai To
- Department of Anatomical and Cellular Pathology, State Key Laboratory in Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, People's Republic of China.
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13
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Elkady AI, Hussein RAEH, Abu-Zinadah OA. Effects of crude extracts from medicinal herbs Rhazya stricta and Zingiber officinale on growth and proliferation of human brain cancer cell line in vitro. BIOMED RESEARCH INTERNATIONAL 2014; 2014:260210. [PMID: 25136570 PMCID: PMC4130191 DOI: 10.1155/2014/260210] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 06/12/2014] [Accepted: 06/13/2014] [Indexed: 12/18/2022]
Abstract
Hitherto, limited clinical impact has been achieved in the treatment of glioblastoma (GBMs). Although phytochemicals found in medicinal herbs can provide mankind with new therapeutic remedies, single agent intervention has failed to bring the expected outcome in clinical trials. Therefore, combinations of several agents at once are gaining increasing attractiveness. In the present study, we investigated the effects of crude alkaloid (CAERS) and flavonoid (CFEZO) extracts prepared from medicinal herbs, Rhazya stricta and Zingiber officinale, respectively, on the growth of human GBM cell line, U251. R. stricta and Z. officinale are traditionally used in folkloric medicine and have antioxidant, anticarcinogenic, and free radical scavenging properties. Combination of CAERS and CFEZO treatments synergistically suppressed proliferation and colony formation and effectively induced morphological and biochemical features of apoptosis in U251 cells. Apoptosis induction was mediated by release of mitochondrial cytochrome c, increased Bax : Bcl-2 ratio, enhanced activities of caspase-3 and -9, and PARP-1 cleavage. CAERS and CFEZO treatments decreased expression levels of nuclear NF-κBp65, survivin, XIAP, and cyclin D1 and increased expression level of p53, p21, and Noxa. These results suggest that combination of CAERS and CFEZO provides a useful foundation for studying and developing novel chemotherapeutic agents for the treatment of GBM.
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Affiliation(s)
- Ayman I. Elkady
- Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Zoology Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Rania Abd El Hamid Hussein
- Department of Clinical Nutrition, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Gamal Abd El Nasser Hospital, Alexandria, Egypt
| | - Osama A. Abu-Zinadah
- Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
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14
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Chin YR, Yuan X, Balk SP, Toker A. PTEN-deficient tumors depend on AKT2 for maintenance and survival. Cancer Discov 2014; 4:942-55. [PMID: 24838891 DOI: 10.1158/2159-8290.cd-13-0873] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
UNLABELLED Loss of PTEN is a common event in many cancers and leads to hyperactivation of the PI3K-AKT signaling pathway. The mechanisms by which AKT isoforms mediate signaling to phenotypes associated with PTEN inactivation in cancer have not been defined. Here, we show that AKT2 is exclusively required for PTEN-deficient prostate tumor spheroid maintenance, whereas AKT1 is dispensable. shRNA silencing of AKT2 but not AKT1 promotes regression of prostate cancer xenografts. Mechanistically, we show that AKT2 silencing upregulates p21 and the proapoptotic protein BAX and downregulates the insulin-like growth factor receptor-1. We also show that p21 is an effector of AKT2 in mediating prostate tumor maintenance. Moreover, AKT2 is also exclusively required for the maintenance and survival of other PTEN-deficient solid tumors, including breast cancer and glioblastoma. These findings identify a specific function for AKT2 in mediating survival of PTEN-deficient tumors and provide a rationale for developing therapeutics targeting AKT2. SIGNIFICANCE Depletion of AKT2, but not AKT1, induces potent tumor regression in PTEN-deficient prostate cancer xenografts, concomitant with upregulation of p21, which may serve as a potential biomarker for screening AKT2 activity in clinical samples. The specific role of AKT2 in tumor maintenance provides a rationale for the development of isoform-specific inhibitors for patients with PTEN-deficient cancers.
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Affiliation(s)
| | - Xin Yuan
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Steven P Balk
- Hematology-Oncology Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
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15
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Liu B, Pang B, Hou X, Fan H, Liang N, Zheng S, Feng B, Liu W, Guo H, Xu S, Pang Q. Expression of high-mobility group AT-hook protein 2 and its prognostic significance in malignant gliomas. Hum Pathol 2014; 45:1752-8. [PMID: 24935062 DOI: 10.1016/j.humpath.2014.02.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 01/29/2014] [Accepted: 02/07/2014] [Indexed: 10/25/2022]
Abstract
High-mobility group AT-hook protein 2 (HMGA2) is an architectural transcription factor associated with malignancy, invasiveness, and poor prognosis in a variety of human neoplasms. This study investigated HMGA2 expression and prognostic value in human gliomas. We also correlated HMGA2 expression with Ki-67 labeling index and matrix metalloproteinase-2. Expression of HMGA2 in 78 human gliomas and 7 human normal brain samples was studied using immunohistochemistry, and 29 gliomas were randomly selected and studied along with the normal brain by real-time quantitative polymerase chain reaction and Western blot analysis. Expression of HMGA2 protein was significantly higher in glioblastoma multiforme (World Health Organization [WHO] grade IV; P = .007) and anaplastic astrocytoma (WHO grade III; P = .037) than in diffuse astrocytoma (WHO grade II). Expression of HMGA2 correlated significantly with expression of Ki-67 (r = 0.415, P < .01) and matrix metalloproteinase-2 (r = 0.363, P < .01), but not with patient sex and age. The real-time quantitative polymerase chain reaction and Western blot analysis revealed similar results. Patients with tumors expressing HMGA2 at a higher level had a significantly shorter progression-free survival time (11.2 months versus 18.8 months; P = .021). Expression of HMGA2 significantly correlates with tumor cell proliferation, invasion, and survival in gliomas. The results suggest that HMGA2 has an important role in the treatment and prognosis of these cancers.
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Affiliation(s)
- Bin Liu
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China; Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto 606-8527, Japan
| | - Bo Pang
- Department of Neurosurgery, Qilu Hospital of Shandong University, Jinan, Shandong 250021, People's Republic of China
| | - Xianzeng Hou
- Department of Neurosurgery, Qianfoshan Hospital of Shandong University, Jinan, Shandong 250021, People's Republic of China
| | - Haitao Fan
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China
| | - Nan Liang
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China
| | - Shuai Zheng
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China
| | - Bin Feng
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China
| | - Wei Liu
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China
| | - Hua Guo
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China
| | - Shangchen Xu
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China.
| | - Qi Pang
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, People's Republic of China.
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16
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Wang Q, Fan SY, Qian J, Wang JY, Lu YC, Hu GH, Luo C. AKT2 expression in histopathologic grading and recurrence of meningiomas. EUROPEAN JOURNAL OF SURGICAL ONCOLOGY 2014; 40:1056-61. [PMID: 24656454 DOI: 10.1016/j.ejso.2014.02.243] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 01/30/2014] [Accepted: 02/28/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND AKT2 (protein kinase B), an important protein in PI3K signaling pathway, is overexpressed in a variety of malignant tumors. However, in patients with meningiomas, the potential correlation between AKT2 and clinical outcome remains unknown. METHODS The expression of AKT2 and Ki-67 in meningioma tissues were evaluated immunohistochemically in 94 patients with meningiomas. The correlation of AKT2 immunoreactivity with clinicopathological features and the prognostic value of AKT2 in patients were also analyzed. RESULTS In this study, we examined the expression of AKT2 in meningiomas and unveiled its possible relationship with the clinical outcome. Immunohistochemical analysis revealed high AKT2 expression in 46 patients (46/94, 48.9%) and low AKT2 expression in the remaining 48 patients (48/94, 51.1%). There was a positive correlation between AKT2 and Ki-67 immunoreactivity (r = 0.35, P = 0.01). Clinicopathological evaluation suggested that AKT2 expression was associated with pathological grade and recurrence (P < 0.05). Univariate and Cox analysis indicated a significant correlation between high levels of AKT2 immunoreactivity and high rates of tumor recurrence (P < 0.05). CONCLUSIONS We conclude that AKT2 may play an important role in the development of meningioma. High AKT2 labeling index indicates higher grade of meningioma, and therefore AKT2 may be a useful molecular marker for predicting the prognosis of meningioma.
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Affiliation(s)
- Q Wang
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai 200003, China; Department of Neurosurgery, PLA No. 322 Hospital, 2 Yunzhong Road, Shanxi 037000, China
| | - S-Y Fan
- Department of Neurosurgery, PLA No. 322 Hospital, 2 Yunzhong Road, Shanxi 037000, China
| | - J Qian
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai 200003, China
| | - J-Y Wang
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai 200003, China
| | - Y-C Lu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai 200003, China.
| | - G-H Hu
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai 200003, China
| | - C Luo
- Department of Neurosurgery, Changzheng Hospital, Second Military Medical University, 415 Fengyang Road, Shanghai 200003, China
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17
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Chautard E, Ouédraogo ZG, Biau J, Verrelle P. Role of Akt in human malignant glioma: from oncogenesis to tumor aggressiveness. J Neurooncol 2014; 117:205-15. [PMID: 24477623 DOI: 10.1007/s11060-014-1382-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 01/19/2014] [Indexed: 12/21/2022]
Abstract
Gathering evidence has revealed that Akt signaling pathway plays an important role in glioma progression and aggressiveness. Among Akt kinases the most studied, Akt1, has been involved in many cellular processes that are in favor of cell malignancy. More recently, the actions of the two other isoforms, Akt2 and Akt3 have emerged in glioma. After a description of Akt pathway activation, we will explore the role of each isoform in malignant glioma that strengthens the current preclinical and clinical studies evaluating the impact of Akt pathway targeting in glioblastomas.
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Affiliation(s)
- Emmanuel Chautard
- Clermont Université, Université d'Auvergne, EA7283 CREaT, 28 Place Henri Dunant, 63000, Clermont-Ferrand, France,
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18
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Tamim S, Vo DT, Uren PJ, Qiao M, Bindewald E, Kasprzak WK, Shapiro BA, Nakaya HI, Burns SC, Araujo PR, Nakano I, Radek AJ, Kuersten S, Smith AD, Penalva LOF. Genomic analyses reveal broad impact of miR-137 on genes associated with malignant transformation and neuronal differentiation in glioblastoma cells. PLoS One 2014; 9:e85591. [PMID: 24465609 PMCID: PMC3899048 DOI: 10.1371/journal.pone.0085591] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 12/05/2013] [Indexed: 02/05/2023] Open
Abstract
miR-137 plays critical roles in the nervous system and tumor development; an increase in its expression is required for neuronal differentiation while its reduction is implicated in gliomagenesis. To evaluate the potential of miR-137 in glioblastoma therapy, we conducted genome-wide target mapping in glioblastoma cells by measuring the level of association between PABP and mRNAs in cells transfected with miR-137 mimics vs. controls via RIPSeq. Impact on mRNA levels was also measured by RNASeq. By combining the results of both experimental approaches, 1468 genes were found to be negatively impacted by miR-137--among them, 595 (40%) contain miR-137 predicted sites. The most relevant targets include oncogenic proteins and key players in neurogenesis like c-KIT, YBX1, AKT2, CDC42, CDK6 and TGFβ2. Interestingly, we observed that several identified miR-137 targets are also predicted to be regulated by miR-124, miR-128 and miR-7, which are equally implicated in neuronal differentiation and gliomagenesis. We suggest that the concomitant increase of these four miRNAs in neuronal stem cells or their repression in tumor cells could produce a robust regulatory effect with major consequences to neuronal differentiation and tumorigenesis.
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Affiliation(s)
- Saleh Tamim
- Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Dat T. Vo
- Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Philip J. Uren
- Molecular and Computational Biology Section, Division of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Mei Qiao
- Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Eckart Bindewald
- Basic Science Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Wojciech K. Kasprzak
- Basic Science Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Bruce A. Shapiro
- Center for Cancer Research Nanobiology Program, National Cancer Institute, Frederick, Maryland, California
| | - Helder I. Nakaya
- Department of Clinical Analyses and Toxicology, Institute of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Suzanne C. Burns
- Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Patricia R. Araujo
- Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Ichiro Nakano
- Department of Neurological Surgery, James Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, United States of America
| | - Agnes J. Radek
- Epicentre (An Illumina Company), Madison, Wisconsin, United States of America
| | - Scott Kuersten
- Epicentre (An Illumina Company), Madison, Wisconsin, United States of America
| | - Andrew D. Smith
- Molecular and Computational Biology Section, Division of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Luiz O. F. Penalva
- Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
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19
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Rensing KL, de Jager SC, Stroes ES, Vos M, Twickler MT, Dallinga-Thie GM, de Vries CJ, Kuiper J, Bot I, von der Thüsen JH. Akt2/LDLr double knockout mice display impaired glucose tolerance and develop more complex atherosclerotic plaques than LDLr knockout mice. Cardiovasc Res 2013; 101:277-87. [DOI: 10.1093/cvr/cvt252] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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20
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RNA interference--a silent but an efficient therapeutic tool. Appl Biochem Biotechnol 2013; 169:1774-89. [PMID: 23340870 DOI: 10.1007/s12010-013-0098-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/10/2013] [Indexed: 12/12/2022]
Abstract
RNA interference (RNAi) is an evolutionary conserved gene regulation pathway that has emerged as an important discovery in the field of molecular biology. One of the important advantages of RNAi in therapy is that it brings about efficient downregulation of gene expression by targeting complementary transcripts in comparison with other antisense-based techniques. RNAi can be can be achieved by introducing chemically synthesized small interfering RNAs (siRNAs) into a cell system. A more stable knockdown effect can be brought about by the use of plasmid or viral vectors encoding the siRNA. RNAi has been used in reverse genetics to understand the function of specific genes and also as a therapeutic tool in treating human diseases. This review provides a brief insight into the therapeutic applications of RNAi against debilitating diseases.
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