scholarly journals A novel antisense long noncoding RNA within the IGF1R gene locus is imprinted in hematopoietic malignancies

2014 ◽  
Vol 42 (15) ◽  
pp. 9588-9601 ◽  
Author(s):  
Jingnan Sun ◽  
Wei Li ◽  
Yunpeng Sun ◽  
Dehai Yu ◽  
Xue Wen ◽  
...  

AbstractDysregulation of the insulin-like growth factor type I receptor (IGF1R) has been implicated in the progression and therapeutic resistance of malignancies. In acute myeloid leukemia (AML) cells, IGF1R is one of the most abundantly phosphorylated receptor tyrosine kinases, promoting cell growth through the PI3K/Akt signaling pathway. However, little is known regarding the molecular mechanisms underlying IGF1R gene dysregulation in cancer. We discovered a novel intragenic long noncoding RNA (lncRNA) within the IGF1R locus, named IRAIN, which is transcribed in an antisense direction from an intronic promoter. The IRAIN lncRNA was expressed exclusively from the paternal allele, with the maternal counterpart being silenced. Using both reverse transcription-associated trap and chromatin conformation capture assays, we demonstrate that this lncRNA interacts with chromatin DNA and is involved in the formation of an intrachromosomal enhancer/promoter loop. Knockdown of IRAIN lncRNA with shRNA abolishes this intrachromosomal interaction. In addition, IRAIN was downregulated both in leukemia cell lines and in blood obtained from high-risk AML patients. These data identify IRAIN as a new imprinted lncRNA that is involved in long-range DNA interactions.

2012 ◽  
Vol 443 (3) ◽  
pp. 627-634 ◽  
Author(s):  
Xin Lin ◽  
Xin Li ◽  
Ming Jiang ◽  
Linhai Chen ◽  
Chanjuan Xu ◽  
...  

Many GPCRs (G-protein-coupled receptors) can activate RTKs (receptor tyrosine kinases) in the absence of RTK ligands, a phenomenon called transactivation. However, the underlying molecular mechanisms remain undefined. In the present study we investigate the molecular basis of GABAB (γ-aminobutyric acid B) receptor-mediated transactivation of IGF-1R (insulin-like growth factor type I receptor) in primary neurons. We take a chemical biology approach by developing an activity-based probe targeting the GABAB receptor. This probe enables us first to lock the GABAB receptor in an inactive state and then activate it with a positive allosteric modulator, thereby permitting monitoring of the dynamic of the protein complex associated with IGF-1R transactivation. We find that activation of the GABAB receptor induces a dynamic assembly and disassembly of a protein complex, including both receptors and their downstream effectors. FAK (focal adhesion kinase), a non-RTK, plays a key role in co-ordinating this dynamic process. Importantly, this dynamic of the GABAB receptor-associated complex is critical for transactivation and transactivation-dependent neuronal survival. The present study has identified an important mechanism underlying GPCR transactivation of RTKs, which was enabled by a new chemical biology tool generally applicable for dissecting GPCR signalling.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3592-3592
Author(s):  
Jingnan Sun ◽  
Jifan Hu ◽  
Wei Li ◽  
Yunpeng SUN

Abstract Background:In acute myeloid leukemia (AML) cells, the insulin-like growth factor type I receptor (IGF1R) is one of the most abundantly phosphorylated receptor tyrosine kinases, promoting cell growth and therapeutic resistance through the PI3K/Akt signaling pathway. However, little is known regarding the molecular mechanisms underlying IGF1R gene dysregulation in AML. Long non-coding RNAs have been implicated in a variety of important biological processes by epigenetic mechanisms. Materials and methods:AML cell lines used in this study, KG-1, KG-1a were purchased from ATCC. The full length of IRAIN lncRNA was characterized by Marathon cDNA Amplification Kit. For qPCR, cDNA samples were amplified using CFX96TM real-time system (BIO-RAD) by SYBR PrimeScript™ RT-PCR Kit (TaKaRa). Both reverse transcription-associated trap (RAT) and chromatin conformation capture (3C) assays were used to examine the chromosome architecture of IGF1R and DNA-RNA interaction. The protocol of AMLpatients bone marrow and peripheral blood cell samples was approved by the Human Medical Ethical Review Committee from Jilin University First Hospital and informed consent was obtained from each AML patient and normal donor. Results: 1. we discovered a novel intragenic 5366bp long noncoding RNA (lncRNA) within the IGF1R locus, named IRAIN, which is transcribed in an antisense direction from an intronic promoter. 2. we demonstrated IRAIN was expressed exclusively from the paternal allele, with the maternal counterpart being silenced in normal donor and AML patients. 3. we confirmed that IRAIN interacts with IGF1R chromatin DNA and is involved in the formation of an intrachromosomal enhancer/promoter loop. Knockdown of IRAIN lncRNA with shRNA abolishes this intrachromosomal interaction. 4. We demonstrated IRAIN was downregulated both in AML cell lines and high risk AML patients. Furthermore,the expression of IRAIN was dramatical higher in APL patients achieved molecular remission. Conclusion:Our results identify IRAIN as a new imprinted suppressive lncRNA involved in long range IGF1R DNA interactions in AML. As a putative tumor suppressor and a novel treatment target, further studies are needed to delineate the specific role of this newly identified lncRNA in the uregulation of the IGF pathway in AML. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Liang Liang ◽  
Wenbin Gu ◽  
Meng Li ◽  
Ran Gao ◽  
Xin Zhang ◽  
...  

AbstractAcquired resistance to glucocorticoids (GCs) is an obstacle to the effective treatment of leukemia, but the molecular mechanisms of steroid insensitivity have not been fully elucidated. In this study, we established an acquired GC-resistant leukemia cell model and found a long noncoding RNA, HOTAIRM1, was overexpressed in the resistant cells by transcriptional profiling, and was higher expressed in patients with poor prognosis. The whole-genome-binding sites of HOTAIRM1 were determined by ChIRP-seq (chromatin isolation by RNA purification combined with sequencing) analysis. Further study determined that HOTAIRM1 bound to the transcriptional inhibitory region of ARHGAP18 and repressed the expression of ARHGAP18, which led to the increase of RHOA/ROCK1 signaling pathway and promoted GC resistance through antiapoptosis of leukemia cells. The inhibition of ROCK1 in GC-resistant cells could restore GCs responsiveness. In addition, HOTAIRM1 could also act as a protein sequester to prevent transcription factor AML1(acute myeloid leukemia 1) from binding to the regulatory region of ARHGAP18 by interacting with AML1. At last, we also proved AML1 could directly activate the expression of HOTAIRM1 through binding to the promoter of HOTAIRM1, which enriched the knowledge on the regulation of lncRNAs. This study revealed epigenetic causes of glucocorticoid resistance from the perspective of lncRNA, and laid a foundation for the optimization of glucocorticoid-based leukemia treatment strategy in clinic.


Endocrinology ◽  
2021 ◽  
Vol 162 (11) ◽  
Author(s):  
Tsai-Der Chuang ◽  
Derek Quintanilla ◽  
Drake Boos ◽  
Omid Khorram

Abstract The objective of this study was to determine the expression and functional role of a long noncoding RNA (lncRNA) MIAT (myocardial infarction–associated transcript) in leiomyoma pathogenesis. Leiomyoma compared with myometrium (n = 66) expressed significantly more MIAT that was independent of race/ethnicity and menstrual cycle phase but dependent on MED12 (mediator complex subunit 12) mutation status. Leiomyomas bearing the MED12 mutation expressed higher levels of MIAT and lower levels of microRNA 29 family (miR-29a, -b, and -c) compared with MED12 wild-type leiomyomas. Using luciferase reporter activity and RNA immunoprecipitation analysis, MIAT was shown to sponge the miR-29 family. In a 3-dimensional spheroid culture system, transient transfection of MIAT siRNA in leiomyoma smooth muscle cell (LSMC) spheroids resulted in upregulation of miR-29 family and downregulation of miR-29 targets, collagen type I (COL1A1), collagen type III (COL3A1), and TGF-β3 (transforming growth factor β-3). Treatment of LSMC spheroids with TGF-β3 induced COL1A1, COL3A1, and MIAT levels, but repressed miR-29 family expression. Knockdown of MIAT in LSMC spheroids blocked the effects of TGF-β3 on the induction of COL1A1 and COL3A1 expression. Collectively, these results underscore the physiological significance of MIAT in extracellular matrix accumulation in leiomyoma.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yuhua He ◽  
Shuifang Xu ◽  
Yi Qi ◽  
Jinfang Tian ◽  
Fengying Xu

Abstract Background Small nucleolar RNA host gene 25 (SNHG25), a long noncoding RNA, has been well-studied in epithelial ovarian cancer. However, the specific functions of SNHG25 in endometrial cancer (EC) have not been studied yet. In this study, we aimed to elucidate the clinical significance of SNHG25 in EC and determine the regulatory activity of SNHG25 on the tumor-associated EC phenotype. We also thoroughly explored the molecular mechanisms underlying SNHG25 function in EC. Methods Gene expression was measured using quantitative real-time polymerase chain reaction. The detailed functions of SNHG25 in EC were examined by performing loss-of-function experiments. Moreover, the regulatory mechanisms involving SNHG25, microRNA-497-5p, and fatty acid synthase (FASN) were unveiled using the luciferase reporter assay and RNA immunoprecipitation. Results We observed a high level of SNHG25 in EC using the TCGA dataset and our study cohort. Patients with a high SNHG25 level had shorter overall survival than those with a low SNHG25 level. SNHG25 deficiency resulted in tumor-repressing activities in EC cells by decreasing cell proliferation, migration, and invasion and promoting cell apoptosis. Furthermore, the function of SNHG25 depletion in impairing tumor growth in vivo was confirmed. SNHG25 sequestered miR-497-5p as a competing endogenous RNA in EC and consequently positively regulated FASN expression. Thus, the decrease in miR-497-5p or increase in FASN could neutralize the modulatory actions of SNHG25 knockdown in EC cells. Conclusions The depletion of SNHG25 impedes the oncogenicity of EC by targeting the miR-497-5p/FASN axis. The newly elucidated SNHG25/miR-497-5p/FASN pathway may be a promising target for the molecular-targeted management of EC.


2021 ◽  
Author(s):  
hafiza sobia ramzan ◽  
Kashif Aziz Ahmad

Background: Osteoarthritis (OA) is a common disease of the joints among old populace until today. The treatment possibilities and roles of miRNA and long non-coding RNA (lncRNA) in therapy of OA has previously been explored. However, the functional roles of Long noncoding RNA KCNQ1OT1 and miRNA let-7a-5p on Osteoarthritis development and progression remains unclear. This study aimed at investigating the influence of KCNQ1OT1 on let-7a-5p in moderation of OA development and advancement. Materials and Methods: RT-qPCR examined expression of KCNQ1OT1and let-7a-5p in cultured human primary chondrocyte cell lines. Cell transfection overexpressed or knocked down the genes and CCK-8 assay measured cell viability in the proliferation biomarkers Ki87 and PCNA. While caspase-8 and caspase-3 activity determined rate of apoptosis. Furthermore, luciferase assay analyzed the luciferase activity and western blotting analysis determined the protein expression of KCNQ1OT1 and let-7a-5p in proliferation and apoptosis biomarkers. Results: The results demonstrated that KCNQ1OT1 is upregulated in OA-mimic cells and promotes the cell viability. KCNQ1OT1 knockdown suppresses cell viability of OA cells. Furthermore KCNQ1OT1 directly binds the 3'-UTR of let-7a-5p to negatively regulate let-7a-5p expression and OA progression. While upregulated let-7a-5p abolishes the proliferation effect of KCNQ1OT1 in OA cells. Conclusion: In summary, our study provides further insights into the underlying molecular mechanisms of KCNQ1OT1 and let-7a-5p suggesting a novel therapeutic approach to OA


2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Baiyao Wang ◽  
Jieling Zheng ◽  
Rong Li ◽  
Yunhong Tian ◽  
Jie Lin ◽  
...  

Abstract Radiotherapy is essential to treat breast cancer and microRNA (miRNA) miR-200c is considered as a radiosensitizer of breast cancer. However, the molecular mechanisms by which miR-200c regulates radiosensitivity remain largely unknown. In the present study, we showed that induction of miR-200c led to widespread alteration in long noncoding RNA (lncRNA) expression in breast cancer cells. We identified lncRNA LINC02582 as a target of miR-200c. Inhibition of LINC02582 expression increased radiosensitvity, while overexpression of LINC02582 promoted radioresistance. Mechanistically, LINC02582 interacts with deubiquitinating enzyme ubiquitin specific peptidase 7 (USP7) to deubiquitinate and stabilize checkpoint kinase 1 (CHK1), a critical effector kinase in DNA damage response, thus promoting radioresistance. Furthermore, we detected an inverse correlation between the expression of miR-200c vs. LINC02582 and CHK1 in breast cancer samples. These findings identified LINC02582 as a downstream target of miR-200c linking miR-200c to CHK1, in which miR-200c increases radiosensitivity by downregulation of CHK1.


Author(s):  
Hengzhou Lin ◽  
Dahui Zuo ◽  
Jiabin He ◽  
Tao Ji ◽  
Jianzhong Wang ◽  
...  

The long noncoding RNA WEE2 antisense RNA 1 (WEE2-AS1) plays anoncogenic role in hepatocellular carcinoma and triple negative breast cancerprogression. In this study, we investigated the expression and roles of WEE2-AS1 inglioblastoma (GBM). Furthermore, the molecular mechanisms behind the oncogenicactions of WEE2-AS1 in GBM cells were explored in detail. WEE2-AS1 expressionwas detected using quantitative real-time polymerase chain reaction. The roles ofWEE2-AS1 in GBM cells were evaluated by the Cell Counting Kit-8 assay, flowcytometric analysis, and Transwell cell migration and invasion assays, and tumorxenograft experiments. WEE2-AS1 expression was evidently enhanced in GBM tissuesand cell lines compared with their normal counterparts. An increased level of WEE2-AS1 was correlated with the average tumor diameter, Karnofsky Performance Scalescore, and shorter overall survival among GBM patients. Functionally, depleted WEE2-AS1 attenuated GBM cell proliferation, migration, and invasion in vitro, promoted cellapoptosis, and impaired tumor growth in vivo. Mechanistically, WEE2-AS1 functionedas a molecular sponge for microRNA-520f-3p (miR-520f-3p) and consequentlyincreased specificity protein 1 (SP1) expression in GBM cells. A series of recoveryexperiments revealed that the inhibition of miR-520f-3p and upregulation of SP1 couldpartially abrogate the influences of WEE2-AS1 downregulation on GBM cells. Inconclusion, WEE2-AS1 can adsorb miR-520f-3p to increase endogenous SP1expression, thereby facilitating the malignancy of GBM. Therefore, targeting theWEE2-AS1-miR-520f-3p-SP1 pathway might be a promising therapy for themanagement of GBM in the future.


Author(s):  
Tatsuya Aonuma ◽  
Bruno Moukette ◽  
Satoshi Kawaguchi ◽  
Nipuni P. Barupala ◽  
Marisa N. Sepúlveda ◽  
...  

Background: MicroRNA-150 (miR-150) plays a protective role in heart failure (HF). Long noncoding RNA, myocardial infarction–associated transcript (MIAT) regulates miR-150 function in vitro by direct interaction. Concurrent with miR-150 downregulation, MIAT is upregulated in failing hearts, and gain-of-function single-nucleotide polymorphisms in MIAT are associated with increased risk of myocardial infarction (MI) in humans. Despite the correlative relationship between MIAT and miR-150 in HF, their in vivo functional relationship has never been established, and molecular mechanisms by which these 2 noncoding RNAs regulate cardiac protection remain elusive. Methods: We use MIAT KO (knockout), Hoxa4 (homeobox a4) KO, MIAT TG (transgenic), and miR-150 TG mice. We also develop DTG (double TG) mice overexpressing MIAT and miR-150. We then use a mouse model of MI followed by cardiac functional, structural, and mechanistic studies by echocardiography, immunohistochemistry, transcriptome profiling, Western blotting, and quantitative real-time reverse transcription-polymerase chain reaction. Moreover, we perform expression analyses in hearts from patients with HF. Lastly, we investigate cardiac fibroblast activation using primary adult human cardiac fibroblasts and in vitro assays to define the conserved MIAT/miR-150/HOXA4 axis. Results: Using novel mouse models, we demonstrate that genetic overexpression of MIAT worsens cardiac remodeling, while genetic deletion of MIAT protects hearts against MI. Importantly, miR-150 overexpression attenuates the detrimental post-MI effects caused by MIAT. Genome-wide transcriptomic analysis of MIAT null mouse hearts identifies Hoxa4 as a novel downstream target of the MIAT/miR-150 axis. Hoxa4 is upregulated in cardiac fibroblasts isolated from ischemic myocardium and subjected to hypoxia/reoxygenation. HOXA4 is also upregulated in patients with HF. Moreover, Hoxa4 deficiency in mice protects the heart from MI. Lastly, protective actions of cardiac fibroblast miR-150 are partially attributed to the direct and functional repression of profibrotic Hoxa4 . Conclusions: Our findings delineate a pivotal functional interaction among MIAT, miR-150, and Hoxa4 as a novel regulatory mechanism pertinent to ischemic HF.


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