scholarly journals LncRNA GAS5 Inhibits Temozolomide Chemoresistance to Glioma Via Inactivating Wnt/β-Catenin Pathway by Interacting with PTBP1

2021 ◽  
Author(s):  
Xin He ◽  
Jie Sheng ◽  
Yingxi Chen ◽  
Xuan Long ◽  
Wei Yu ◽  
...  
Keyword(s):  
Therapeutic Strategy ◽  
Rna Binding ◽  
Regulatory Mechanism ◽  
Binding Protein ◽  
Polypyrimidine Tract Binding Protein ◽  
Novel Approach ◽  
Non Coding Rna ◽  
Apoptosis Assay ◽  
Long Non Coding Rna

Abstract Purpose Temozolomide-based therapeutic resistance has become the crucial cause of chemotherapy failure in glioma treatment. Long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5) is reported to be downregulated in glioma and to inhibit tumor progression and metastasis. This study aimed to investigate function and potential regulatory mechanism of GAS5 in temozolomide (TMZ) chemoresistance to glioma.Methods qRT-PCR, western blotting and immunofluorescence were used to measure the levels of GAS5 and proteins. RNA-binding protein immunoprecipitation assay was used to analyze the interaction between GAS5 and PTBP1. Flow cytometry apoptosis assay, CCK-8 assay, colony formation assay and nude mice xenograft experiments were used to detect the effects of GAS5 on TMZ resistance in glioma.Results Downregulation of GAS5 might predict a poor prognosis in glioma patients. Overexpression of GAS5 improves the sensitivity to TMZ in glioma cells. Mechanistically, GAS5 could interact with polypyrimidine tract binding protein 1 (PTBP1) to downregulate its expression, thereby inactivating the Wnt/β-catenin pathway. Moreover, GAS5 could increase the anti-tumor effect of TMZ in vivo. Conclusion This study indicated that GAS5 contributed to TMZ chemoresistance of glioma through interacting with PTBP1, and then inhibiting Wnt/β-catenin pathway, which provides a novel approach to develop promising therapeutic strategy.

scholarly journals Polypyrimidine tract-binding protein blocks miRNA-124 biogenesis to enforce its neuronal-specific expression in the mouse

2018 ◽  
Vol 115 (47) ◽  
pp. E11061-E11070 ◽  
Author(s):  
Kyu-Hyeon Yeom ◽  
Simon Mitchell ◽  
Anthony J. Linares ◽  
Sika Zheng ◽  
Chia-Ho Lin ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Rna Binding ◽  
Binding Protein ◽  
Embryonic Stem ◽  
Specific Expression ◽  
Stem Loop ◽  
Polypyrimidine Tract Binding Protein ◽  
Precursor Rna

MicroRNA (miRNA)-124 is expressed in neurons, where it represses genes inhibitory for neuronal differentiation, including the RNA binding protein PTBP1. PTBP1 maintains nonneuronal splicing patterns of mRNAs that switch to neuronal isoforms upon neuronal differentiation. We find that primary (pri)-miR-124-1 is expressed in mouse embryonic stem cells where mature miR-124 is absent. PTBP1 binds to this precursor RNA upstream of the miRNA stem–loop to inhibit mature miR-124 expression in vivo and DROSHA cleavage of pri-miR-124-1 in vitro. This function for PTBP1 in repressing miR-124 biogenesis defines an additional regulatory loop in the already intricate interplay between these two molecules. Applying mathematical modeling to examine the dynamics of this regulation, we find that the pool of pri-miR-124 whose maturation is blocked by PTBP1 creates a robust and self-reinforcing transition in gene expression as PTBP1 is depleted during early neuronal differentiation. While interlocking regulatory loops are often found between miRNAs and transcriptional regulators, our results indicate that miRNA targeting of posttranscriptional regulators also reinforces developmental decisions. Notably, induction of neuronal differentiation observed upon PTBP1 knockdown likely results from direct derepression of miR-124, in addition to indirect effects previously described.

scholarly journals Differentiation-induced Colocalization of the KH-type Splicing Regulatory Protein with Polypyrimidine Tract Binding Protein and the c-srcPre-mRNA

2004 ◽  
Vol 15 (2) ◽  
pp. 774-786 ◽  
Author(s):  
Megan P. Hall ◽  
Sui Huang ◽  
Douglas L. Black
Keyword(s):  
Rna Binding ◽  
Binding Protein ◽  
Neuroblastoma Cell ◽  
Regulatory Protein ◽  
Neuroblastoma Cells ◽  
Neuroblastoma Cell Line ◽  
Polypyrimidine Tract ◽  
Polypyrimidine Tract Binding ◽  
Polypyrimidine Tract Binding Protein

We have examined the subcellular localization of the KH-type splicing regulatory protein (KSRP). KSRP is a multidomain RNA-binding protein implicated in a variety of cellular processes, including splicing in the nucleus and mRNA localization in the cytoplasm. We find that KSRP is primarily nuclear with a localization pattern that most closely resembles that of polypyrimidine tract binding protein (PTB). Colocalization experiments of KSRP with PTB in a mouse neuroblastoma cell line determined that both proteins are present in the perinucleolar compartment (PNC), as well as in other nuclear enrichments. In contrast, HeLa cells do not show prominent KSRP staining in the PNC, even though PTB labeling identified the PNC in these cells. Because both PTB and KSRP interact with the c-src transcript to affect N1 exon splicing, we examined the localization of the c-src pre-mRNA by fluorescence in situ hybridization. The src transcript is present in specific foci within the nucleus that are presumably sites of src transcription but are not generally perinucleolar. In normally cultured neuroblastoma cells, these src RNA foci contain PTB, but little KSRP. However, upon induced neuronal differentiation of these cells, KSRP occurs in the same foci with src RNA. PTB localization remains unaffected. This differentiation-induced localization of KSRP with src RNA correlates with an increase in src exon N1 inclusion. These results indicate that PTB and KSRP do indeed interact with the c-src transcript in vivo, and that these associations change with the differentiated state of the cell.

Long non-coding RNA LINC-PINT attenuates paclitaxel resistance in triple-negative breast cancer cells via targeting the RNA-binding protein NONO

2020 ◽  
Vol 52 (8) ◽  
pp. 801-809 ◽  
Author(s):  
Jinghua Chen ◽  
Meiqin Zhu ◽  
Liqiu Zou ◽  
Junxian Xia ◽  
Jiacheng Huang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Non Coding Rna ◽  
Long Non Coding Rna

Abstract The treatment of triple-negative breast cancer (TNBC) relies largely on chemotherapies. However, it is frequent that TNBC patients develop resistance to the chemotherapy drugs. Generation of drug-resistant cell lines facilitates the identification of drug resistance. Here, we established two paclitaxel (PTX)-resistant TNBC cancer cell lines using an intermittent and stepwise method and found that long non-coding RNA long intergenic non-protein-coding RNA p53-induced transcript (LINC-PINT) was significantly decreased in PTX-resistant cancer cells. Ectopic expression of LINC-PINT sensitized both PTX-resistant TNBC and wild-type TNBC to PTX. Moreover, RNA immunoprecipitation showed that LINC-PINT bound to RNA-binding protein NONO. Overexpression of LINC-PINT resulted in the degradation of NONO in a proteasome-dependent manner and vice versa. Knockdown of NONO with siRNA sensitized TNBC to PTX. We further analyzed the expression level of LINC-PINT and NONO in patient samples via online database and found that LINC-PINT and NONO may function antagonistically in all types of breast cancers. Taken together, our data illustrated a tumor suppressor role of LINC-PINT in sensitizing TNBC to chemotherapies via destabilizing NONO.

scholarly journals Long noncoding RNA ASB16-AS1 inhibits adrenocortical carcinoma cell growth by promoting ubiquitination of RNA-binding protein HuR

2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Bo Long ◽  
Xufei Yang ◽  
Xixia Xu ◽  
Xiaoxin Li ◽  
Xinjie Xu ◽  
...  
Keyword(s):  
Adrenocortical Carcinoma ◽  
Noncoding Rna ◽  
Rna Binding ◽  
Carcinoma Cell ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Ubiquitin E3 Ligase ◽  
Non Coding Rna

AbstractAdrenocortical carcinoma is one of the aggressive malignancies and it originates from the cortex of adrenal gland. Dysregulation of long non-coding RNA plays important roles in the development of adrenocortical carcinoma. Here, we found that lncRNA ASB16-AS1 was down-regulated in adrenocortical carcinoma and ASB16-AS1 functions as tumor suppressor in vitro and in vivo. We then found that IGF1R and CDK6 are regulated by ASB16-AS1 in adrenocortical carcinoma cells by transcriptome RNA sequencing. ASB16-AS1 associates with RNA-binding protein HuR (ELAVL1) as revealed by RNA pull-down following mass spectrometry. Also, ASB16-AS1 inhibits HuR expression post-translationally by promoting its ubiquitination. ASB16-AS1 regulates IGF1R and CDK6 mRNA expression through RNA-binding protein HuR. We then found that inhibition of ASB16-AS1 attenuates the binding of ubiquitin E3 ligase BTRC to HuR and subsequently inhibits HuR protein unbiquitination and degradation. BTRC knock-down could reverse the effect of AB16-AS1 on HuR, CDK6, and IGF1R levels. Collectively, these results demonstrate that ASB16-AS1 regulates adrenocortical carcinoma cell proliferation and tackling the level of ASB16-AS1 may be developed to treat adrenocortical carcinoma.

scholarly journals Polypyrimidine Tract Binding Protein blocks microRNA-­124 biogenesis to enforce its neuronal specific expression

2018 ◽  
Author(s):  
Kyu-Hyeon Yeom ◽  
Simon Mitchell ◽  
Anthony J. Linares ◽  
Sika Zheng ◽  
Chia-Ho Lin ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Rna Binding ◽  
Binding Protein ◽  
Embryonic Stem ◽  
Specific Expression ◽  
Polypyrimidine Tract Binding Protein ◽  
Microrna 124 ◽  
Precursor Rna

AbstractMicroRNA-124 is expressed in neurons, where it represses genes inhibitory for neuronal differentiation, including the RNA binding protein PTBP1. PTBP1 maintains non-neuronal splicing patterns of mRNAs that switch to neuronal isoforms upon neuronal differentiation. We find that pri-miR-124-1 is expressed in mouse embryonic stem cells (mESCs) where mature miR-124 is absent. PTBP1 binds to this precursor RNA upstream of the miRNA stem-loop to inhibit mature miR-124 expression in vivo, and DROSHA cleavage of pri-miR-124-1 in vitro. This new function for PTBP1 in repressing miR-124 biogenesis adds an additional regulatory loop to the already intricate interplay between these two molecules. Applying mathematical modeling to examine the dynamics of this regulation, we find that the pool of pri-miR-124 whose maturation is blocked by PTBP1 creates a robust and self-reinforcing transition in gene expression as PTBP1 is depleted during early neuronal differentiation. While interlocking regulatory loops are often modeled between miRNAs and transcriptional regulators, our results indicate that miRNA targeting of posttranscriptional regulators also reinforces developmental decisions. Notably, induction of neuronal differentiation observed upon PTBP1 knockdown likely results from direct de-repression of miR-124, in addition to indirect effects previously described.

scholarly journals Long Non-Coding RNA CYP4B1-PS1-001 Inhibits Proliferation and Fibrosis in Diabetic Nephropathy by Interacting with Nucleolin

2018 ◽  
Vol 49 (6) ◽  
pp. 2174-2187 ◽  
Author(s):  
Suyu Wang ◽  
Xin Chen ◽  
Min Wang ◽  
Di Yao ◽  
Tianyu Chen ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Rna Binding ◽  
Mesangial Cells ◽  
Critical Role ◽  
Underlying Mechanism ◽  
Non Coding Rna ◽  
Ubiquitin Proteasome ◽  
Long Non Coding Rna

Background/Aims: Our previous studies demonstrated that a novel long non-coding RNA, CYP4B1-PS1-001, was significantly downregulated in early diabetic nephropathy in vivo and in vitro, and CYP4B1-PS1-001 overexpression could inhibit the proliferation and fibrosis of mouse mesangial cells (MMCs). However, the underlying mechanism of the CYP4B1-PS1-001-mediated regulation of proliferation and fibrosis in diabetic nephropathy remains undetermined. Methods: RNA-protein pull-down assay, RNA-binding protein immunoprecipitation, and mass spectrometry were used to investigate CYP4B1-PS1-001 interacted with the upregulated protein nucleolin (NCL). siRNA method was applied to knockdown NCL in MMCs, the interaction between CYP4B1-PS1-001 and NCL were determined by Western blot analysis and RT-qPCR. The effect of CYP4B1-PS1-001 in the regulation of NCL was detected by cycloheximide (CHX) and ubiquitination assays. Results: We found that CYP4B1-PS1-001 interacts with NCL, and CYP4B1-PS1-001 inhibits the proliferation and fibrosis of MMCs depending on interaction with NCL. Furthermore, degradation of CYP4B1-PS1-001-associated NCL was mediated by a ubiquitin proteasome-dependent pathway. Conclusion: Our study provides evidence that CYP4B1-PS1-001 regulates the ubiquitination and degradation of NCL and thereby plays a critical role in the proliferation and fibrosis of MMCs, indicating that CYP4B1-PS1-001 and NCL may be promising prognostic biomarkers and molecular targets for the treatment of diabetic nephropathy.

The Variant rs145204276 of GAS5 is Associated with the Development and Prognosis of Gastric Cancer

2018 ◽  
Vol 27 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Qianjun Li ◽  
Gang Ma ◽  
Huimin Guo ◽  
Suhua Sun ◽  
Ying Xu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Survival Rate ◽  
Cancer Progression ◽  
Regulatory Mechanism ◽  
Tumor Stage ◽  
Kaplan Meier ◽  
Non Coding Rna ◽  
Early Tumor ◽  
Long Non Coding Rna ◽  
Clinicopathological Variables

Background & Aims: Down-regulation of the growth arrest specific transcript 5 (GAS5) (long non-coding RNA) is associated with cell proliferation of gastric cancer (GC) and a poor prognosis. We aimed to investigate whether the variant rs145204276 of GAS5 is associated with the prognosis of GC in the Chinese population, and to unveil the regulatory mechanism underlying the GAS5 expression in GC tissues.Method: 1,253 GC patients and 1,354 healthy controls were included. The frequency of the genotype del/del and the allele del of rs145204276 were compared between the patients and the controls and between different subgroups of patients classified by clinicopathological variables. The overall survival rate was analyzed according to the Kaplan-Meier method using the log-rank test.Results: The frequency of genotype del/del was significantly lower in patients than in the controls (7.0% vs. 9.1%, p = 0.001). Kaplan-Meier analysis showed that genotype del/del was significantly associated with a higher survival rate (p = 0.01). Patients with late tumor stage were found to have a significantly lower rate of genotype del/del than those with an early tumor stage (4.9% vs. 8.8%, p = 0.01). Patients with UICC III and IV were found to have a significantly lower rate of genotype del/del than those with UICC I and II (5.3% vs. 8.1%, p = 0.02).Conclusion: The variant rs145204276 of GAS5 is associated with the development and prognosis of GC. The allele del of rs145204276 is associated with a remarkably lower incidence of cancer progression and metastasis.

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