lncRNA CRNDE Research Articles

METTL3 mediates m6A modification of lncRNA CRNDE to promote ATG10 expression and improve brain ischemia/reperfusion injury through YTHDC1

BackgroundIschemia/reperfusion (I/R) injury is a severe brain disorder with currently limited effective treatments. This study aims to explore the role of N6-methyladenosine (m6A) modification and associated regulatory factors in I/R to identify potential therapeutic targets.MethodsWe utilized a middle cerebral artery occlusion (MCAO) rat model and SH-SY5Y cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to assess m6A levels and investigate the impact of METTL3 overexpression on long non-coding RNA (lncRNA) CRNDE expression. The effects of silencing lncRNA CRNDE on the interaction between YTHDC1 and ATG10 mRNA, as well as the stability of ATG10 mRNA, were evaluated. Additionally, apoptosis rates, pro-inflammatory and anti-inflammatory factor levels, ATG10 expression, and autophagic activity were analyzed to determine the effects of METTL3. The reverse effects of YTHDC1 overexpression were also examined.ResultsMCAO rats and OGD/R-treated SH-SY5Y cells exhibited reduced m6A levels. METTL3 overexpression significantly inhibited lncRNA CRNDE expression. Silencing lncRNA CRNDE mitigated OGD/R-induced apoptosis and inflammation in SH-SY5Y cells, while enhancing autophagy and stabilizing ATG10 mRNA. METTL3 overexpression decreased cell apoptosis, reduced the levels of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and increased IL-10 secretion. Furthermore, METTL3 overexpression upregulated ATG10 expression and promoted autophagy. Conversely, lncRNA CRNDE overexpression negated these effects.ConclusionThe inhibition of lncRNA CRNDE affects the interaction between YTHDC1 and ATG10 mRNA and stabilizes ATG10 mRNA, mediated by METTL3 overexpression. These findings suggest that targeting lncRNA CRNDE to reduce apoptosis, inhibit inflammation, increase ATG10 expression, and enhance autophagy could offer new therapeutic strategies for I/R injury.

Long Non-Coding RNA CRNDE, LINC00957, and AC072061.1 as a Promising Diagnostic and Prognostic Biomarker in Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is one of the most invasive types of brain cancer. LncRNAs can be considered a new prognostic and diagnostic biomarker in GBM. This study comprehensively explored the interaction of lncRNAs with mRNAs in the TCGA database and proposed a novel promising biomarker with favorable diagnostic and prognostic values. The public data of RNA-seq and related clinical data were downloaded from the TCGA database. Differential expression analysis was conducted in R. GO and KEGG signaling pathways were used for enrichment. The STRING database was used for PPI analysis. CE-network was constructed by STAR database. Kaplan-Meier survival analysis and ROC curve analysis to indicate the biomarkers' diagnostic and prognostic values. Differentially expressed data illustrated that 4428 mRNAs were differentially expressed in GBM. The GO and KEGG pathway analysis showed that the differentially expressed mRNAs were enriched in critical biological processes. The PPI showed that WEE1, BARD1, and CDK6 were the important PPI hubs. The ceRNA network data demonstrated critical lncRNAs. The data revealed that the lncRNA CRNDE, LINC00957, AC072061.1, AC068888.1, and DBH-AS1 are potential diagnostic prognostic biomarkers in the GBM patients. Altogether, we demonstrated lncRNA, and mRNA interaction and mentioned regulatory networks, considered a therapeutic option in GBM. In addition, we proposed potential diagnostic and prognostic biomarkers for the patients.

LncRNA CRNDE Drives the Progression of Hepatocellular Carcinoma by inducing the Immunosuppressive Niche.

As a crucial protumorigenic long noncoding RNA, colorectal tumor differential expression (CRNDE) has been confirmed to facilitate the progression of various cancers. However, its role in the tumor microenvironment (TME) of hepatocellular carcinoma (HCC) is still unclear. Here we determined that CRNDE was upregulated in HCC samples and that CRNDE-positive cells were predominantly enriched in malignant tumor cells. In vivo functional assays revealed that CRNDE-induced tumor cells supported HCC progression, recruited abundant granulocyte myeloid-derived suppressor cells (G-MDSCs) and restricted the infiltration of T cells. In terms of mechanisms, CRNDE bound with Toll-like receptor 3 (TLR3) and activated NF-κB signaling to increase the secretion of c-x-c motif chemokine ligand 3 (CXCL3). CRNDE knockdown could significantly suppress the accumulation of G-MDSCs and enhance the infiltration of T cells in the TME of HCC in vivo. Taken together, our study reveals the CRNDE-NF-κB-CXCL3 axis plays a crucial role in driving the immunosuppressive niche to facilitate HCC progression by recruiting G-MDSCs.

LncRNA CRNDE is downregulated and associated with poor prognostic markers in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is characterized by a very heterogeneous clinical outcome. Thus, a plethora of prognostic factors and systems has been identified to place patients into different risk categories and to guide therapy decisions. The classic clinical staging models by Rai and Binet have been the cornerstone of patient management for several years. The greater insight into the molecular biology of CLL facilitated the advent of prognostic genetic biomarkers that are expected to impact clinical practice soon in the future. Therefore, we aimed to investigate the expression of long non-coding RNA (lncRNA) CRNDE in patients with CLL, and to analyze its relationship with the clinicopathological parameters of CLL. In this study, 40 untreated CLL patients and 30 age- and gender-matched controls were enrolled. The analysis of lncRNA CRNDE expression was determined using reverse transcription-quantitative polymerase chain reaction technique. Our result confirmed the downregulated expression of LncRNA CRNDE in CLL patients compared to controls (p < 0.001). The low expression of CRNDE was significantly associated with poor prognostic markers including advanced stage of CLL, high levels of serum beta-2 microglobulin and lactic dehydrogenase, and the presence of del17p (p = 0.029, p = 0.013, p = 0.003, p = 0.028; respectively). Our study demonstrated that LncRNA CRNDE is significantly downregulated and associated with poor prognostic markers in CLL. It provides a rationale to assess its biological and prognostic impact in CLL.

LncRNA CRNDE Affects Th17/IL-17A and Inhibits Epithelial-Mesenchymal Transition in Lung Epithelial Cells Reducing Asthma Signs.

Asthma treatment is difficult due to disease heterogeneity and comorbidities. In addition, the development of drugs targeting the underlying mechanisms of asthma remains slow. We planned to identify the most upregulated differentially expressed long noncoding RNA in asthma to explore its regulatory patterns and pathways in asthma. We sensitized mice using a mixture of ovalbumin, house dust mites, and lipopolysaccharide to establish an asthma mouse model. We also sensitized asthma cells with TGF-β1 in an in vitro model. We performed a microarray analysis to identify the lncRNA with the differential expression level in model mice. We applied hematoxylin and eosin and Masson's trichrome stainings to mouse tissues to quantify the tissue damage extent. Next, we assess the levels of lncRNA CRNDE, miR-29a-3p, TGF-β1, MCL-1, E-cadherin, vimentin, and snail. We counted the percentages of Th17 cells using flow cytometry. Finally, we performed a dual-luciferase reporter assay to assess the association between lncRNA CRNDE and miR-29a-3p. We successfully established asthma mouse/cell models and selected the lncRNA CRNDE for our study. Transfection of si-CRNDE reduced the degree of injury and inflammation in the mouse model and reversed the TGF-β1-induced epithelial-mesenchymal transition (EMT) in the cell model. Moreover, the E-cadherin level was upregulated, and the levels of IL-17A, vimentin, snail, and α-SMA were downregulated. We also discovered that lncRNA CRNDE negatively regulated miR-29a-3p and that this one in turn inhibited MCL-1 in mice. After lncRNA CRNDE expression downregulation, the level of miR-29a-3p was increased, and we detected reduced levels of MCL-1 and EMTs. lncRNA CRNDE expression downregulation led to reduced inflammation and reduced lung damage in mice with induced asthma, it inhibited the EMTs of lung epithelial cells via the miR-29a-3p/MCL-1 pathway, and it reduced the levels of Th17/IL-17A cells to reduce asthma signs.

LncRNA CRNDE binds hnRNPA1 to facilitate carbon monoxide poisoning-induced delayed encephalopathy via inhibiting UCHL5-mediated SMO deubiquitination.

Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is one of the most common complications following carbon monoxide intoxication. Long noncoding RNAs (lncRNAs) exert critical functions in numerous neurological disorders. We intended to investigate the role of CRNDE in DEACMP. The DEACMP model in rats and the oxygen-glucose deprivation/reoxygenation (OGD/R) model in PC-12 cells were established. Brain and cell injuries were assessed with H&E staining, Nissl staining, TUNEL and CCK8 assays, respectively. Related proteins and RNAs were quantified with western blot and qRT-PCR. The N6-methyladenosine (m6A) level was determined using MeRIP-qPCR and immunofluorescence. Loss and gain function studies were performed to investigate the biological function of CRNDE. The potential mechanisms between each factor were explored using RNA immunoprecipitation, RNA-pull down and co-immunoprecipitation. CRNDE was increased in the hippocampal tissues of DEACMP rats and in OGD/R-treated PC-12 cells, which was positively correlated to m6A modification. Knockdown of CRNDE reduced cell damage and elevated UCHL5 and SMO expressions in OGD/R-treated PC-12 cells. hnRNPA1 was upregulated in DEACMP. In addition, inhibiting hnRNPA1 prevented apoptosis in PC-12 cells subjected to OGD/R. hnRNPA1 bound to CRNDE and remained in the nucleus, which inhibited UCHL5 expression through the formation of CRNDE-hnRNPA1-mRNA complex. UCHL5 could inhibit SMO ubiquitination and suppress PC-12 cell apoptosis during OGD/R. CRNDE silencing blocked brain injury in DEACMP, while knocking down UCHL5 reversed these effects. CRNDE interacted with hnRNPA1 to facilitate DEACMP via inhibition of UCHL5-mediated SMO deubiquitination. CRNDE might be a latent therapeutic target for treating DEACMP.

LncRNA CRNDE is involved in the pathogenesis of renal fibrosis by regulating renal epithelial cell mesenchymal-epithelial transition via targeting miR-29a-3p

Results of previous studies suggested that renal fibrosis and epithelial-mesenchymal transition (EMT) plays an important role in the process of renal fibrosis, but the underlying mechanism remains unclear. Long coding RNA (lncRNA) CRNDE has emerged as potent regulators of EMT programs, therefore, in present work, we examined the roles of LncRNA CRNDE/miR-29a-3p axis in renal fibrosis and the underlying mechanism. We found that in both renal fibrosis animal and cell models, lncRNA CRNDE was dynamically upregulated in animal models or cells by the treatment of TGF-β. Furthermore, knockdown of CRNDE to rat significantly inhibited EMT, prevented renal fibrosis. Finally, CRNDE regulates renal fibrosis through suppression of miR-29a-3p expression. Together, our results demonstrated that CRNDE acted as a regulator of renal fibrosis via targeting miR-29a-3p. Our findings may provide a potential therapeutic target for the treatment of renal fibrosis.

Systematic discrimination of the repetitive genome in proximity of ferroptosis genes and a novel prognostic signature correlating with the oncogenic lncRNA CRNDE in multiple myeloma.

Emerging insights into iron-dependent form of regulated cell death ferroptosis in cancer have opened a perspective for its use in cancer therapy. Of interest, a systematic profiling of ferroptosis gene signatures as prognostic factors has gained special attention in several cancers. Herein, we sought to investigate the presence of repetitive genomes in the vicinity of ferroptosis genes that may influence their expression and to establish a prognostic gene signature associated with multiple myeloma (MM). Our analysis showed that genes associated with ferroptosis were enriched with the repetitive genome in their vicinity, with a strong predominance of the SINE family, followed by LINE, of which the most significant discriminant values were SINE/Alu and LINE/L1, respectively. In addition, we examined in detail the performance of these genes as a cancer risk prediction model and specified fourteen ferroptosis-related gene signatures, which identified MM high-risk patients with lower immune/stromal scores with higher tumor purity in their immune microenvironment. Of interest, we also found that lncRNA CRNDE correlated with a risk score and was highly associated with the majority of genes comprising the signature. Taken together, we propose to investigate the molecular impact of the repetitive genome we have highlighted on the local transcriptome of ferroptosis genes in cancer. Furthermore, we revealed a genomic signature/biomarker related to ferroptosis that can be used to predict the risk of survival in MM patients.

Retracted: Reversal of Radiotherapy Resistance of Ovarian Cancer Cell Strain CAOV3/R by Targeting lncRNA CRNDE.

[This retracts the article DOI: 10.1155/2021/8556965.].

Silencing of lncRNA CRNDE attenuates nonsmall-cell lung cancer progression by mediating the miR-455-3p/HDAC2 axis.

Nonsmall-cell lung carcinoma (NSCLC) is one of the deadliest malignancies in the world. LncRNAs are confirmed to be involved in the progression of NSCLC. Meanwhile, lncRNA CRNDE is known to be upregulated in NSCLC; however, the mechanism by which CRNDE regulates the tumourigenesis of NSCLC remains unclear. To test the function of CRNDE in NSCLC, cell proliferation, invasion, and migration were investigated by colony formation and Transwell assays, respectively. qPCR and Western blotting were applied to test gene and protein levels. In addition, the relationship among CRNDE, miR-455-3p, and HDAC2 was explored by dual-luciferase and RIP assays. The data revealed that the expression of CRNDE was upregulated in NSCLC tissues, while miR-455-3p was downregulated. CRNDE knockdown inhibited the viability, migration and invasion of NSCLC cells or epidermal growth factor receptor gene (EGFR)-mutant NSCLC cells. Moreover, inhibition of miR-455-3p exhibited the opposite effect. CRNDE bound with miR-455-3p, and HDAC2 was found to be targeted by miR-455-3p. Meanwhile, miR-455-3p downregulation reversed the effect of CRNDE knockdown on NSCLC cell function. Furthermore, miR-455-3p notably inhibited the growth and invasion of NSCLC cells via downregulation of HDAC2. Knockdown of CRNDE attenuated NSCLC progression via modulation of the miR-455-3p/HDAC2 axis. Thus, those findings might provide a novel strategy against NSCLC.

Statement of Retraction: Downregulated lncRNA CRNDE contributes to the enhancement of nerve repair after traumatic brain injury in rats

This article refers to:RETRACTED ARTICLE: Downregulated lncRNA CRNDE contributes to the enhancement of nerve repair after traumatic brain injury in rats

A Comprehensive Risk Assessment and Stratification Model of Papillary Thyroid Carcinoma Based on the Autophagy-Related LncRNAs.

BackgroundPapillary thyroid carcinoma (PTC) is one of the most common malignant carcinomas in the endocrine system, and it has a growing incidence worldwide. Despite the development of diagnosis and treatment modalities for thyroid carcinoma, the outcome remains uncertain. Autophagy participates in the process of cancer invasion, malignancy, metastasis, and drug resistance. Emerging research has shown that long noncoding RNAs (lncRNAs) play an important role in the process of different types of cancers. However, the interaction between the process of autophagy and lncRNA and the value of autophagy-related lncRNA for risk assessment, prediction of drug sensitivity, and prognosis prediction in PTC patients remains unknown.Materials and MethodsWe screened 1,283 autophagy-related lncRNAs and identified 144 lncRNAs with prognostic value in The Cancer Genome Atlas (TCGA) cohorts. Univariate and multivariate Cox regression analyses were used to establish the prognosis-related autophagy-related lncRNA risk classification consisting of 10 lncRNAs to indicate the level of risk, according to which the patients were grouped into high-risk group and low risk-group.ResultsThe high-risk group had dramatically worse overall survival compared with the low-risk group. Cox regression analysis was performed to confirm the independent prognostic value of the autophagy-related lncRNA risk stratification, and the time-dependent receiver operating characteristic curves of the risk stratification were 0.981 (1 year), 0.906 (3 years), and 0.963 (5 years). LncRNA CRNDE (LINC00180) is overexpressed in the tumor, and its high expression matched with poorer survival state. So, we chose it for further experiment. Finally, knockdown of the CRNDE in PTC increased the sensitivity to sorafenib.ConclusionCollectively, we successfully established a novel risk stratification for PTC based on the expression profiles of autophagy-related lncRNAs.

LncRNA CRNDE promotes cell proliferation, migration and invasion of ovarian cancer via miR-423-5p/FSCN1 axis.

Ovarian cancer seriously threatens the health of women. LncRNA CRNDE is known to be upregulated in ovarian cancer. However, the mechanism by which CRNDE regulates the progress of ovarian cancer is largely unknown. MTT assay was applied to measure the cell viability. Colony formation assay was used to measure the cell proliferation. Cell migration was tested by wound healing, and Transwell assay was performed to detect cell invasion. In addition, the expression of miR-423-5p, CRNDE and FSCN1 were detected by RT-qPCR and western blotting, respectively. Meanwhile, dual-luciferase reporter assay and RIP assay were performed to explore the correlation between miR-423-5p and CRNDE (or FSCN1). CRNDE and FSCN1 were upregulated in ovarian cancer cells (SKOV3, CAOV-3, IGROV1, A2780 and C13K), while miR-423-5p was downregulated. Moreover, silencing of FSCN1/CRNDE significantly decreased proliferation, migration and invasion of ovarian cancer cells (SKOV3 and CI3K) via suppressing MMP-2 and MMP-9. In addition, CRNDE could sponge miR-423-5p, and FSCN1 was confirmed to be the direct target of miR-423-5p. Furthermore, CRNDE knockdown-induced inhibition of FSCN1 was notably reversed by miR-423-5p downregulation. Knockdown of CRNDE inhibited cell proliferation, migration and invasion of ovarian cancer via miR-423-5p/FSCN1 axis. Thus, CRNDE may serve a new target for ovarian cancer.

Knockdown of long non-coding RNA CRNDE alleviates apoptosis and inflammation in ischemia-reperfusion induced brain injury via mir-489-3p /FOXO3 pathway.

Ischemia-reperfusion IR injury has a major effect on the pathophysiology of stroke. Colorectal tumor differential expression (CRNDE) is an upregulated lncRNA in cerebral ischemic injury. We examined the role and mechanism of CRNDE in brain injury induced by ischemic-reperfusion. Sh-SY5Y cells were cultured, and oxygen and glucose deprivation/reperfusion (OGD/R) injury tests were performed. The effects on SH-SY5Y cells were evaluated by the Cell Counting Kit-8 (CCK-8) assay, qPCR, apoptosis analysis, western blot analysis, ELISA, a luciferase reporter assay, and an RNA pull-down assay. Knockdown of CRBDE ameliorated SH-SY5Y cell impairment induced by OGD/R. CRNDE, the target of mir-489-3p, was directly bound to FOXO3. Mir-489-3p knockdown partially reversed OGD/R-mediated impairment in CRBDE knockdown SH-SY5Y cells. The results indicate that knockdown of lncRNA CRNDE ameliorates apoptosis and the inflammatory response in ischemia-reperfusion-induced brain injury through the mir-489-3p/FOXO3 axis. LncRNA CRNDE may represent a novel therapeutic target for brain injury.

Long Noncoding RNA CRNDE Functions as an Oncogene to Facilitate Aggressive Behaviors of Nasopharyngeal Carcinoma Cells by Modulating miR-3163/TWIST1 Axis.

Long noncoding RNA (lncRNA) CRNDE has been broadly implicated in many malignancies. The aim of this study was to explore the function and potential mechanisms of CRNDE in nasopharyngeal carcinoma (NPC). Here, we discovered that CRNDE level was increased in NPC tissues and cell lines. Additionally, elevated CRNDE positively correlated with large tumor size, advanced TNM stage, distant metastasis, EBV infection and worse prognosis. Furthermore, depletion of CRNDE significantly impaired the capacity of proliferation, migration and invasion in NPC cells. Mechanically, CRNDE could serve as a molecular sponge of miR-3163 to regulate the expression of TWIST1. Importantly, the inhibitory effects of CRNDE knockdown on cell proliferation and metastasis were blocked by silence of miR-3163 or restoration of TWIST1 expression. Overall, our data highlighted that CRNDE could promote NPC progression via altering miR-3163/TWIST1 axis, suggesting CRNDE as a potential prognostic biomarker and therapeutic target for NPC treatment.

Repression of CRNDE enhances the anti-tumour activity of CD8+T cells against oral squamous cell carcinoma through regulating miR-545-5p and TIM-3.

Immunotherapy has been identified a promising treatment of cancers, including Oral squamous cell carcinoma (OSCC). CRNDE is highly overexpressed in various cancers. Many lncRNAs have been reported in CD8 T lymphocytes. Little is investigated about their effects in the functions of CD8 + T cells in OSCC. Currently, the influence of lncRNA CRNDE on the function of CD8 + T cells in OSCC progression was investigated. Here, CRNDE was obviously elevated and negatively correlated with IFN‐γ production in tumour‐infiltrating CD8 + T cells isolated from OSCC patients. CRNDE can exhibit a crucial role in activating CD8 + T‐cell exhaustion. Mechanistically, CRNDE specifically sponged miR‐545‐5p to induce T‐cell immunoglobulin and mucin domain‐3 (TIM‐3), thus contributing to CD8 + T‐cell exhaustion. The function of miR‐545‐5p on T‐cell function remains poorly known. TIM‐3 is a significant immune checkpoint, and it inhibits cancer immunity. TIM‐3 can demonstrate an important role in CD8 + T‐cell exhaustion. In summary, loss of CRNDE could induce miR‐545‐5p and inhibit TIM3 expression, thus significantly activated the anti‐tumour effect of CD8 + T cells.

Serum exosomal long noncoding RNA CRNDE as a prognostic biomarker for hepatocellular carcinoma.

BackgroundAccumulating evidence has shown that long noncoding RNA (lncRNA) CRNDE functions as an oncogene in many cancer types. However, its clinical value has not yet been explored in hepatocellular carcinoma (HCC).MethodsA total of 166 patients with HCC and 100 healthy volunteers were enrolled in this study. The expression levels of serum exosomal lncRNA CRNDE were detected in patients with HCC and controls by quantitative real‐time PCR (qRT‐PCR).ResultsThe serum exosomal lncRNA CRNDE expression levels were significantly increased in patients with HCC compared with normal controls. High serum exosomal lncRNA CRNDE expression was significantly associated with tumor size, tumor differentiation, and TNM stage. Receiver operating characteristic (ROC) analysis revealed that an area under the ROC curve (AUC) of 0.839, with a sensitivity and specificity of 69.3% and 85.0%. In addition, the overall survival (OS) and disease‐free survival (DFS) were significantly longer in patients with lower serum exosomal lncRNA CRNDE expression compared to those with higher CRNDE expression. Moreover, HCC patients with cirrhosis had worse OS and DFS than those without cirrhosis. Univariate and multivariate analyses indicated that high serum exosomal lncRNA CRNDE expression was an independent indicator of poor prognosis.ConclusionTaken together, serum exosomal lncRNA CRNDE might serve as a potential biomarker for HCC diagnosis and prognosis.

Retraction.

Retraction: "LncRNA CRNDE promotes hepatocellular carcinoma cell proliferation, invasion, and migration through regulating miR-203/BCAT1 axis, by Degang Ji, Chengwei Jiang, Lirong Zhang, Na Liang, Tiechao Jiang, Bin Yang, and Haiying Liang, J Cell Physiol. 2019; 6548-6560: The above article, published online on 19 September 2018 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/jcp.27396) has been retracted by agreement between the journal's Editor in Chief, Prof. Dr. Gregg Fields, and Wiley Periodicals LLC. The retraction has been agreed after the authors stated that unintentional errors occurred during the research process, and the experimental results cannot be verified. Thus, the conclusions are considered to be invalid.

Reversal of Radiotherapy Resistance of Ovarian Cancer Cell Strain CAOV3/R by Targeting lncRNA CRNDE.

Radiotherapy resistance is one of the key factors of poor prognosis of ovarian cancer clinical treatment. The search for key targets of ovarian cancer radiotherapy resistance has become a high priority. Long noncoding RNA plays an important role in tumor development. However, the key lncRNA in ovarian cancer radiotherapy resistance is not identified. Our finding that lncRNA CRNDE is highly expressed in the radiotherapy resistance cell line CAOV3/R drew our attention. Therefore, in this study, we targeted lncRNA CRNDE to analyze whether it is a key factor of radiotherapy resistance in ovarian cancer. Ultimately, we found that silencing lncRNA CRNDE could reverse CAOV3/R radiotherapy resistance, which would be a boon to clinical treatment.

Knockdown lncRNA CRNDE enhances temozolomide chemosensitivity by regulating autophagy in glioblastoma

BackgroundThe regulatory roles of long non-coding RNA (lncRNA) CRNDE in temozolomide (TMZ) chemoresistance to glioblastoma multiforme (GBM) are still poorly understood. Therefore, the function, characteristics, and possible mechanism of CRNDE in TMZ-induced chemoresistance to GBM were explored.MethodsFirstly, the expression level of CRNDE in 58 cases of glioma tissue specimens and 30 cases of normal brain tissues were tested by qRT-PCR. Meanwhile, the correlation between CRNDE expression level, the clinicopathological characteristics, and survival time of patients with glioma were analyzed. Then, the CRNDE expression in various glioma cell lines was detected, and CRNDE knockdown cell models were constructed. Subsequently, to explore the effect of CRNDE on chemosensitivity to TMZ, cell viability was detected by the CCK-8 assay and IC50 values, and cell proliferation was detected by cell clone assay and EdU assay, as well as cell survival was detected by apoptosis with flow cytometry under TMZ treatment. Further, the expression of drug-resistance protein ABCG2, autophagy related proteins, and PI3K/Akt/mTOR pathway were measured by western blot or qRT-PCR in TMZ-treated glioma cells. Finally, the mouse tumor xenograft model was established and the tumor volume and weight were measured, and ABCG2 expression was conducted by immunohistochemistry assay.ResultsThe integrated results demonstrated lncRNA CRNDE was a poor prognosis factor for GBM patient, which was upregulated in patients who were resistant to TMZ, and closely associated with chemotherapeutic response status to TMZ treatment. Further, functional assays revealed that knockdown of CRNDE could notably reduce glioma cell viability and proliferation, and elevate cell apoptosis to enhance the chemosensitivity to TMZ in vitro and in vivo. Mechanistically, the depression of CRNDE could diminish the expression of LC3 II/I, Beclin1 and Atg5 and increase the p62 expression level to inhibit autophagy due to the activation of PI3K/Akt/mTOR pathway as well as highly correlated with ABCG2 expression.ConclusionsOverall, the study provided that lncRNA CRNDE is a reliable clinical predictor of outcome and prognosis and a potential biomarker for predicting TMZ treatment response in GBM by modulating the autophagy through PI3K/Akt/mTOR pathway and ABCG2 expression which may be a novel therapeutic target for regulating TMZ sensitivity to GBM.