LncRNA CRNDE promotes hepatoma cell proliferation by regulating the metabolic reprogramming of M2 macrophages via ERK pathway.

BACKGROUND: LncRNA colorectal neoplasia differentially expressed (CRNDE) was found to be an important regulator in many cancers. This project focuses on the function of CRNDE on macrophage metabolic reprogramming and Hepatocellular carcinoma (HCC). METHOD: qRT-PCR and Immunofluorescence were used to analyze Arg-1, IL-10, CD163, CCL-18, CD206, and CRNDE expression in HCC tissues and macrophages. Western Blotting was used to analyze ERK and p-ERK expression. Edu assay, transwell assay and xenograft experiments were carried out to study cell viability, migrated and invasive capability. Immunohistochemical staining was used to evaluate Ki67 expression. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed for macrophages metabolites analysis. RESULTS: Arg-1, IL-10, CD163, CD206, and CRNDE were significantly up-regulated in HCC tissues, M2 macrophage and M0 macrophage with CRNDE overexpressed (OV-CRNDE-M0), which downregulated in M0 macrophage with CRNDE knockdown (sh-CRNDE-M0). The conditioned medium (CM) of M2 cells and OV-CRNDE-M0 cells promoted cell viability, invasion, and migration of HCC cells, the effect was reversed by sh-CRNDE-M0 cells CM. OV-CRNDE-M0 cells promoted tumor growth, Ki67 and CD206 expression in xenograft model. 61 metabolites were detected, of which 18 metabolites changed significantly in OV-CRNDE-M0 group compared to M0 group, with 9 upregulated and 9 downregulated. KEGG analysis showed the enrichment pathways were biosynthesis, glyoxylate and dicarboxylate metabolism. SMPDB analysis showed the enrichment pathways were hypoacetylaspartia, canavan disease, and aspartate metabolism. CONCLUSION: CRNDE regulated the metabolic reprogramming of M2 macrophage via ERK pathway, which thereby contributed to HCC proliferation, migration, and invasion.

Long term exercise-derived exosomal LncRNA CRNDE mitigates myocardial infarction injury through miR-489-3p/Nrf2 signaling axis.

Myocardial infarction (MI) is a cardiovascular disease and troubles patients all over the world. Exosomes produced after long-term exercise training were discovered to mediate intercellular communication and alleviate MI-induced heart injury. However, the detailed roles of long-term exercise-derived exosomal long noncoding RNAs (LncRNAs) in MI remain uncovered. In this study, we collected and identified long-term exercise-derived exosomes, and established MI or hypoxia/reoxygenation (H/R) model after LncRNA colorectal neoplasia differentially expressed (CRNDE) depletion. This work proved that LncRNA CRNDE was highly expressed in long-term exercise-derived exosomes (p = 0.0078). CRNDE knockdown increased cardiomyocytes apoptosis and oxidative stress (p = 0.0036), and suppressed MI progress (p = 0.0005). CRNDE served as the sponge of miR-489-3p to affect Nrf2 expression (p = 0.0001). MiR-489-3p inhibition effectively reversed the effects of CRNDE depletion on hypoxia cardiomyocytes (p = 0.0002). These findings offered a promising therapeutic option for the treatment of MI.

The Clinical Significance of CRNDE Gene Methylation, Polymorphisms, and CRNDEP Micropeptide Expression in Ovarian Tumors.

CRNDE is an oncogene expressed as a long non-coding RNA. However, our team previously reported that the CRNDE gene also encodes a micropeptide, CRNDEP. The amino acid sequence of CRNDEP has recently been revealed by other researchers, too. This study aimed to investigate genetic alterations within the CRNDEP-coding region of the CRNDE gene, methylation profiling of this gene, and CRNDEP expression analysis. All investigations were performed on clinical material from patients with ovarian tumors of diverse aggressiveness. We found that CRNDEP levels were significantly elevated in highly aggressive tumors compared to benign neoplasms. Consistently, a high level of this micropeptide was a negative, independent, prognostic, and predictive factor in high-grade ovarian cancer (hgOvCa) patients. The cancer-promoting role of CRNDE(P), shown in our recent study, was also supported by genetic and epigenetic results obtained herein, revealing no CRNDEP-disrupting mutations in any clinical sample. Moreover, in borderline ovarian tumors (BOTS), but not in ovarian cancers, the presence of a single nucleotide polymorphism in CRNDE, rs115515594, significantly increased the risk of recurrence. Consistently, in BOTS only, the same genetic variant was highly overrepresented compared to healthy individuals. We also discovered that hypomethylation of CRNDE is associated with increased aggressiveness of ovarian tumors. Accordingly, hypomethylation of this gene's promoter/first exon correlated with hgOvCa resistance to chemotherapy, but only in specimens with accumulation of the TP53 tumor suppressor protein. Taken together, these results contribute to a better understanding of the role of CRNDE(P) in tumorigenesis and potentially may lead to improvements in screening, diagnosis, and treatment of ovarian neoplasms.

A Multi-Faceted Analysis Showing CRNDE Transcripts and a Recently Confirmed Micropeptide as Important Players in Ovarian Carcinogenesis.

CRNDE is considered an oncogene expressed as long non-coding RNA. Our previous paper is the only one reporting CRNDE as a micropeptide-coding gene. The amino acid sequence of this micropeptide (CRNDEP) has recently been confirmed by other researchers. This study aimed at providing a mass spectrometry (MS)-based validation of the CRNDEP sequence and an investigation of how the differential expression of CRNDE(P) influences the metabolism and chemoresistance of ovarian cancer (OvCa) cells. We also assessed cellular localization changes of CRNDEP, looked for its protein partners, and bioinformatically evaluated its RNA-binding capacities. Herein, we detected most of the CRNDEP sequence by MS. Moreover, our results corroborated the oncogenic role of CRNDE, portraying it as the gene impacting carcinogenesis at the stages of DNA transcription and replication, affecting the RNA metabolism, and stimulating the cell cycle progression and proliferation, with CRNDEP being detected in the centrosomes of dividing cells. We also showed that CRNDEP is located in nucleoli and revealed interactions of this micropeptide with p54, an RNA helicase. Additionally, we proved that high CRNDE(P) expression increases the resistance of OvCa cells to treatment with microtubule-targeted cytostatics. Furthermore, altered CRNDE(P) expression affected the activity of the microtubular cytoskeleton and the formation of focal adhesion plaques. Finally, according to our in silico analyses, CRNDEP is likely capable of RNA binding. All these results contribute to a better understanding of the CRNDE(P) role in OvCa biology, which may potentially improve the screening, diagnosis, and treatment of this disease.

Implications of CRNDE in prognosis, tumor immunity, and therapeutic sensitivity in low grade glioma patients.

BACKGROUND: Colorectal tumor differentially expressed (CRNDE) is specifically expressed in human brains and is the most highly expressed lncRNA in gliomas. Nevertheless, its implications in low grade glioma (LGG) are still indistinct. This study presented systematic analyses of CRNDE in LGG biology. METHODS: We retrospectively retrieved TCGA, CGGC and GSE16011 LGG cohorts. Survival analysis was conducted for evaluating the prognostic significance of CRNDE in LGG. A CRNDE-based nomogram was established, and its predictive performance was verified. Signaling pathways underlying CRNDE were analyzed through ssGSEA and GSEA approaches. The abundance of immune cells and activity of cancer-immunity cycle were estimated with ssGSEA approach. Immune checkpoints, HLAs, chemokines, and immunotherapeutic response indicators (TIDE, and TMB) was quantified. U251 and SW1088 cells were transfected with specific shRNAs of CRNDE, and flow cytometry (apoptosis) and western blot (ß-catenin and Wnt5a) assays were conducted. RESULTS: Up-regulated CRNDE was found in LGG, and was linked to unfavorable clinical outcomes. The CRNDE-based nomogram enabled to accurately predict patients' prognosis. High CRNDE expression was linked to more genomic variations, activity of tumorigenic pathways, tumor immunity (increase in infiltration of immune cells, expression of immune checkpoints, HLAs and chemokines, and cancer-immunity cycle), and therapeutic sensitivity. CRNDE knockdown mitigated malignant phenotypes of LGG cells. CONCLUSIONS: Our study determined CRNDE as a novel predictor for patient prognosis, tumor immunity and therapeutic response in LGG. Assessment of CRNDE expression is a promising approach for predicting the therapeutic benefits of LGG patients.

Transfer of LncRNA CRNDE in TAM-derived exosomes is linked with cisplatin resistance in gastric cancer.

This study explores the role of the long noncoding RNA (LncRNA) CRNDE in cisplatin (CDDP) resistance of gastric cancer (GC) cells. Here, we show that LncRNA CRNDE is upregulated in carcinoma tissues and tumor-associated macrophages (TAMs) of GC patients. In vitro experiments show that CRNDE is enriched in M2-polarized macrophage-derived exosomes (M2-exo) and is transferred from M2 macrophages to GC cells via exosomes. Silencing CRNDE in M2-exo reverses the promotional effect of M2-exo on cell proliferation in CDDP-treated GC cells and homograft tumor growth in CDDP-treated nude mice. Mechanistically, CRNDE facilitates neural precursor cell expressed developmentally downregulated protein 4-1 (NEDD4-1)-mediated phosphatase and tensin homolog (PTEN) ubiquitination. Silencing CRNDE in M2-exo enhances the CDDP sensitivity of GC cells treated with M2-exo, which is reduced by PTEN knockdown. Collectively, these data reveal a vital role for CRNDE in CDDP resistance of GC cells and suggest that the upregulation of CRNDE in GC cells may be attributed to the transfer of TAM-derived exosomes.

Long non-coding RNA crnde promotes deep vein thrombosis by sequestering miR-181a-5p away from thrombogenic Pcyox1l.

BACKGROUND: Deep vein thrombosis (DVT) is an interplay of genetic and acquired risk factors, where functional interactions in lncRNA-miRNA-mRNA ceRNA networks contribute to disease pathogenesis. Based on the high-throughput transcriptome sequencing prediction, we have assessed the contribution of lncRNA Crnde/miR-181a-5p/Pcyox1l axis to thrombus formation. METHODS: DVT was modeled in mice by inferior vena cava stenosis, and inferior vena cava tissues were harvested for high-throughput transcriptome sequencing to screen differentially expressed lncRNAs and mRNAs. The key miRNA binding to Crnde and Pcyox1l was obtained through searching the RNAInter and mirWalk databases. The binding affinity between Crnde, miR-181a-5p, and Pcyox1l was examined by FISH, dual luciferase reporter gene, RNA pull-down, and RIP assays. Functional experiments were conducted in DVT mouse models to assess thrombus formation and inflammatory injury in inferior vena cava. RESULTS: It was noted that Crnde and Pcyox1l were upregulated in the blood of DVT mice. Crnde competitively bound to miR-181a-5p and inhibited miR-181a-5p expression, and Pcyox1l was the downstream target gene of miR-181a-5p. Silencing of Crnde or restoration of miR-181a-5p reduced inflammatory injury in the inferior vena cava, thus curtailing thrombus formation in mice. Ectopic expression of Pcyox1l counterweighed the inhibitory effect of Crnde silencing. CONCLUSIONS: Therefore, Crnde sequesters miR-181a-5p to release Pcyox1l expression via ceRNA mechanism, thus aggravating thrombus formation in DVT.

LncRNA CRNDE hinders the progression of osteoarthritis by epigenetic regulation of DACT1.

Osteoarthritis (OA) is mainly characterized by articular cartilage degeneration, synovial fibrosis, and inflammation. LncRNA CRNDE (colorectal neoplasia differentially expressed) has been reported to be down-regulated in age-related OA, but its role in injury-induced OA needs to be further explored. In this study, an OA rat model was established using anterior cruciate ligament transection, and the adenovirus-mediated CRNDE overexpression (Ad-CRNDE) or DACT1 (dapper antagonist of catenin-1) interference (sh-DACT1) vectors were administered by intraarticular injection. Moreover, chondrocyte­like ATDC5 cells were treated with IL-1ß (10 ng/mL) to simulate OA conditions in vitro. We found that overexpression of CRNDE alleviated cartilage damage and synovitis in OA rats, and suppressed IL-1ß-induced apoptosis, inflammation, and extracellular matrix (ECM) degradation in chondrocyte­like ATDC5 cells, while silencing DACT1 effectively antagonized the protective effect of CRNDE both in vivo and in vitro. Mechanism studies revealed that DACT1 could act as a downstream target of CRNDE. By recruiting p300, CRNDE promoted the enrichment of H3K27ac in the DACT1 promoter, thus promoting DACT1 transcription. In addition, CRNDE hindered the activation of the Wnt/ß-catenin pathway in IL-1ß-stimulated cells by inducing DACT1 expression. In conclusion, CRNDE promoted DACT1 expression through epigenetic modification and restrained the activation of Wnt/ß-catenin signaling to impede the progression of OA.

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.

CRNDE: A Pivotal Oncogenic Long Non-Coding RNA in Cancers.

Colorectal Neoplasia Differentially Expressed (CRNDE), a long non-coding RNA that was initially identified as aberrantly expressed in colorectal cancer (CRC) has also been observed to exhibit elevated expression in various other human malignancies. Recent research has accumulated substantial evidence implicating CRNDE as an oncogenic player, exerting influence over critical cellular processes linked to cancer progression. Particularly, its regulatory interactions with microRNAs and proteins have been shown to modulate pathways that contribute to carcinogenesis and tumorigenesis. This review will comprehensively outline the roles of CRNDE in colorectal, liver, glioma, lung, cervical, gastric and prostate cancer, elucidating the mechanisms involved in modulating proliferation, apoptosis, migration, invasion, angiogenesis, and radio/chemoresistance. Furthermore, the review highlights CRNDE's potential as a multifaceted biomarker, owing to its presence in diverse biological samples and stable properties, thereby underscoring its diagnostic, therapeutic, and prognostic applications. This review aims to provide comprehensive insights of CRNDE-mediated oncogenesis and identify CRNDE as a promising target for future clinical interventions.

The prognosis biomarkers based on m6A-related lncRNAs for myeloid leukemia patients.

BACKGROUND: Chronic myeloid leukemia (CML) and acute myeloid leukemia (AML) are two common malignant disorders in leukemia. Although potent drugs are emerging, CML and AML may still relapse after the drug treatment is stopped. N6-methyladenosine (m6A) and lncRNAs play certain roles in the occurrence and development of tumors, but m6A-modified LncRNAs in ML remain to be further investigated. METHODS: In this study, we extracted and analyzed the TCGA gene expression profile of 151 ML patients and the clinical data. On this basis, we then evaluated the immune infiltration capacity of ML and LASSO-penalized Cox analysis was applied to construct the prognostic model based on m6A related lncRNAs to verify the prognostic risk in clinical features of ML. Quantitative reverse transcription PCR was used to detect the expression level of LncRNA in in ML cell lines K562, MOLM13 and acute monocytic leukemia cell line THP-1. RESULTS: We found 70 m6A-related lncRNAs that were related to prognosis, and speculated that the content of stromal cells and immune cells would correlate with the survival of patients with ML. Next, Prognostic risk model of m6A-related lncRNAs was validated to have excellent consistency in clinical features of ML. Finally, we verified the expression levels of CRNDE, CHROMR and NARF-IT1 in ML cell lines K562, MOLM13 and acute monocytic leukemia cell line THP-1, which were significant. CONCLUSIONS: The research provides clues for the prognosis prediction of ML patients by using the m6A-related lncRNAs model we have created, and clarifies the accuracy and authenticity of it.

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.

LncRNA CRNDE Exacerbates IgA Nephropathy Progression by Promoting NLRP3 Inflammasome Activation in Macrophages.

BACKGROUND: Activation of NLRP3 inflammasome in macrophages contributes greatly to IgA nephropathy (IgAN) progression. This study intended to investigate the underlying mechanism of NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation in the development of IgAN. METHODS: We examined the expression levels of colorectal neoplasia differentially expressed (CRNDE), NLRP3 inflammasome-related proteins in peripheral blood mononuclear cells (PBMCs) and J774A.1 cells and detected inflammatory cytokine levels in the serum of IgAN patients and cell supernatants of in vitro IgAN model. RNA pull-down and RNA immunoprecipitation (RIP) experiments were conducted to evaluate the interaction between CRNDE and NLRP3. Then, the ubiquitin level of NLRP3 and its binding ability to TRIM family member 31 (TRIM31) were determined. RESULTS: Compared with the control group, the expressions of CRNDE and NLRP3 inflammasome-related proteins in PBMCs and J774A.1 cells and levels of IL-1ß, TNF-α and IL-12 in serum of IgAN patients and cell supernatants of IgA-IC-induced J774A.1 cells were all increased. CRNDE silencing down-regulated NLRP3 inflammasome-related proteins and the levels of IL-1ß, TNF-α and IL-12 in cell supernatants, while NLRP3 overexpression reversed these effects. Additionally, CRNDE could interact with NLRP3 and promote NLRP3 expression. Furthermore, inhibition of CRNDE reduced NLRP3 protein level and promoted TRIM31-mediated NLRP3 ubiquitination and degradation. CONCLUSION: CRNDE exacerbates IgA nephropathy progression through restraining ubiquitination and degradation of NLRP3 and facilitating NLRP3 inflammasome activation in macrophages.

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.

The mechanism of lncRNA-CRNDE in regulating tumour-associated macrophage M2 polarization and promoting tumour angiogenesis.

M2 macrophages can promote liver cancer metastasis by promoting tumour angiogenesis; however, the mechanism underlying macrophage polarization has not been completely revealed. In this study, we mainly explored the mechanism underlying long non-coding RNA-CRNDE (lncRNA-CRNDE) in regulating M2 macrophage polarization and promoting liver cancer angiogenesis. The expression of CRNDE was up-regulated or down-regulated in THP-1 cells (CRNDE-/- -THP-1 cells and pcDNA3.1-CRNDE-THP-1). THP-1 cells were co-cultured with liver cancer cell line H22, and M2 polarization was induced in THP-1 by IL-4/13 to simulate tumour-induced macrophage polarization. As a result, after CRNDE overexpression, THP-1 cell viability was up-regulated, the expression of M2 membrane marker CD163 was up-regulated, and the proportion of F4/80 + CD163+ cells was also up-regulated. ELISA assay showed that the expression of M2 markers (including TGF-ß1 and IL-10) and chemokines (including CCl22 and CCL22) was up-regulated, and the expression of key signals (including STAT6, JAK-1, p-AKT1, and Arg-1) was also up-regulated, which were significantly different compared with the control group (Con). In addition, the intervention effect of CRNDE on THP-1 was consistent between co-culture with H22 cells and IL-4/13 induction assay. The induced M2 THP-1 cells were co-cultured with HUVEC. As a result, THP-1 cells with CRNDE overexpression can promote the migration and angiogenesis of HUVEC cells in vitro and simultaneously up-regulate the expression of Notch1, Dll4 and VEGFR2, indicating that THP-1 M2 polarization induced by CRNDE could further promote angiogenesis. The H22 cell tumour-bearing mouse model was constructed, followed by injection of CRNDE anti-oligosense nucleotides and overexpression plasmids to interfere CRNDE expression in tumour-bearing tissues. Consequently, down-regulation of CRNDE could down-regulate tumour volume, simultaneously down-regulate the expression of CD163 and CD31 in tissues, decrease the expression of key proteins (including JAK-1, STAT-6, p-STAT6 and p-AKT1), and down-regulate the expression of key angiogenesis-related proteins (including VEGF, Notch1, Dll4 and VEGFR2). In this study, we found that CENDE could indirectly regulate tumour angiogenesis by promoting M2 polarization of macrophages, which is also one of the mechanisms of microenvironmental immune regulation in liver cancer.

LncRNA CRNDE attenuates chemoresistance in gastric cancer via SRSF6-regulated alternative splicing of PICALM.

De novo and acquired resistance, which are mainly mediated by genetic alterations, are barriers to effective routine chemotherapy. However, the mechanisms underlying gastric cancer (GC) resistance to chemotherapy are still unclear. We showed that the long noncoding RNA CRNDE was related to the chemosensitivity of GC in clinical samples and a PDX model. CRNDE was decreased and inhibited autophagy flux in chemoresistant GC cells. CRNDE directly bound to splicing protein SRSF6 to reduce its protein stability and thus regulate alternative splicing (AS) events. We determined that SRSF6 regulated the PICALM exon 14 skip splice variant and triggered a significant S-to-L isoform switch, which contributed to the expression of the long isoform of PICALM (encoding PICALML). Collectively, our findings reveal the key role of CRNDE in autophagy regulation, highlighting the significance of CRNDE as a potential prognostic marker and therapeutic target against chemoresistance in GC.

Knockdown lncRNA CRNDE enhances temozolomide chemosensitivity by regulating autophagy in glioblastoma.

BACKGROUND: The 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. METHODS: Firstly, 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. RESULTS: The 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. CONCLUSIONS: Overall, 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.

Long non-coding RNA CRNDE exacerbates NPC advancement mediated by the miR-545-5p/CCND2 axis.

BACKGROUND: Previous studies indicated CRNDE to have a pivotal part within tumorigenesis. Notwithstanding, precise details on CRNDE activities within NPC are still uncertain. The investigation described in this article served to focus in greater depth on the mechanistics regarding CRNDE, together with all associated regulatory networks, on nasopharyngeal carcinoma (NPC) and its treatment possibilities. METHODS: Quantitative real-time polymerase chain reaction (RT-qPCR) analyzed CRNDE, miR-545-5p and CCND2 expression within NPCs and representative cell lineages. CCK-8 cell counting-, EdU-, wound-healing-/transwell-assays analyzed cellular proliferation, migrative, together with invasive properties. Apoptosis/cell cycle progression were scrutinized through flow cytometry. Dual-luciferase reporter assays validated CRNDE/miR-545-5p/CCND2 interplay. Proteomic expression of apoptosis-related protein, EMT-related protein and CCND2 protein were evaluated through Western blotting. In addition, Ki67 expression was evaluated through immunohistochemical staining. The effect of CRNDE in vivo was assessed by nude murine xenograft model studies. RESULTS: This study demonstrated up-regulated expression of CRNDE and CCND2 within NPC tissues/cell lines. Meanwhile, miR-545-5p was down-regulated. CRNDE knock-down or miR-545-5p over-expression drastically reduced NPC proliferative, migrative and invasive properties, promoted apoptosis/altered cell cycle, and inhibited CCND2 expression. However, miR-545-5p down-regulation had opposing effects. All inhibiting functions generated by CRNDE down-regulation upon NPC progression could be counterbalanced or synergistically exacerbated, depending on miR-545-5p down-regulation or up-regulation, respectively. Multiple-level investigations revealed CRNDE to serve as a sponge for miR-545-5p, and can target CCND2 within NPCs. CONCLUSIONS: CRNDE increases CCND2 expression by competitive binding with miR-545-5p, thus accelerating the development of NPC. This provides potential therapeutic targets and prognostic markers against NPC.

lncRNA-CRNDE regulates BMSC chondrogenic differentiation and promotes cartilage repair in osteoarthritis through SIRT1/SOX9.

Osteoarthritis (OA) is the most common chronic and degenerative joint disease. Although traditional OA medications can partially relieve pain, these medications cannot completely cure OA. Therefore, it is particularly important to find an effective treatment for OA. This study explored the function of long non-coding RNA (lncRNA)-colorectal neoplasia differentially expressed gene (CRNDE) in the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and the underlying molecular mechanism, aiming to develop a new treatment method for osteoarthritis. BMSCs were isolated from rat bone marrow using the gradient centrifugation method. And BMSC chondrogenic differentiation was induced with chondrogenic medium. The expression of lncRNA-CRNDE was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Silent information regulator factor 2-related enzyme 1 (SIRT1) and cartilage marker genes Aggrecan and collagen 2 (α1) protein expression were researched using western blot. Alcian blue staining was employed to examine the content of cartilage matrix proteoglycan glycosaminoglycan (GAG). The interaction between lncRNA-CRNDE and SIRT1 was detected by RNA pull-down and RNA immunoprecipitation (RIP) assay. Ubiquitination experiments were performed to measure the ubiquitination level of SIRT1. The combination between SMAD ubiquitination regulatory factor 2 (SMURF2) and SIRT1, as well as SRY-related high-mobility-group box 9 (SOX9) and collagen 2 (α1) promoter, was detected by Co-immunoprecipitation or ChIP. With the prolongation of induction time, the expression of lncRNA-CRNDE, SIRT1, cartilage marker genes Aggrecan and collagen 2 (α1) in BMSC osteogenic differentiation was gradually increased. Also, the content of cartilage matrix proteoglycan GAG was gradually elevated with the extension of the induction time. Further increase in the expression of SIRT1, cartilage marker genes Aggrecan and collagen 2 (α1) by overexpression of lncRNA-CRNDE also indicated elevated GAG content. RNA pull-down and RIP assay confirmed the binding between lncRNA-CRNDE and SIRT1. qRT-PCR and western blot showed that interference with lncRNA-CRNDE significantly inhibited the protein expression of SIRT1. BMSCs transfected with si-CRNDE increased ubiquitination levels of SIRT1 mediated by the E3 ligase SMURF2, leading to the reduced protein stability of SIRT1. However, overexpression of lncRNA-CRNDE increased the binding ability of SOX9 and collagen 2 (α1) promoter, which was reversed by the simultaneous transfection of CRNDE overexpression (pcDNA-CRNDE) and SIRT1 small interfering RNA (si-SIRT1). lncRNA-CRNDE regulates BMSC chondrogenic differentiation to promote cartilage repair in osteoarthritis through SIRT1/SOX9.

Long noncoding RNA CRNDE functions as a diagnostic and prognostic biomarker in osteosarcoma, as well as promotes its progression via inhibition of miR-335-3p.

BACKGROUND: This study was performed to evaluate the diagnostic and prognostic value, as well as the role of long-chain noncoding RNA (lncRNA) colorectal neoplasia differentially expressed (CRNDE) in osteosarcoma (OS). MATERIALS AND METHODS: A quantitative real-time polymerase chain reaction assay was to determine lncRNA CRNDE and microRNA-335-3p (miR-335-3p) expressions. The Kaplan-Meier analysis was to analyze the relationship between lncRNA CRNDE expression and survival in patients with OS. Receiver operating characteristic curves were to evaluate the diagnostic value of lncRNA CRNDE in OS. Bioinformatics analysis and luciferase reporter assays were used to predict and confirm the relationship between lncRNA CRNDE and miR-335-3p. Cell counting Kit-8 and transwell migration assays assessed the role of lncRNA CRNDE and miR-335-3p in OS cells. RESULTS: lncRNA CRNDE expression was upregulated and miR-355-3p expression was downregulated in OS. In patients with OS, low lncRNA CRNDE expression demonstrated higher overall survival, whereas high lncRNA CRNDE expression was an independent poor prognostic factor. Furthermore, increased lncRNA CRNDE expression was associated with distant metastasis and the tumor-node-metastasis stage in patients with OS, which can be considered as an independent diagnostic biomarker in OS. We revealed that miR-335-3p was the target of lncRNA CRNDE. It also demonstrated that knockdown of lncRNA CRNDE inhibited OS cell proliferation, migration, and invasion, and inhibition of miR-355-3p promoted this effect. Finally, miR-335-3p partially mediated the stimulatory effects of lncRNA CRNDE in OS. CONCLUSION: We demonstrated that lncRNA CRNDE is a potential diagnostic and prognostic biomarker for OS, and the lncRNA CRNDE/miR-335-3p axis participates in OS progression.