lncRNA DANCR Research Articles

LncRNA DANCR promotes macrophage lipid accumulation through modulation of membrane cholesterol transporters.

The progression of atherosclerosis (AS), the pathological foundation of coronary artery disease (CAD), is featured by massive lipid deposition in the vessel wall. LncRNAs are implicated in lipid disorder and AS, whereas the specific role of lncRNA DANCR in atherogenesis remains unknown. Here, we demonstrated that DANCR promotes macrophage lipid accumulation by regulating the expression of membrane cholesterol transport proteins. qPCR showed that compared to control groups, CAD patients and atherosclerotic mice had higher DANCR levels. Treating human THP-1 macrophages and mouse RAW264.7 macrophages with ox-LDL significantly upregulated the expression levels of DANCR. Oil Red O staining showed that the silence of DANCR robustly reduced, while overexpression of DANCR significantly increased the numbers and size of lipid droplets in ox-LDL-treated THP-1 macrophages. In contrast, the opposite phenomena were observed in DANCR overexpressing cells. The expression of ABCA1, ABCG1, SR-BI, and NBD-cholesterol efflux was increased obviously by DANCR inhibition and decreased by DANCR overexpression, respectively. Furthermore, transfection with DANCR siRNA induced a robust decrease in the levels of CD36, SR-A, and Dil-ox-LDL uptake, while DANCR overexpression amplified the expression of CD36, SR-A and the uptake of Dil-ox-LDL in lipid-laden macrophages. Lastly, we found that the effects of DANCR on macrophage lipid accumulation and the expression of membrane cholesterol transport proteins were not likely related to miR-33a. The present study unraveled the adverse role of DANCR in foam cell formation and its relationship with cholesterol transport proteins. However, the competing endogenous RNA network underlying these phenomena warrants further exploration.

Activation of lncRNA DANCR by H3K27 acetylation regulates proliferation of colorectal cancer cells

The long noncoding DANCR functions as a tumor oncogene in many cancers, including colorectal cancer (CRC). However, the molecular mechanism of DANCR in CRC has not been explored. This study probed the function and potential mechanism by which DANCR contributes to the progression of CRC. The obtained data indicated that DANCR is overexpressed in CRC tissues and cell lines. Knockdown of DANCR hindered CRC cell proliferation, which was mediated by cyclin D1 and CDK4. Bioinformatic analysis, luciferase reporter assays and subcellular fractionation verified that DANCR directly binds to miR-508-5p. Moreover, DANCR acts as a miR-508-5p ceRNA to regulate expression of ATF1. In addition, upregulation of DANCR is attributed to H3K27 acetylation at the promoter region. In conclusion, our study confirmed that activation of lncRNA DANCR by H3K27 acetylation has an oncogenic role in CRC progression and provides a potential therapeutic target for CRC.

HOXB2 promotes cisplatin resistance by upregulating lncRNA DANCR in ovarian cancer

Ovarian cancer (OV) is a highly fatal malignant disease that commonly manifests at an advanced stage. Drug resistance, particularly platinum resistance, is a leading cause of treatment failure because first-line systemic chemotherapy primarily relies on platinum-based regimens. By analyzing the gene expression levels in the Cancer Genome Atlas database, Genotype-Tissue Expression database, and Gene Expression Omnibus datasets, we discerned that HOXB2 was highly expressed in OV and was associated with poor prognosis and cisplatin resistance. Immunohistochemistry and loss-of-function experiments on HOXB2 were conducted to explore its role in OV. We observed that suppressing HOXB2 could impair the growth and cisplatin resistance of OV in vivo and in vitro. Mechanical investigation and experimental validation based on RNA-Seq revealed that HOXB2 regulated ATP-binding cassette transporter members and the ERK signaling pathway. We further demonstrated that HOXB2 modulated the expression of long non-coding RNA DANCR, a differentiation antagonizing non-protein coding RNA, and thus influenced its downstream effectors ABCA1, ABCG1, and ERK signaling to boost drug resistance and cancer proliferation. These results verified that high expression of HOXB2 correlated with platinum resistance and poor prognosis of OV. Therefore, targeting HOXB2 may be a promising strategy for OV therapy.

Dancr-BRG1 regulates Nfatc1 transcription and Pgc1β-dependent metabolic shifts in osteoclastogenesis

Long non-coding RNA (lncRNA) serves as a vital regulator of bone metabolism, but its role in pathologically overactive osteoclast differentiation remains elusive. Here, we identify lncRNA Dancr (Differentiation Antagonizing Non-protein Coding RNA) as a critical suppressor of osteoclastogenesis and bone resorption, which is down-regulated in response to estrogen deficiency. Global or osteoclast-specific Dancr Knockout mice display significant trabecular bone deterioration and enhanced osteoclast activity, but minimal alteration of bone formation. Moreover, the bone-targeted delivery of Dancr by Adeno-associated viral remarkably attenuates ovariectomy-induced osteopenia in mice. Mechanistically, Dancr establishes a direct interaction with Brahma-related gene 1 to prevent its binding and preserve H3K27me3 enrichment at the nuclear factor of activated T cells 1 and proliferator-activated receptor gamma coactivator 1-beta promoters, thereby maintaining appropriate expression of osteoclastic genes and metabolic programs during osteoclastogenesis. These results demonstrate that Dancr is a key molecule maintaining proper osteoclast differentiation and bone homeostasis under physiological conditions, and Dancr overexpression constitutes a potential strategy for treating osteoporosis.

Long Non-Coding RNA Dancr Affects Myocardial Fibrosis in Atrial Fibrillation Mice via the MicroRNA-146b-5p/Smad5 Axis.

Atrial fibrillation (AF) is the most frequent arrhythmia, and myocardial fibrosis (MF) has a close association with atrial remodeling and leads to AF. This study aimed to explore the function of the long non-coding RNA (lncRNA) differentiation antagonizing non-protein coding RNA (Dancr)/microRNA (miR)-146b-5p/Smad5 axis on MF in AF mice. AF mouse models were established. Overexpression Dancr lentivirus was injected into AF mice to increase Dancr expression in myocardial tissues. LncRNA Dancr, miR-146b-5p, and Smad5 expression levels and inflammatory factors (IL-18 and TNF-α) in the myocardial tissues were measured. MF was measured and the expression levels of MF-related genes (COL1A1, α-SMA, and FN1) were detected. In addition, in vitro HL-1 cell rapid pacing models were constructed, and after lncRNA Dancr and miR-146b-5p-related construct transfection, cell viability and cell apoptosis were determined. LncRNA Dancr up-regulation ameliorated MF in the AF mice, reduced IL-18 and TNF-α expression levels in myocardial tissues, and decreased COL1A1, α-SMA, and FN1 expression levels. The in vitro HL-1 cell rapid pacing models suggested that miR-146b-5p overexpression reversed the inhibitory effects of lncRNA Dancr overexpression on MF in HL-1 cells, and Smad5 interference reversed the ameliorative effects of miR-146b-5p interference on MF in HL-1 cells. LncRNA Dancr can sponge miR-146b-5p to promote Smad5 expression, thereby delaying MF in AF mice.

Inhibition of lncRNA DANCR Prevents Heart Failure by Ameliorating Cardiac Hypertrophy and Fibrosis Via Regulation of the miR-758-3p/PRG4/Smad Axis.

The current work was developed to explore the functions and possible mechanism of PRG4 in cardiac hypertrophy and heart failure. Ang II-stimulated H9c2 cells and AC16 cells were used as in vitro cell models. The binding relation between genes in cells was explored using luciferase reporter assays and RNA immunoprecipitation assay. The cardiac functions of rats received transverse-ascending aortic constriction (TAC) surgery and adeno-associated virus (AAV) injection were examined with echocardiography. The myocardial histological changes were observed using H&E, wheat germ agglutinin, and sirius red staining. It was discovered that PRG4 silencing attenuated cell hypertrophy and fibrosis and inactivated the Smad pathway under Ang II treatment. PRG4 was targeted by miR-758-3p, and miR-758-3p interacted with long noncoding RNA DANCR. DANCR silencing inhibited cardiac dysfunction, fibrosis, and TGFβ1/Smad pathway. In addition, DANCR was highly expressed in myocardial extracellular vesicles. Overall, DANCR depletion prevents heart failure by inhibiting cardiac hypertrophy and fibrosis via the miR-758-3p/PRG4/Smad pathway.

LncRNA DANCR deficiency promotes high glucose-induced endothelial to mesenchymal transition in cardiac microvascular cells via the FoxO1/DDAH1/ADMA signaling pathway

Cardiac fibrosis is the main pathological basis of diabetic cardiomyopathy (DCM), and endothelial-to-meschenymal transition (EndMT) is a key driver to cardiac fibrosis and plays an important role in the pathogenesis of DCM. Asymmetric dimethylarginine (ADMA), a crucial pathologic factor in diabetes mellitus, is involved in organ fibrosis. This study aims to evaluate underlying mechanisms of ADMA in DCM especially for EndMT under diabetic conditions. A diabetic rat model was induced by streptozotocin (STZ) injection, and human cardiac microvascular endothelial cells (HCMECs) were stimulated with high glucose to induce EndMT. Subsequently, the role of ADMA in EndMT was detected either by exogenous ADMA or by over-expressing dimethylarginine dimethylaminohydrolase 1 (DDAH1, degradation enzyme for ADMA) before high glucose stimulation. Furthermore, the relationships among forkhead box protein O1 (FoxO1), DDAH1 and ADMA were evaluated by FoxO1 over-expression or FoxO1 siRNA. Finally, we examined the roles of LncRNA DANCR in FoxO1/DDAH1/ADMA pathway and EndMT of HCMECs. Here, we found that EndMT in HCMECs was induced by high glucose, as evidenced by down-regulated expression of CD31 and up-regulated expression of FSP-1 and collagen Ⅰ. Importantly, ADMA induced EndMT in HCMECs, and over-expressing DDAH1 protected from developing EndMT by high glucose. Furthermore, we demonstrated that over-expression of FoxO1-ADA with mutant phosphorylation sites of T24A, S256D, and S316A induced EndMT of HCMECs by down-regulating of DDAH1 and elevating ADMA, and that EndMT of HCMECs induced by high glucose was reversed by FoxO1 siRNA. We also found that LncRNA DANCR siRNA induced EndMT of HCMECs, activated FoxO1, and inhibited DDAH1 expression. Moreover, over-expression of LncRNA DANCR could markedly attenuated high glucose-mediated EndMT of HCMECs by inhibiting the activation of FoxO1 and increasing the expression of DDAH1. Collectively, our results indicate that LncRNA DANCR deficiency promotes high glucose-induced EndMT in HCMECs by regulating FoxO1/DDAH1/ADMA pathway.

IGF2BP2 promotes lncRNA DANCR stability mediated glycolysis and affects the progression of FLT3-ITD + acute myeloid leukemia

Internal tandem duplication (ITD) is the most common type of FLT3 mutation (FLT3-ITD), accounting for about 25% of AML patients. The expression of DANCR in FLT3-ITD AML had not been paid attention to, and whether its regulatory relationship with IGF2BP2 can affect the progression of FLT3-ITD AML was unclear. Our study sought to verify the biological role of IGF2BP2 as an m6A reading protein in FLT3-ITD AML. To further explore the role and mechanism of DANCR in AML, and provide a basis for the screening of biomarkers and the development of targeted drugs. The results show that IGF2BP2 was upregulated in FLT3-ITD+ AML patients and cells. Si-IGF2BP2 could inhibit the proliferation, glycolytic and promote the apoptosis in MV4-11 cells. IGF2BP2 could promote the DANCR RNA stability. This discovery will provide new horizons for early screening and targeted therapy of FLT3-ITD+ AML.

LncRNA DANCR counteracts premature ovarian insufficiency by regulating the senescence process of granulosa cells through stabilizing the interaction between p53 and hNRNPC

BackgroundPremature ovarian insufficiency (POI) is one of the common women reproductive endocrine diseases which adversely impacts female fertility, but the etiology and pathogenesis still remain elusive. Recently increasing researches focus on the roles of lncRNA in POI. LncRNA DANCR was involved in cell differentiation and multiple cancers. It’s highly expressed in ovary while the role of DANCR in POI is still unknown.ResultsHere, we identify a new POI related lncRNA DANCR, which negatively contributes to ovarian granulosa cells aging and follicular atresia. DANCR is proved to be decreasingly expressed in POI patients’ granulosa cells. Additionally, Dancr knockout (Dancr−/−) mice were constructed and characterized with POI phenotypes and fertility decline, compared with Dancr+/+ mice. Further, in vitro experiments indicated that DANCR knockdown in granulosa cells led to cell aging and series of aging-related changes including proliferation inhibition, cell cycle G1 arrest and DNA damage. Mechanism research revealed DANCR binds with hNRNPC and p53, while DANCR knockdown attenuates the binding of hNRNPC and p53, thus enhancing protein level of p53 and promoting granulosa cells aging significantly.ConclusionThe newly identified lncRNA DANCR inhibits p53-dependent granulosa cells aging by regulating hNRNPC-p53 interaction, and eventually counteracting POI. This provides new insights into the pathogenesis of POI and provides a potential target for future diagnosis and treatment.

Long noncoding RNA DANCR expression and its predictive value in patients with atherosclerosis

ABSTRACT Long noncoding RNAs (lncRNAs) act crucial roles in the progression of vascular diseases, including atherosclerosis. This study aims to investigate the expression levels of the atherosclerosis-associated lncRNA DANCR in patients diagnosed with atherosclerosis and whether its abnormal expression affects the progress of atherosclerosis. The expression of DANCR in the serum samples of all study participants was quantified using RT-qPCR. Then, the predictive capacities of DANCR for the detection of atherosclerosis patients were evaluated via receiver operating characteristic (ROC) curve analysis. The effects of DANCR on vascular smooth muscle cells (VSMCs) proliferation and migration were then explored using cell counting kit-8 (CCK-8) and Transwell migration assays. The DANCR exhibited increased expression trends in patients with atherosclerosis than healthy controls. Moreover, there were differences in the levels of low-density lipoprotein cholesterol (LDL-C), homocysteine (Hcy), and C-reactive protein (CRP) between the healthy controls and atherosclerosis patients. The DANCR expression was positively correlated with serum LDL-C, Hcy, and CRP levels. DANCR expression could distinguish patients with atherosclerosis from healthy individuals with a high area under the ROC curve (AUC), sensitivity, and specificity. Additionally, knockdown of DANCR weakened the proliferative abilities and migration capacities of VSMCs. It was also shown that DANCR could compete with miR-335-5p binding. Herein, it appears that the LncRNA DANCR was closely associated with the progression of atherosclerosis by targeting miR-335-5p, which might be a potential detective predictor and target for the treatment of atherosclerosis.

IGF2BP2 Induces U251 Glioblastoma Cell Chemoresistance by Inhibiting FOXO1-Mediated PID1 Expression Through Stabilizing lncRNA DANCR.

Glioma is the most common type of malignant tumor of the nervous system and is characterized by high mortality and poor outcome. This study aims to investigate the mechanism underlying IGF2 mRNA-binding protein 2 (IGF2BP2) and long noncoding RNA DANCR in etoposide resistance of glioblastoma (GBM) cells. Bioinformatics analysis identified the IGF2BP2-related regulators and DANCR target genes, which were subsequently evaluated by RNA pull-down and RIP assays. We exposed GBM cells to etoposide and thus established etoposide-resistant cells. Through functional experiments, we evaluated the interrelationship among IGF2BP2, DANCR, phosphotyrosine interaction domain containing 1 (PID1), and forkhead box protein O1 (FOXO1) and further assessed their impact on the sensitivity of GBM cells to etoposide. IGF2BP2 and DANCR were highly expressed in glioma cells and tissues, whereas PID1 and FOXO1 were poorly expressed. Mechanistically, overexpression of IGF2BP2 promoted DANCR stability and reduced DANCR methylation, whereas silencing of IGF2BP2 reduced survival of GBM cells and etoposide-resistant cells. Besides, DANCR interacted with FOXO1 to promote the ubiquitination of FOXO1. FOXO1 promoted the transcriptional expression of PID1, enhancing the chemotherapy sensitivity of GBM cells, but overexpression of PID1 reversed the impact of IGF2BP2. Collectively, IGF2BP2 inhibits PID1 expression through the DANCR/FOXO1 axis, inducing drug resistance in GBM cells, and promoting glioma progression.

METTL3 Contributes to Osteosarcoma Progression by Increasing DANCR mRNA Stability via m6A Modification.

Background: Osteosarcoma (OS) is the most prevalent bone cancer among children and adolescents, with relatively high mortality rates. RNA N6-methyladenosine (m6A) is the most common human mRNA modification with diverse functions in a variety of biological processes. Previous studies indicated that methyltransferase-like 3 (METTL3), the first methyltransferase to be identified, acted as an oncogene or tumor suppressor in multiple human cancers. However, its functions and underlying mechanisms in OS progression remain unclear; therefore, we explored these processes. Methods: We used real-time quantitative PCR (RT-qPCR) and Western blot assays to explore METTL3 expression in OS tumor tissues and five OS cell lines to assess its clinical significance. To further examine the functional role of METTL3 during OS progression, CCK-8 analyses, transwell assays, and xenograft model studies were conducted after silencing METTL3. Additionally, underlying mechanisms were also explored using RIP-seq and RIP-qPCR approaches. Results: METTL3 was upregulated in OS tumor tissues and cell lines and was associated with a worse prognosis. Moreover, METTL3 silencing suppressed OS cell proliferation, migration, and invasion. Also, in vivo METTL3 oncogenic functions were confirmed in the xenograft model. Comprehensive mechanistic analyses identified long non-coding RNA (lncRNA) DANCR as a potential target of METTL3, as indicated by reduced DANCR levels after METTL3 silencing. Also, lncRNA DANCR knockdown repressed OS cell proliferation, migration, and invasion. Furthermore, both METTL3 and lncRNA DANCR silencing significantly suppressed OS growth and metastasis. Finally, we hypothesized that METTL3 regulated DANCR expression via m6A modification-mediated DANCR mRNA stability. Conclusion: METTL3 contributes to OS progression by increasing DANCR mRNA stability via m6A modification, meaning that METTL3 may be a promising therapeutic target for OS treatment.

LncRNA DANCR promotes the migration an invasion and of trophoblast cells through microRNA-214-5p in preeclampsia

ABSTRACT Studies have shown that lncRNA DANCR is down-regulated in placental tissues of patients with preeclampsia (PE). The aim of this study was to explore the effect of lncRNA DANCR on trophoblast cells as well as its acting mechanism. We disrupted or overexpressed lncRNA DANCR in trophoblast cells HTR-8/SVneo and JEG-3 and detected the associated cellular functional changes by MTT, flow cytometry, Transwell experiment, and scratch experiment. The results showed that overexpression of lncRNA DANCR significantly increased the proliferation, invasion, migration, and EMT process of trophoblast cells. Interfering with lncRNA DANCR showed the opposite result. Further, the targeted interaction between lncRNA DANCR and miR-214-5p was confirmed by the dual-luciferase reporter gene assay. In addition, the expression of PI3K/AKT signaling pathway-related proteins was analyzed by Western blot. Overexpression of lncRNA DANCR can increase the phosphorylation of PI3K/AKT protein and activate this signaling pathway. In conclusion, the enforcing of lncRNA DANCR activates the activation of the PI3K/AKT pathway by down-regulating miR-214-5p, and promotes the migration and invasion of chorionic trophoblast cells. This provides a potential new target for PE therapy.

LncRNA DANCR Restrains Sensitivity to 5-fluorouracil in Prostate Cancer through Sponging MiR-577

ABSTRACT This present study explored the functions of lncRNA DANCR on regulating sensitivity to 5-fluorouracil (5- FU) in prostate cancer in vitro. The RT-qPCR examined RNA expressions of LNCRNA DANCR in RWPE-1, VCaP, PC3 and LNCaP cells, which also measured RNA levels of miR-577 in PC3 cells. DANCR was highly expressed in prostate cancer cell lines. 5-FU (0, 1, 5 and 10¼M) treatment induced the decrease of PC3 cell viability and low RNA expressions of DANCR but increased miR-577 in PC3 cells. The luciferase reporter test detected the binding between DNACR and miR- 577 . Interactions between DANCR and miR-577 were examined. Knockdown of DANCR downregulated DANCR and Bcl- 2 RNA expressions but accelerated cell viability and upregulated Bax, which were enhanced by the overexpression of miR- 577. Hence, DANCR might restrain sensitivity of prostate cancer cells to 5-FU by downregulating miR-577

Long Non-coding RNA DANCR in Cancer: Roles, Mechanisms, and Implications.

Long non-coding RNA (lncRNA) DANCR (also known as ANCR)—differentiation antagonizing non-protein coding RNA, was first reported in 2012 to suppress differentiation of epithelial cells. Emerging evidence demonstrates that DANCR is a cancer-associated lncRNA abnormally expressed in many cancers (e.g., lung cancer, gastric cancer, breast cancer, hepatocellular carcinoma). Increasing studies suggest that the dysregulation of DANCR plays critical roles in cancer cell proliferation, apoptosis, migration, invasion, and chemoresistance in vitro and tumor growth and metastasis in vivo. Mechanistic analyses show that DANCR can serve as miRNA sponges, stabilize mRNAs, and interact with proteins. Recent research reveals that DANCR can be detected in many body fluids such as serum, plasma, and exosomes, providing a quick and convenient method for cancer monitor. Thus DANCR can be used as a promising diagnostic and prognostic biomarker and therapeutic target for various types of cancer. This review focuses on the role and mechanism of DANCR in cancer progression with an emphasis on the clinical significance of DANCR in human cancers.

KLF5 activates lncRNA DANCR and inhibits cancer cell autophagy accelerating gastric cancer progression

Cancer cell autophagy has been associated with the progression of gastric cancer (GC), but involvement of long noncoding RNAs (lncRNAs) remains unclear. Initial bioinformatics analysis has identified abnormally highly expressed KLF5 in GC, as well as the predicted regulatory mechanism associating with lncRNA DANCR, miR-194, and AKT2. The expression of KLF5, DANCR, and AKT2 in GC tissue was upregulated, and the expression of miR-194 was downregulated. We knocked KLF5 down and manipulated the expression of DANCR, miR-194, and AKT2 to characterize their roles in GC cell viability, autophagy, and apoptosis. The mechanistic investigations revealed that KLF5 activated the transcription of DANCR in the promoter region and elevated its expression. DANCR acted as a miR-194 sponge to repress its expression in GC. MiR-194 targeted and inhibited AKT2 expression. Silencing KLF5 augmented GC cell autophagy, apoptosis and impeded its viability through the DANCR/miR-194/AKT2 axis. The tumor-inhibiting properties of KLF5 knockdown were substantiated in vivo. Together, our study uncovered the oncogenic role of KLF5-dependent lncRNA DANCR transcription in GC in vivo and in vitro, which implicates the miR-194/AKT2 axis in tumor growth regulation, and it may be a potential therapeutic target for human GC.

Prognostic significance of lncRNA DANCR expression in human cancers: a systematic review and meta-analysis.

Several studies demonstrated that lncRNA differentiation antagonizing non-protein coding RNA (lncRNA DANCR) expression might have the potential capacity to predict the cancer prognosis; however, definite conclusion has not been obtained. The aim of this meta-analysis was to evaluate the prognostic value of lncRNA DANCR expression in cancers. PubMed, Web of Science, Scopus, and Embase were comprehensively searched for relevant studies. Studies meeting all inclusion standards were included into this meta-analysis. The analysis of overall survival (OS), disease-free survival (DFS), or clinicopathological features was conducted. Total 11 studies containing 1154 cancer patients were analyzed in this meta-analysis. The results showed, compared with low lncRNA DANCR expression, high lncRNA DANCR expression was significantly associated with shorter OS (hazard ratio [HR] = 1.85; 95% CI = 1.52–2.26; P<0.01) and DFS (HR = 1.82; 95% CI = 1.43–2.32; P<0.01) in cancers. Besides, high lncRNA DANCR expression predicted deeper tumor invasion (P<0.01), earlier lymph node metastasis (P<0.01), earlier distant metastasis (P<0.01), and more advanced clinical stage (P<0.01) compared with low lncRNA DANCR expression in cancer populations. High lncRNA DANCR expression was associated with worse prognosis compared with low lncRNA DANCR expression in cancers. LncRNA DANCR expression could serve as a prognostic factor of human cancers.

Assessment of lncRNA DANCR, miR-145-5p and NRAS axis as biomarkers for the diagnosis of colorectal cancer.

Recent evidence reveals that miRNA sponges neutralize miRNAs activity by binding to miRNAs and sequester them from their relevant targets to regulate expression. The detailed mechanisms of sponge RNAs in colorectal cancer remain to be exactly determined. In this study DANCR, miR-145-5p, NRAS axis was evaluated and the diagnostic value of these targets was assessed in colorectal cancer patients. A case-control study was carried out on 40 samples of tumor tissues and 40 adjacent tissues. Total RNA was extracted, and then, the expression level of DANCR, miR-145-5p and NRAS was evaluated using qRT-PCR. In addition, the sensitivity and specificity of these markers were evaluated by receiver operating characteristic (ROC) curve analysis. Our results revealed that the expression level of DANCR was significantly upregulated in colorectal cancer tissues (p < 0.001). It was demonstrated that DANCR could regulate NRAS expression by sponging miR-145-5 in colorectal cancer patients. Furthermore, the mean expression of miR-145-5p (p < 0.001) and NRAS (p < 0.001) was significantly different between tumor and normal tissue. A significant correlation was observed between DANCR and miR-145-5p (p = 0.001), and also between miR-145-5p and NRAS (p < 0.001). Sensitivity and specificity value for DANCR, miR-145-5p and NRAS were (0.875 and 0.725), (0.875 and 0.745), and (0.877 and 0.694), respectively. According to the values of sensitivities and specificity of DANCR, miR-145-5p and NRAS, confirmed with ROC curve analysis, these biomarkers may be useful in the screening and differentiating between tumor and control sample in colorectal neoplasm.

LncRNA DANCR represses Doxorubicin-induced apoptosis through stabilizing MALAT1 expression in colorectal cancer cells

Long non-coding RNA (lncRNA) DANCR has been reported to participate in key processes such as stem cell differentiation and tumorigenesis. In a high throughput screening for lncRNAs involved in Doxorubicin-induced apoptosis, we found DANCR was suppressed by Doxorubicin and it acted as an important repressor of apoptosis in colorectal cancer. Further studies demonstrated that DANCR promoted the oncogenic lncRNA MALAT1 expression via enhancing the RNA stability of MALAT1 to suppress apoptosis. MALAT1 could efficiently mediate the suppressive function of DANCR on apoptosis. Mechanistic studies found the RNA-binding protein QK served as an interacting partner of both DANCR and MALAT1, and the protein level of QK was subjected to the regulation by DANCR. Furthermore, QK was able to modulate the RNA stability of MALAT1, and the interaction between QK and MALAT1 was controlled by DANCR. In addition, QK could mediate the function of DANCR in regulating the expression of MALAT1 and suppressing apoptosis. These results revealed DANCR played a critical role in Doxorubicin-induced apoptosis in colorectal cancer cells, which was achieved by the interaction between DANCR and QK to enhance the expression of MALAT1.

Crosstalk between lncRNA DANCR and miR-125b-5p in HCC cell progression.

To investigate the mechanism of long noncoding RNA (lncRNA) DANCR on the progression of hepatocellular carcinoma (HCC) cells. The expression levels of DANCR and miR-125b-5p were measured in normal hepatocytes (LO2) and HCC cell lines by quantitative reverse transcription polymerase chain reaction. HepG2 and Huh-7 cells were transfected with sh-DANCR, the negative control (sh-NC), miR-125b-5p mimic, or mimic NC or cotransfected with sh-DANCR and miR-125b-5p inhibitor. HCC cell proliferation was assessed through CCK8 and plate colony formation assay. Western blot quantified the expression levels of Bcl-2, Bax, caspase-3, and cleaved-caspase-3. Apoptotic rate was detected as well as migratory and invasive capacities. The implication of the MAPK signal pathway was assessed by detecting the expression levels of p38, ERK1/2, JNK, p-p38, p-ERK1/2, and p-JNK. Interactions between DANCR and miR-125b-5p were detected by dual luciferase reporter assay. In HCC cells, DANCR was highly expressed and miR-125b-5p was decreased. sh-DANCR or miR-125b-5p mimic stimulation reduced HepG2 or Huh-7 cell progression while promoted cell apoptosis evidenced by increased apoptotic rate, elevated levels of Bax and cleaved-caspase-3, and decreased Bcl-2. Moreover, the migration rate and invasiveness of HCC cells were also inhibited by sh-DANCR and miR-125b-5p mimic. Levels of p-p38/p38, p-ERK1/2/ERK1/2, and p-JNK/JNK were suppressed by sh-DANCR and miR-125b-5p mimic. LncRNA DANCR negatively targeted and directly bound to miR-125b-5p. Knockdown of miR-125b-5p could reverse the inhibitory effects of sh-DANCR on HCC cells. In HCC cells, lncRNA DANCR sponges miR-125b-5p and activates MAPK pathway, thus facilitating HCC cell progression.