Expression Of KCNQ1OT1 Research Articles

KCNQ1OT1 contributes to sorafenib resistance and programmed death‑ligand‑1‑mediated immune escape via sponging miR‑506 in hepatocellular carcinoma cells.

Drug resistance and immune escape of tumor cells severely compromise the treatment efficiency of hepatocellular carcinoma (HCC). Long non-coding RNA KCNQ1 overlapping transcript 1 (lncRNA KCNQ1OT1) has been shown to be involved in drug resistance in several cancers. The aim of the present study was to investigate the role of KCNQ1OT1 in sorafenib resistance and immune escape of HCC cells. Reverse transcription-quantitative PCR analysis, western blotting and immunohistochemistry were performed to detect the expression of KCNQ1OT1, miR-506 and programmed death-ligand-1 (PD-L1). Cell Counting Kit-8 assay, flow cytometry and Transwell assays were used to evaluate IC50 value, cell apoptosis and metastasis. ELISA was performed to detect the secretion of cytokines. Dual-luciferase reporter assay was conducted to verify the targeting relationships between miR-506 and KCNQ1OT1 or PD-L1. KCNQ1OT1 and PD-L1 were found to be upregulated and miR-506 was downregulated in sorafenib-resistant HCC tissues and cells. Furthermore, KCNQ1OT1 knockdown reduced the IC50 value of sorafenib, suppressed cell metastasis and promoted apoptosis in sorafenib-resistant HCC cells. Moreover, KCNQ1OT1 knockdown changed the tumor microenvironment and T-cell apoptosis in a sorafenib-resistant HCC/T-cell co-culture model. In addition, it was demonstrated that KCNQ1OT1 functioned as a competing endogenous RNA of miR-506 and increased PD-L1 expression in sorafenib-resistant HCC cells. miR-506 inhibition abolished the effects of KCNQ1OT1 knockdown on sorafenib sensitivity, tumor growth, the tumor microenvironment and T-cell apoptosis. In conclusion, KCNQ1OT1 knockdown inhibited sorafenib resistance and PD-L1-mediated immune escape by sponging miR-506 in sorafenib-resistant HCC cells.

LncRNA KCNQ1OT1 is a key factor in the reversal effect of curcumin on cisplatin resistance in the colorectal cancer cells.

The development of cisplatin resistance is a common cause of cancer recurrence in colorectal cancer (CRC). Though many studies have reported the oncogenic function of long non-coding RNA (LncRNA) KCNQ1OT1 in multiple cancers, few studies explored its role in cisplatin resistance of CRC. Curcumin is a natural phenolic compound extracted from turmeric, which can effectively suppress cisplatin resistance in CRC. This study aims to expound the role of KCNQ1OT1 in cisplatin resistance in CRC cells and whether KCNQ1OT1 participates in the reversal effect of curcumin on cisplatin resistance in CRC. The interplay between KCNQ1OT1 and miR-497 was determined using RNA pull-down assay and dual-luciferase reporter gene assay. The combination of B-cell lymphoma 2 (Bcl-2) and miR-497 was confirmed using dual-luciferase reporter gene assay. Compared with CRC cell line HCT8, the cisplatin-resistant CRC cell line HCT8/DDP exhibited a higher expression level of KCNQ1OT1. Functionally, the silence of KCNQ1OT1 suppressed proliferation and boosted apoptosis in HCT8/DDP cells. Subsequently, we found that KCNQ1OT1 could act as a sponge of miR-497 and remove the suppressive effect of miR-497 on Bcl-2 expression. Curcumin treatment restrained proliferation and facilitated apoptosis in HCT8/DDP cells. While KCNQ1OT1 overexpression removed the effect of curcumin on HCT8/DDP cells via miR-497/ Bcl-2 axis. Finally, the in vivo experiments showed that the inhibitory effect of curcumin on the growth of cisplatin-resistant CRC cells was reserved by the ectopic expression of KCNQ1OT1. In conclusion,KCNQ1OT1 aggravated cisplatin resistance in CRC cells via the miR-497/Bcl-2 axis. Administration of curcumin could effectively downregulate KCNQ1OT1 expression, thus reversing cisplatin resistance in CRC cells.

Long Non-Coding RNA KCNQ1OT1 Promotes Multidrug Resistance in Chordoma by Functioning as a Molecular Sponge of miR-27b-3p and Subsequently Increasing ATF2 Expression.

BackgroundChordoma, a rare bone tumor, occurs most commonly at the sacrococcygeal and skull base region. To date, chemotherapy is used to treat patients with advanced-stage chordoma. However, multidrug resistance (MDR) greatly hinders the effect of chemotherapy in chordoma. Here, we studied the correlation between KCNQ1OT1 and chemotherapy resistance.MethodsRT-PCR assay was used to examine KCNQ1OT1, miR-27b-3p, and ATF2 mRNA expression. CCK8 assay was exercised to detect IC50 values of cisplatin in chordoma cells. ATF2 protein expression was detected by Western blot.ResultsKCNQ1OT1 was increased in chemotherapy-resistant patients and cisplatin-resistant cells, and downregulation of KCNQ1OT1 expression weakened MDR in chordoma. In addition, KCNQ1OT1 promoted MDR in chordoma by sponging miR-27b-3p and subsequently increasing ATF2 expression.ConclusionKCNQ1OT1 is proved to be strikingly raised in the chemotherapy-resistant group and to promote MDR in chordoma. Our findings demonstrated the role of the KCNQ1OT1/miR-27b-3p/ATF2 axis in MDR of chordoma, which provides new insight into the molecular mechanism of chordoma MDR, and may determine the effect of therapy after receiving chemotherapy by detecting the expression of KCNQ1OT1 in serum.

6-Gingerol protects cardiomyocytes against hypoxia-induced injury by regulating the KCNQ1OT1/miR-340-5p/PI3K/AKT pathway.

Hypoxia could induce cardiomyocytes injury and lead to heart disease. Studies have shown that 6-Gingerol has a protective effect on cardiomyocytes injury, but its molecular mechanism is still unclear. Cell counting kit 8 (CCK8) and flow cytometry assays were used to measure the viability and apoptosis of cardiomyocytes. Western blot (WB) analysis was performed to assess the levels of proliferation, apoptosis, and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway-related proteins. The reactive oxygen species (ROS) level, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level were detected by their corresponding Assay Kits. Besides, the expression levels of potassium voltage-gated channel subfamily Q member 1 opposite strand 1 (KCNQ1OT1) and microRNA-340-5p (miR-340-5p) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Furthermore, dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to verify the interaction between KCNQ1OT1 and miR-340-5p. Hypoxia could inhibit the viability and enhance the apoptosis and oxidative stress of cardiomyocytes to induce cardiomyocytes injury, while 6-Gingerol could alleviate this effect. Overexpression of KCNQ1OT1 aggravated hypoxia-induced cardiomyocytes injury and reversed the protective effect of 6-Gingerol on cardiomyocytes injury. Besides, miR-340-5p could be sponged by KCNQ1OT1, and its overexpression could invert the promotion effect of KCNQ1OT1 overexpression on hypoxia-induced cardiomyocytes injury. Moreover, miR-340-5p expression was regulated by 6-Gingerol and KCNQ1OT1. In addition, hypoxia inactivated the PI3K/AKT signaling pathway, whereas 6-Gingerol and miR-340-5p could reverse this effect. 6-Gingerol could hinder the expression of KCNQ1OT1 to protect cardiomyocytes from hypoxia-induced injury through regulation of the miR-340-5p/ PI3K/AKT pathway, providing a new mechanism of 6-Gingerol protecting cardiomyocytes from injury.

Long noncoding RNA KCNQ1OT1 promotes colorectal carcinogenesis by enhancing aerobic glycolysis via hexokinase-2.

In this study, we investigated the mechanistic role and prognostic significance of the long coding RNA (lncRNA) KCNQ1OT1 in colorectal cancer (CRC). KCNQ1OT1 levels were significantly higher in CRC tissues than adjacent normal colorectal tissues (n=79). High KCNQ1OT1 expression correlated with poorer prognosis in CRC patients. KCNQ1OT1-silenced CRC cells showed reduced proliferation, colony formation, extracellular acidification, and lactate and glucose secretion. This suggests KCNQ1OT1 promotes CRC cell proliferation by increasing aerobic glycolysis. RNA pull-down assays with biotinylated KCNQ1OT1 followed by mass spectrometry analysis showed that KCNQ1OT1 directly binds to hexokinase 2 (HK2). This was confirmed by RNA immunoprecipitation assays using anti-hexokinase 2 antibody. HK2 protein levels were reduced in KCNQ1OT1 knockdown CRC cells, but were restored by treatment with the proteasomal inhibitor MG132. KCNQ1OT1 knockdown CRC cells also showed higher ubiquitinated-HK2 levels, suggesting KCNQ1OT1 enhances aerobic glycolysis by stabilizing HK2. HK2 overexpression in KCNQ1OT1 knockdown CRC cells restored proliferation and aerobic glycolysis. KCNQ1OT1 levels correlated positively with HK2 expression and prognosis in CRC patients. These findings show that KCNQ1OT1 promotes colorectal carcinogenesis by increasing aerobic glycolysis through HK2.

LncRNA Kcnq1ot1 renders cardiomyocytes apoptosis in acute myocardial infarction model by up-regulating Tead1

Acute myocardial infarction (AMI) is a major cardiovascular disease with high mortality worldwide. Hypoxia is a key inducing factor for AMI. We aimed to examine the expression and functions of Kcnq1ot1 (KCNQ1 overlapping transcript 1) in hypoxia-induced cardiomyocytes in the process of AMI. The left anterior descending coronary artery ligation (LAD) was used for inducing in-vivo AMI model and the primary cardiomyocytes were extracted; in-vitro H9c2 cell model was simulated by hypoxia treatment. TUNEL, flow cytometry and JC-1 assay were carried out to evaluate cell apoptosis. Mechanism assays including luciferase reporter assay and RIP assay revealed interplays between RNAs. To begin with, Kcnq1ot1 was revealed to be conspicuously upregulated in myocardium infracted zone and border zone within 2 days since establishment of the model. Moreover, inhibition of Kcnq1ot1 protected cardiomyocytes against hypoxia-triggered cell apoptosis during the process of AMI. Then, miR-466k and miR-466i-5p were proved to bind with Kcnq1ot1 and participated in Kcnq1ot1-mediated cardiomyocyte injury under hypoxia. Subsequently, Kcnq1ot1 was found to elevate Tead1 (TEA domain transcription factor 1) expression via sponging miR-466k and miR-466i-5p. Finally, it was verified that Kcnq1ot1 regulated hypoxia-induced cardiomyocyte injury dependent on Tead1. In conclusion, Kcnq1ot1 sponged miR-466k and miR-466i-5p to up-regulate Tead1, thus triggering cardiomyocyte injury in the process of AMI.

LncRNA KCNQ1OT1 promotes cell proliferation, migration and invasion via regulating miR-129-5p/JAG1 axis in non-small cell lung cancer

BackgroundNon-small cell lung cancer (NSCLC) is the most deadly cancer worldwide. LncRNA KCNQ1OT1 has been reported to be involved in the progression of various tumors, including NSCLC. However, the precise mechanism of KCNQ1OT1 in NSCLC requires further investigation.MethodsThe expression levels of KCNQ1OT1, miR-129-5p and JAG1 were detected by qRT-PCR or western blot. Kaplan–Meier survival analysis was used to assess the correlation between KCNQ1OT1 expression and the overall survival of NSCLC patients. CCK-8 assay was used to measure cell viability. Cell migration and invasion were detected by transwell assay. The targets of KCNQ1OT1 and miR-129-5p were predicted by bioinformatics, which was confirmed by dual-luciferase reporter assay or pull-down assay.ResultsKCNQ1OT1 expression was significantly enhanced, while miR-129-5p expression was dramatically reduced in NSCLC tissues and cells. Higher KCNQ1OT1 shortened overall survival and was positively associated with tumor stage and lymph node metastasis. KCNQ1OT1 knockdown inhibited proliferation, migration and invasion of NSCLC cells. Inhibition of miR-129-5p attenuated the inhibition of NSCLC cell viability, migration and invasion induced by KCNQ1OT1 knockdown. In addition, JAG1 was confirmed as a target of miR-129-5p. Knockdown of JAG1 reversed the effects of miR-129-5p knockdown on NSCLC progression. KCNQ1OT1 regulated JAG1 expression by sponging miR-129-5p in NSCLC cells.ConclusionKCNQ1OT1 induced proliferation, migration and invasion of NSCLC cells by sponging miR-129-5p and regulating JAG1 expression, indicating that KCNQ1OT1 was a therapeutic target for NSCLC.

ARTICLE WITHDRAWN] Long Noncoding RNA KCNQ1OT1 Accelerates the Progression of Ovarian Cancer via MicroRNA-212-3/LCN2 Axis.

Long noncoding RNA KCNQ1OT1 (KCNQ1OT1) has been identified to be deregulated in several kinds of cancers. However, its expression pattern and functions in ovarian cancer remain unknown. Bioinformatics analysis showed that miR-212-3p, an identified suppressor in ovarian cancer, was a direct target of KCNQ1OT1, suggesting that KCNQ1OT1 may play a role in ovarian cancer progression via targeting miR-212-3p. Here we aimed to explore the effect of KCNQ1OT1 on the carcinogenesis of ovarian cancer, as well as to investigate miR-212-3p roles in this process. The expression of KCNQ1OT1 and miR-212-3p in ovarian cancer tissues and cells was detected by qPCR. MTT, flow cytometry, wound healing, Transwell chambers, and in vivo tumor formation assays were carried out to assess cell proliferation, apoptosis, migration, invasion, and tumorigenesis, respectively. RNA pulldown and luciferase gene reporter assays were used to evaluate the RNA–RNA interaction. The results showed that KCNQ1OT1 was overexpressed in ovarian cancer tissues and cells, which closely associated with the advanced clinic process and poor prognosis in ovarian cancer patients. Upregulation of KCNQ1OT1 significantly enhanced cell growth, migration, and invasion and inhibited cell apoptosis via miR-212-3p. In addition, we identified that lipocalin2 (LCN2) was a direct target of miR-212-3p and functioned as an oncogene to promote cell growth and to inhibit cell apoptosis. Furthermore, we observed that KCNQ1OT1 overexpression significantly enhanced the tumorigenesis of SKOV3 cells, whereas this effect was significantly impaired when LCN2 expression was downregulated. Overall, the present study reveals that KCNQ1OT1 functions as an oncogene in ovarian cancer via targeting miR-212-3p/LCN2 axis, which might provide new markers and targets for ovarian cancer diagnosis and treatment.

PNN and KCNQ1OT1 Can Predict the Efficacy of Adjuvant Fluoropyrimidine-Based Chemotherapy in Colorectal Cancer Patients.

The benefit of adjuvant chemotherapy in the early stages of colorectal cancer (CRC) is still disappointing and the prediction of treatment outcome quite difficult. Recently, through a transcriptomic approach, we evidenced a role of PNN and KCNQ1OT1 gene expression in predicting response to fluoropyrimidine-based adjuvant chemotherapy in stage III CRC patients. Thus, the aim of this study was to validate in an independent cohort of stages II–III CRC patients our previous findings. PNN and KCNQ1OT1 mRNA expression levels were evaluated in 74 formalin-fixed paraffin-embedded tumor and matched normal mucosa samples obtained by stages II–III CRC patients treated with fluoropyrimidine-based adjuvant chemotherapy. PININ, the protein encoded by PNN, was immunohistochemically evaluated in 15 tumor and corresponding normal mucosa samples, selected on the basis of a low, medium, or high mRNA expression tumor/mucosa ratio. PNN and KCNQ1OT1 mRNA mean expression levels were significantly higher in tumor compared with normal tissues. Patients with high PNN or KCNQ1OT1 tumor mRNA levels according to ROC-based cutoffs showed a shorter disease-free survival (DFS) compared with patients with low tumor mRNA gene expression. Also, patients with tumor mRNA expression values of both genes below the identified cutoffs had a significantly longer DFS compared with patients with the expression of one or both genes above the cutoffs. In a representative large cohort of stages II–III CRC untreated patients retrieved from GEO datasets, no difference in DFS was observed between patients with high and low PNN or KCNQ1OT1 gene expression levels. These data confirm our previous findings and underscore the relevance of PNN and KCNQ1OT1 expression in predicting DFS in early stages of CRC treated with fluoropyrimidine-based adjuvant chemotherapy. If further validated in a prospective case series, both biomarkers could be used to identify patients who benefit from this treatment and to offer alternative chemotherapy regimens to potential unresponsive patients. In relation to the suggested biological role of PNN and KCNQ1OT1 in CRC, they might also be exploited as potential therapeutic targets.

Knockdown of lncRNA KCNQ1OT1 inhibits glioma progression by regulating miR-338-3p/RRM2

AbstractThe dysregulated lncRNA play essential roles in glioma development. This study aimed to investigate the role and mechanism of lncRNA potassium voltage-gated channel subfamily Q member 1 opposite strand/ antisense transcript 1 (KCNQ1OT1) in glioma progression. Tumor tissues and adjacent normal samples were collected from 30 glioma patients. The expression levels of lncRNA KCNQ1OT1, microRNA (miR)-338-3p and ribonucleotide reductase M2 (RRM2) were detected by quantitative real-time polymerase chain reaction or western blot analyses. Levels of cell viability, apoptosis, cell migration and invasion in glioma cell lines were determined using cell counting kit-8, flow cytometry with annexin V-FITC and trans-well assays, respectively. The role of KCNQ1OT1 in glioma development in vivo was investigated using a xenograft model. The target association between miR-338-3p and KCNQ1OT1 or RRM2 was validated by luciferase reporter assay. The results found that expression of KCNQ1OT1 was enhanced in glioma tissues and cells, and KCNQ1OT1 knockdown inhibited cell viability, migration and invasion, and xenograft tumor growth, but promoted apoptosis. miR-338-3p was targeted via KCNQ1OT1 and could reverse the effect of KCNQ1OT1 on glioma progression. RRM2 was targeted via miR-338-3p and attenuated the suppressive effect of miR-338-3p on glioma cell viability, migration and invasion. Besides, KCNQ1OT1 overexpression increased RRM2 expression, and this event was weakened via miR-338-3p up-regulation. In conclusion, the present finding suggest that silencing of KCNQ1OT1 can suppress the development and progression of glioma by up-regulating miR-338-3p and down-regulating RRM2.

KCNQ1OT1 regulates osteogenic differentiation of hBMSC by miR-320a/Smad5 axis.

Osteogenic differentiation plays a crucial role in maintaining general bone homeostasis. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) act as important regulators during the osteogenesis process. This study aimed to elucidate the mechanism of Potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (KCNQ1OT1) in osteogenic differentiation. Quantitative Real-time polymerase chain reaction (qRT-PCR) was conducted to detect the expression of KCNQ1OT1, osteonectin (OCN), osteopontin (OPN), runt-related transcription factor 2 (RUNX2), miR-320a, mothers against DPP homolog 5 (Smad5). Protein levels of OCN, OPN, RUNX2 and Smad5 were measured by Western blot assay. Alkaline phosphatase (ALP) activity detection assay was performed to examine the ALP activity. The interactions among KCNQ1OT1, miR-320a and Smad5 were determined by dual-luciferase reporter assay. KCNQ1OT1, OCN, OPN and RUNX2 expression were enhanced in human bone marrow-derived mesenchymal stem cells (hBMSCs) treated with osteogenic medium (OM). KCNQ1OT1 positively regulated OCN, OPN and RUNX2 expression and ALP activity of hBMSCs. Furthermore, KCNQ1OT1 directly bound to miR-320a, and KCNQ1OT1 knockdown reduced OCN, OPN and RUNX2 expression and ALP activity by suppressing miR-320a expression. Moreover, Smad5 was a target of miR-320a, and miR-320a inhibition abated the effects of Smad5 silencing in OCN, OPN and RUNX2 expression and ALP activity of hBMSCs. Also, KCNQ1OT1 knockdown reduced OCN, OPN and RUNX2 expression by targeting miR-320a/Smad5 axis. KCNQ1OT1 promoted osteogenic differentiation of hBMSCs by regulating Smad5 expression via sponging miR-320a.

<p>Silencing of KCNQ1OT1 Decreases Oxidative Stress and Pyroptosis of Renal Tubular Epithelial Cells</p>

BackgroundLong noncoding RNAs (lncRNAs) can regulate the progression of DN. This research aimed to study the effect of lncRNA KCNQ1OT1 on the oxidative stress and pyroptosis of the renal tubular epithelial cells induced by high glucose (HG).MethodsRT-qPCR analysis detected the KCNQ1OT1 expression in serum with DN and HG-induced HK-2 cells, detect the expression of NLRP3, cleaved-caspase1, P-caspase1, IL-1β, p-IL-1β and GSDMD-N in HG-induced HK-2 cells, and confirm the transfection effects. The expression of NLRP3, cleaved-caspase1, P-caspase1, IL-1β, p-IL-1β and GSDMD-N in HG-induced HK-2 cells was also analyzed by Western blot analysis. ELISA assay detected the levels of TNF-α, IL-6 and MCP-1. The levels of ROS, MDA and SOD were determined by respective ELISA kits and ROS was also detected by the ROS assay kit (containing DCFH-DA).ResultsWe found that KCNQ1OT1 was increased in the plasma of patients with DN and HG-induced HK-2 cells and KCNQ1OT1 interference could decrease the inflammation, oxidative stress and pyroptosis of HG-induced HK-2 cells. In addition, KCNQ1OT1 directly targets miR-506-3p. MiR-506-3p was downregulated in the plasma of patients with DN and HG-induced HK-2 cells and KCNQ1OT1 interference promoted the expression of miR-506-3p. MiR-506-3p overexpression suppressed the inflammation, oxidative stress and pyroptosis of HG-induced HK-2 cells.ConclusionThis study demonstrated that downregulation of KCNQ1OT1 inhibited the inflammation, oxidative stress and pyroptosis of HG-induced HK-2 cells by up-regulating the expression of miR-506-3p, which provide new insights into the treatment of DN.

Diagnostic Value of Serum Long-Chain Noncoding RNA KCNQ1OT1 in Airway Remodeling in Children with Bronchial Asthma.

The current study aims to investigate the clinical value of serum long non-coding RNA (lncRNA) KCNQ1OT1 in airway remodeling in children with bronchial asthma. Serum and clinical data of 58 children with bronchial asthma were collected and divided into remodeling group and non-remodeling group. Twenty children with respiratory inflammatory diseases were selected as a control group. Real-time fluorescence quantitative PCR (RT-PCR) was used to detect the expression of serum lnc-RNA KCNQ1OT1. The relationship between serum lncRNA KCNQ1OT1 and asthma remodeling was also analyzed. The expression level of serum lncRNA KCNQ1OT1 in the remodeling group was higher than that in the non-remodeling group and the control group, and the difference was statistically significant. In the remodeling group, serum lncRNA KCNQ1OT1 was significantly correlated with the thickness of bronchial mucosal reticular basement membrane and the number of fibroblasts. Receiver operating characteristic curve (ROC) analysis showed that serum lncRNA KCNQ1OT1 could differentiate non-remodeling group from remodeling group. Serum lncRNA KCNQ1OT1 can predict the occurrence of airway remodeling in children with bronchial asthma, thereby initiating early intervention and treatment of airway inflammation.

Long Non-Coding RNA KCNQ1OT1 Promotes Progression of Hepatocellular Carcinoma by miR-148a-3p/IGF1R Axis.

Accumulating evidence have suggested that long non-coding RNAs (lncRNAs) act as a critical regulator in tumorgenesis. LncRNA KCNQ1OT1 (KCNQ1OT1) has been recently shown to be dysregulated in many cancers. This study was aimed to explore the biological role of KCNQ1OT1 in hepatocellular carcinoma (HCC). In our study, we first observed the expression level of KCNQ1OT1 was distinctly up-regulated in HCC tissues and cell lines compared with adjacent non-cancer tissues and normal liver cell line. And clinical results indicated that higher expression of KCNQ1OT1 was correlated with poor prognosis of patients with HCC. Next, functional studies revealed that knockdown of KCNQ1OT1 induced apoptosis and repressed proliferation, migration and invasion of HCC cells. In addition, knockdown of KCNQ1OT1 suppressed xenograft tumor growth in vivo. Mechanically, we found that KCNQ1OT1 can promote the expression of IGF1R by functioning as a competing endogenous RNA of miR-148a-3p. In conclusion, our results shown the oncogenic role of KCNQ1OT1 in HCC by regulating the miR-148a-3p/IGF1R axis and may provide a new insight and a potential therapeutic target for HCC.

Long Non-coding RNA KCNQ1OT1 Contributes to Antiepileptic Drug Resistance Through the miR-138-5p/ABCB1 Axis in vitro

Compelling evidence has verified that long non-coding RNAs (lncRNAs) play a critical role on drug resistance in various diseases, especially cancer. However, the role of lncRNAs underlying multidrug resistance in epilepsy remains to be clarified. In the present study, we investigated the potential regulatory mechanism of the lncRNA KCNQ1OT1 in regulating antiepileptic drug (AED) resistance in human brain microvascular endothelial cells (HBMECs). The results revealed that expression of P-glycoprotein (P-gp) and KCNQ1OT1 was significantly elevated in phenytoin-resistant HBMECs (HBMEC/PHT). Meanwhile, the activity of nuclear factor-kappa B (NF-κB) was increased in HBMECs/PHT cells. Microarray analysis indicated that miR-138-5p was downregulated in HBMEC/PHT cells. Interestingly, bioinformatics prediction tools indicated miR-138-5p could directly target the transcripts of KCNQ1OT1 and NF-κB p65, and these results were confirmed by luciferase assays. Moreover, KCNQ1OT1 downregulation or miR-138-5p upregulation in vitro could inhibit P-gp expression and suppress NF-κB signaling pathway activation. Additionally, knockdown of KCNQ1OT1 or overexpression of miR-138-5p could increase the accumulation of rhodamine 123 (Rh123) and AEDs in HBMEC/PHT cells. Collectively, our results suggested that KCNQ1OT1 contributes to AED resistance through the miR-138-5p/NF-κB/ABCB1 axis in HBMEC/PHT cells, and these results provide a promising therapeutic target for the treatment of medically intractable epilepsy.

LncRNA KCNQ1OT1 contributes to oxygen-glucose-deprivation/reoxygenation-induced injury via sponging miR-9 in cultured neurons to regulate MMP8

Our study proposed to investigate the function of potassium voltage-gated channel sub-family Q member 1 opposite strand 1 (KCNQ1OT1) in cerebral ischemia-reperfusion (I/R) injury and the underlying mechanism. We constructed an oxygen-glucose-deprivation/reoxygenation (OGD/R) model using the primary cortical neurons to mimic the cerebral I/R injury in vitro. Small inference RNA (siRNA) was used to silencing KCNQ1OT1. Dual luciferase assay was conducted to verify the interaction between KCNQ1OT1 and miR-9 and interaction between miR-9 and MMP8. CCK8 assay and flow cytometry analysis were applied for determing the viability and apoptosis of neurons, accordingly. QPCR and Western blot were performed to determine the RNA and protein expression. Our outcomes revealed that the expression of KCNQ1OT1 in cultured neurons was notably enhanced after suffered to OGD/R. Knockdown of KCNQ1OT1 weakened OGD/R-induced injury in neurons. Moreover, depletion of KCNQ1OT1 lead to the up-regulation of miR-9 and down-regulation of MMP8. Dual luciferase target validation assays demonstrated that KCNQ1OT1 directly interact with miR-9 and MMP8 is a direct target of miR-9, suggesting that KCNQ1OT1/miR-9/MMP8 might constitute the competing endogenous RNA (ceRNA) mechanism. Knockdown of MMP8 or up-regulation of miR-9 also could weaken OGD/R-induced injury. Furthermore, cells co-transfected with si-KCNQ1OT1, miR-9 mimic and si-MMP8 could significantly abolish the injury on neurons caused by OGD/R. Taken together, our data manifested that KCNQ1OT1 possibly acts as a facilitator in cerebral I/R injury through modulating miR-9/MMP8 axis as a ceRNA.

LncRNA KCNQ1OT1 contributes to the progression and chemoresistance in acute myeloid leukemia by modulating Tspan3 through suppressing miR-193a-3p

AimsAcute myeloid leukemia (AML) is an aggressive cancer that invariably produces drug resistance after treatment. The aim is to explore the role of lncRNA potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (KCNQ1OT1) and associated novel mechanisms in the progression and chemoresistance of AML. Main methodsThe expression of KCNQ1OT1, miR-193a-3p, and Tspan3 was measured by qRT-PCR. The values of IC50 for adriamycin (ADR) and the ability of proliferation were analyzed by CCK-8 assay. Cell migration and invasion were assessed by transwell assay. Cell apoptosis was monitored by flow cytometry assay. The expression of Tspan3, MRP1, P-gp and LRP at the protein level was quantified by western blot. The relationship between miR-193a-3p and KCNQ1OT1 or Tspan3 was predicted by bioinformatics tool Diana and verified by dual-luciferase reporter assay, RIP assay or RNA pull-down assay. Key findingsKCNQ1OT1 and Tspan3 were up-regulated, while miR-193a-3p was down-regulated in ADR resistant AML samples and cells. KCNQ1OT1 knockdown reduced ADR resistance, inhibited proliferation, migration and invasion but promoted apoptosis of ADR resistant AML cells, miR-193a-3p inhibition reversed these effects. MiR-193a-3p was a target of KCNQ1OT1 and combined with Tspan3 3′ untranslated region (3′ UTR). Enrichment of miR-193a-3p decreased ADR resistance, inhibited proliferation, migration and invasion and stimulated apoptosis in ADR resistant AML cells, but Tspan3 overexpression overturned these impacts. SignificanceKCNQ1OT1 aggravates AML progression and chemoresistance to ADR by inducing Tspan3 expression via adsorbing miR-193a-3p in ADR resistant AML cells, providing a theoretical basis for the treatment of AML with chemoresistance.

KCNQ1OT1 promotes migration and inhibits apoptosis by modulating miR-185-5p/Rab14 axis in oral squamous cell carcinoma.

Long non-coding RNAs (lncRNAs) play essential roles in the regulation of gene transcription in carcinogenesis and metastasis via interacting with microRNA. In this study, we explored the expressions and functions of lncRNA KCNQ1OT1 and miR-185-5p in oral squamous cell carcinoma (OSCC) cells. KCNQ1OT1 expression in OSCC tissues and cells was examined by qRT-PCR. Small interfering RNAs against KCNQ1OT1 (si- KCNQ1OT1) were used to knockdown KCNQ1OT1 in OSCC cells. Cell function was assessed by wound healing assay, transwell assay, and apoptosis detection. The binding region between KCNQ1OT1 and miR-185-5p was confirmed by luciferase assays. MiR-185-5p expression was measured by qRT-PCR. Rab14 was confirmed as a downstream target gene of miR-185-5p by measuring luciferase activities. The protein level of Rab14 in OSCC cells transfected with miR-185-5p or si-KCNQ1OT1 was determined by Western blot. The OSCC cell function and Rab14 expression after co-transfection of si-KCNQ1OT1 and miR-185-5p inhibitor were also examined. KCNQ1OT1 was upregulated in OSCC tissues and cells. KCNQ1OT1 silencing suppressed OSCC cell malignancy and downregulated miR-185-5p level, which showed upregulated expression in OSCC samples. Rab14 as a target gene of miR-185-5p was highly expressed in OSCC. KCNQ1OT1 knockdown impaired the invasion capability of OSCC cells, promoted apoptosis, and suppressed Rab14 expression. The inhibition of miR-185-5p in KCNQ1OT1 silencing cells reversed the suppression of Rab14 and restored the cancerous growth of OSCC cells. These results indicated that KCNQ1OT1 promoted OSCC tumorigenesis via the modulation of miR-185-5p/Rab14 axis, which may serve as a therapeutic target for the treatment of OSCC.

Long noncoding RNA KCNQ1OT1 promotes proliferation, migration, and invasion in maxillary sinus squamous cell carcinoma by regulating miR-204/EphA7 axis.

Long noncoding RNAs have been demonstrated to contribute to the development and progression of various cancers. However, the underlying regulatory mechanisms of KCNQ1OT1 in tumorigenesis of maxillary sinus squamous cell carcinoma (MSSCC) remain unknown. Herein, we found that KCNQ1OT1 expression was markedly upregulated in MSSCC tissues and MSSCC cell line (IMC-3) by using quantitative reverse transcription-polymerase chain reaction. Loss-of-function experiments revealed that the deletion of KCNQ1OT1 inhibited cell proliferation, migration, and invasion. Moreover, we confirmed KCNQ1OT1 could directly interact with miR-204 by bioinformatic prediction and dual luciferase assay, and miR-204 inhibitor markedly reversed MSSCC tumor phenotypes induced by shKCNQ1OT1. Finally, we demonstrated that KCNQ1OT1/miR-204 facilitated MSSCC progression by regulating Eph receptor A7 (EphA7). Taken together, these results revealed a novel regulatory mechanism KCNQ1OT1/miR-204/EphA7 axis, which could provide a new understanding of MSSCC tumorigenesis and develop potential targets for MSSCC therapy.

Methylation-dependent transcriptional repression of RUNX3 by KCNQ1OT1 regulates mouse cardiac microvascular endothelial cell viability and inflammatory response following myocardial infarction.

Myocardial infarction (MI) is a major contributor to death and disability throughout the world. Increasing evidence shows that long noncoding RNAs (lncRNAs) are involved in the progression of MI. Here, we hypothesized that lncRNA potassium voltage-gated channel subfamily q member 1 overlapping transcript 1 (KCNQ1OT1) could affect the development of MI via regulation of Runt-related transcription factor (RUNX)3 by methylation. Initially, by ligation of the left anterior descending coronary artery, an acute MI (AMI) mouse model was established to collect the cardiac microvascular endothelial cells (CMECs), which revealed a high KCNQ1OT1 expression and a low RUNX3 expression with its high methylation. After that, KCNQ1OT1 knockdown or RUNX3 overexpression were transduced into the CMECs in order to detect their role in CMEC proliferation, apoptosis, and inflammatory response. Moreover, we assessed their interaction with the inflammatory Notch pathway, by determining the expression of Jagged 1, Hey1, Hes1, Notch intracellular domain, and Notch1. It was observed that after KCNQ1OT1 knockdown, the proliferation of AMI-CMECs was promoted, whereas their apoptosis was inhibited, accompanied by reduced level of inflammatory factors. These trends could also be achieved by RUNX3 overexpression via the Notch pathway. Finally, the regulation of DNA methyltransferase (DNMT)1-dependent methylation in RUNX3 by KCNQ1OT1 was determined, suggesting that KCNQ1OT1 could result in down-regulated RUNX3 expression through promoted RUNX3 methylation caused by recruiting DNMT1. Overall, this study demonstrates that KCNQ1OT1 silencing inhibits RUNX3 methylation, thereby offering protection against CMEC injury and inflammatory response in AMI, which may serve as a promising target for the disease treatment. -Wang, Y., Yang, X., Jiang, A., Wang, W., Li, J., Wen, J. Methylation-dependent transcriptional repression of RUNX3 by KCNQ1OT1 regulates mouse cardiac microvascular endothelial cell viability and inflammatory response following myocardial infarction.