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

The Traces of Dysregulated lncRNAs-Associated ceRNA Axes in Retinoblastoma: A Systematic Scope Review

PURPOSE

Long non-coding RNAs are an essential component of competing endogenous RNA regulatory axes and play their role by sponging microRNAs and interfering with the regulation of gene expression. Because of the broadness of competing endogenous RNA interaction networks, they may help investigate treatment targets in complicated disorders.

METHODS

This study performed a systematic scoping review to assess verified loops of competing endogenous RNAs in retinoblastoma, emphasizing the competing endogenous RNAs axis related to long non-coding RNAs. We used a six-stage approach framework and the PRISMA guidelines. A systematic search of seven databases was done to locate suitable papers published before February 2022. Two reviewers worked independently to screen articles and collect data.

RESULTS

Out of 363 records, fifty-one articles met the inclusion criteria, and sixty-three axes were identified in desired articles. The majority of the research reported several long non-coding RNAs that were experimentally verified to act as competing endogenous RNAs in retinoblastoma: XIST/NEAT1/MALAT1/SNHG16/KCNQ1OT1, respectively. At the same time, around half of the studies investigated unique long non-coding RNAs.

CONCLUSIONS

Understanding the many features of this regulatory system may aid in elucidating the unknown etiology of Retinoblastoma and providing novel molecular targets for therapeutic and clinical applications.

LncRNA KCNQ1OT1/miR-496/HMGB1 Signaling Axis Promotes Invasion and Migration of Non-small Cell Lung Cancer Cells

Enhanced invasion and migration of non-small cell lung cancer (NSCLC) cells is the major cause of metastasis and poor prognosis in NSCLC. This study was conducted to investigate the role and mechanism of lncRNA KCNQ1OT1 in the proliferation, invasion, and migration of NSCLC cells. The expression of KCNQ1OT1 in NSCLC was analyzed in the StarBase database, and the target miRNA of KCNQ1OT1 as well as the target genes of the miRNA was predicted. Then, the mRNA expression levels of KCNQ1OT1, miR-496, and HMGB1 were detected in clinical tissue samples and cells by qRT-PCR assay. Besides, the protein levels of HMGB1 were detected by Western blot. MTT assay, transwell assay, and scratch assay were used to determine the proliferation, invasion, and migration ability of NSCLC cells, respectively. Correlation analysis was performed to assess the correlation between the expression of KCNQ1OT1, miR-496, and HMGB1 in clinical NSCLC samples. Dual-luciferase reporter gene assay was conducted to analyze the interaction between KCNQ1OT1 and miR-496 and between miR-496 and HMGB1. The database results showed that KCNQ1OT1 was highly expressed in NSCLC. Similarly, we found that the expression level of KCNQ1OT1 was significantly higher in NSCLC tissues and cells than that in the corresponding normal tissues and cells. The results of MTT assay, transwell assay, and scratch assay demonstrated that KCNQ1OT1 significantly enhanced the proliferation, invasion, and migration of NSCLC cells. Further mechanism exploration revealed that KCNQ1OT1 could sponge miR-496, and miR-496 directly targeted and regulated the expression of HMGB1. The expression of miR-496 and either KCNQ1OT1 or HMGB1 were negatively correlated in NSCLC, while the expression of KCNQ1OT1 and HMGB1 were positively correlated. Compared with normal paracancer tissues, miR-496 was much lower and HMGB1 was much higher expressed in NSCLC tissues. The results of cotransfection also further demonstrated that miR-496 inhibitor or sh-HMGB1 cotransfected with sh-KCNQ1OT1 could significantly decrease or increase the ability of sh-KCNQ1OT1 to inhibit the proliferation, invasion, and migration of H1299 cells, respectively. In conclusion, lncRNA KCNQ1OT1 promotes the invasion and migration of NSCLC cells through miR-496/HMGB1 signaling axis.

Down-regulating lncRNA KCNQ1OT1 relieves type II alveolar epithelial cell apoptosis during one-lung ventilation via modulating miR-129-5p/HMGB1 axis induced pulmonary endothelial glycocalyx

OBJECTIVE

Endothelial glycocalyx (EG) maintains vascular homeostasis and is destroyed after one-lung ventilation (OLV)-induced lung injury. Long noncoding RNAs (lncRNAs) are critically involved in various lung injuries. This study aimed to investigate the role and regulatory mechanism of KCNQ1 overlapping transcript 1 (KCNQ1OT1) in OLV-induced lung injury and LPS-induced type II alveolar epithelial cell (AECII) apoptosis.

METHODS

The rat OLV model was established, and the effects of KCNQ1OT1 on OLV-induced ALI in vivo were explored. Bax and Caspase-3 expression in rat lung tissues was measured by immunochemistry (IHC). AECIIs were isolated from rat lungs and treated with LPS or normal saline (control) for in vitro analysis. The expression of KCNQ1OT1, miR-129-5p, and HMGB1 was measured by quantitative real-time PCR (qRT-PCR) or Western blot (WB). Cell proliferation and apoptosis were examined by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) and flow cytometry. The downstream targets of KCNQ1OT1 were predicted by bioinformatics, and the binding relationship between KCNQ1OT1 and miR-129-3p was verified by dual-luciferase reporter assays. The potential target of miR-129-5p was further explored on the Targetscan website and revealed to target HMGB1. Enzyme-linked immunosorbent assay (ELISA) or WB was adopted to determine the levels of IL-1β, TNF-α, MDA, SOD, heparanase (HPA), matrix metalloproteinase 9 (MMP9), heparan sulfate (HS) and syndecan-1 (SDC-1).

RESULTS

KCNQ1OT1 and HMGB1 were up-regulated during OLV-induced lung injury, and their expression was positively correlated. KCNQ1OT1 knockdown reduced OLV-induced pulmonary edema and lung epithelial cell apoptosis, increased vascular permeability, reduced IL-1β, TNF-α, MDA, and SOD levels and glycocalyx markers by targeting miR-129-5p or upregulating HMGB1. Overexpressing KCNQ1OT1 promoted cell apoptosis, reduced cell proliferation, aggravated inflammation and oxidative stress, and up-regulated HMGB1, HPA and MMP9 in LPS-treated AECIIs, while the HMGB1 silencing showed the opposite effects. MiR-129-5p mimics partially eliminated the KCNQ1OT1-induced effects, while recombinant HMGB1 restored the effects of miR-129-5p overexpression on AECIIs. Additionally, KCNQ1OT1 was demonstrated to promote the activation of the p38 MAPK/Akt/ERK signaling pathways in AECIIs via HMGB1.

CONCLUSION

KCNQ1OT1 knockdown alleviated AECII apoptosis and EG damage during OLV by targeting miR-129-5p/HMGB1 to inactivate the p38 MAPK/Akt/ERK signaling. The findings of our study might deepen our understanding of the molecular basis in OLV-induced lung injury and provide clues for the targeted disease management.

A review on the role of KCNQ1OT1 lncRNA in human disorders

KCNQ1OT1 is an lncRNA located within KCNQ1 gene on chromosome 11p15.5. This lncRNAs participates in the pathogenesis of a diversity of cancers as well as non-cancerous conditions. In most types of cancers, KCNQ1OT1 is regarded as an oncogene. In a wide array of cancers, high level of KCNQ1OT1 is associated with lower overall survival time. This lncRNA has been found to adsorb a variety of miRNAs, namely miR-15a, miR-211-5p, hsa-miR-107, miR-145, miR-34a, miR-204-5p, miR-129-5p, miR-372-3p, miR-491-5p, miR-153, miR-185-5p, miR-124-3p, miR-211-5p, miR-149, miR-148a-3p, miR-140-5p, miR-125b-5p, miR-9, miR-329-3p, miR-760, miR-296-5p, miR-3666 and miR-129-5p, thus regulating the downstream targets of these miRNAs. In this manuscript, our attention is on this lncRNA and its biomolecular roles in human cancers and other disorders. KCNQ1OT1 plays significant roles in the tumorigenesis and may function as a prospective target for cancer therapy.

Biological role of long non-coding RNA KCNQ1OT1 in cancer progression

Long non-coding RNAs (lncRNAs) are a type of RNAs that are more than 200 nucleotides without protein-coding potential. In recent years, more and more attention has been paid to the role of lncRNAs in cancer pathogenesis. LncRNA KCNQ1 overlapping transcript 1 (KCNQ1OT1) is located on chromosome 11p15.5 with a total length of 91 kb and is highly expressed in various malignancies, which is closely related to tumor growth, lymph node metastasis, survival cycle and recurrence rate. In addition, KCNQ1OT1 is involved in the regulation of PI3K/AKT and Wnt/β-catenin signaling pathways. In this review, the mechanism and related progress of KCNQ1OT1 in different cancers were reviewed. It was found that KCNQ1OT1 can stabilize mRNA expression through sponging miRNA, which not only induced tumor cell proliferation, migration, invasion, drug resistance, epithelial-mesenchymal transition (EMT) and inhibited cell apoptosis in vitro, but also promoted tumor growth and metastasis in vivo. Therefore, as a new biomarker and therapeutic target, KCNQ1OT1 has broad prospects for the diagnosis and treatment of different cancers.

Big data analysis identified a telomere-related signature predicting the prognosis and drug sensitivity in lung adenocarcinoma

Telomeres exert a critical role in chromosome stability and aberrant regulation of telomerase may result in telomeres dysfunction and genomic instability, which are involved in the occurrence of cancers. However, limited studies have been performed to fully clarify the immune infiltration and clinical significance of telomeres-related genes (TRGs) in lung adenocarcinoma (LUAD). The number of clusters of LUAD was determined by consensus clustering analysis. The prognostic signature was constructed and verified using TCGA and GSE42127 dataset with Least Absolute Shrinkage and Selection Operator cox regression analysis. The correlation between different clusters and risk-score and drug therapy response was analyzed using TIDE and IMvigor210 dataset. Using several miRNA and lncRNA related databases, we constructed a lncRNA-miRNA-mRNA regulatory axis. We identified 2 telomeres-related clusters in LUAD, which had distinct differences in prognostic stratification, TMB score, TIDE score, immune characteristics and signal pathways and biological effects. A prognostic model was developed based on 21 TRGs, which had a better performance in risk stratification and prognosis prediction compared with other established models. TRGs-based risk score could serve as an independent risk factor for LUAD. Survival prediction nomogram was also developed to promote the clinical use of TRGs risk score. Moreover, LUAD patients with high risk score had a high TMB score, low TIDE score and IC50 value of common drugs, suggesting that high risk score group might benefit from receiving immunotherapy, chemotherapy and target therapy. We also developed a lncRNA KCNQ1QT1/miR-296-5p/PLK1 regulatory axis. Our study identified 2 telomeres-related clusters and a prognostic model in LUAD, which could be helpful for risk stratification, prognosis prediction and treatment approach selection.

Long non coding RNAs reveal important pathways in childhood asthma: a future perspective

Asthma is a long-term inflammatory disease of the airways of the lungs refers changes that occur in conjunction with, or as a result of, chronic airway inflammation. Airway remodeling the subsequent of inflammation constitutes cellular and extracellular matrix changes in the wall airways, epithelial-to-mesenchymal-transition and airway smooth muscle cell proliferation. Diseases often begin in childhood and despite extensive research, causative pathogenic mechanisms still remain unclear. Transcriptome analysis of childhood asthma reveals distinct gene expression profiles of Long noncoding RNAs which have been reported to play a central regulatory role in various aspects of pathogenesis, clinical course and treatment of asthma. We briefly review current understanding of lnc-RNA dysregulation in children with asthma, focusing on their complex role in the inflammation, cell proliferation and remodeling of airway to guide future researches. We found that the lnc-RNAs increases activity of several oncogenes such c-Myc, Akt, and ERK and various signaling pathways such as MAPK (PI3K, Ras, JNK and p38), NF-κB and Wnt and crosstalk between these pathways by TGFβ, β-catenin, ERK and SKP2. Moreover, two different signal transduction pathways, Wnt and Notch1, can be activated by two lnc-RNAs through sponging the same miRNA for exacerbation cell proliferation.

Long non‑coding RNAs as potential therapeutic targets in non‑small cell lung cancer (Review)

Non‑small cell lung cancer (NSCLC) is one of the most common malignancies with a high morbidity and mortality rate. Long non‑coding RNAs (lncRNAs) have been reported to be closely associated with the occurrence and progression of NSCLC. In addition, lncRNAs have been documented to participate in the development of drug resistance and radiation sensitivity in patients with NSCLC. Due to their extensive functional characterization, high tissue specificity and sex specificity, lncRNAs have been proposed to be novel biomarkers and therapeutic targets for NSCLC. Therefore, in the current review, the functional classification of lncRNAs were presented, whilst the potential roles of lncRNAs in NSCLC were also summarized. Various physiological aspects, including proliferation, invasion and drug resistance, were all discussed. It is anticipated that the present review will provide a perspective on lncRNAs as potential diagnostic molecular biomarkers and therapeutic targets for NSCLC.

Upregulation and the clinical significance of KCNQ1OT1 and HAGLROS lncRNAs in papillary thyroid cancer: An observational study

Long noncoding RNAs (lncRNAs) play an important role in regulating gene expression. Changes in their expression have been associated with many types of cancer, including thyroid cancer. This study aimed to investigate how changes in the expression of potassium voltage-gated channel subfamily Q member 1 opposite strand/antisense transcript 1 (KCNQ1OT1) and HAGLR opposite strand lncRNA (HAGLROS) lncRNAs correlate with the development and clinicopathological characteristics of papillary thyroid cancer (PTC). Reverse transcription-quantitative polymerase chain reaction was used to investigate the expression of lncRNAs in both tumor and adjacent normal thyroid tissue samples of the patients. Expressions of KCNQ1OT1 and HAGLROS were upregulated in the patients tumor samples compared to the adjacent normal thyroid samples. KCNQ1OT1 expression was linked to microcarcinoma and gender, while HAGLROS expression was linked to microcarcinoma and tumor size. When only microcarcinoma samples were evaluated, KCNQ1OT1 expression was higher in tumor tissues compared to normal tissues; however, no significant difference was observed in HAGLROS expression. Our data suggests that high expressions of KCNQ1OT1 and HAGLROS might contribute to the development of PTC and disease progression, and both lncRNAs may be potential therapeutic targets in PTC patients.

Analysis of Angiogenesis-Related Signatures in the Tumor Immune Microenvironment and Identification of Clinical Prognostic Regulators in Lung Adenocarcinoma

Tumor angiogenesis is considered to be an important part of the mechanism of tumor progression and metastasis, and its specific function in lung adenocarcinoma has not been fully studied. In this study, we used the transcriptome and genome data of lung adenocarcinoma patients to analyze the expression of 36 angiogenesis regulators in lung adenocarcinoma. Consensus clustering analysis divided lung adenocarcinoma samples into 4 subtypes, A, B, C, and D, and the expression of most angiogenesis regulators in subtype B was higher than that in other subtypes. Immunological analysis indicated that subtype B is likely to display the characteristics of a hot tumor with a more active TME. With the help of Lasso-Cox regression analysis, we successfully constructed a risk model involving five Angiogenesis Regulators genes (CCND2, JAG1, MSX1, STC1, TIMP1), which will be helpful for clinical personalized treatment and prognosis prediction. In addition, JAG1 has the highest mutation rate in tumors, and its cancer-promoting function is reflected in a variety of tumors, which provides important clues for the development of new broad-spectrum anti-cancer targets in the future. We successfully constructed a risk model involving five angiogenesis regulators genes (CCND2, JAG1, MSX1, STC1, TIMP1), which may be helpful for clinical personalized treatment and prognosis prediction. In addition, JAG1 has the highest mutation rate in tumors and plays a leading role in the protein interaction network. Its tumor-promoting function is reflected in a variety of tumors and may become a broad-spectrum anti-cancer target in the future.

Circular RNA in multiple myeloma: A new target for therapeutic intervention

Circular RNAs (circRNAs) are RNA molecules with a stable closed-loop structure that are found in a variety of organisms. CircRNAs are highly stable and conserved, and they play important roles in transcriptional regulation and splicing. Multiple Myeloma (MM) is a malignant proliferative disease for which there are currently no effective and comprehensive treatments. Numerous circRNAs may contribute to the development and progression of MM by acting as oncogenes or regulators. Due to the unique function of circRNAs, they have a high potential for regulating the biological functions (including proliferation and apoptosis) of MM cells, and their expression levels and molecular mechanism are closely related to their diagnostic value, therapeutic sensitivity, and clinical prognosis of MM patients. In this review, we aim to provide a detailed overview of the structure and function of circRNAs and demonstrate the potential therapeutic value and potential mechanism of circRNAs in MM via experiments and clinical trials.

LncRNA KCNQ1OT1 accelerates ovarian cancer progression via miR-125b-5p/CD147 axis

BACKGROUND

Ovarian cancer (OC) is one of the most common gynecological malignancies with a high incidence. Researches showed that lncRNA KCNQ1OT1 (KCNQ1OT1) was involved various tumors progression, including OC. However, the precise mechanism of KCNQ1OT1 in OC needs to be further clarified.

OBJECTIVE

For investigate the underlying mechanism of KCNQ1OT1 regulating OC progression.

METHODS

CCK-8 assay, colony formation assay, Transwell assay, Western blot and quantitative real-time PCR (qRT-PCR) were performed to examine viability, proliferation, migration and invasion, genes and proteins' level. To identify KCNQ1OT1 as a regulator of miR-125b-5p and miR-125b-5p as a regulator of CD147, we used miRNA target prediction algorithms, Pearson's correlation analysis and dual-luciferase reporter gene assay.

RESULTS

KCNQ1OT1 was high expression and miR-125b-5p was low expression in OC, and KCNQ1OT1 was negatively correlated with that of miR-125b-5p in OC specimens. KCNQ1OT1 promoted OC cell proliferation and metastasis by binding to miR-125b-5p. miR-125b-5p targeted CD147, and which was negatively correlated with that of miR-125b-5p in OC specimens. KCNQ1OT1 was positively correlated with that of CD147 in OC specimens, and KCNQ1OT1 accelerated OC progression via miR-125b-5p/CD147 axis.

CONCLUSION

KCNQ1OT1 accelerated OC progression via miR-125b-5p/CD147 axis indicating KCNQ1OT1 serve as a novel biomarker for OC treatment. Our research provides a new direction for OC treatment.

Multifunctional mesoporous silica-cerium oxide nanozymes facilitate miR129 delivery for high-quality healing of radiation-induced skin injury

Radiation-induced skin injury (RISI) is an important challenge for clinical treatments. The main causes of RISI include hypoxia in the wound microenvironment, reactive oxygen species (ROS) activation, and downregulation of DNA repair proteins. Here, a multiple radioresistance strategy was designed for microRNA therapy and attenuating hypoxia. A novel mesoporous silica (MS) firmly anchored and dispersed cerium (IV) oxide (CeO₂) nanoparticles to form MS-CeO₂ nanocomposites, which exhibit superior activity in inhibiting radiation-induced ROS and HIF-1α activation and ultimately promote RISI wound healing. The miR129 serum concentrations in patients can promote radioresistance by directly targeting RAD17 and regulating the Chk2 pathway. Subsequently, MS-CeO₂ nanocomposites with miR129 were conjugated with iRGD-grafted polyoxyethylene glycol (short for nano-miR129), which increased the stability and antibacterial character, efficiently delivered miR129 to wound blood capillaries, and exhibited low toxicity. Notably, nano-miR129 promoted radioresistance and enhanced anti-ROS therapeutic efficacy in a subcutaneous RISI mouse model. Overall, this MS-CeO₂ nanozyme and miR129-based multiresistance radiotherapy protection strategy provided a promising therapeutic approach for RISI.

LncRNA KCNQ1OT1-mediated cervical cancer progression by sponging miR-1270 as a ceRNA of LOXL2 through PI3k/Akt pathway

BACKGROUND

Dysregulated noncoding RNAs participated in progressions of cervical cancer.

PURPOSE

To verify impacts of KCNQ1OT1 on modulating progressions of cervical cancer cells.

METHOD

Expressions of KCNQ1OT1, miR-1270, and LOXL2 were analyzed through RT-qPCR and protein expressions of LOXL2, p-AKT, and AKT were validated using western blot. Bindings of miR-1270 with KCNQ1OT1 or LOXL2 were verified using luciferase reporter assay. CCK-8 and flow cytometry evaluated cell viability and apoptosis, respectively. The PI3K/AKT signaling pathway suppressor, LY294002, was applied to treat the cells and the changes of KCNQ1OT1 expression and LOXL2, p-AKT, and AKT protein expressions were examined.

RESULTS

KCNQ1OT1 expression was the highest in HeLa cells but lowest in SiHa cells whose upregulation improved the viability but inhibited the apoptosis in SiHa cells while knockdown of KCNQ1OT1 caused opposite results in HeLa cells. MiR-1270 was sponged and negatively modulated by KCNQ1OT1. MiR-1270 mimics caused low viability and high apoptosis of SiHa cells but miR-1270 inhibitor reverse its roles in HeLa cells. LOXL2, the target of miR-1270, positively interplayed with KCNQ1OT1 but had negative interaction with miR-1270. LOXL2 overexpression promoted viability and decreased apoptosis of SiHa cells but knockdown of LOXL2 restored its effects in HeLa cells. Moreover, LOXL2 and phosphorylated AKT (p-AKT) protein expressions were downregulated by suppressed KCNQ1OT1 and LOXL2 and miR-1270 mimics but promoted by overexpressed KCNQ1OT1 and LOXL2 and miR-1270 inhibitor. Additionally, LY294002 treatment caused low KCNQ1OT1 RNA expression and decreased LOXL2 and p-AKT protein expressions.

CONCLUSION

KCNQ1OT1/miR-1270/LOXL2 axis modulated viability and apoptosis of cervical cancer cells.

KCNQ1OT1: An Oncogenic Long Noncoding RNA

Long noncoding RNAs (lncRNAs) are transcripts greater than 200 nucleotides that do not code for proteins but regulate gene expression. Recent studies indicate that lncRNAs are involved in the modulation of biological functions in human disease. KCNQ1 Opposite Strand/Antisense Transcript 1 (KCNQ1OT1) encodes a lncRNA from the opposite strand of KCNQ1 in the CDKN1C/KCNQ1OT1 cluster that is reported to play a vital role in the development and progression of cancer. KCNQ1OT1 regulates cancer cell proliferation, cell cycle, migration and invasion, metastasis, glucose metabolism, and immune evasion. The aberrant expression of KCNQ1OT1 in cancer patients is associated with poor prognosis and decreased survival. This review summarizes recent literature related to the biological functions and molecular mechanisms of KCNQ1OT1 in various human cancers, including colorectal, bladder, breast, oral, melanoma, osteosarcoma, lung, glioma, ovarian, liver, acute myeloid leukemia, prostate, and gastric. We also discuss the role of KCNQ1OT1 as a promising diagnostic biomarker and a novel therapeutic target in human cancers.

Long non-coding RNA KCNQ1OT1 facilitates the progression of cervical cancer and tumor growth through modulating miR-296-5p/HYOU1 axis

Literature reports that lncRNA KCNQ1OT1 is markedly up-regulated in cervical cancer (CC) tissues and cell lines, and KCNQ1OT1 can promote the proliferation and metastasis of CC cells. This current work was designed to investigate the molecular mechanism underlying the participation of KCNQ1OT1 in CC progression. Herein, RT-qPCR was utilized for determining the levels of KCNQ1OT1, miR-296-5p and HYOU1 in clinical tumor tissue specimens and CC cell lines. Then, starBase predicted the complementary binding sites of KCNQ1OT1 and miR-296-5p or miR-296-5p and HYOU1. Dual-luciferase reporter assay/RIP assay validated the interplays among KCNQ1OT1/miR-296-5p/HYOU1. In addition, CCK-8, wound healing and transwell assays were employed to assess the proliferative, migrative and invasive properties of CC cells. Moreover, nude mice xenograft model was established by subcutaneously injection with SiHa cells in order to validate the precise functions of KCNQ1OT1/miR-296-5p/HYOU1 axis in CC in vivo. Besides, Immunohistochemical staining examined Ki-67 expression in xenograft tumors and western blotting analysis detected expressions of MMP2/9 and Wnt/β-catenin signaling pathway in CC cells and xenograft tumors. Elevated KCNQ1OT1 and HYOU1 as well as reduced miR-296-5p were observed in clinical tumor tissue specimens and CC cell lines. Results revealed that upregulation of miR-296-5p counteracted the enhancing effects of overexpressed KCNQ1OT1 on the proliferative, migrative and invasive abilities of CC cells. Additionally, HYOU1 overexpression abolished the suppressing effects of silenced KCNQ1OT1 on the malignant behaviors of CC cells and tumor growth. To conclude, KCNQ1OT1 could aggravate the malignant behaviors of CC and facilitate tumor growth through modulating miR-296-5p/HYOU1 axis.

Long non-coding RNA MCM3AP antisense RNA 1 promotes non-small cell lung cancer progression through targeting microRNA-195-5p

Lung cancer (LC) ranks first among all causes of cancer-related death, with non-small cell lung cancer (NSCLC) taking up 85% of lung cancer cases. Although lncRNA MCM3AP antisense RNA 1 (MCM3AP-AS1) has been reported to be an oncogenic factor in NSCLC, its detailed mechanism in NSCLC is unknown. In this study, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine MCM3AP-AS1, microRNA (miR)-195-5p and E2F transcription factor 3 (E2F3) mRNA expressions in NSCLC tissues and cells. Western blot was utilized to determine the expression levels of E2F3, BCL2-associated X protein (Bax), B-cell lymphoma-2 (Bcl-2), E-cadherin and N-cadherin. CCK-8 and Transwell assays were conducted to examine cell proliferation, migration and invasion, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation experiments were used to determine the regulatory relationships between MCM3AP-AS1 and miR-195-5p, and miR-195-5p and E2F3. We demonstrated that MCM3AP-AS1 was overexpressed in NSCLC tissues and cells, and MCM3AP-AS1 overexpression accelerated the proliferation, migration and invasion of NSCLC cells. In addition, MCM3AP-AS1 overexpression markedly up-modulated Bcl-2 expression and repressed Bax expression; MCM3AP-AS1 overexpression also significantly up-regulated N-cadherin expression and suppressed E-cadherin expression in NSCLC cells. What is more, in NSCLC cells, miR-195-5p was a target of MCM3AP-AS1, and the latter worked as a molecular sponge for miR-195-5p to regulate E2F3 expression. Collectively, MCM3AP-AS1, serving as a competitive endogenous RNA (ceRNA) to regulate miR-195-5p/E2F3 axis, promotes NSCLC progression, which is a promising therapeutic target for NSCLC.

Identification of the pyroptosis‑related prognostic gene signature and the associated regulation axis in lung adenocarcinoma

Lung adenocarcinoma (LUAD) remains the most common deadly disease and has a poor prognosis. Pyroptosis could regulate tumour cell proliferation, invasion, and metastasis, thereby affecting the prognosis of cancer patients. However, the role of pyroptosis-related genes (PRGs) in LUAD remains unclear. In our study, comprehensive bioinformatics analysis was performed to construct a prognostic gene model and ceRNA network. The correlations between PRGs and tumour-immune infiltration, tumour mutation burden, and microsatellite instability were evaluated using Pearson’s correlation analysis. A total of 23 PRGs were upregulated or downregulated in LUAD. The genetic mutation variation landscape of PRG in LUAD was also summarised. Functional enrichment analysis revealed that these 33 PRGs were mainly involved in pyroptosis, the NOD-like receptor signalling pathway, and the Toll-like receptor signalling pathway. Prognosis analysis indicated a poor survival rate in LUAD patients with low expression of NLRP7, NLRP1, NLRP2, and NOD1 and high CASP6 expression. A prognostic PRG model constructed using the above five prognostic genes could predict the overall survival of LUAD patients with medium-to-high accuracy. Significant correlation was observed between prognostic PRGs and immune-cell infiltration, tumour mutation burden, and microsatellite instability. A ceRNA network was constructed to identify a lncRNA KCNQ1OT1/miR-335-5p/NLRP1/NLRP7 regulatory axis in LUAD. In conclusion, we performed a comprehensive bioinformatics analysis and identified a prognostic PRG signature containing five genes (NLRP7, NLRP1, NLRP2, NOD1, and CASP6) for LUAD patients. Our results also identified a lncRNA KCNQ1OT1/miR-335-5p/NLRP1/NLRP7 regulatory axis, which may also play an important role in the progression of LUAD. Further study needs to be conducted to verify this result.

Long Noncoding RNA KCNQ1OT1 is a Prognostic Biomarker and mediates CD8+ T cell exhaustion by regulating CD155 Expression in Colorectal Cancer

Background: Long noncoding RNA KCNQ1 opposite strand/antisense transcript 1 (lncRNA KCNQ1OT1) is abnormally expressed in various solid tumors. The purpose of this study was to explore the prognostic value and potential functional role of lncRNA KCNQ1OT1 across cancers. Methods: We performed a meta-analysis of published literature to evaluate the prognostic value of lncRNA KCNQ1OT1 across cancers. Verification, functional analysis, and genomic variation analysis were performed using the GEPIA, TIMER, and LnCeVar databases. According to the immune cell infiltration level, we established a prognostic model of lncRNA KCNQ1OT1 expression using public datasets of TIMER. We used quantitative real-time polymerase chain reaction (RT-qPCR) and western blot to detect the expression levels of lncRNA KCNQ1OT1 and the CD155 protein in colorectal cancer (CRC) tissues and cell lines. Then, a lncRNA KCNQ1OT1-knockdown cell line was cocultured to explore the role of lncRNA KCNQ1OT1 and CD155 in the T cell response by flow cytometric analysis. Results: Our results showed that the high expression of lncRNA KCNQ1OT1 was significantly related to poor overall survival across cancers, especially CRC. Interestingly, we found that COAD patients with high lncRNA KCNQ1OT1 expression and high CD8⁺ T cell infiltration levels had a worse prognosis than those with low lncRNA KCNQ1OT1 expression and high CD8⁺ T cell infiltration levels. Moreover, lncRNA KCNQ1OT1 and CD155 showed significantly higher expression in CRC tissue than in normal tissue, and lncRNA KCNQ1OT1 expression was positively correlated with CD155 expression in CRC. Finally, knockdown of lncRNA KCNQ1OT1 reduced CD155 expression in HCT116 and SW620 cells and enhanced the immune response in coculture with CD8⁺ T cells. Conclusions: High lncRNA KCNQ1OT1 expression is significantly correlated with poor prognosis of CRC patients and mediates the CD8⁺ T cell response in CRC. These findings indicate that lncRNA KCNQ1OT1 is a prognostic biomarker and potential immune therapeutic target for enhancing the CD8⁺ T cell response in CRC.

Downregulation of lncRNA KCNQ1OT1 relieves traumatic brain injury induced neurological deficits via promoting "M2" microglia polarization

BACKGROUND

Microglia-induced neuroinflammation is one of the main characteristics of traumatic brain injury (TBI). Presently, we aim to investigate the role of long non-coding RNA (lncRNA) KCNQ1 overlapping transcript 1 (KCNQ1OT1) in TBI-induced neurological deficits and the related mechanism.

METHODS

An in-vivo TBI model was established in mice, and in-vitro experiments were carried out on BV2 microglia. Then the neurological functions, microglial activation, inflammatory cytokines, and proteins were detected.

RESULTS

Our data indicated that KCNQ1OT1 was markedly overexpressed in the cerebral tissues of TBI mice, accompanied by a higher level of the cytokines (including IL-1β, IL-6, and TNFα). However, knocking down KCNQ1OT1 relieved neurological deficits, neuron loss, and blood-brain barrier damage. Besides, overexpressing miR-873-5p enhanced the "M2″ polarization of microglia by repressing the TRAF6-mediated p38 and NF-κB pathways. In contrast, downregulating KCNQ1OT1 repressed microglial neuroinflammation by attenuating the "M1″ polarization of microglia and promoting "M2″ polarization of microglia, and inactivating the p38 and NF-κB pathway.

CONCLUSIONS

Mechanistically, KCNQ1OT1 functioned as a competitive endogenous RNA (ceRNA) by sponging miR-873-5p, which targeted the 3' untranslated region (UTR) of TRAF6. Overall, our data confirmed that downregulating lncRNA KCNQ1OT1 exerted neuroprotective effects on TBI mice by modulating the miR-873-5p-TRAF6-p38/NF-κB axis.

[Kcnq1ot1 promotes osteogenic differentiation and suppresses osteoclast differentiation]

OBJECTIVE

To investigate the regulatory role of long non-coding RNA Kcnq1ot1 in osteoclast differentiation, osteogenic differentiation and osteoporosis.

METHODS

The expression of lnc-Kcnq1ot1, Bglap, Runx2, Alp, Bsp, Nfatc1, Mmp9, Ctsk and Oscar were detected by real-time quantitative PCR (qRT-PCR) in the femoral bones from mouse models of postmenopausal osteoporosis (ovariectomized mice, n=8), disuse osteoporosis (induced by tail suspension, n=14) and agerelated osteoporosis (18-month-old mice, n=8), and also in MC3T3-E1 cells during osteoblast differentiation and in murine bone marrow-derived macrophages (BMMs) and RAW264.7 cells during osteoclast differentiation. MC3T3-E1 cells with lncKcnq1ot1 knockdown by lentivirus infection were induced to differentiate into osteoblasts using osteogenic induction medium, and the expression of lnc-Kcnq1ot1, Alp and Bglap was detected with qRT-PCR and ALP activity was assessed with ALP staining. BMMs and RAW264.7 cells were transfected with siRNAs targeting lnc-Kcnq1ot1 and stimulated with RANKL and/or M-CSF, and the expression of lnc-Kcnq1ot1, Ctsk and Oscar was detected by qRT-PCR, and TRAP activity was assessed by TRAP staining. The subcellular localization of lnc-Kcnq1ot1 in MC3T3-E1 and RAW264.7 cells was determined using cell fractionation followed by qRT-PCR.

RESULTS

The expression of lnc-Kcnq1ot1 was significantly upregulated during osteoblast differentiation but downregulated in the bone tissues of osteoporotic mice and during osteoclast differentiation (P < 0.05). Silencing lnc-Kcnq1ot1 obviously decreased the expression of Bglap and Alp (P < 0.05) and attenuated osteogenic medium-induced osteoblast differentiation. Knockdown of lnc-Kcnq1ot1 also promoted the expression of Ctsk and Oscar (P < 0.05) and aggravated RANKL-induced osteoclast differentiation. The results of cell fractionation and qRT-PCR demonstrated that lnc-Kcnq1ot1 was located mainly in the nuclei of MC3T3-E1 and RAW264.7 cells.

CONCLUSIONS

Our data demonstrate that lnc-Kcnq1ot1 promotes osteogenic differentiation and alleviates osteoclast differentiation, suggesting the potential of lnc-Kcnq1ot1 as a therapeutic target against osteoporosis.

Long non-coding RNA KCNQ1 overlapping transcript 1 promotes the progression of esophageal squamous cell carcinoma by adsorbing microRNA-133b

OBJECTIVE

The long non-coding RNA (lncRNA) KCNQ1 overlapping transcript 1 (KCNQ1OT1) exerts vital regulatory functions in diverse tumors. However, the biological function of KCNQ1OT1 in esophageal squamous cell carcinoma (ESCC) remains unclear.

METHODS

KCNQ1OT1 expression was detected in ESCC tissues using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, migration, and invasion were detected by the CCK-8 assay, EdU assay, flow cytometry analysis, and Transwell experiments, respectively. Bioinformatics analysis, luciferase reporter experiments, and RNA immunoprecipitation assays were used to predict and validate the regulatory relationships between KCNQ1OT1, microRNA-133b (miR-133b) and epidermal growth factor receptor (EGFR).

RESULTS

KCNQ1OT1 expression was remarkably upregulated in ESCC tissues and cell lines. Overexpression of KCNQ1OT1 markedly promoted ESCC cell proliferation, migration, and invasion and enhanced the expression of N-cadherin, MMP-2, and MMP-9, but inhibited apoptosis and E-cadherin expression in ESCC cell lines; KCNQ1OT1 knockdown exerted the opposite effects. KCNQ1OT1 could directly bind to miR-133b and suppress its expression, and miR-133b reversed the effects of KCNQ1OT1 overexpression in ESCC cells. MiR-133b reduced the expression of epidermal growth factor receptor (EGFR); further, KCNQ1OT1 activated the phosphatidylinositol 3-kinase/AKT serine/threonine kinase 1 (PI3K/AKT) signaling pathway by repressing miR-133b repression and indirectly upregulating EGFR. KCNQ1OT1 expression was positively correlated with EGFR mRNA expression and negatively correlated with miR-133b expression.

CONCLUSION

KCNQ1OT1 facilitates ESCC progression by sponging miR-133b and activating the EGFR/PI3K/AKT pathway.

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.

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.

Long noncoding RNA DNAH17-AS1 promotes tumorigenesis and metastasis of non-small cell lung cancer via regulating miR-877-5p/CCNA2 pathway

A growing number of studies have revealed that long noncoding RNAs (lncRNAs) can function as important oncogenes or tumor suppressors. This study aimed to investigate the regulatory role of lncRNA DNAH17 antisense RNA 1 (DNAH17-AS1) on non-small cell lung cancer (NSCLC) and the underlying molecular mechanisms. We observed that the expression of DNAH17-AS1 and CCNA2 mRNA was distinctly upregulated in NSCLC specimens and cell lines, while miR-877-5p expression was significantly decreased. DNAH17-AS1 could be used to distinguish NSCLC specimens from adjacent non-tumor tissues. Clinical assays revealed that high DNAH17-AS1 was associated with TNM stage, distant metastasis and shorter overall survival and disease-free survival. Functional assays indicated that knockdown of DNAH17-AS1 suppressed the proliferation, migration and invasion of H1299 and 95D cells, and promoted apoptosis. Mechanically, DNAH17-AS1 served as competing endogenous RNA (ceRNA) for miR-877-5p to positively recover CCNA2. Overall, we identified a novel NSCLC-related lncRNA, DNAH17-AS1 which may exert an oncogenic function via serving as a sponge for miR-877-5p to upregulate CCNA2. Our study presents novel insights into NSCLC progression and provided a prospective therapeutic target for NSCLC.