LncRNA NR2F2-AS1 promotes tumourigenesis through modulating BMI1 expression by targeting miR-320b in non-small cell lung cancer

The therapeutic potential of RNA m(6)A in lung cancer

Lung cancer (LC) is a highly malignant and metastatic form of cancer. The global incidence of and mortality from LC is steadily increasing; the mean 5-year overall survival (OS) rate for LC is less than 20%. This frustrating situation may be attributed to the fact that the pathogenesis of LC remains poorly understood and there is still no cure for mid to advanced LC. Methylation at the N6-position of adenosine (N6mA) of RNA (m(6)A) is widely present in human tissues and organs, and has been found to be necessary for cell development and maintenance of homeostasis. However, numerous basic and clinical studies have demonstrated that RNA m(6)A is deregulated in many human malignancies including LC. This can drive LC malignant characteristics such as proliferation, stemness, invasion, epithelial-mesenchymal transition (EMT), metastasis, and therapeutic resistance. Intriguingly, an increasing number of studies have also shown that eliminating RNA m(6)A dysfunction can exert significant anti-cancer effects on LC such as suppression of cell proliferation and viability, induction of cell death, and reversal of treatment insensitivity. The current review comprehensively discusses the therapeutic potential of RNA m(6)A and its underlying molecular mechanisms in LC, providing useful information for the development of novel LC treatment strategies.

The role of m6A in angiogenesis and vascular diseases

Angiogenesis, whether physiological or pathological, plays a pivotal role in various physiological and disease conditions. This intricate process relies on a complex and meticulously orchestrated signal transduction network that connects endothelial cells, their associated parietal cells (VSMCs and pericytes), and various other cell types, including immune cells. Given the significance of m6A and its connection to angiogenesis and vascular disease, researchers must adopt a comprehensive and ongoing approach to their investigations. This study aims to ascertain whether a common key mechanism of m6A exists in angiogenesis and vascular diseases and to elucidate the potential application of m6A in treating vascular diseases.

ZEB1-AS1 mediates bone metastasis through targeting miR-320b/BMPR1A axis in lung cancer

OBJECTIVE

This study aimed to explore the role and regulatory mechanism of lncRNA ZEB1-AS1 in lung cancer.

METHODS

The expression of ZEB1-AS1 and miR-320b was determined by qRT-PCR. Cell viability, proliferation migration, and invasion were assessed using the CCK-8, colony-forming, and Transwell assay. EMT markers were quantified using western blot. The growth of subcutaneous tumor growth and metastatic bone tumors was evaluated in mouse model of lung cancer. Additionally, metastatic bone tumors were examined using H&E staining.

RESULTS

ZEB1-AS1 expression was upregulated, while miR-320b levels were downregulated in lung cancer. Knockdown of ZEB1-AS1 resulted in a significant suppression of cell viability, proliferation, migration, invasion, and EMT in A549 cells. Furthermore, we confirmed the targeting relationship between ZEB1-AS1 and miR-320b, as well as between miR-320b and BMPR1A. Our findings suggested that ZEB1-AS1 regulated cell viability, proliferation, migration, and invasion, as well as EMT, in lung cancer cells by targeting the miR-320b/BMPR1A axis. Moreover, our in vivo experiments confirmed that ZEB1-AS1 mediated bone metastasis through targeting miR-320b/BMPR1A axis in mice with lung cancer.

CONCLUSION

ZEB1-AS1 mediated bone metastasis through targeting miR-320b/BMPR1A axis in lung cancer.

Long intergenic non-protein coding RNA 115 (Linc00115): A notable oncogene in human malignancies

Long noncoding RNAs (LncRNAs) are RNA transcripts ranging from 200 to 1000 nucleotides that have emerged as critical regulators of gene expression. Growing evidence highlights their involvement in tumor development. In particular, long intergenic non-protein coding RNA115 (Linc00115) has been identified as an oncogene across various human malignancies, with aberrant expression strongly linked to poor clinical outcomes in cancer patients. This review aims to delve into the expression patterns of Linc00115 and elucidate the underlying molecular mechanisms behind its oncogenic properties. Moreover, we discuss the potential utility of Linc00115 as a valuable diagnostic and prognostic biomarker in cancer.

Investigating the Association between LncRNA NR2F2-AS1, miR-320b, and BMI1 in Gastric Cancer: Insights into Expression Profiles as Potential Biomarkers for Disease Management

AIM

This study aims to investigate the potential role of lncRNA NR2F2-AS1 in the development of gastric cancer by affecting the levels of miR-320b and BMI1.

BACKGROUND

Gastric cancer is a high-mortality malignancy, and understanding the underlying molecular mechanisms is crucial. Non-coding RNAs play an important role in gene expression, and their dysregulation can lead to tumor initiation and progression.

OBJECTIVE

This study aims to determine the pathological role of LncRNA NR2F2-AS1 in gastric cancer progression and its association with the clinicopathological characteristics of patients.

METHODS

Bioinformatics databases were used to predict the expression levels and interactions between the studied factors to achieve this objective. The expression pattern of NR2F2-AS1/miR- 320b/BMI1 in 40 pairs of tumor and adjacent normal tissues was examined using RT-PCR, IHC, and western blot. The correlation, ROC curve, and survival analyses were also conducted for the aforementioned factors.

RESULTS

The results showed an increase of more than 2-fold for BMI-1 and lncRNA NR2F2-AS1 in lower stages, and the elevation continued with the increasing stage of the disease. This correlated with significant downregulation of miR-320b and PTEN, indicating their association with gastric cancer progression and decreased patient survival. LncRNA NR2F2-AS1 acts as an oncogene by influencing the level of miR-320b, altering the amount of BMI1. A reduction in the amount of miR-320b against lncRNA NR2F2-AS1 and BMI1 directly correlates with a reduced overall survival rate of patients, especially if this disproportion is more than 3.0. ROC curve analysis indicated that alteration in the lncRNA NR2F2-AS1 level showed more than 98.0% sensitivity and specificity to differentiate the lower from higher stages of GC and predict the early onset of metastasis.

CONCLUSION

In conclusion, these results suggest that NR2F2-AS1/miR-320b/BMI1 has the potential to be a prognostic as well as diagnostic biomarker for gastric cancer.

MAPKAPK5-AS1/miR-515-5p/CAB39 Axis Contributes to Non-small Cell Lung Cancer Cell Proliferation and Migration

Several studies have elucidated the pivotal function that long noncoding RNAs (lncRNAs) exerted on the initiation and development of various human carcinomas, encompassing non-small cell lung cancer (NSCLC). In spite of the fact that lncRNA MAPKAPK5 antisense RNA 1 (MAPKAPK5-AS1) has already been investigated by researchers and confirmed to play oncogenic roles in colorectal cancer, the underlying regulatory function of MAPKAPK5-AS1 in NSCLC cells still remain unclear. In our research, we found that MAPKAPK5-AS1 was expressed at high levels in NSCLC cells. Biological functional assays unclosed that downregulation of MAPKAPK5-AS1 repressed proliferative and migratory capacities whereas promoted apoptotic level in NSCLC cells. Molecular mechanism experiments confirmed that, in NSCLC cells, MAPKAPK5-AS1 combined with miR-515-5p and negatively modulated miR-515-5p expression level. Besides, calcium-binding protein 39 (CAB39) expression level was verified to be negatively modulated by miR-515-5p whereas positively modulated by MAPKAPK5-AS1 in NSCLC cells. Furthermore, rescued-function assays disclosed that inhibited miR-515-5p expression or overexpressed CAB39 could restore the suppressive influence of MAPKAPK5-AS1 silence on NSCLC progression. In summary, MAPKAPK5-AS1 upregulates CAB39 expression level to facilitate NSCLC progression by sequestering miR-515-5p, providing promising biomarkers for NSCLC treatment.

SNHG1 functions as a ceRNA in hypertrophic scar fibroblast proliferation and apoptosis through miR-320b/CTNNB1 axis

Hypertrophic scar (HS) is a fibrotic disease caused by skin injury. Competing endogenous RNA (ceRNA) has been demonstrated to implicate in the regulation of cell malignant phenotypes. This research aims to reveal the effect of catenin beta 1 (CTNNB1) on the functions of hypertrophic scar fibroblasts (HSFBs) and its role in a ceRNA network. RNA expression level was assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). The proliferation and apoptosis of HSFB was detected via Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis. Mechanism experiments included RNA pull down assay, luciferase reporter assay and RNA-binding protein immunoprecipitation (RIP) assay were applied to analyze the upstream molecular mechanism of CTNNB1. CTNNB1 was highly expressed in HSFB. CTNNB1 depletion repressed malignant growth of HSFB. Mechanically, CTNNB1 was targeted by microRNA-320b (miR-320b) in HSFB. Small nucleolar RNA host gene 1 (SNHG1) aced as a ceRNA to upregulate CTNNB1 expression via sponging miR-320b in HSFB. CTNNB1 overexpression could reverse the impact of SNHG1 depletion on the proliferation and apoptosis of HSFB. SNHG1 acts as a ceRNA in modulating HSFB proliferation and apoptosis through miR-320b/CTNNB1 axis. SNHG1 act as a ceRNA to promote HSFB growth by sponging miR-320b to upregulate CTNNB1.

Risk score = LncRNAs associated with doxorubicin metabolism can be used as molecular markers for immune microenvironment and immunotherapy in non-small cell lung cancer

Doxorubicin is the most effective anthracycline chemotherapy drug in the treatment of cancer, and it is an effective single agent in the treatment of non-small cell lung cancer (NSCLC). There is a lack of studies on the differentially expressed doxorubicin metabolism-related lncRNAs in NSCLC. In this study, we extracted related genes from the TCGA database and matched them with lncRNAs. Doxorubicin metabolism-related lncRNA-based gene signatures (DMLncSig) were gradually screened from univariate regression, LASSO regression, and multivariate regression analysis, and the risk score model was constructed. These DMLncSig were subjected to a GO/KEGG analysis. We then used the risk model to construct the TME model and analyze drug sensitivity. The IMvigor 210 immunotherapy model was cited for validation. Eventually, we performed tumor stemness index differences, survival, and clinical correlation analyses.

A novel prognostic signature for lung adenocarcinoma based on cuproptosis-related lncRNAs: A Review

Lung adenocarcinoma (LUAD) is a highly heterogeneous disease with complex pathogenesis, high mortality, and poor prognosis. Cuproptosis is a new type of programmed cell death triggered by copper accumulation that may play an important role in cancer. LncRNAs are becoming valuable prognostic factors in cancer patients. The effect of cuproptosis-related lncRNAs (CRlncRNAs) on LUAD has not been clarified. Based on the Cancer Genome Atlas database, CRlncRNAs were screened by co-expression analysis of cuproptosis- related genes and lncRNAs. Using CRlncRNAs, Cox and LASSO regression analyses constructed a risk prognostic model. The predictive efficacy of the model was assessed and validated using survival analysis, receiver operating characteristic curve, univariate and multifactor Cox regression analysis, and principal component analysis. A nomogram was constructed and calibration curves were applied to enhance the predictive efficacy of the model. Tumor Mutational Burden analysis and chemotherapeutic drug sensitivity prediction were performed to assess the clinical feasibility of the risk model. The novel prognostic signature consisted of 5 potentially high-risk CRlncRNAs, MAP3K20-AS1, CRIM1-DT, AC006213.3, AC008035.1, and NR2F2-AS1, and 5 potentially protective CRlncRNAs, AC090948.1, AL356481.1, AC011477.2, AL031600.2, and AC026355.2, which had accurate and robust predictive power for LUAD patients. Collectively, the novel prognostic signature constructed based on CRlncRNAs can effectively assess and predict the prognosis of patients and provide a new perspective for the diagnosis and treatment of LUAD.

BMI1 induces ubiquitination and protein degradation of Nod-like receptor family CARD domain containing 5 and suppresses human leukocyte antigen class I expression to induce immune escape in non-small cell lung cancer

The Nod-like receptor (NLR) family CARD domain containing 5 (NLRC5) has been reported as an activator of human leukocyte antigen (HLA) class I that is responsible for immune activity in cancer treatment. This work focuses on the role of BMI1 proto-oncogene (BMI1) in the NLRC5-HLA class I axis and in immune escape in non-small cell lung cancer (NSCLC). First, immunoblot analysis and/or reverse transcription-quantitative polymerase chain reaction were performed, which identified decreased NLRC5 and HLA class I levels in NSCLC tissues and cell lines. NSCLCs were co-cultured with activated CD8⁺ T cells. Overexpression of NLRC5 in NSCLC cells elevated the expression of HLA class I and increased the activity of T cells and IL-2 production, and it reduced the PD-1/PD-L1 levels. The ubiquitination and immunoprecipitation assays confirmed that BMI1 bound to NLRC5 to induce is ubiquitination and protein degradation. Downregulation of BMI1 in NSCLC cells elevated NLRC5 and HLA class I levels, and consequently promoted T cell activation and decreased PD-1/PD-L1 levels in the co-culture system. However, overexpression of BMI1 in cells led to inverse trends. In summary, this study demonstrates that BMI1 induces ubiquitination and protein degradation of NLRC5 and suppresses HLA class I expression, which potentially helps immune escape in NSCLC.

Long non-coding RNA NR2F2-AS1 regulates human osteosarcoma growth and metastasis through miR-425-5p-mediated HMGB2

BACKGROUND

Multiple studies have revealed that long non-coding RNA (lncRNA) NR2F2-AS1 plays a role in affecting cancer cell proliferation and metastasis. Here, both in vitro and in vivo experiments were performed for investigating the function and mechanism of NR2F2-AS1 in human osteosarcoma (OS).

METHODS

The NR2F2-AS1 level in human OS tissues and adjacent non-tumor tissues was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The NR2F2-AS1 overexpression model was constructed in OS cells, then cell proliferation, invasion, and apoptosis were monitored. The OS xenograft model was established in nude mice using NR2F2-AS1-overexpressed OS cells. The downstream target genes of NR2F2-AS1 were predicted. qRT-PCR and Western blot were implemented to validate the profiles of miR-425-5p and HMGB2. The targeting link between NR2F2-AS1 and miR-425-5p, miR-425-5p and HMGB2 was further probed by dual-luciferase reporter experiment.

RESULTS

In comparison to adjacent non-tumor tissues, OS tissues showed upregulated NR2F2-AS1 expression. Higher NR2F2-AS1 level was predominantly correlated with worse clinical stages. In vivo and in vitro tests corroborated that NR2F2-AS1 overexpression spurred OS cell proliferation, growth, invasion, and choked apoptosis. Mechanistically, NR2F2-AS1 hampered miR-425-5p expression as its competitive endogenous RNA (ceRNA). Thus, NR2F2-AS1 facilitated the HMGB2 expression. However, miR-425-5p inhibited HMGB2 expression by targeting the latter.

CONCLUSION

NR2F2-AS1 expedited the evolution of OS by elevating HMGB2 levels through sponging miR-425-5p. The NR2F2-AS1/miR-425-5p/HMGB2 regulatory axis is a promising target in treating human OS.

A novel inflammation-related lncRNAs prognostic signature identifies LINC00346 in promoting proliferation, migration, and immune infiltration of glioma

In this study, a total of 13 inflammation-related lncRNAs with a high prognostic value were identified with univariate, multivariate Cox regression analysis, and LASSO analysis. LINC00346, which is one of the 13 lncRNAs identified, was positively associated with type 2 macrophage activation and the malignant degree of glioma. Fluorescence in situ hybridization (FISH) and immunohistochemical staining showed that LINC00346 was highly expressed in high-grade glioma, while type 2 macrophages key transcription factor STAT3 and surface marker CD204 were also highly expressed simultaneously. LINC00346 high-expression gliomas were more sensitive to the anti–PD-1 and anti-CTLA-4 therapy. LINC00346 was also associated with tumor proliferation and tumor migration validated by EdU, cell colony, formation CCK8, and transwell assays. These findings reveal novel biomarkers for predicting glioma prognosis and outline relationships between lncRNAs inflammation, and glioma, as well as possible immune checkpoint targets for glioma.

Research Progress for RNA Modifications in Physiological and Pathological Angiogenesis

As a critical layer of epigenetics, RNA modifications demonstrate various molecular functions and participate in numerous biological processes. RNA modifications have been shown to be essential for embryogenesis and stem cell fate. As high-throughput sequencing and antibody technologies advanced by leaps and bounds, the association of RNA modifications with multiple human diseases sparked research enthusiasm; in addition, aberrant RNA modification leads to tumor angiogenesis by regulating angiogenesis-related factors. This review collected recent cutting-edge studies focused on RNA modifications (N⁶-methyladenosine (m⁶A), N⁵-methylcytosine (m⁵C), N⁷-methylguanosine (m⁷G), N¹-methyladenosine (m¹A), and pseudopuridine (Ψ)), and their related regulators in tumor angiogenesis to emphasize the role and impact of RNA modifications.

Long non-coding RNA NR2F2-AS1: its expanding oncogenic roles in tumor progression

Long non-coding RNA (LncRNA) is a new type of non-coding RNA whose transcription is more than 200 nucleotides in length and can be up to 100 kb. The crucial regulatory function of lncRNAs in different cellular processes is now notable in many human diseases, especially in different steps of tumorigenesis, making them clinically significant. This research tried to collect all evidence obtained so far regarding Nuclear Receptor subfamily 2 group F member 2 Antisense RNA 1 (NR2F2-AS1) to explore its role in carcinogenesis and molecular mechanism in several cancers. Collecting evidence value an oncogenic role for NR2F2-AS1, whose dysregulation changes the status for cancerous cells to gain the supremacy toward cellular proliferation, dissemination, and ultimately migration. The NR2F2-AS1 acts as competitive endogenous RNA (ceRNA) and contains several microRNA response elements (MREs) for different microRNAs involved in various pathways such as PI3K/AKT, Wnt/β-catenin, and TGF-β. This clinically makes NR2F2-AS1 a remarkable lncRNA which contributes to cancer progression and invasion and perhaps could be a candidate as a prognostic marker or even a therapeutic target.

Characterization of a Novel LUCAT1/miR-4316/VEGF-A Axis in Metastasis and Glycolysis of Lung Adenocarcinoma

Objective: Accumulating literatures suggested that long non-coding RNAs (lncRNAs) were involved in tumorigenesis and cancer progression in lung adenocarcinoma (LUAD). However, the precise regulatory mechanism of lncRNA Lung cancer-associated transcript 1 (LUCAT1) in LUAD is not well defined. In this study, we aimed to investigate the biological function and mechanism of lncRNA LUCAT1 in regulating tumor migration and glycolysis of LUAD.

Methods: High throughput sequencing was performed to identify differentially expressed lncRNAs between LUAD patients and healthy controls. The expression levels of LUCAT1 in LUAD clinical specimens or cell lines were evaluated by In situ hybridization (ISH) and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Functional experiments, including wound-healing, transwell invasion assays, glucose absorption, lactate metabolism and tumor xenograft experiments were conducted to identify the biological functions of LUCAT1 in LUAD. Silencing of LUCAT1, over-expression of LUCAT1 and miR-4316 were generated in LUAD cell lines to verify the regulatory mode of LUCAT1-mir-4316-VEGFA axis.

Results: Our findings revealed that lncRNA LUCAT1 was significantly up-regulated in LUAD serum exosomes, tumor tissues, and LUAD cells in comparison with corresponding controls. Receiver operating characteristic curve (ROC) analysis indicated that the area under the curve (AUC) value of serum exosomal LUCAT1 reached 0.852 in distinguishing LUAD patients from healthy individuals. High expression of LUCAT1 in LUAD patient tissues was associated with enhanced Lymph Node Metastasis (LNM), advanced Tumor Node Metastasis (TNM) stage and poorer clinical outcome in LUAD patients. Knockdown of LUCAT1 inhibited LUAD cell metastasis and glycolysis in vitro as well as tumor metastasis in vivo, while overexpression of LUCAT1 induced a promoted LUAD metastasis and glycolysis. Furthermore, mechanistic investigations revealed that LUCAT1 elevated LUAD cell metastasis and glycolysis by sponging miR-4316, which further led to the upregulation of VEGFA. Finally, the regulatory axis LUCAT1-miR-4316-VEGFA was verified in LUAD.

Conclusion: Our present research suggested that LUCAT1 facilitate LUAD cell metastasis and glycolysis via serving as a competing endogenous RNA to regulate miR-4316/VEGFA axis, which provided a novel diagnostic marker and therapeutic target for LUAD patients.

Comprehensive Analysis of an Individualized Immune-Related lncRNA Pair Signature in Gastric Cancer

Long noncoding RNAs (lncRNAs) have diverse functions, including immune regulation. Increasing studies have reported immune-related lncRNAs in the prognosis of multiple cancers. In this study, we developed an individualized signature containing 13 immune-related lncRNA pairs (IRLPs) which could predict the overall survival, disease-free survival, progression-free survival, and disease-specific survival of gastric cancer (GC) patients in The Cancer Genome Atlas (TCGA) cohort, and internal and external validations, signature comparisons, and subgroup analyses further confirmed its superiority, stability, and generalizability. Notably, this signature also showed good applicability in discriminating the prognosis of pan-cancer patients. Then, we constructed and validated a nomogram for overall survival based on the signature and clinical factors, which allowed more accurate predictions of GC prognosis. In addition, we revealed that the low survival rate of patients with high-risk scores may be due to their aggressive clinical features, enriched cancer-related signaling pathways, the infiltration of specific immunosuppressive cells, and low tumor mutation burden. We further predicted obviously worse immunotherapeutic responses in the high-risk groups and identified some candidate compounds targeting GC risk group differentiation. This signature based on the IRLPs may be promising for predicting the survival outcomes and immunotherapeutic responses of GC patients in clinical practice.

A Prognostic Signature of Glycolysis-Related Long Noncoding RNAs for Molecular Subtypes in the Tumor Immune Microenvironment of Lung Adenocarcinoma

Purpose

Long noncoding RNAs (lncRNAs) and glycolysis regulate multiple types of cancer. However, the prognostic roles and biological functions of glycolysis-related lncRNAs in lung adenocarcinoma (LUAD) remain unclear. In this study, we investigated the role of glycolysis-related lncRNAs in LUAD.

Patients and Methods

We retrieved glycolysis-related genes from the Molecular Signatures Database and screened for prognostic glycolysis-related lncRNAs from The Cancer Genome Atlas.

Results

We identified three LUAD subtypes (clusters 1–3) by univariate Cox regression analysis and consensus clustering. Patients in cluster 1 had the best overall survival rates. Immune, stromal, and cytolytic-activity scores were the highest in cluster 1. The expression of immune checkpoint molecules (programmed cell death protein 1 and cytotoxic T-lymphocyte-associated protein 4) and other immune-related indicators was the highest in cluster 1, whereas that of epithelial cell biomarkers (Cadherin 1, Cadherin 2, and MET) was the lowest. Therefore, patients in cluster 1 may benefit from immunotherapy. Lasso–Cox regression and multivariate Cox regression analyses were used to select nine lncRNAs to build a robust prognostic model of LUAD. The area under the curve classifier values and a nomogram performed well in predicting survival times for patients with LUAD. The expression levels of nine lncRNAs were validated by quantitative reverse transcriptase-polymerase chain reaction analysis, and most of these lncRNAs were significantly related to immune-related mRNAs. Gene set enrichment analysis revealed that the high-risk group was enriched for cell cycle-related pathways and the low-risk group was enriched for pathways associated with immunity or immune-related diseases.

Conclusion

The LUAD subtypes and prognostic model developed here may help in clinical risk stratification, prognosis management, and treatment decisions for patients with LUAD.

USP21 regulates Hippo signaling to promote radioresistance by deubiquitinating FOXM1 in cervical cancer

The ectopic expression of ubiquitin-specific peptidase 21 (USP21) is common in different types of cancer. However, its relationship with radio-sensitivity in cervical cancer (CC) remains unclear. In this study, we aimed to uncover the effect of USP21 on CC radio-resistance and its underlying mechanism. Our results showed that the expression of USP21 was markedly increased in CC tissues of radio-resistant patients and CC cells treated with radiation. Besides, knockdown of USP21 restrained the survival fractions, and facilitated apoptosis of CC cells in the absence or presence of radiation. Additionally, USP21 in combination with FOXM1 regulated the stability and ubiquitination of FOXM1. However, FOXM1 reversed the effects of USP21 knockdown on the radio-resistance of CC cells. Furthermore, FOXM1 knockdown activated the Hippo pathway by inhibiting the nuclear translocation of Yes-associated protein 1 (YAP1), and FOXM1 knockdown attenuated the radio-resistance of CC cells via inhibiting the Hippo-YAP1 pathway. USP21 activated the Hippo pathway by mediating FOXM1. Knockdown of USP21 enhanced the radio-sensitivity of CC cells in vivo. In summary, USP21 contributed to the radio-resistance of CC cells via FOXM1/Hippo signaling, and may serve as a promising target for radio-sensitizers in the radiotherapy of CC.

lncRNA NR2F2-AS1 inhibits the methylation of miR-494 to regulate oral squamous cell carcinoma cell proliferation

OBJECTIVE

This study aimed to investigate the role of lncRNA NR2F2-AS1 in oral squamous cell carcinoma cells (OSCC).

MATERIALS AND METHODS

The TCGA datasets were used to explore the differential expression of NR2F2-AS1 in OSCC. To further explore the potential interaction between NR2F2-AS1 and miR-494, SCC090 cells were transfected with the NR2F2-AS1 expression vector, NR2F2-AS1 siRNA, and a miR-494 mimic. The effect of NR2F2-AS1 on miR-494 methylation was evaluated by performing methylation-specific PCR (MSP). Cell Counting Kit-8 (CCK-8) assay was used to assess the effects of NR2F2-AS1 silencing and miR-494 and NR2F2-AS1 overexpression on OSCC cell proliferation.

RESULTS

NR2F2-AS1 expression was downregulated in OSCC and positively correlated with miR-494 expression. In OSCC cells, NR2F2-AS1 overexpression upregulated miR-494 level, while NR2F2-AS1 silencing decreased miR-494 expression. MSP results showed that NR2F2-AS1 overexpression decreased miR-494 methylation while NR2F2-AS1 silencing increased miR-494 methylation. In addition, NR2F2-AS1 silencing increased OSCC cell proliferation rate while overexpression of miR-494 and NR2F2-AS1 decreased OSCC cell proliferation. Furthermore, miR-494 overexpression attenuated the effects of NR2F2-AS1 silencing on cell proliferation.

CONCLUSION

NR2F2-AS1 may inhibit miR-494 methylation to regulate cell proliferation in OSCC.

AVAILABILITY OF DATA AND MATERIALS

The analyzed data sets generated during the study are available from the corresponding author upon reasonable request.

LINC00184 plays an oncogenic role in non-small cell lung cancer via regulation of the miR-524-5p/HMGB2 axis

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. We aimed to investigate the role of LINC00184 in NSCLC. Migration, proliferation and invasion of NSCLC cells were analysed using the wound healing assay, cell counting kit-8 assay and transwell assay, respectively. Apoptosis and cell cycle were assessed using flow cytometry. Online bioinformatics tools were utilized to predict downstream microRNAs (miRNA) or genes related to LINC00184 expression. The RNA pull-down experiment and luciferase reporter assay were performed to verify the predictions thereof. LINC00184, miR-524-5p, and high mobility group 2 protein (HMGB2) expression levels in NSCLC tissues and cell lines were detected using quantitative real-time polymerase chain reaction. An NSCLC mouse model was constructed for in vivo experiments. LINC00184 overexpression was observed in NSCLC tissues and cell lines and was found to be correlated with poor prognosis. LINC00184 knockdown inhibited cell proliferation, migration and invasion, induced cell cycle arrest and accelerated apoptosis in NSCLC cell lines. LINC00184 suppressed tumour growth and proliferation in NSCLC mouse models and directly targeted the miR-524-5p/HMGB2 axis. Moreover, the expression levels of LINC00184 and HMGB2 were negatively correlated with miR-524-5p expression, whereas LINC00184 expression was positively correlated with HMGB2 expression. LINC00184 affected the cell cycle, proliferation, apoptosis, migration and invasion in NSCLC via regulation of the miR-524-5p/HMGB2 axis.

LncRNA NR2F2-AS1 induces epithelial-mesenchymal transition of non-small cell lung cancer by modulating BVR/ATF-2 pathway via regulating miR-545-5p/c-Met axis

Non-small cell lung cancer (NSCLC) is one type of the most common cancers, which results in the major death worldwide. This study focuses on the understanding of the molecular mechanism of lncRNA NR2F2-AS1 and its regulation on epithelial-mesenchymal transition (EMT) in the development of NSCLC. Expressions of lncRNA NR2F2-AS1, miR-545-5p, c-Met, biliverdin reductase (BVR), ATF-2 and EMT-related markers in NSCLC tissues and cells were measured by western blotting and RT-qPCR assays. The impact of lncRNA NR2F2-AS1 and miR-545-5p on the cell proliferation, migration, invasion and EMT were analyzed by CCK-8, colony formation, wound healing and transwell assays. The interactions among lncRNA NR2F2-AS1, miR-545-5p and c-Met predicted by bioinformatic analysis were evaluated through dual luciferase reporter assay and fluorescence in situ hybridization (FISH). After generating tumor xenografts, immunohistochemistry was utilized to measure the expression of Ki-67 and EMT-related proteins in vivo. Our results showed that lncRNA NR2F2-AS1, c-Met, BVR and ATF-2 were overexpressed while miR-545-5p was silenced in NSCLC tissues and cells. Silencing of lncRNA NR2F2-AS1 or upregulating miR-545-5p significantly inhibited the cell proliferation, migration, invasion and EMT process. The EMT process could be inhibited by suppressing c-Met/BVR/ATF-2 axis. The tumor xenograft experiments demonstrated that the tumor growth and EMT process were significantly inhibited by silencing lncRNA NR2F2-AS1 or overexpression of miR-545-5p in vivo. LncRNA NR2F2-AS1 promoted the NSCLC development through suppressing miR-545-5p to activate EMT process through c-Met/BVR/ATF-2 axis. Our study indicated that lncRNA NR2F2-AS1 and miR-545-5p could be used as potential therapeutic targets to improve NSCLC treatment.

Research updates on the clinical implication of long noncoding RNA in digestive system cancers and chemoresistance

Long noncoding RNAs (lncRNAs) are implicated in various biological processes, such as cell proliferation, differentiation, apoptosis, migration, and invasion. They are also key players in various biological pathways. LncRNA was considered as 'translational noise' before 1980s. It has been reported that lncRNAs are aberrantly expressed in different cancers, either as oncogene or tumor suppressor gene. Therefore, more and more lncRNAs are recognized as potential diagnostic biomarkers and/or therapeutic targets. As competitive endogenous RNA, lncRNAs can interact with microRNA to alter the expression of target genes, which may have extensive clinical implications in cancers, including diagnosis, treatment, prognosis, and chemoresistance. This review comprehensively summarizes the functions and clinical relevance of lncRNAs in digestive system cancers, especially as a potential tool to overcome chemoresistance.

SNAI2-Induced CircMTO1 Promotes Cell Proliferation and Inhibits Apoptosis Through the miR-320b/MCL1 Axis in Human Granulosa-Like Tumor Cells

Polycystic ovary syndrome (PCOS), one of the most common types of endocrine diseases, is characterized by a high prevalence among women of reproductive-age. However, its pathogenesis and molecular mechanisms remain unclear. CircMTO1 has been reported to participate in numerous biological processes, but, its role in PCOS progression remains unknown. In the current study, we elucidated the expression and circRNA characterization of circMTO1 in human granulosa-like tumor cells. We found that circMTO1 knockdown promoted human granulosa-like tumor cell proliferation and inhibited its apoptosis rate. Next, we explored the underlying molecular mechanisms by using a series of experiments. Our results revealed the effect of the novel circMTO1/miR-320b/MCL1 axis in human granulosa-like tumor cells. Furthermore, we found that the expression of circMTO1 was induced by Snail family transcriptional repressor 2 (SNAI2) in human granulosa-like tumor cells. Our results may provide potential targets for PCOS research and a novel direction for the diagnosis and treatment of PCOS.

Network analysis of miRNA targeting m6A-related genes in patients with esophageal cancer

Background

We investigated the miRNA-m6A related gene network and identified a miRNA-based prognostic signature in patients with esophageal cancer using integrated genomic analysis.

Methods

We obtained expression data for m6A-related genes and miRNAs from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. Survival analysis was conducted to identify potential prognostic biomarkers. LASSO Cox regression was performed to construct the overall survival (OS) associated prediction signature. We used the Kaplan-Meier (K-M) curve and receiver operating characteristic (ROC) curves to explore the signature's efficiency and accuracy. Interactions between the m6A-related genes and miRNAs were identified in starBase3.0 and used to construct the miRNA-m6A related gene network.

Results

We found that HNRNPC, YTHDF, ZC3H13, YTHDC2, and METTL14 were dysregulated in esophageal cancer tissues. Multivariate Cox regression analysis revealed that HNRNPC may be an independent risk factor for OS. Five hundred twenty-two potential upstream miRNAs were obtained from starBase3.0. Four miRNAs (miR-186, miR-320c, miR-320d, and miR-320b) were used to construct a prognostic signature, which could serve as a prognostic predictor independent from routine clinicopathological features. Finally, we constructed a key miRNA-m6A related gene network and used one m6A-related gene and four miRNAs associated with the prognosis. The results of our bioinformatics analysis were successfully validated in the human esophageal carcinoma cell lines KYSE30 and TE-1.

Conclusion

Our study identified a 4-miRNA prognostic signature and established a key miRNA-m6A related gene network. These tools may reliably assist with esophageal cancer patient prognosis.

microRNA-320b suppresses HNF4G and IGF2BP2 expression to inhibit angiogenesis and tumor growth of lung cancer

We examined the effect of microRNA-320b (miR-320b) on tumor growth and angiogenesis in lung cancer and also determined its downstream molecular mechanisms. Lung cancer tissues and adjacent non-cancerous tissues were collected from 66 patients with lung cancer. miR-320b expression was experimentally determined to be expressed at low level in cancer tissues. The results of gain-of-function experiments suggested that miR-320b overexpression suppressed cancer cell invasion, tube formation, tumor volume and angiogenesis in xenografted nude mice. Hepatocyte nuclear factor 4 gamma (HNF4G) was identified as a target of miR-320b based on in silico analysis. Dual-luciferase reporter gene assays further identified the binding relationship between HNF4G and miR-320b. Lung cancer tissues exhibited increased expression of HNF4G and insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2). Meanwhile, HNF4G knockdown suppressed IGF2BP2 expression, thereby repressing cancer cell invasion and tube formation. Furthermore, IGF2BP2 modified m6A to increase the expression of thymidine kinase 1 (TK1), thus promoting angiogenesis. In nude mice, restoration of TK1 reversed the suppressive effect of miR-320b overexpression on tumor growth rate and CD31 expression. In conclusion, miR-320b suppresses lung cancer growth and angiogenesis by inhibiting HNF4G, IGF2BP2 and TK1.

Long non‑coding RNA LINC00460 serves as a potential biomarker and oncogene via regulation of the miR‑320b/PBX3 axis in acute myeloid leukemia

Long non-coding RNA 00460 (LINC00460) has been reported to be involved in the tumorigenesis of various cancer types. However, the function of LINC00460 in acute myeloid leukemia (AML) remains elusive. Therefore, the present study aimed to investigate the role of LINC00460 in AML. The expression of LINC00460 in the serum of 80 diagnosed patients with AML and 67 healthy controls was measured via reverse transcription-quantitative polymerase chain reaction, and the results were compared with clinical features and patient outcomes. The expression of LINC00460 in 45 patients with cytogenetically normal-AML (CN-AML) was also assayed. Receiver operating characteristic (ROC) curves were generated to evaluate the sensitivity and specificity of serum LINC00460. In addition, the effects of LINC00460 on the viability, cell cycle distribution and apoptosis of AML cells were investigated. Bioinformatics tools were used to identify the possible mechanisms of how LINC00460 affects AML cells. It was found that the expression of LINC00460 was significantly upregulated in the serum of patients with AML and those with CN-AML. Higher expression of serum LINC00460 was positively associated with French-American-British classification and cytogenetics. Furthermore, ROC curve analyses demonstrated that serum LINC00460 could differentiate patients with AML from healthy individuals with an area under the curve of 0.8488 (95% CI, 0.7697–0.9279). The serum LINC00460 expression was also significantly decreased when the patients achieved complete remission. Kaplan-Meier analysis indicated that patients with high serum LINC00460 expression had a shorter overall survival time compared with the low serum LINC00460 expression group. Knockdown of LINC00460 inhibited viability, while inducing cell cycle arrest and apoptosis in AML cells. LINC00460 was also a decoy of microRNA (miR)-320b, which can further inhibit the expression of PBX homeobox 3 (PBX3). Collectively, the results suggested that LINC00460 may be applied as a potential diagnostic and prognostic biomarker for patients with AML. It was identified that LINC00460 may exert its effects, at least partly, via the miR-320b/PBX3 axis in AML.

NR2F2-AS1 accelerates cell proliferation through regulating miR-4429/MBD1 axis in cervical cancer

Cervical cancer is one of the most frequent malignant tumors in female. Increasing studies have demonstrated that long noncoding RNAs (lncRNAs) play a key role in the development of multiple cancers. Although some studies have confirmed that lncRNA NR2F2 antisense RNA 1 (NR2F2-AS1) is a pro-cancer gene in many cancers, the molecular mechanism of NR2F2-AS1 in cervical cancer has not been completely elucidated. In the present study, our results revealed that NR2F2-AS1 expression was up-regulated in cervical cancer tissues and cells, notably in patients with advanced cervical cancer. NR2F2-AS1 accelerated progression of cervical cancer by facilitating cell proliferation, migration, invasion, and EMT process, but inhibiting cell apoptosis. Moreover, NR2F2-AS1 acted as a molecular sponge of miR-4429 and methyl-CpG-binding domain protein 1 (MBD1) was a downstream target of miR-4429 in cervical cancer. Furthermore, there was a negative correlation between miR-4429 expression and NR2F2-AS1 or MBD1 expression in tumor tissues. Rescue experiments confirmed that MBD1 overexpression partly rescued NR2F2-AS1 knockdown-mediated inhibition of progression in cervical cancer. To sum up, these results suggested the potential mechanism of NR2F2-AS1 in cervical cancer and revealed that NR2F2-AS1 exerted its carcinogenic effect via regulating miR-4429/MBD1 axis, indicating a promising insight into the therapeutic target of cervical cancer.

LINC00460 facilitated tongue squamous cell carcinoma progression via the miR-320b/IGF2BP3 axis

OBJECTIVE

We aimed to explore the role of long intergenic non-protein coding RNA 460 (LINC00460) in tongue squamous cell carcinoma (TSCC).

METHODS

We enrolled 27 TSCC patients to explore LINC00460 expression in clinical TSCC samples. RT-qPCR measured expression of molecules in this research. Loss-of-function assays explored biological function of LINC00460 in TSCC cells. RNA pull-down assay, luciferase reporter assay, and RIP assay investigated mechanism of LINC00460 underlying TSCC cells.

RESULTS

TSCC tissues and cell lines both showed high expression of LINC00460. Functionally, LINC00460 downregulation inhibited TSCC cell growth and promoted TSCC cell apoptosis. Additionally, LINC00460 silencing suppressed tumor growth in vivo. Mechanistically, LINC00460 bound with microRNA 320b (miR-320b) in TSCC cells. MiR-320b overexpression suppressed TSCC cell growth and promoted TSCC cell apoptosis. Moreover miR-320b targeted insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) 3'untranslated region in TSCC cells. Furthermore, IGF2BP3 silencing suppressed TSCC cell growth and promoted TSCC cell apoptosis. IGF2BP3 upregulation countervailed effects of silenced LINC00460 on TSCC cells. The LINC00460/miR-320b/IGF2BP3 axis was associated with lymph node metastasis of TSCC patients.

CONCLUSION

Our research illustrated that LINC00460 facilitated TSCC progression via the miR-320b/IGF2BP3 axis, highlighting a potential insight for the treatment of TSCC.

A transposon screen identifies enhancement of NF-κB pathway as a mechanism of resistance to eribulin

BACKGROUND

Eribulin mesylate (eribulin) is an efficient microtubule inhibitor that is used for metastatic breast cancer. However, breast cancer can develop resistance to eribulin. This resistance mechanism needs to be elucidated.

METHODS

A transposon mutagenesis screen was conducted using a pPB-SB-CMV-puro-SD plasmid and pCMV-PBase transposase. Viability and cytotoxicity were analyzed by MTT assay and flow cytometry, respectively. Real-time PCR and western blot were used for gene expression analysis. In addition, vivo study was also designed to analyze therapy efficiency.

RESULTS

TAB2, which is part of the nuclear factor-kappa B (NF-κB) pathway, was identified as a candidate eribulin-resistant gene. TAB2 down-regulation resulted in significantly lower cell viability and higher cytotoxicity of cells treated with eribulin, while TAB2 up-regulation showed opposite results. Similarly, combination of NF-κB inhibitors [Bay-117082 and QNZ (quinazoline derivative)] with eribulin showed significantly lower cell viability and higher drug cytotoxicity than single agent treatment with eribulin in MDA-MB-231 cells. However, QNZ increased NF-κB activity in MCF7 cells by up-regulating TAB2, which reduced the sensitivity to eribulin. Furthermore, combination of Bay-117082 with eribulin induced greater regression of MDA-MB-231 tumors compared to eribulin monotherapy in vivo.

CONCLUSIONS

These results consistently illustrated that TAB2-NF-κB pathway may increases resistance to eribulin in breast cancer models. Moreover, these results support the use of a combination strategy of eribulin with NF-κB inhibitors, and provide evidence that transposon mutagenesis screens are capable of identifying drug-resistant genes.

Fusion of the COL4A5 Gene With NR2F2-AS1 in a Hemangioma Carrying a t(X;15)(q22;q26) Chromosomal Translocation

BACKGROUND/AIM

Hemangiomas are benign neoplastic proliferations of blood vessels. Cytogenetic information on hemangiomas is limited to four tumors with abnormal karyotypes. We report here a solitary chromosomal translocation and its molecular consequence in a hemangioma.

MATERIALS AND METHODS

A cavernous hemangioma was extirpated from the foot of a 62 years old man and genetically studied with cytogenetic and molecular genetic methodologies.

RESULTS

G-Banding analysis of short-term cultured tumor cells yielded the karyotype 46,Y,t(X;15)(q22;q26)[4]/46,XY[12]. RNA sequencing detected fusion of the collagen type IV alpha 5 chain gene (COL4A5 on Xq22.3) with intronic sequences of nuclear receptor subfamily 2 group F member 2 antisense RNA 1 (NR2F2-AS1 on 15q26.2) resulting in a putative COL4A5 truncated protein. The fusion was verified by RT-PCR together with Sanger sequencing and FISH analyses.

CONCLUSION

The involvement of COL4A5 indicates that some hemangiomas have pathogenetic similarities with other benign tumors such as leiomyomas and subungual exostosis.

Identification of miR-320 family members as potential diagnostic and prognostic biomarkers in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are characterized by ineffective hematopoiesis and the abnormal differentiation of hematopoietic stem cells. An increasing number of researches have demonstrated that microRNAs play crucial roles in the pathogenesis of myelodysplastic syndromes. Herein, we aimed to identify novel potential microRNAs bound up with the diagnosis and prognosis of MDS. MiRNA microarray analysis was used to screen deregulated microRNAs in the bone marrow of MDS patients. qRT-PCR was employed to confirm the microarray results. All members of miR-320 family (miR-320a, miR-320b, miR-320c, miR-320d, and miR-320e) were significantly increased in MDS patients compared to normal control. Although we found no correlation between miR-320 family and most clinical characteristics, high miR-320c and miR-320d expression seemed to be associated with high numbers of bone marrow (BM) blasts and worse karyotype. High expression of all the members of the miR-320 family seemed to be associated with a high prognostic score based on International Prognostic Scoring System (IPSS). The areas under the miR-320 family member ROC curves were 0.9037 (P < 0.0001), 0.7515 (P = 0.0002), 0.9647 (P < 0.0001), 0.8064 (P < 0.0001) and 0.9019 (P < 0.0001). Regarding Kaplan-Meier analysis, high miR-320c and miR-320d expression were related to shorter overall survival (OS). Moreover, multivariate analysis revealed the independent prognostic value of miR-320d for OS in MDS. The expression of miR-320 family members was up-regulated in MDS, and miR-320 family members could serve as candidate diagnostic biomarkers for MDS. High expression of miR-320d was an independent prognostic factor for OS in MDS.

LINC01255 combined with BMI1 to regulate human mesenchymal stromal senescence and acute myeloid leukemia cell proliferation through repressing transcription of MCP-1

BACKGROUND

Long non-coding RNAs (lncRNAs) govern fundamental biochemical and cellular biology processes, for example, participate in chromatin remodeling, imprinting, splicing, transcriptional regulation and translation. Dysregulation of lncRNA expression is act as a feature of various diseases and cancers, including hematopoietic malignancies. However, the clinical relevance of myelodysplastic syndrome (MDS) and acute myeloid leukemia preceded by MDS (MDS-AML) requires further research. Recently, lncRNAs have been demonstrated, which play an important role in hematopoiesis, thus, to further finding more functional lncRNA seemed particularly important.

METHODS

Western blotting, real-time PCR, RNA-pulldown, RIP (RNA immunoprecipitation), Chromatin immunoprecipitation (ChIP), cellular compartments extraction assays, SA-β-gal staining, lentivirus transfection, cell viability assay and cell proliferation assays were used to examine the relationship between lncRNA LINC01255 and its regulation of p53-p21 pathway in human mesenchymal stromal and acute myeloid leukemia cells.

RESULTS

LncRNA LINC01255 is highly expressed in bone marrow cells of AML patients, CD34+ cells of MDS-AML patients and AML cell lines and the higher expression of LINC01255 is associated with poor survival rate of AML patients. LINC01255 can interact with BMI1 and repress the transcription of MCP-1 to active p53-p21 pathway, thus inhibiting the senescence of human mesenchymal stromal and proliferation of acute myeloid leukemia cell.

CONCLUSIONS

We discovered a novel functional lncRNA LINC01255, which can regulate the senescence of human mesenchymal stromal and the proliferation of acute myeloid leukemia cell through inhibiting the transcription of MCP-1.

Competing endogenous RNAs in lung cancer

Competing endogenous RNAs (ceRNAs) containing microRNA response elements can competitively interact with microRNA via miRNA response elements, which can combine non-coding RNAs with protein-coding RNAs through complex ceRNA networks. CeRNAs include non-coding RNAs (long non-coding RNAs, circular RNAs, and transcribed pseudogenes) and protein-coding RNAs (mRNAs). Molecular interactions in ceRNA networks can coordinate many biological processes; however, they may also lead to ceRNA network imbalance and thus contribute to cancer occurrence when disturbed. Recent studies indicate that many dysregulated RNAs derived from lung cancer may function as ceRNAs to regulate multitudinous biological functions for lung cancer, including tumor cell proliferation, apoptosis, growth, invasion, migration, and metastasis. This study therefore reviewed the research progress in the field of non-coding and protein-coding RNAs as ceRNAs in lung cancer, and highlighted validated ceRNAs involved in biological lung cancer functions. Furthermore, the roles of ceRNAs as novel prognostic and diagnostic biomarkers were also discussed. Interpreting the involvement of ceRNAs networks in lung cancer will provide new insight into cancer pathogenesis and treatment strategies.

Intermittent hypoxia-induced downregulation of microRNA-320b promotes lung cancer tumorigenesis by increasing CDT1 via USP37

Obstructive sleep apnea-hypopnea (OSAH) is correlated with an increased incidence of lung cancer. In our study, we explored the functional roles of microRNAs (miRNAs) in lung cancer patients that were complicated with OSAH involving the deubiquitination enzyme. The miR-320b expression pattern in lung cancer tissues and cells was determined. The interactions between ubiquitin-specific peptidase 37 (USP37) and miR-320b were evaluated by a dual-luciferase reporter gene assay, whereas USP37 and Cdc10-dependent transcript 1 (CDT1) was assessed by co-immunoprecipitation and immunofluorescence. After the induction of intermittent hypoxia (IH), a gain-of function approach was performed to investigate roles of miR-320b, USP37, and CDT1 in lung cancer cell proliferation and invasion. In addition, nude mouse xenograft models were used to study their effects on tumor growth in vivo. miR-320b was poorly expressed in lung cancer patients with OSAH. IH treatment downregulated the expression of miR-320b but promoted the proliferation and invasion capabilities of lung cancer cells, both of which were suppressed by the overexpression of miR-320b through decreasing USP37. USP37 interacted with and deubiquitinated CDT1 to protect it from proteasomal degradation. Our study uncovered that IH-induced downregulation of miR-320b promoted the tumorigenesis of lung cancer by the USP37-mediated deubiquitination of CDT1.

MiR-320b/RAD21 axis affects hepatocellular carcinoma radiosensitivity to ionizing radiation treatment through DNA damage repair signaling

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world and is associated with high mortality. Ionizing radiation (IR)-based therapy causes DNA damage, exerting a curative effect; however, DNA damage repair signaling pathways lead to HCC resistance to IR-based therapy. RAD21 is a component of the cohesion complex, crucial for chromosome segregation and DNA damage repair, while it is still unclear whether RAD21 is implicated in DNA damage and influences IR sensitivity in HCC. The current research explores the effect and upstream regulatory mechanism of RAD21 on IR sensitivity in HCC. In the present study, RAD21 mRNA and protein expression were increased within HCC tissue samples, particularly within IR-insensitive HCC tissues. The overexpression of RAD21 partially attenuated the roles of IR in HCC by promoting the viability and suppressing the apoptosis of HCC cells. RAD21 overexpression reduced the culture medium 8-hydroxy-2-deoxyguanosine concentration and decreased the protein levels of γH2AX and ATM, suggesting that RAD21 overexpression attenuated IR treatment-induced DNA damage to HCC cells. miR-320b targeted RAD21 3'-UTR to inhibit RAD21 expression. In HCC tissues, particularly in IR-insensitive HCC tissues, miR-320b expression was significantly downregulated. miR-320b inhibition also attenuated IR treatment-induced DNA damage to HCC cells; more importantly, RAD21 silencing significantly attenuated the effects of miR-320b inhibition on IR treatment-induced DNA damage, suggesting that miR-320b plays a role through targeting RAD21. In conclusion, an miR-320b/RAD21 axis modulating HCC sensitivity to IR treatment through acting on IR-induced DNA damage was demonstrated. The miR-320b/RAD21 axis could be a novel therapeutic target for further study of HCC sensitivity to IR treatment.

Study on Targeting Relationship Between miR-320b and FGD5-AS1 and Its Effect on Biological Function of Osteosarcoma Cells

Objective

To probe into the expression of FGD5-AS1 in osteosarcoma and its relationship with miR-320b.

Methods

The tissue and serum samples of 97 patients with osteosarcoma were collected, and the serum samples of 100 healthy subjects who concurrently underwent physical examination were selected as the control. FGD5-AS1 expression in tissues and serum was detected, and osteosarcoma cells were transfected to measure cell behaviors such as proliferation, invasion and apoptosis.

Results

FGD5-AS1 was highly expressed in osteosarcoma, and its elevated expression indicated poor survival of patients. Serum FGD5-AS1 was related to tumor size and clinical stage and could be used for the diagnosis of osteosarcoma. The study of osteosarcoma cell lines U2OS and SaOS-2 showed that after inhibiting FGD5-AS1, the viability and invasion capacity of osteosarcoma cells decreased statistically compared with the control group (CG), while the apoptosis ability could be improved by further regulating apoptotic proteins (P<0.05). Detection of EMT-related proteins identified that E-cadherin increased while N-cadherin decreased significantly after FGD5-AS1 inhibition (P<0.05). Correlation analysis revealed a negative correlation between miR-320b and FGD5-AS1 (r = −0.410, P<0.001). Overexpression of miR-320b significantly inhibited cell viability, invasion and EMT ability, and increased the apoptosis rate, while inhibiting miR-320b expression produced the opposite results. The targeting relationship between miR-320b and FGD5-AS1 was confirmed through the biological prediction website, luciferase assay and RNA binding protein immunoprecipitation (RIP) assay. Inhibition of miR-320b could reverse the regulatory effect of FGD5-AS1 knockdown on osteosarcoma cells.

Conclusion

FGD5-AS1 is highly expressed in osteosarcoma and is involved in the biological procession of osteosarcoma by targeting miR-320b.

LncRNA DHRS4-AS1 Inhibits the Stemness of NSCLC Cells by Sponging miR-224-3p and Upregulating TP53 and TET1

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death. This study aimed to examine the roles of DHRS4-AS1/miR-224-3p signaling in the cancer cell stemness of NSCLC. Real-time PCR showed that DHRS4-AS1 was downregulated in cancerous tissues, and bioinformatics analysis revealed that high DHRS4-AS1 expression indicated a good prognosis for NSCLC patients. Sphere and colony formation assays showed that DHRS4-AS1 overexpression significantly suppressed NSCLC cell colony formation and stem cell-like properties. DHRS4-AS1 also abrogated the expression of OCT4, SOX2, CD34, and CD133, markedly inhibited the expression of epithelial-mesenchymal transition (EMT)-related factors, N-cadherin, ZEB1, and Vimentin, and increased E-cadherin expression in spheres. Furthermore, luciferase reporter assays and real-time PCR analysis demonstrated that DHRS4-AS1 and miR-224-3p were antagonistically repressed in NSCLC cells. RNA immunoprecipitation (RIP) analysis revealed that DHRS4-AS1 interacted with miR-224-3p. DHRS4-AS1 partially reversed the miR-224-3p-decreased TP53 and TET1, resulting in the inhibition of tumor growth in vivo. Finally, TP53 and TET1 were antagonistically regulated by DHRS4-AS1 and miR-224-3p in NSCLC cells. In conclusion, TP53- and TET1-associated DHRS4-AS1/miR-224-3p axis is an essential mechanism by which NSCLC modulates cancer cell stemness.

LncRNA NR2F2-AS1 positively regulates CDK4 to promote cancer cell proliferation in prostate carcinoma

We in this study investigated the role of lncRNA NR2F2-AS1 in prostate carcinoma (PC). We showed that NR2F2-AS1 was upregulated in PC and positively correlated with CDK4. In PC cells, NR2F2-AS1 overexpression led to upregulated, while NR2F2-AS1 siRNA silencing led to downregulated CDK4. Follow-up study revealed that high levels of NR2F2-AS1 and CDK4 in PC tissues were closely correlated with the poor survival of PC patients. Cell proliferation data showed that NR2F2-AS1 overexpression led to increased, while NR2F2-AS1 siRNA silencing led to proliferation rate of PC cells. Moreover, NR2F2-AS1 also showed positive effects on cell cycle progression. In addition, CDK4 overexpression reduced the effects of NR2F2-AS1 siRNA silencing. Therefore, NR2F2-AS1 positively regulates CDK4 to promote cancer cell proliferation in PC.

RETRACTED: LncRNA GAS6-AS1 facilitates the progression of breast cancer by targeting the miR-324-3p/SETD1A axis to activate the PI3K/AKT pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the current Editor in Chief, with the agreement of all authors. The article is being retracted due to inappropriate manipulation of the original data for presentation in Figures 2C, 5C and 6C. Upon further investigation and discussion with the authors, insufficient evidence was provided to support a reasonable explanation for these mistakes. In addition, the authors could not provide convincing original data supporting other figures of the manuscript, e.g. Figures 2G, 4 and 6A. Based on these findings, the Editor in Chief and the authors have decided to retract the study. The authors apologize for any inconvenience caused.

Exosomes Derived from Mesenchymal Stem Cells Protect the Myocardium Against Ischemia/Reperfusion Injury Through Inhibiting Pyroptosis

Objective

Mesenchymal stem cells (MSCs) show unique advantages in cardiomyocyte repairment. Exosomes derived from MSCs can enhance the viability of myocardial cells after ischemia/reperfusion (I/R) injury and regulate inflammation response. The study was designed to ascertain whether MSCs-exo protect the myocardium against I/R injury through inhibiting pyroptosis, and the underlying mechanisms.

Methods and Results

Experiments were carried out in H/R and I/R model. Cell viability was inhibited and NLRP3 and caspase1 protein levels were upregulated in H/R model. However, MSCs could inhibit cell apoptosis and pyroptosis in H/R model. Moreover, we used MSCs-exo to treated H/R model, and flow cytometric analysis results showed the inhibition function of MSCs-exo on cell apoptosis, and Western blot data suggested that NLRP3 and Caspase-1 expressions were downregulated in H/R model. Furthermore, exosomal miR-320b targeted NLRP3 protein, and MSCs-exo OE could inhibit NLRP3 expression and pyroptosis in H/R. In addition, the inhibition function of MSCs-exo on pyroptosis also was found in I/R model, and HE and Tunel staining also got similar results.

Conclusion

Exosomes derived from mesenchymal stem cells could protect the myocardium against ischemia/reperfusion injury through inhibiting pyroptosis.

LncRNA MCM3AP-AS1 promotes breast cancer progression via modulating miR-28-5p/CENPF axis

Breast cancer is one of the commonly occurred cancers among women and poses a huge threat against female health. Abnormal expression of lncRNA has been confirmed to be an important inducer of cancer. By searching GEO and TCGA database, we found that CENPF was upregulated in breast cancer tissues. Through RT-qPCR, CENPF was found to be upregulated in breast cancer cells. Functional experiments revealed that CENPF had positive effect on the cellular functions, including proliferation, migration and invasion. Subsequently, CENPF was confirmed to combine with miR-28-5p, and its expression was suppressed by miR-28-5p. Furthermore, it was found that miR-28-5p bound to MCM3AP-AS1, and MCM3AP-AS1 expressed at a high level in breast cancer cells. Besides, MCM3AP-AS1 was confirmed as a cytoplasmic RNA. In addition, there was a positive expression correlation between MCM3AP-AS1 and CENPF. Therefore, MCM3AP-AS1 was confirmed to regulate CENPF via competitively binding to miR-28-5p. At last, rescue assays demonstrated that knockdown of CENPF restored miR-28-5p repression-induced cellular processes in MCM3AP-AS1-silenced cells. In vivo assay revealed that MCM3AP-AS1 could hasten tumor growth in breast cancer by targeting CENPF. All results indicated that MCM3AP-AS1/miR-28-5p/CENPF axis accelerates breast cancer progression.

Identification of lncRNA-associated ceRNA network in high-grade serous ovarian cancer metastasis

Aim: To uncover a novel lncRNA-miRNA-mRNA network associated with high-grade serous ovarian cancer metastasis. Material & methods: The candidate differentially expressed lncRNAs were obtained from RNA-sequencing data and determined by functional experiments. The downstream miRNAs and mRNAs were identified by bioinformatic prediction and subjected to functional enrichment analysis. Results: The expression levels of lncRNA ENTPD1-AS1/PRANCR/NR2F2-AS1 were reduced in omental metastatic tissues. Similar differential expression patterns of these lncRNAs were also found in lnCAR database and we verified their tumor suppressive roles by performing functional experiments. Furthermore, we predicted miRNAs and mRNAs via bioinformatic tools and validated their alteration in expression levels in presence of lncRNA interference. Conclusion: We proposed a potential ceRNA regulatory mechanism in high-grade serous ovarian cancer omental metastasis.

LncRNA NR2F2-AS1 Silencing Induces Cell Cycle Arrest in G0/G1 Phase via Downregulating Cyclin D1 in Colorectal Cancer

Purpose

LncRNA NR2F2-AS1 has been characterized as an oncogenic lncRNA in non-small cell lung cancer. This study aims to explore the role of NR2F2-AS1 in colorectal cancer (CRC).

Methods

All CRC patients (n=60, 35 males and 25 females, 40 to 68 years old) in this study were enrolled in Changzhou No.2 People’s Hospital of Nanjing Medical University during the time period between July 2011 and December 2013. Tumor samples, CRC cells, vectors, transient transfections, RT-qPCR, western-blotting, as well as measurements of cell cycle, apoptosis and cell proliferation assay were carried out during the research.

Results

Our data showed that NR2F2-AS1 was upregulated in CRC and CRC patients with high levels of NR2F2-AS1 showed a low overall survival rate. Cyclin D1 was also upregulated in CRC and a positive correlation was found between Cyclin D1 and NR2F2-AS1. In CRC cells, NR2F2-AS1 siRNA silencing mediated the downregulation of Cyclin D1 and G0/G1 arrest, while Cyclin D1 overexpression rescued G0/G1 arrest caused by NR2F2-AS1 siRNA silencing.

Conclusion

Our results indicated that NR2F2-AS1 silencing mediates the downregulation of Cyclin D1 to induce G0/G1 arrest in colorectal cancer.

LncRNA NR2F2-AS1 Upregulates Rac1 to Increase Cancer Stemness in Clear Cell Renal Cell Carcinoma

Background: Zhang et al. characterized a novel oncogenic long noncoding RNA (lncRNA) named NR2F2-AS1 in lung cancer. In this study, the role of lncRNA NR2F2-AS1 in clear cell renal cell carcinoma (ccRCC) was explored. Materials and Methods: Levels of NR2F2-AS1 and Rac1 mRNA expression in both cancer and noncancer tissues from 60 patients with ccRCC were measured by performing RT-qPCR. NR2F2-AS1 siRNA silencing and overexpression experiments were performed to analyze the role of NR2F2-AS1 in regulating Rac1 expression. Cell stemness was analyzed by stemness assay. Results: NR2F2-AS1 was upregulated in ccRCC, and high NR2F2-AS1 expression levels in ccRCC tissues were associated with poor survival. Rac1 was also upregulated in ccRCC and positively correlated with NR2F2-AS1. In ccRCC cells, NR2F2-AS1 overexpression mediated the upregulation of Rac1, whereas NR2F2-AS1 siRNA was accompanied by Rac1 downregulation. NR2F2-AS1 and Rac1 overexpression resulted in the increased ccRCC cell stemness, whereas NR2F2-AS1 and Rac1 siRNA silencing played an opposite role. Rac1 overexpression inhibited the role of NR2F2-AS1 siRNA silencing. Conclusions: NR2F2-AS1 may upregulate Rac1 to increase cancer stemness in ccRCC.

Non-coding RNA profile in lung cancer

Lung cancer is the most frequently diagnosed malignancy and the leading source of cancer-associated mortality. This kind of cancer has heterogeneous nature and is divided into two broad classes of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). In addition to aberrant expression of several signaling pathways and oncogenes, lung cancer is associated with dysregulation of expression of non-coding RNAs including both long non-coding RNAs (lncRNAs) and miRNAs. These aberrantly expressed transcripts are putative therapeutic targets and diagnostic/ prognostic markers. Integrative assessment of expression of lncRNAs, miRNAs and mRNAs has led to construction of competing endogenous RNA networks in which several lncRNAs act as molecular sponges to inhibit regulatory function of miRNAs on mRNAs. Notably, some of these networks seem to have subtype-specific functions in lung cancer. In this review, we summarize recent findings about the importance of these networks in the pathogenesis of lung cancer and provide a list of onco-miRNAs, tumor suppressor miRNAs, oncogenic lncRNAs and tumor suppressor lncRNAs based on their roles in the carcinogenic process in lung cancer.

Long non-coding RNA LEF1-AS1 is involved in the progression of retinoblastoma through regulating the Wnt/β-catenin pathway

The lymphoid enhancer binding factor 1 antisense RNA 1 (LEF1-AS1) has been suggested to function as a tumour-associated lncRNA in several types of human cancers, but there is no study to date about the role of LEF1-AS1 in retinoblastoma. In our study, LEF1-AS1 expression was increased in retinoblastoma tissues and cell lines compared with paired adjacent normal tissues and the retinal pigment epithelial cell line, respectively. Meanwhile, we found that patients with retinoblastoma with IIRC D-E or undifferentiated type had notably higher levels of LEF1-AS1 expression than those with IIRC A-C or differentiated type. High LEF1-AS1 expression predicted poor disease-free survival in patients with retinoblastoma. The in vitro assays suggested that silencing of LEF1-AS1 suppressed retinoblastoma cell proliferation, migration, and invasion through regulating the Wnt/β-catenin pathway. In conclusion, LEF1-AS1 functions as an oncogenic lncRNA in retinoblastoma.

A novel tumour suppressor lncRNA F630028O10Rik inhibits lung cancer angiogenesis by regulating miR-223-3p

Lung cancer is the world's leading cause of cancer‐related morbidity and mortality despite advances in surgery, chemotherapy and immunotherapy; thus, there is an urgent need to find new molecules to develop novel treatment strategies. Although ncRNAs were found to account for 98% transcripts, the number of lncRNAs with distinct function in lung cancer is extremely limited. We previously demonstrated that Plasmodium infection inhibits tumour growth and metastasis, but the exact mechanisms involved have not been fully understood. In this study, we carried out RNA sequencing (RNA‐Seq) of tumour tissues isolated from LLC tumour‐bearing mice treated with either Plasmodium yoelli (Py)‐infected red blood cells or uninfected red blood cells. We found that F630028O10Rik (abbreviated as F63) is a novel lncRNA that was significantly up‐regulated in tumours isolated from mice treated with Py‐infected red blood cells compared to the control. By using gene silencing technique, F63 was found to inhibit both tumour Vascular Endothelial Growth Factor A (VEGFA) secretion and endothelial cells clone formation, migration, invasion and tube formation. Injection of cholesterol‐modified siRNA‐F63 into mice tumour tissues produced a significant increase in tumour volume, blood vessel formation and angiogenesis 17 days after injection. We further showed that inhibiting miR‐223‐3p results in the down‐regulation of VEGFA and VEGFR2 which are vital molecules for angiogenesis. These results reveal that F63 inhibit tumour growth and progression by modulating tumour angiogenesis suggesting F63 can be a novel lncRNA with great potential as a candidate molecule for gene therapy in lung cancer.

Long non-coding RNAs: How to regulate the metastasis of non-small-cell lung cancer

Non–small‐cell lung cancer (NSCLC) has become the most lethal human cancer because of the high rate of metastasis. Hence, clarifying the molecular mechanism underlying NSCLC metastasis is very important to improve the prognosis of patients with NSCLC. Long non‐coding RNAs (LncRNAs) are a class of RNA molecules longer than 200 nucleotides, which can participate in diverse biological processes. About 18% of human LncRNAs were recently found to be associated with tumours. Many studies indicated that aberrant expression of LncRNAs played key roles in the progression and metastasis of NSCLC. According to the function in tumours, LncRNAs can be divided into two classes: oncogenic LncRNAs and tumour‐suppressor LncRNAs. In this review, we summarized the main molecular mechanism of LncRNAs regulating NSCLC metastasis, including three aspects: (a) LncRNAs interact with miRNAs as ceRNAs; (b) LncRNAs bind with target proteins; and (c) LncRNAs participate in the transduction of different signal pathways. Then, LncRNAs can exert their function to regulate the metastasis of NSCLC through influencing the progression of epithelial‐mesenchymal transition (EMT) and the properties of cancer stem cell (CSC). But, it is necessary to do some further research to demonstrate the LncRNAs particular regulatory mechanism of inhibiting the metastasis of NSCLC and explore new drugs targeting LncRNAs.

Downregulation of lncRNA NR2F2 Antisense RNA 1 Induces G1 Arrest of Colorectal Cancer Cells by Downregulating Cyclin-Dependent Kinase 6

AIMS

Long non-coding RNA (lncRNA) NR2F2 antisense RNA 1 (NR2F2-AS1) is an oncogenic lncRNA in lung cancer. This study aimed to investigate the role of NR2F2-AS1 in colorectal cancer (CRC).

METHODS

Tissue specimens were obtained from 63 CRC patients, and gene expression was analyzed by qPCR and western blot. Overexpression was performed to analyze gene interactions. A 5-year follow-up was carried out to perform survival analysis. Cell cycle progression and proliferation were analyzed by cell cycle assay and CCK-8 assay, respectively.

RESULTS

We found that NR2F2-AS1 and cyclin-dependent kinase 6 (CDK6) were both upregulated in CRC and were positively correlated. NR2F2-AS1 siRNA silencing led to downregulated CDK6 and induced Gap 1 (G1) arrest of CRC cells. CDK6 overexpression rescued G1 arrest caused by NR2F2-AS1 siRNA silencing. High expression levels of NR2F2-AS1 were closely correlated with low overall 5-year survival rate. NR2F2-AS1 siRNA silencing led to decreased rate of CRC cell proliferation. CDK6 overexpression attenuated the effects of NR2F2-AS1 siRNA silencing on cancer cell proliferation.

CONCLUSIONS

Downregulation of NR2F2-AS1 induces G1 arrest of CRC cells by downregulating CDK6.

Downregulation of long non-coding RNA NR2F2-AS1 inhibits proliferation and induces apoptosis of nasopharyngeal carcinoma cells by upregulating the expression of PTEN

The novel long non-coding RNA NR2F2-AS1 has been characterized as an oncogene in lung cancer. The present study aimed to investigate the role of NR2F2-AS1 in nasopharyngeal carcinoma (NPC). The results demonstrated that expression of NR2F2-AS1 and phosphatase and tensin homolog (PTEN) were negatively associated with each other in NPC tissues. Furthermore, upregulated NR2F2-AS1 expression levels and downregulated PTEN expression levels in NPC tissues predicted less favorable survival outcomes in patients with NPC. Transfection of NPC cells with NR2F2-AS1 small interfering RNA resulted in increased expression of PTEN. In addition, NR2F2-AS1 silencing and PTEN overexpression resulted in decreased proliferation and an increase in the apoptotic rate of NPC cells. In conclusion, NR2F2-AS1 downregulation decreased proliferation and increased apoptosis of NPC cells via upregulation of PTEN.