Long noncoding RNA SOX2-OT facilitates prostate cancer cell proliferation and migration via miR-369-3p/CFL2 axis

Role of actin-binding proteins in prostate cancer

The molecular mechanisms driving the onset and metastasis of prostate cancer remain poorly understood. Actin, under the control of actin-binding proteins (ABPs), plays a crucial role in shaping the cellular cytoskeleton, which in turn supports the morphological alterations in normal cells, as well as the invasive spread of tumor cells. Previous research indicates that ABPs of various types serve distinct functions, and any disruptions in their activities could predispose individuals to prostate cancer. These ABPs are intricately implicated in the initiation and advancement of prostate cancer through a complex array of intracellular processes, such as severing, linking, nucleating, inducing branching, assembling, facilitating actin filament elongation, terminating elongation, and promoting actin molecule aggregation. As such, this review synthesizes existing literature on several ABPs linked to prostate cancer, including cofilin, filamin A, and fascin, with the aim of shedding light on the molecular mechanisms through which ABPs influence prostate cancer development and identifying potential therapeutic targets. Ultimately, this comprehensive examination seeks to contribute to the understanding and management of prostate diseases.

Parkinson's Disease and MicroRNAs: A Duel Between Inhibition and Stimulation of Apoptosis in Neuronal Cells

Parkinson's disease (PD) is one of the most prevalent diseases of central nervous system that is caused by degeneration of the substantia nigra's dopamine-producing neurons through apoptosis. Apoptosis is regulated by initiators' and executioners' caspases both in intrinsic and extrinsic pathways, further resulting in neuronal damage. In that context, targeting apoptosis appears as a promising therapeutic approach for treating neurodegenerative diseases. Non-coding RNAs-more especially, microRNAs, or miRNAs-are a promising target for the therapy of neurodegenerative diseases because they are essential for a number of cellular processes, including signaling, apoptosis, cell proliferation, and gene regulation. It is estimated that a substantial portion of coding genes (more than 60%) are regulated by miRNAs. These small regulatory molecules can have wide-reaching consequences on cellular processes like apoptosis, both in terms of intrinsic and extrinsic pathways. Furthermore, it was recommended that a disruption in miRNA expression levels could also result in perturbation of typical apoptosis pathways, which may be a factor in certain diseases like PD. The latest research on miRNAs and their impact on neural cell injury in PD models by regulating the apoptosis pathway is summarized in this review article. Furthermore, the importance of lncRNA/circRNA-miRNA-mRNA network for regulating apoptosis pathways in PD models and treatment is explored. These results can be utilized for developing new strategies in PD treatment.

Prediction of lncRNA and disease associations based on residual graph convolutional networks with attention mechanism

LncRNAs are non-coding RNAs with a length of more than 200 nucleotides. More and more evidence shows that lncRNAs are inextricably linked with diseases. To make up for the shortcomings of traditional methods, researchers began to collect relevant biological data in the database and used bioinformatics prediction tools to predict the associations between lncRNAs and diseases, which greatly improved the efficiency of the study. To improve the prediction accuracy of current methods, we propose a new lncRNA-disease associations prediction method with attention mechanism, called ResGCN-A. Firstly, we integrated lncRNA functional similarity, lncRNA Gaussian interaction profile kernel similarity, disease semantic similarity, and disease Gaussian interaction profile kernel similarity to obtain lncRNA comprehensive similarity and disease comprehensive similarity. Secondly, the residual graph convolutional network was used to extract the local features of lncRNAs and diseases. Thirdly, the new attention mechanism was used to assign the weight of the above features to further obtain the potential features of lncRNAs and diseases. Finally, the training set required by the Extra-Trees classifier was obtained by concatenating potential features, and the potential associations between lncRNAs and diseases were obtained by the trained Extra-Trees classifier. ResGCN-A combines the residual graph convolutional network with the attention mechanism to realize the local and global features fusion of lncRNA and diseases, which is beneficial to obtain more accurate features and improve the prediction accuracy. In the experiment, ResGCN-A was compared with five other methods through 5-fold cross-validation. The results show that the AUC value and AUPR value obtained by ResGCN-A are 0.9916 and 0.9951, which are superior to the other five methods. In addition, case studies and robustness evaluation have shown that ResGCN-A is an effective method for predicting lncRNA-disease associations. The source code for ResGCN-A will be available at https://github.com/Wangxiuxiun/ResGCN-A .

FOXD1-AS1 upregulates FOXD1 to promote oral squamous cell carcinoma progression

OBJECTIVES

Recently, increasing attention has been concentrated on decrypting the potential of long non-coding RNAs (lncRNAs) in influencing the progression of human tumors, oral squamous cell carcinoma (OSCC) included. The role of a novel lncRNA, forkhead box D1 antisense RNA 1 (FOXD1-AS1), has been discussed in multiple cancers. Nevertheless, its function and relevant mechanism in OSCC have been not probed yet.

MATERIALS AND METHODS

FOXD1-AS1 expression was detected via RT-qPCR. Colony formation, EdU, transwell and Western blot analyses tested the functional role of FOXD1-AS1 in OSCC cells. The relationship between RNAs was assessed by a series of mechanical assays.

RESULTS

FOXD1-AS1 was expressed at a high level in head and neck squamous cell carcinoma (HNSC). Knockdown of FOXD1-AS1 exerted repressive impacts on OSCC cell proliferation, migration, invasion, and EMT. Moreover, FOXD1-AS1 positively regulated its nearby gene FOXD1 via interacting with miR-369-3p. In addition, adenosine deaminase RNA specific (ADAR), known as a RNA-binding protein (RBP), was capable to bind with FOXD1-AS1 and FOXD1 simultaneously, and could regulate the stability of FOXD1 mRNA. Aside from that, rescue assays delineated that FOXD1-AS1 promoted OSCC progression via upregulating FOXD1.

CONCLUSIONS

FOXD1-AS1 elevates FOXD1 expression to promote OSCC malignant phenotypes through miR-369-3p and ADAR.

GLIDR promotes the aggressiveness progression of prostate cancer cells by sponging miR-128-3p

Glioblastoma downregulated RNA (GLIDR) is a newly discovered long non-coding RNA (lncRNA) that its increased expression indicates a poor prognosis of prostate cancer (PCa). However, the effect of GLIDR on PCa cells is not clear. Our study investigated the role and molecular mechanism of GLIDR in PCa cells. The results showed that GLIDR expression levels were higher in PCa samples and cells than in control. GLIDR could regulate the invasive potential, epithelial-to-mesenchymal transition (EMT) and proliferation in PC-3 and LnCaP cells. Besides, GLIDR could weaken the inhibitory effects of miR-128-3p on invasion, EMT and proliferation in PCa cells. Western blotting proved that miR-128-3p affected the expression of EMT markers, such as E-cadherin, Snail and N-cadherin, and GLIDR could reversed the effects of miR-128-3p on the expression levels of EMT markers in PCa cells. In addition, knockdown of miR-128-3p stimulated the invasion, EMT, and proliferation in PCa cells, whereas these effects were reversed when GLIDR expression was knocked down. GLIDR knockdown inhibited the invasion, EMT, and proliferation in PCa cells, and GLIDR was shown to sponge miR-128-3p. Together, these results highlight GLIDR as a potential therapeutic target for the PCa treatment.

Novel plasma exosome biomarkers for prostate cancer progression in co-morbid metabolic disease

Comorbid Type 2 diabetes (T2D), a metabolic complication of obesity, associates with worse cancer outcomes for prostate, breast, head and neck, colorectal and several other solid tumors. However, the molecular mechanisms remain poorly understood. Emerging evidence shows that exosomes carry miRNAs in blood that encode the metabolic status of originating tissues and deliver their cargo to target tissues to modulate expression of critical genes. Exosomal communication potentially connects abnormal metabolism to cancer progression. Here, we hypothesized that T2D plasma exosomes induce epithelial-mesenchymal transition (EMT) and immune checkpoints in prostate cancer cells. We demonstrate that plasma exosomes from subjects with T2D induce EMT features in prostate cancer cells and upregulate the checkpoint genes CD274 and CD155. We demonstrate that specific exosomal miRNAs that are differentially abundant in plasma of T2D adults compared to nondiabetic controls (miR374a-5p, miR-93-5p and let-7b-3p) are delivered to cancer cells, thereby regulating critical target genes. We build on our previous reports showing BRD4 controls migration and dissemination of castration-resistant prostate cancer, and transcription of key EMT genes, to show that T2D exosomes require BRD4 to drive EMT and immune ligand expression. We validate our findings with gene set enrichment analysis of human prostate tumor tissue in TGCA genomic data. These results suggest novel, non-invasive approaches to evaluate and potentially block progression of prostate and other cancers in patients with comorbid T2D.

Crosstalk between Long Non Coding RNAs, microRNAs and DNA Damage Repair in Prostate Cancer: New Therapeutic Opportunities?

Simple Summary

Non-coding RNAs are a type of genetic material that doesn’t make protein, but performs diverse regulatory functions. In prostate cancer, most treatments target proteins, and resistance to such therapies is common, leading to disease progression. Targeting non-coding RNAs may provide alterative treatment options and potentially overcome drug resistance. Major types of non-coding RNAs include tiny ‘microRNAs’ and much longer ‘long non-coding RNAs’. Scientific studies have shown that these form a major part of the human genome, and play key roles in altering gene activity and determining the fate of cells. Importantly, in cancer, their activity is altered. Recent evidence suggests that microRNAs and long non-coding RNAs play important roles in controlling response to DNA damage. In this review, we explore how different types of non-coding RNA interact to control cell DNA damage responses, and how this knowledge may be used to design better prostate cancer treatments and tests.

Abstract

It is increasingly appreciated that transcripts derived from non-coding parts of the human genome, such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are key regulators of biological processes both in normal physiology and disease. Their dysregulation during tumourigenesis has attracted significant interest in their exploitation as novel cancer therapeutics. Prostate cancer (PCa), as one of the most diagnosed malignancies and a leading cause of cancer-related death in men, continues to pose a major public health problem. In particular, survival of men with metastatic disease is very poor. Defects in DNA damage response (DDR) pathways culminate in genomic instability in PCa, which is associated with aggressive disease and poor patient outcome. Treatment options for metastatic PCa remain limited. Thus, researchers are increasingly targeting ncRNAs and DDR pathways to develop new biomarkers and therapeutics for PCa. Increasing evidence points to a widespread and biologically-relevant regulatory network of interactions between lncRNAs and miRNAs, with implications for major biological and pathological processes. This review summarises the current state of knowledge surrounding the roles of the lncRNA:miRNA interactions in PCa DDR, and their emerging potential as predictive and diagnostic biomarkers. We also discuss their therapeutic promise for the clinical management of PCa.

Downregulation of Circular RNA PSEN1 ameliorates ferroptosis of the high glucose treated retinal pigment epithelial cells via miR-200b-3p/cofilin-2 axis

Ferroptosis is a form of programmed cell death that participates in the progression of numerous diseases. Long noncoding RNAs (lncRNAs) are dysregulated in diabetic retinopathy (DR). However, the role of lncRNAs in DR-induced ferroptosis is unclear. Adult retinal pigment epithelial cell line-19 (ARPE19) cells were treated with a high concentration of glucose (high glucose, HG) to mimic DR in vitro. The intracellular contents of glutathione, malondialdehyde, and ferrous ions were analyzed using the corresponding kits. The MTT assay was performed to measure the cell survival rate, and cell death was determined using propidium iodide and terminal deoxynucleotidyl transferase dUTP nick end labeling staining assays. Western blotting was conducted to detect the protein levels of GPX4, SLC7A11, and TFR1. The targeting relationships were verified using luciferase reporter and RNA pull-down assays. circ-PSEN1 was upregulated in HG-treated ARPE19 cells and showed high resistance to RNase R and Act D. Inhibition of circ-PSEN1 in ARPE19 cells ameliorated the ferroptosis induced by HG was ameliorated, as evidenced by changes in the ferroptosis-related biomarkers/genes and decreased cell death. Subsequently, circ-PSEN1 acted as a sponge for miR-200b-3p. Inhibition of miR-200b-3p partially reversed the effects of circ-PSEN1 on ferroptosis. Furthermore, cofilin-2 (CFL2) was the target gene of miR-200b-3p, and it abrogated the inhibitory effect of miR-200b-3p on ferroptosis. Taken together, the findings indicate that knockdown of circ-PSEN1 can mitigate ferroptosis of ARPE19 cells induced by HG via the miR-200b-3p/CFL2 axis.

Long noncoding RNA SRY-box transcription factor 2 overlapping transcript participates in Parkinson's disease by regulating the microRNA-942-5p/nuclear apoptosis-inducing factor 1 axis

Parkinson's disease (PD) is a neurodegenerative disorder. Studies have shown that long noncoding RNA SRY-box transcription factor 2 overlapping transcript (lncRNA SOX2-OT) is highly expressed in PD patients, but its specific functions and mechanisms require further research. To address this gap, this study utilized an in vitro PD cell model induced by 1-methyl-4-phenylpyridinium (MPP+). Cell viability, apoptosis, lactate dehydrogenase (LDH) activity, inflammatory factor secretion, and oxidative stress indicators were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-dipheyltetrazolium bromide assay, LDH assay, flow cytometry, enzyme linked immunosorbent assay (ELISA), and corresponding kits, respectively. Gene and protein expression were measured using quantitative real-time-PCR and western blotting, respectively. The results indicated that microRNA-942-5p (miR-942-5p) was a direct target of lncRNA SOX2-OT and nuclear apoptosis-inducing factor 1 (NAIF1) was a direct target of miR-942-5p. The expression levels of lncRNA SOX2-OT and NAIF1 were increased, and miR-942-5p expression was decreased in SH-SY5Y cells following MPP+ treatment. In addition, MPP+ treatment reduced SH-SY5Y cell viability, increased apoptosis; increased cleaved caspase-3 protein expression and cleaved caspase-3/caspase-3 ratio; enhanced lactate dehydrogenase viability; increased tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and reactive oxygen species, and decreased superoxide dismutase activity in SH-SY5Y cells were inhibited by SOX2-OT-siRNA, and these inhibitions were reversed by miR-942-5p inhibitor. Moreover, the protective role of miR-942-5p mimic in MPP+-induced SH-SY5Y cells was eliminated by the NAIF1 plasmid. Overall, lncRNA SOX2-OT-mediated regulation of oxidative stress, inflammation, and neuronal apoptosis were directly controlled by the miR-942-5p/NAIF1 signal axis in MPP+-induced SH-SY5Y cells.

Exosome long non-coding RNA SOX2-OT contributes to ovarian cancer malignant progression by miR-181b-5p/SCD1 signaling

Ovarian cancer is a common gynecologic cancer with increased mortality and morbidity. Exosome-delivered long non-coding RNAs have been well found in cancer development. However, the function of exosomal SOX2-OT in ovarian cancer development is still unreported. In the present study, we were interested in the investigation of the effect of exosomal SOX2-OT during ovarian cancer pathogenesis. Significantly, we revealed that the SOX2-OT expression levels were up-regulated in the ovarian cancer patients' plasma exosomes. The depletion of exosomal SOX2-OT inhibited migration, invasion, and proliferation and induced apoptosis in ovarian cancer cells. In mechanical exploration, SOX2-OT could sponge miR-181b-5p, and miR-181b-5p was able to target SCD1 in the ovarian cancer cells. The SCD1 overexpression and miR-181b-5p inhibitor could reverse exosomal SOX2-OT-mediated ovarian cancer progression. Functionally, the depletion of exosomal SOX2-OT significantly reduced tumor growth of ovarian cancer cells in vivo. In summary, we concluded that exosomal SOX2-OT enhanced ovarian cancer malignant phenotypes by miR-181b-5p/SCD1 axis. Our finding presents novel insights into the mechanism by which exosomal lncRNA SOX2-OT promotes ovarian cancer progression. SOX2-OT, miR-181b-5p, and SCD1 may serve as potential targets for the treatment of ovarian cancer.

LncRNA SOX2-OT regulates miR-192-5p/RAB2A axis and ERK pathway to promote glioblastoma cell growth

Glioblastoma (GBM) is the most frequent tumor in the central nervous system. Long non-coding RNAs (lncRNAs) have been widely accepted as essential participators in cancer progression. Nonetheless, the specific role and mechanism of lncRNA SRY-box transcription factor 2 overlapping transcript (SOX2-OT) in GBM have not been studied. We evaluated expression levels of SOX2-OT, miR-192-5p and Ras-related protein Rab-2A (RAB2A) in GBM cells via qRT-PCR. To investigate the roles of SOX2-OT in GBM cells, CCK-8, JC-1, EdU, and western blot assays were performed. The connection among SOX2-OT, miR-192-5p and RAB2A in GBM cells was explored through pull down, luciferase reporter, and RIP assays. Western blot and qRT-PCR were employed to analyze the activity of extracellular-signal-regulated kinase (ERK) signaling pathway. SOX2-OT expression was higher in GBM cell lines than in normal cells. SOX2-OT knockdown repressed proliferation and promoted apoptosis of GBM cells. Mechanism assays revealed that SOX2-OT could sponge miR-192-5p. Moreover, RAB2A was certified to be the target gene of miR-192-5p. Overexpression of RAB2A reversed the repressive function of SOX2-OT knockdown on GBM cell growth. Furthermore, SOX2-OT activated ERK signaling pathway in GBM cells. SOX2-OT regulated miR-192-5p/RAB2A axis and ERK pathway to promote GBM cell growth.

LncRNA SOX2-OT/miR-30d-5p/PDK1 Regulates PD-L1 Checkpoint Through the mTOR Signaling Pathway to Promote Non-small Cell Lung Cancer Progression and Immune Escape

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Currently, treatment methods generally cause poor prognosis. Therefore, in order to seek new treatment options, we explored the internal mechanism of NSCLC. Firstly, the SOX2-OT/miR-30d-5p/PDK1 axis regulated by lncRNA SOX2-OT was predicted by bioinformatics methods, and the expression of SOX2-OT, miR-30d-5p, and PDK1 mRNA in cells were detected by qRT-PCR while PDK1 protein expression was detected by western blot. The results expressed that in NSCLC, SOX2-OT, and PDK1 were notably overexpressed while miR-30d-5p was markedly under-expressed. The interaction between them was verified by dual-luciferase reporter and RNA binding protein immunoprecipitation assays. Subsequently, through CCK8, scratch healing, cell invasion and flow cytometry assays, we revealed that inhibiting the expression of SOX2-OT could inhibit the proliferation, migration and invasion of NSCLC cells and promote cell apoptosis; while simultaneous overexpression of PDK1 or inhibition of miR-30d-5p expression could reverse the inhibitory effect of SOX2-OT silence-mediated malignant progression of NSCLC cells. Then, the combined application of overexpressed PDK1 and rapamycin verified that PDK1 could regulate the expression of PD-L1 in NSCLC cells through the mTOR signaling pathway. Co-culture of CD8⁺ T cells verified that silencing SOX2-OT could inhibit the apoptosis of CD8⁺ T cells through miR-30d-5p/PDK1. Finally, tumor formation assay in animals confirmed that overexpression of SOX2-OT could promote the growth of NSCLC tumor in vivo. In this study, assays in vitro and in vivo were conducted to elucidate the mechanism by which SOX2-OT/miR-30d-5p/PDK1 drives PD-L1 through the mTOR signaling pathway to promote the malignant progression and immune escape of NSCLC.

Circ_0008673 regulates breast cancer malignancy by miR-153-3p/CFL2 axis

BACKGROUND

Breast cancer is an aggressive tumor, which poses a heavy burden to human health. Circular RNAs have been involved in the pathogenesis of breast cancer. This study aims to investigate whether circ_0008673 mediates breast cancer malignant progression by microRNA-153-3p (miR-153-3p)/cofilin 2 (CFL2) pathway.

METHODS

The RNA levels of circ_0008673, miR-153-3p and CFL2 were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression of CFL2, E-cadherin and N-cadherin was determined by western blot analysis. Cell proliferation was demonstrated through cell counting kit-8 and cell colony-formation assays. Cell apoptosis was detected by flow cytometry analysis. Cell migratory and invasive capacities were determined by transwell assay. The associated relationship between miR-153-3p and circ_0008673 or CFL2 was predicted by online databases, and testified by dual-luciferase reporter and RNA immunoprecipitation assays. In vivo assay was employed to demonstrate the effects of circ_0008673 silencing on tumor formation in vivo.

RESULTS

Circ_0008673 and CFL2 expressions were upregulated, while miR-153-3p expression was downregulated in breast cancer tissues and cells compared with adjacent normal breast tissues and cells, respectively. Circ_0008673 overexpression promoted cell proliferation, migration and invasion, and repressed cell apoptosis, while circ_0008673 silencing had opposite effects. Additionally, circ_0008673 served as a sponge of miR-153-3p. And circ_0008673 was proved to regulate breast cancer cell malignancy by sponging miR-153-3p. MiR-153-3p was found to modulate breast cancer cell carcinogenesis via targeting CFL2. Furthermore, circ_0008673 silencing repressed tumor growth in vivo.

CONCLUSION

Circ_0008673 promoted breast cancer progression by upregulating CFL2 expression through sponging miR-153-3p. This study provides a theoretical basis for researching circRNA-directed treatment of breast cancer.

Downregulation of SOX2-OT Prevents Hepatocellular Carcinoma Progression Through miR-143-3p/MSI2

OBJECTIVE

LncRNA SOX2-OT is involved in a variety of cancers. This study explored the effect of lncRNA SOX2-OT on hepatocellular carcinoma (HCC) cells.

METHODS

SOX2-OT expressions were detected in HCC tissues and normal tissues, normal cells, and HCC cells. The relationship between SOX2-OT and prognosis was analyzed by TCGA. After SOX2-OT expression was inhibited using siRNA, HCC cell malignant behaviors were evaluated. The subcellular localization of SOX2-OT in HCC cells was predicted and analyzed. The binding relationships among SOX2-OT, miR-143-3p, and MSI2 were analyzed by bioinformatics website, dual-luciferase assay, and RNA pull-down assay. The effect of miR-143-3p and MSI2 on the regulation of SOX2-OT on biological behaviors of HCC cells was confirmed by functional rescue experiments. The effect of SOX2-OT on the tumorigenicity of HCC was evaluated by subcutaneous tumorigenesis in nude mice.

RESULTS

SOX2-OT was highly expressed in HCC cells and tissues. The prognosis was poor in HCC patients with high SOX2-OT expression. Downregulating SOX2-OT inhibited HCC cell malignant behaviors. SOX2-OT bound to miR-143-3p to promote MSI2 expression. Downregulating miR-143-3p or upregulating MSI2 averted the role of si-SOX2-OT in HCC cells. Nude mouse subcutaneous tumorigenesis showed that SOX2-OT downregulation decreased the tumorigenicity of HCC, and affected the levels of miR-143-3p and MSI2 mRNA in tumor tissues.

CONCLUSION

SOX2-OT inhibited the targeted inhibition of miR-143-3p on MSI2 through competitively binding to miR-143-3p, thus promoting MSI2 expression and proliferation, invasion, and migration of HCC cells.

miR-369 inhibits Liver Cancer progression by targeting ZEB1 pathway and predicts the prognosis of HCC patients

Increasing evidences show that microRNAs (miRNAs) are involved in the regulation of tumorigenesis, progression, recurrence and drug resistance of hepatocellular carcinoma (HCC). miR-369 works as a tumor suppressor in both lung cancer and thyroid cancer. However, the potential biological function of miR-369 in HCC is unknown. Herein, we for first found that miR-369 expression was downregulated in HCC tissues and predicted the poor prognosis of HCC patients. Forced miR-369 expression inhibited the proliferation and metastasis of HCC cells in vitro and in vivo. Mechanically, bioinformatics and luciferase reporter analysis identified Zinc finger E-box binding homeobox 1 (ZEB1) as a direct target of miR-369 in HCC cells. miR-369 overexpressing downregulated the ZEB1 mRNA and protein expression in HCC cells. miR-369 expression was negatively associated with ZEB1 expression in human HCC tissues. More importantly, the ZEB1 siRNA diminished the discrepancy of growth and metastasis capacity between miR-369 overexpression HCC cells and control cells.

Circ_0006404 Accelerates Prostate Cancer Progression Through Regulating miR-1299/CFL2 Signaling

Background

Circular RNAs (circRNAs) have been proven to function as pivotal regulators in cancer occurrence and progression. However, the function of circ_0006404 (circRNA Forkhead box O3 (circFOXO3)in prostate cancer (PCa) is poorly understood.

Methods

The enrichment of circ_0006404, FOXO3, microRNA-1299 (miR-1299) and cofilin 2 (CFL2) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The viability, metastasis and proliferation were determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, transwell and colony formation assays, respectively. Flow cytometry was used to assess cell cycle progression and apoptosis. Circ_0006404/miRNAs interactions were explored using Circular RNA Interactome database, while TargetScan software was used for seeking the targets of miR-1299. Dual-luciferase reporter assay, RNA-pull down and RNA immunoprecipitation (RIP) assays were conducted to verify the target interaction between miR-1299 and circ_0006404 or CFL2. CFL2 protein level was analyzed by Western blot assay. Animal experiments were performed to test the role of circ_0006404 in PCa tumor growth in vivo.

Results

Circ_0006404 level was notably elevated in PCa. Circ_0006404 contributed to the viability, metastasis and proliferation and impaired the apoptosis of PCa cells. Circ_0006404 directly targeted miR-1299, and miR-1299 silencing largely reversed circ_0006404 interference-induced influences in PCa cells. CFL2 directly bound to miR-1299, and miR-1299-induced effects in PCa cells were largely attenuated by CFL2 overexpression. CFL2 was regulated by circ_0006404/miR-1299 axis in PCa cells. Circ_0006404 promoted PCa progression via miR-1299/CFL2 axis in vivo.

Conclusion

Circ_0006404 accelerated the survival, motility and proliferation while impeded the apoptosis of PCa cells via miR-1299/CFL2 axis. Circ_0006404 might be a stable potential bio-marker for PCa diagnosis and treatment.

Long Non-Coding RNA SOX2 Overlapping Transcript Aggravates H9c2 Cell Injury via the miR-215-5p/ZEB2 Axis and Promotes Ischemic Heart Failure in a Rat Model

Heart failure is a common cardiovascular disease, which has been regarded as one of the highest health care costs with high morbidity and mortality in the western countries. Long noncoding RNAs have been widely reported to regulate the initiation or progression of cardiovascular diseases. However, the specific role of SOX2 overlapping transcript (SOX2-OT) in ischemic heart failure remains uncharacterized. The present study aimed to explore the function and mechanism of SOX2-OT in ischemic heart failure. The starBase website was used to predict potential miRNAs or target mRNAs. Western blot assay was implemented to test collagen protein levels. Functional assays were conducted to evaluate the effects of SOX2-OT on H9c2 cell viability and apoptosis. RNA pull down and luciferase reporter assays were used to confirm the combination between miR-215-5p and SOX2-OT. We found out that SOX2-OT level was increased by oxygen glucose deprivation/reoxygenation treatment in H9c2 cells. Silencing of SOX2-OT ameliorated cell injury by promoting cell viability, inhibiting cell apoptosis and reducing productions of collagens. Mechanistically, miR-215-5p was confirmed to bind with SOX2-OT after prediction and screening. In addition, we discovered that miR-215-5p negatively regulated zinc finger E-box binding homeobox 2 (ZEB2) protein level by directly binding with ZEB2 3' untranslated region. Finally, we verified that SOX2-OT aggravated cell injury by targeting ZEB2 in H9c2 cells. In conclusion, SOX2-OT aggravated heart failure in vivo and promoted H9c2 cell injury via the miR-215-5p/ZEB2 axis in vitro, implying a novel insight into heart failure treatment.

Silenced SOX2-OT alleviates ventricular arrhythmia associated with heart failure by inhibiting NLRP3 expression via regulating miR-2355-3p

Background

Nucleotide‐binding oligomerization domain‐like receptor family pyrin domain containing 3 (NLRP3) inflammasomes are the most important factors in ventricular arrhythmia associated with heart failure (VA‐HF). However, how the relationship between lncRNA and NLRP3 inflammasomes is regulated in VA‐HF has not been investigated in detail. Thus, we aimed to determine the effects of SOX2‐overlapping transcripts (SOX2‐OT) by targeting NLRP3 in rats with VA‐HF.

Methods

We established rats (SPF, male, weight: 240 ± 10 g) with VA‐HF by aortic coarctation and constant‐current stimulation, then injected them with small interfering SOX2‐OT and anti‐miR‐2355‐3p. Six weeks later, SOX2‐OT and miR‐2355‐3p expression was measured using the quantitative reverse transcriptase‐polymerase chain reaction and NLRP3, ASC, caspase‐1, IL‐1β, and TGF‐β1 expression were measured by Western blot analysis; the ventricular chambers were histopathologically analyzed by staining with hematoxylin and eosin, Masson trichrome, and Picro Sirius Red and reactive oxygen species (ROS) levels were assessed by flow cytometry. The targeting relationship between miR‐2355‐3p and SOX2‐OT or NLRP3 was verified using dual‐luciferase reporter gene assays.

Results

The expression of SOX2‐OT and levels of NLRP3 inflammasomes gradually increased in normal rats, and in those with heart failure and with VA‐HF. Silencing SOX2‐OT expression inhibited NLRP3, ASC, caspase‐1, IL‐1β, and TGF‐β1 expression and ROS production, reduced the degrees of cardiomyocyte necrosis and fibrosis and alleviated cardiac dysfunction in rats with VA‐HF. MicroR‐2355‐3p can bind the SOX2‐OT and the 3′‐untranslated region of NLRP3. Inhibiting miR‐2355‐3p reversed the effect of SOX2‐OT in rats with VA‐HF.

Conclusions

Silencing SOX2‐OT alleviated cardiac dysfunction in rats by reducing the activation of NLRP3 inflammasomes via regulating miR‐2355‐3p.

Long Noncoding RNA SOX2-OT: Regulations, Functions, and Roles on Mental Illnesses, Cancers, and Diabetic Complications

SRY-box transcription factor 2 (SOX2) overlapping transcript (SOX2-OT) is an evolutionarily conserved long noncoding RNA. Its intronic region contains the SOX2 gene, the major regulator of the pluripotency of embryonic stem cells. The human SOX2-OT gene comprises multiple exons and has multiple transcription start sites and generates hundreds of transcripts. Transcription factors (IRF4, AR, and SOX3), transcriptional inhibitors (NSPc1, MTA3, and YY1), and miRNAs (miR-211 and miR-375) have been demonstrated to control certain SOX2-OT transcript level at the transcriptional or posttranscriptional levels. Accumulated evidence indicates its crucial roles in the regulation of the SOX2 gene, miRNAs, and transcriptional process. Restricted expression of SOX2-OT transcripts in the brain results in the association between SOX2-OT single nucleotide polymorphisms and mental illnesses such as schizophrenia and anorexia nervosa. SOX2-OT is notably elevated in tumor tissues, and a high level of SOX2-OT is well correlated with poor clinical outcomes in cancer patients, leading to the establishment of its role as an oncogene and a prognostic or diagnostic biomarker for cancers. The emerging evidence supports that SOX2-OT mediates diabetic complications. In summary, SOX2-OT has diversified functions and could be a therapeutic target for various diseases.

LncRNA EMX2OS, Regulated by TCF12, Interacts with FUS to Regulate the Proliferation, Migration and Invasion of Prostate Cancer Cells Through the cGMP-PKG Signaling Pathway

Background

LncRNA EMX2OS (EMX2 opposite strand/antisense RNA) is notably downregulated in prostate cancer (PCa) tissues and may be regarded as a potential molecular biomarker for diagnosis and prognosis. However, its exact role in regulating the development of PCa is obscure.

Methods

The EMX2OS expression was assessed in PCa tissues, paracancer tissues, PCa cells and normal prostate epithelial cells by qPCR. Gain- and loss-of-function experiments were performed to investigate the role of EMX2OS and FUS in cGMP-PKG (cyclic guanosine monophosphate-dependent protein kinase)-mediated proliferation, invasion, and migration in human PCa cell lines DU145 and PC3. Then, the interaction of transcription factor 12 (TCF12) with EMX2OS promoter was confirmed by using the dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assays. RNA binding protein immunoprecipitation and RNA pull-down assays were used to verify the interaction between EMX2OS and FUS protein. Finally, the role of EMX2OS and FUS in tumor growth in vivo was validated in a xenograft nude mouse model.

Results

TCF12 and EMX2OS were both downregulated in PCa tissues and cells, and they negatively regulated cell proliferation, migration and invasion, and activated cGMP-PKG pathway in DU145 and PC3 cells. TCF12 was a transcription factor of EMX2OS. TCF12 and EMX2OS overexpression both down-regulated cell proliferation, migration and invasion, and activated cGMP-PKG pathway in DU145 and PC3 cells. Furthermore, EMX2OS directly bound with FUS protein and had a synergy effect with FUS protein on cGMP-PKG-mediated cell functions, which could be suppressed by (D)-DT-2 (a cGMP-PKG inhibitor). In addition, the overexpression of FUS or EMX2OS individually markedly decreased the volume and weight of tumors in vivo, and co-overexpression of them further inhibited tumor growth.

Conclusion

EMX2OS, transcriptionally regulated by TCF12, played a synergy role with FUS protein in regulating the proliferation, migration and invasion of PCa cells by activating the cGMP-PKG pathway.

Long Noncoding RNA SOX2-OT Knockdown Inhibits Proliferation and Metastasis of Prostate Cancer Cells Through Modulating the miR-452-5p/HMGB3 Axis and Inactivating Wnt/β-Catenin Pathway

Background: Recent studies have proven that abnormal expression of long noncoding RNAs (lncRNAs) often contributes to growth and invasion of cancer cells. The purpose of this study was to investigate the biological function and regulatory mechanism of lncRNA SOX2 overlapping transcript (SOX2-OT) in prostate cancer (PCa) progression. Materials and Methods: The expression of SOX2-OT, microRNA-452-5p (miR-452-5p), and high mobility group box 3 (HMGB3) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Flow cytometry was performed to determine the cell cycle distribution. Western blot assay was conducted to measure the protein levels of cyclin D1, p21, p27, E-cadherin, vimentin, and N-cadherin. The interaction between miR-452-5p and SOX2-OT or HMGB3 was predicted by bioinformatics analysis and verified by dual-luciferase reporter assay and RNA immunoprecipitation assay. The mice xenograft model was established to investigate the role of SOX2-OT in vivo. Results: SOX2-OT and HMGB3 were upregulated, whereas miR-452-5p was downregulated in PCa tissues and cells. Knockdown of SOX2-OT inhibited PCa cell growth and metastasis. MiR-452-5p could directly bind to SOX2-OT and its knockdown reversed the inhibitory effects of SOX2-OT interference on growth and metastasis of PCa cells. HMGB3 was a direct target of miR-452-5p and its knockdown weakened the promotive effects of miR-452-5p silence on growth and metastasis of PCa cells. Moreover, HMGB3 expression was inversely regulated by miR-452-5p and positively modulated by SOX2-OT. Furthermore, SOX2-OT activated the Wnt/β-catenin signaling pathway through increasing HMGB3 expression. Finally, SOX2-OT knockdown hindered tumor growth in vivo by regulating miR-452-5p/HMGB3 axis. Conclusions: SOX2-OT downregulation limited PCa cell growth and metastasis by regulating miR-452-5p/HMGB3 axis and inactivating Wnt/β-catenin signaling pathway, which might offer lncRNA-directed diagnosis and therapy for PCa.

Comprehensive biological function analysis of lncRNAs in hepatocellular carcinoma

Thousands of long non-coding RNAs (lncRNAs) have been discovered in human genomes by gene chip, next-generation sequencing, and/or other methods in recent years, which represent a significant subset of the universal genes involved in a wide range of biological functions. An abnormal expression of lncRNAs is associated with the growth, invasion, and metastasis of various types of human cancers, including hepatocellular carcinoma (HCC), which is an aggressive, highly malignant, and invasive tumor, and a poor prognosis in China. With a more in-depth understanding of lncRNA research for HCC and the emergence of new molecular-targeted therapies, the diagnosis, treatment, and prognosis of HCC will be considerably improved. Therefore, this review is expected to provide recommendations and directions for future lncRNA research for HCC.