Down-regulation of MBNL1-AS1 contributes to tumorigenesis of NSCLC via sponging miR-135a-5p

Detailed role of microRNA-mediated regulation of PI3K/AKT axis in human tumors

The regulation of signal transmission and biological processes, such as cell proliferation, apoptosis, metabolism, migration, and angiogenesis are greatly influenced by the PI3K/AKT signaling pathway. Highly conserved endogenous non-protein-coding RNAs known as microRNAs (miRNAs) have the ability to regulate gene expression by inhibiting mRNA translation or mRNA degradation. MiRNAs serve key role in PI3K/AKT pathway as upstream or downstream target, and aberrant activation of this pathway contributes to the development of cancers. A growing body of research shows that miRNAs can control the PI3K/AKT pathway to control the biological processes within cells. The expression of genes linked to cancers can be controlled by the miRNA/PI3K/AKT axis, which in turn controls the development of cancer. There is also a strong correlation between the expression of miRNAs linked to the PI3K/AKT pathway and numerous clinical traits. Moreover, PI3K/AKT pathway-associated miRNAs are potential biomarkers for cancer diagnosis, therapy, and prognostic evaluation. The role and clinical applications of the PI3K/AKT pathway and miRNA/PI3K/AKT axis in the emergence of cancers are reviewed in this article.

The possibilities of LOXL4 as a prognostic marker for carcinomas

Lysyl oxidase-like 4 (LOXL4), a member of lysyl oxidase family, is a copper and lysine tyrosylquinone-dependent amine oxidase that serves the role of catalyzing the cross-linking of elastin and collagen in the extracellular matrix. Numerous studies have shown a significant association between LOXL4 expression levels and tumor proliferation, migration, invasion and patients' prognosis and overall survival in different types of tumors. Here we review their relationship and the molecular pathogenesis behind them, aiming to explore the possibilities of LOXL4 as a prognostic marker for diverse carcinomas and provide some indications for further research in this field.

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

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

A Novel Circ_Arf3/miR-452-5p/Mbnl1 Axis Regulates Proliferation and Expression of Fibrosis-Related Proteins of Mouse Mesangial Cells Under High Glucose

Background

Diabetic nephropathy (DN) is a serious microvascular complication of diabetes that may lead to chronic renal failure and end-stage renal disease. Circular RNAs (circRNAs) play important roles in DN progression. However, the action of circRNA ADP ribosylation factor 3 (circ_Arf3) in high glucose (HG)-induced change is still unclear.

Methods

Mouse mesangial cells (MCs) were treated with 30 mM HG as a DN cell model in vitro. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to examine the expression levels of circ_Arf3, microRNA (miR)-452-5p and muscleblind like splicing regulator 1 (Mbnl1). The proliferation of HG-treated MCs was assessed using 5 Ethynyl 2' deoxyuridine (EdU) and cell counting kit-8 (CCK-8) assays, and the levels of proliferation and fibrosis-related proteins and Mbnl1 were detected by Western blot. Dual-luciferase reporter and RNA pull-down assays were utilized to determine the relationship between miR-452-5p and circ_Arf3 or Mbnl1.

Results

Our results discovered that circ_Arf3 and Mbnl1 were lowly expressed in HG-treated MCs, while miR-452-5p expression was up-regulated. Moreover, circ_Arf3 was mainly located in the cytoplasm and had a ring-like stable structure. Functional assays demonstrated that overexpression of circ_Arf3 prevented cell proliferation and fibrous formation in HG-treated MCs. Circ_Arf3 could sponge miR-452-5p, and the effect of circ_Arf3 overexpression was reversed by enhanced expression of miR-452-5p. Mbnl1 was a direct target of miR-452-5p. Knockdown of Mbnl1 abolished the suppressive effects of miR-452-5p inhibitor on proliferation and fibrosis-related protein expression in HG-treated MCs. Moreover, circ_Arf3 regulated Mbnl1 through miR-452-5p.

Conclusion

Overexpression of circ_Arf3 prevents cell proliferation and fibrous formation in HG-treated MCs by regulating the expression of Mbnl1 via miR-452-5p.

CD24-associated ceRNA network reveals prognostic biomarkers in breast carcinoma

Breast cancer is one of the most common cancer types which is described as the leading cause of cancer death in women. After competitive endogenous RNA (ceRNA) hypothesis was proposed, this triple regulatory network has been observed in various cancers, and increasing evidences reveal that ceRNA network plays a significant role in the migration, invasion, proliferation of cancer cells. In the current study, our target is to construct a CD24-associated ceRNA network, and to further identify key prognostic biomarkers in breast cancer. Using the transcriptom profiles from TCGA database, we performed a comprehensive analysis between CD24^high tumor samples and CD24^low tumor samples, and identified 132 DElncRNAs, 602 DEmRNAs and 26 DEmiRNAs. Through comprehensive analysis, RP1-228H13.5/miR-135a-5p/BEND3 and SIM2 were identified as key CD24-associated biomarkers, which exhibited highly significance with overall survival, immune microenvironment as well as clinical features. To sum up the above, the current study constructed a CD24-associated ceRNA network, and RP1-228H13.5/miR-135a-5p/BEND3 and SIM2 axis worked as a potential therapeutic target and a predictor for BRCA diagnosis and prognosis.

Construction of a ferroptosis scoring system and identification of LINC01572 as a novel ferroptosis suppressor in lung adenocarcinoma

Background: Ferroptosis is a novel process of programmed cell death driven by excessive lipid peroxidation that is associated with the development of lung adenocarcinoma. N6-methyladenosine (m6a) modification of multiple genes is involved in regulating the ferroptosis process, while the predictive value of N6-methyladenosine- and ferroptosis-associated lncRNA (FMRlncRNA) in the prognosis of patients remains with LUAD remains unknown. Methods: Unsupervised cluster algorithm was applied to generate subcluster in LUAD according to ferroptosis-associated lncRNA. Stepwise Cox analysis and LASSO algorithm were applied to develop a prognostic model. Cellular location was detected by single-cell analysis. Also, we conducted Gene set enrichment analysis (GSEA) enrichment, immune microenvironment and drug sensitivity analysis. In addition, the expression and function of the LINC01572 were investigated by several in vitro experiments including qRT-PCR, cell viability assays and ferroptosis assays. Results: A novel ferroptosis-associated lncRNAs-based molecular subtype containing two subclusters were determined in LUAD. Then, we successfully created a risk model according to five ferroptosis-associated lncRNAs (LINC00472, MBNL1-AS1, LINC01572, ZFPM2-AS1, and TMPO-AS1). Our nominated model had good stability and predictive function. The expression patterns of five ferroptosis-associated lncRNAs were confirmed by polymerase chain reaction (PCR) in LUAD cell lines. Knockdown of LINC01572 significantly inhibited cell viability and induced ferroptosis in LUAD cell lines. Conclusion: Our data provided a risk score system based on ferroptosis-associated lncRNAs with prognostic value in LUAD. Moreover, LINC01572 may serve as a novel ferroptosis suppressor in LUAD.

LncRNA MBNL1-AS1 Suppresses Cell Proliferation and Metastasis of Pancreatic Adenocarcinoma through Targeting Carcinogenic miR-301b-3p

Pancreatic adenocarcinoma (PAAD) has been a huge challenge to public health due to its increasing incidence, frequent early metastasis, and poor outcome. The molecular basis of tumorigenesis and metastasis in PAAD is largely unclear. Here, we identified a novel tumor-suppressor long noncoding RNA (lncRNA) MBNL1-AS1, in PAAD and revealed its downstream mechanism. Quantitative real-time PCR (qRT-PCR) data showed that MBNL1-AS1 expression was significantly downregulated in PAAD tissues and cells, which was closely associated with metastasis and poor prognosis. Cell counting kit-8 (CCK-8) assay, transwell assay, and western blot verified that overexpression of MBNL1-AS1 suppressed cell proliferation, migration, and epithelial mesenchymal transformation (EMT) behavior in PAAD cells. By using a dual luciferase reporter gene system, we confirmed that miR-301b-3p was a direct target of MBNL1-AS1. Further mechanismic study revealed that upregulation of miR-301b-3p abolished the inhibitory effect of MBNL1-AS1 overexpression on cell proliferation, tumorigenesis, migration and EMT. Our results demonstrate that MBNL1-AS1 plays a tumor-suppressive role in PAAD mainly by downregulating miR-301b-3p, providing a novel therapeutic target for PAAD.

MBNL1-AS1 Promotes Hypoxia-Induced Myocardial Infarction via the miR-132-3p/RAB14/CAMTA1 Axis

BACKGROUND

Mounting evidence have indicated that long noncoding RNA (lncRNA) muscleblind like splicing regulator 1 antisense RNA 1 (MBNL1-AS1) play a crucial regulatory role in cardiovascular disease, myocardial infarction (MI) included. In this research, we sought to probe into the biological function and potential mechanism of MBNL1-AS1 in MI.

METHODS

Cardiomyocytes were treated under hypoxic conditions for 0-12 h. Functional assays including CCK-8 and flow cytometry were performed to assess hypoxia-stimulated cardiomyocyte viability and apoptosis, respectively. Moreover, bioinformatics analysis and mechanical assays were conducted to reveal the competitive endogenous RNA (ceRNA) mechanism of MBNL1-AS1.

RESULTS

The upregulation of MBNL1-AS1 was found in hypoxia-stimulated cardiomyocytes. Functionally, the downregulation of MBNL1-AS1 dramatically promoted hypoxia-induced cardiomyocyte viability and inhibited apoptosis. Mechanistically, miR-132-3p bound to MBNL1-AS1 in hypoxia-induced cardiomyocytes, and miR-132-3p directly targeted RAB14, member RAS oncogene family (RAB14) and calmodulin binding transcription activator 1 (CAMTA1). Furthermore, MBNL1-AS1 upregulates the expression of RAB14 and CAMTA1 in hypoxia-stimulated cardiomyocytes via targeting miR-132-3p.

CONCLUSIONS

The current study revealed the critical role of the MBNL1-AS1/miR-132-3p/RAB14/CAMTA1 axis in MI, indicating MBNL1-AS1 as an innovative therapeutic target for MI.

Investigation of Transcriptome Patterns in Endometrial Cancers from Obese and Lean Women

Endometrial cancer is the most common gynaecological malignancy in developed countries. One of the largest risk factors for endometrial cancer is obesity. The aim of this study was to determine whether there are differences in the transcriptome of endometrial cancers from obese vs. lean women. Here we investigate the transcriptome of endometrial cancer between obese and lean postmenopausal women using rRNA-depleted RNA-Seq data from endometrial cancer tissues and matched adjacent non-cancerous endometrial tissues. Differential expression analysis identified 12,484 genes (6370 up-regulated and 6114 down-regulated) in endometrial cancer tissues from obese women, and 6219 genes (3196 up-regulated and 3023 down-regulated) in endometrial cancer tissues from lean women (adjusted p-value < 0.1). A gene ontology enrichment analysis revealed that the top 1000 up-regulated genes (by adjusted p-value) were enriched for growth and proliferation pathways while the top 1000 down-regulated genes were enriched for cytoskeleton restructure networks in both obese and lean endometrial cancer tissues. In this study, we also show perturbations in the expression of protein coding genes (HIST1H2BL, HIST1H3F, HIST1H2BH, HIST1H1B, TTK, PTCHD1, ASPN, PRELP, and CDH13) and the lncRNA MBNL1-AS1 in endometrial cancer tissues. Overall, this study has identified gene expression changes that are similar and also unique to endometrial cancers from obese vs. lean women. Furthermore, some of these genes may serve as prognostic biomarkers or, possibly, therapeutic targets for endometrial cancer.

Tumour-suppressing functions of the lncRNA MBNL1-AS1/miR-889-3p/KLF9 axis in human breast cancer cells

This study aimed to explore the role and potential mechanism of the long non-coding (lncRNA) MBNL1-AS1 in human breast cancer. We included 80 patients with breast cancer in this study. Breast cancer cell lines, including MCF7, SKBR3, MDA-MB-231 and MDA-MB-415, and the normal human breast cell line MCF10A were used in this study. MBNL1-AS1, miR-889-3p mimics, si-Krüppel-like factor 9 (KLF9) or their controls were transfected in the cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blotting and immunohistochemistry assay were performed to detect the expression of MBNL1-AS1, miR-889-3p and KLF9. Cell proliferation, invasion and migration were detected. Luciferase reporter gene and pull-down assay were performed to verify the target relationship among MBNL1-AS1, miR-889-3p and KLF9. Glycolysis was also detected after transfection. The expression of the lncRNA MBNL1-AS1 was low in the breast cancer tissues and cells. Lower expression levels of the lncRNA MBNL1-AS1 were associated with poor prognosis of breast cancer. Overexpression of the lncRNA MBNL1-AS1 decreased proliferation, invasion, migration and glycolysis of breast cancer cells. The lncRNA MBNL1-AS1 could interact with miR-889-3p, and KLF9 was the downstream target of miR-889-3p. Moreover, miR-889-3p was negatively correlated with KLF9 and lncRNA MBNL1-AS1. Both miR-889-3p and si-KLF9 could reverse the overexpression of lncRNA MBNL1-AS1 in breast cancer development. The lncRNA MBNL1-AS1 decreased proliferation, invasion, migration and glycolysis of breast cancer via the miR-889-3p/KLF9 axis, which might be a potential biomarker for the diagnosis of breast cancer.

LncRNA MBNL1-AS1 Represses Proliferation and Cancer Stem-Like Properties of Breast Cancer through MBNL1-AS1/ZFP36/CENPA Axis

Background

Emerging studies have revealed long noncoding RNAs (lncRNAs) were key regulators of cancer progression. In this research, the expression and roles of MBNL1-AS1 were explored in breast cancer (BC).

Methods

In this study, the MBNL1-AS1 expression in breast cancer tissue, as well as in cell line, was studied by qRT-PCR assays. The effects of MBNL1-AS1 on proliferation and stemness were evaluated by MTT assays, colony formation assays, orthotopic breast tumor mice models, extreme limiting dilution analysis (ELDA), fluorescence in situ hybridization (FISH), flow cytometry assays, and sphere formation assays. Flexmap 3D assays were performed to show that MBNL1-AS1 downregulated the centromere protein A (CENPA) secretion in BC cells. Western blot, RNA pull-down assays, RNA immunoprecipitation (RIP) assays, and FISH were conducted to detect the mechanism.

Results

The results showed that the expression levels of MBNL1-AS1 were downregulated in breast cancer tissues and cell lines. In vitro and in vivo studies demonstrated that overexpression of MBNL1-AS1 markedly inhibited BC cells proliferation and stemness. RNA pull-down assay, RIP assay, western blot assay, and qRT-PCR assay showed that MBNL1-AS1 downregulated CENPA mRNA via directly interacting with Zinc Finger Protein 36 (ZFP36) and subsequently decreased the stability of CENPA mRNA. Restoration assays also confirmed that MBNL1-AS1 suppressed the CENPA-mediated proliferation and stemness in breast cancer cells.

Conclusions

The new mechanism of how MBNL1-AS1 regulates BC phenotype is elucidated, and the MBNL1-AS1/ZFP36/CENPA axis may be served as a therapeutic target for BC patients.

LncRNA MBNL1-AS1 represses gastric cancer progression via the TGF-β pathway by modulating miR-424-5p/Smad7 axis

Studies over the past decades have implicated lncRNAs in promoting the development, migration and invasion of gastric cancer (GC). However, the role and mechanism of lncRNA MBNL1-AS1 in GC promotion are poorly understood. In this research, qRT-PCR showed that MBNL1-AS1 was down-regulated in GC tissues and cells. Cell experiments and the animal study demonstrated that MBNL1-AS1 knockdown accelerated GC cell proliferation, migration, and invasion, thus restraining cell apoptosis. Meanwhile, overexpression of MBNL1-AS1 repressed GC cell promotion. Bioinformatics analysis confirmed that MBNL1-AS1 binds to miR-424-5p via negative modulation. Rescue experiments showed that decreased miR-424-5p level inhibited GC cell promotion by silencing MBNL1-AS1. Furthermore, Smad7 was identified as a target of miR-424-5p that could reverse the promotion of GC cell growth mediated by miR-424-5p. Western blot results proved that MBNL1-AS1 affected TGF-β/SMAD pathways by regulating the miR-424-5p/Smad7 axis. Collectively, MBNL1-AS1 restrained GC growth via the miR-424-5p/Smad7 axis and thus could be a promising target for GC therapy. These findings illustrate that lncRNA MBNL1-AS1, as a tumor suppressor gene, participates in GC progression by regulating miR-424-5p/Smad7 axis, thus activating TGF-β/EMT pathways. The evidence may provide a potential marker for GC patients.

Knockdown of long non-coding RNA NEAT1 relieves inflammation of ulcerative colitis by regulating the miR-603/FGF9 pathway

Ulcerative colitis (UC) is a significant threat to human life. Hence, there is an urgent requirement to understand the mechanism of UC progression and to develop novel therapeutic interventions for the treatment of UC. The present study aimed to evaluate the potential significance of long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) in the progression of UC. NEAT1 expression was detected in colonic mucosa samples from patients with UC and healthy individuals. Fetal human cells (FHCs) were treated with different concentrations of lipopolysaccharides (LPS) to induce UC-caused inflammatory injury, and the effects of NEAT1 knockdown were investigated on cytokines production, cell apoptosis and viability. Furthermore, the correlation and regulation between NEAT1 and microRNA (miRNA/miR)-603 and the fibroblast growth factor 9 (FGF9) pathway were investigated. The results demonstrated that NEAT1 expression was upregulated in the colonic mucosa tissues of patients with UC. In addition, significant cell injury was observed in FHCs treated with different concentrations of LPS, with decreased cell viability, and increased apoptosis and inflammatory cytokines production. Conversely, NEAT1 knockdown significantly reduced LPS-induced cell injury in FHCs, which was achieved through negative regulation of miR-603 expression. Furthermore, FGF9 was negatively regulated by miR-603, and thus, FGF9 was identified as a potential target of miR-603. Notably, FGF9 knockdown reversed the suppressing effects of miR-603 on LPS-induced injury in FHCs. Taken together, the results of the present study suggest that NEAT1 contributes to the development of UC by regulating the miR-603/FGF9 pathway.

lncRNA FOXD3-AS1 promotes the progression of non-small cell lung cancer by regulating the miR-135a-5p/CDK6 axis

Long non-coding RNA (lncRNA) is essential to the development and progression of malignant human cancer. Growing evidence suggests that the lncRNA forkhead box D3 antisense 1 (FOXD3-AS1) is a crucial regulatory effector for multiple cancer types and is closely associated with poor prognosis. However, in most cases, the molecular mechanism underlying the role of FOXD3-AS1 in cancer development has not yet been fully elucidated. The present study focused on non-small cell lung cancer (NSCLC) in order to gain insight into how FOXD3-AS1 drives cancer progression. First, FOXD3-AS1 expression in NSCLC tissue samples was detected using reverse transcription-quantitative (RT-qPCR). Moreover, cell proliferation and apoptosis were determined using Cell Counting Kit-8 assays and flow cytometry, respectively. A luciferase reporter assay was then performed to determine whether there was a direct binding association between FOXD3-AS1 and microRNA (miR)-135a-5p. Lastly, a tumor subcutaneous xenograft model was established to examine the role of FOXD3-AS1 in tumor growth. FOXD3-AS1 was significantly overexpressed in NSCLC tissue samples and cell lines compared with normal tissue samples and cells. FOXD3-AS1 silencing expression significantly inhibited A549 and H1229 cell proliferation while inducing apoptosis compared with sh-NC group. The luciferase reporter assay demonstrated the direct binding interaction between FOXD3-AS1 and miR-135a-5p. Moreover, FOXD3-AS1 silencing led to the upregulation of miR-135a-5p in A549 and H1229 cells compared with sh-NC group. It was also demonstrated that miR-135a-5p could bind to the 3′ untranslated region of cyclin-dependent kinase 6 (CDK6) and negatively modulate its transcription. miR-135a-5p knockdown or CDK6 overexpression reversed the inhibition on cell proliferation and apoptosis following FOXD3-AS1 knockdown. Altogether, the present study suggests that FOXD3-AS1 sponges miR-135a-5p to promote cell proliferation and concomitantly inhibit apoptosis by regulating CDK6 expression in NSCLC cells.

Muscleblind-like 1 antisense RNA 1 inhibits cell proliferation, invasion, and migration of prostate cancer by sponging miR-181a-5p and regulating PTEN/PI3K/AKT/mTOR signaling

The present study aimed to investigate the role and underlying mechanisms of long non-coding RNA (lncRNA) muscleblind-like 1 antisense RNA 1 (MBNL1-AS1) in the progression of Prostate cancer (PCa). MBNL1-AS1 and microRNA (miR)-181a-5p expression in PCa tissues and several human PCa cell lines were analyzed, respectively, using StarBasev3.0 project and RT-qPCR assay. After MBNL1-AS1 overexpression, cell proliferation, invasion and migration were, respectively, evaluated using CCK-8, colony formation, transwell and wound healing assays. Dual luciferase assay were used for analysis of the interactions among MBNL1-AS1, miR-181a-5p, and phosphatase and tensin homolog (PTEN). Subsequently, the expression of PTEN and proteins in PI3K/AKT/mTOR signaling was examined using western blot analysis after transfection with miR-181a-5p mimic. The rescue assays were performed to investigate the effects of MBNL1-AS1 and miR-181a-5p on the functions of PCa cells and the expression of PTEN/PI3K/AKT/mTOR signaling by co-transfection with MBNL1-AS1 plasmid and miR-181a-5p mimic. Results indicated that MBNL1-AS1 was conspicuously downregulated while miR-181a-5p upregulating in PCa tissues and cell lines. MBNL1-AS1 overexpression decreased the abilities of cell proliferation, invasion, and migration. Further study revealed that MBNL1-AS1 acted as a sponge for miR-181a-5p and positively regulated PTEN by a sponge effect. Additionally, rescue assays proved that the effect of MBNL1-AS1-upregulation on the proliferation, invasion, and migration of PCa cells was dependent on miR-181a-5p. Furthermore, miR-181a-5p overexpression counteracted the expression of PTEN and proteins in PI3K/AKT/mTOR signaling exerted by MBNL1-AS1-upregulation in PCa cells. This study suggests that MBNL1-AS1 inhibits the progression of PCa via sponging miR-181a-5p and regulating PTEN/PI3K/AKT/mTOR pathway.