miR-503-3p induces apoptosis of lung cancer cells by regulating p21 and CDK4 expression

In search of the ratio of miRNA expression as robust biomarkers for constructing stable diagnostic models among multi-center data

MicroRNAs (miRNAs) are promising biomarkers for the early detection of disease, and many miRNA-based diagnostic models have been constructed to distinguish patients and healthy individuals. To thoroughly utilize the miRNA-profiling data across different sequencing platforms or multiple centers, the models accounting the batch effects were demanded for the generalization of medical application. We conducted transcription factor (TF)-mediated miRNA-miRNA interaction network analysis and adopted the within-sample expression ratios of miRNA pairs as predictive markers. The ratio of the expression values between each miRNA pair turned out to be stable across multiple data sources. A genetic algorithm-based classifier was constructed to quantify risk scores of the probability of disease and discriminate disease states from normal states in discovery, with a validation dataset for COVID-19, renal cell carcinoma, and lung adenocarcinoma. The predictive models based on the expression ratio of interacting miRNA pairs demonstrated good performances in the discovery and validation datasets, and the classifier may be used accurately for the early detection of disease.

Downregulation of miR-503-5p Promotes the Development of Pancreatic Cancer by Targeting Cyclin E2

This study aimed to elucidate the role of microRNA-503 (miR-503) in pancreatic cancer (PC) progression and the underlying regulatory mechanisms. We acquired miR-503-3p and miR-503-5p expression data along with survival times of PC and normal samples from the UCSC Xena database. Using the t-test, we compared the expression of miR-503-3p and miR-503-5p between PC and normal samples, and evaluated their prognostic significance via Kaplan-Meier survival analysis. The expression of miR-503-5p in PC cells was detected by quantitative PCR. We subsequently overexpressed miR-503-5p in PC cells and examined cell viability, apoptosis, and migration through CCK8 assay, flow cytometry, and Transwell assay, respectively. Potential functional targets were identified using miRTarBase and validated by dual-luciferase reporter assay. Both miR-503-3p and miR-503-5p expression were found to be downregulated in PC; however, only miR-503-5p was linked to cancer prognosis based on public data. In vitro experiments demonstrated that overexpression of miR-503-5p substantially decreased cell viability, induced apoptosis, caused G0/G1 arrest, and inhibited cell migration. miR-503-5p was found to target cyclin E2 (CCNE2), and overexpression of CCNE2 could counteract the effects of miR-503-5p on PC cells. Conclusion: The downregulation of miR-503-5p enhances the progression of PC by targeting CCNE2. The detection of miR-503-5p expression may provide valuable insights for the prevention and prognostic evaluation of PC.

Circular RNAs as the pivotal regulators of epithelial-mesenchymal transition in gastrointestinal tumor cells

Gastrointestinal (GI) cancers, as the most common human malignancies are always considered one of the most important health challenges in the world. Late diagnosis in advanced tumor stages is one of the main reasons for the high mortality rate and treatment failure in these patients. Therefore, investigating the molecular pathways involved in GI tumor progression is required to introduce the efficient markers for the early tumor diagnosis. Epithelial-mesenchymal transition (EMT) is one of the main cellular mechanisms involved in the GI tumor metastasis. Non-coding RNAs (ncRNAs) are one of the main regulatory factors in EMT process. Circular RNAs (circRNAs) are a group of covalently closed loop ncRNAs that have higher stability in body fluids compared with other ncRNAs. Considering the importance of circRNAs in regulation of EMT process, in the present review we discussed the role of circRNAs in EMT process during GI tumor invasion. It has been reported that circRNAs mainly affect the EMT process through the regulation of EMT-specific transcription factors and signaling pathways such as WNT, PI3K/AKT, TGF-β, and MAPK. This review can be an effective step in introducing a circRNA/EMT based diagnostic panel marker for the early tumor detection among GI cancer patients.

Tumor Suppressor miRNA-503 Inhibits Cell Invasion in Head and Neck Cancer through the Wnt Signaling Pathway via the WNT3A/MMP Molecular Axis

Head and neck cancer (HNC) is the fifth most common cancer worldwide, and its incidence and death rates have been consistently high throughout the past decades. MicroRNAs (miRNAs) have recently gained significant attention because of their role in the regulation of a variety of biological processes via post-transcriptional silencing mechanisms. Previously, we determined a specific profile of miRNAs associated with HNC using a miRNA microarray analysis. Of the 23 miRNAs with highly altered expression in HNC cells, miR-503 was the most significantly downregulated miRNA. In this study, we confirmed that miR-503 acts as a tumor suppressor, as our results showed decreased levels of miR-503 in cancer cells and patients with HNC. We further characterized the role of miR-503 in the malignant functions of HNC. Although there was a minimal effect on cell growth, miR-503 was found to inhibit cellular invasion significantly. Algorithm-based studies identified multiple potential target genes and pathways associated with oncogenic mechanisms. The candidate target gene, WNT3A, was confirmed to be downregulated by miR-503 at both the mRNA and protein levels and validated by a reporter assay. Furthermore, miR-503 modulated multiple invasion-associated genes, including matrix metalloproteinases (MMPs), through the Wnt downstream signaling pathway. Overall, this study demonstrates that miR-503 suppresses HNC malignancy by inhibiting cell invasion through the Wnt signaling pathway via the WNT3A/MMP molecular axis. The modulation of miR-503 may be a novel therapeutic approach to intervene in cancer invasion.

Cell cycle associated miRNAs as target and therapeutics in lung cancer treatment

Lung cancer is the primary cause of cancer related deaths worldwide. Limited therapeutic options and resistance to existing drugs are the major hindrances to the clinical success of this cancer. In the past decade, several studies showed the role of microRNA (miRNA) driven cell cycle regulation in lung cancer progression. Therefore, these small nucleotide molecules could be utilized as promising tools in lung cancer therapy. In this review, we highlighted the recent advancements in lung cancer therapy using cell cycle linked miRNAs. By highlighting the roles of the specific cell cycle core regulators affiliated miRNAs in lung cancer, we further outlined how these miRNAs can be explored in early diagnosis and treatment strategies to prevent lung cancer. With the provided information from our review, more medical efforts can ensure a potential breakthrough in miRNA-based lung cancer therapy.

Human umbilical cord blood mesenchymal stem cells-derived exosomal microRNA-503-3p inhibits progression of human endometrial cancer cells through downregulating MEST

Endometrial cancer (EC) is a group of epithelial malignant tumors that occur in the endometrium. The specific pathogenesis is not revealed, hence, the goal of this study was to investigate the influence of human umbilical cord blood mesenchymal stem cells (hUMSCs)-derived exosomal microRNA-503-3p (miR-503-3p) on human EC cells by mediating mesoderm-specific transcript (MEST). The binding relationship between MiR-503-3p and MEST was searched. HUMSCs were collected and exosomes (Exos) were isolated and identified. Human EC cell lines HEC-1B and RL95-2 were transfected with elevated miR-503-3p or silenced MEST vector or co-cultured with Exos to figure their roles in biological functions of EC cells. The in vitro effect of miR-503-3p, MEST, and Exos on EC cells was further verified in vivo. MEST was a target of miR-503-3p. Overexpression of miR-503-3p or reduction of MEST suppressed the biological functions of EC cells. Enhanced MEST expression mitigated the role of upregulated miR-503-3p on the growth of EC cells. HUMSCs-derived Exos suppressed EC cell growth, upregulated miR-503-3p-modified HUMSCs-derived Exos had a more obvious inhibitory effect on EC cell growth. The anti-tumor effect of elevated miR-503-3p, silenced MEST, and HUMSCs-derived Exos were verified in nude mice. This study highlights that hUMSCs-derived exosomal miR-503-3p inhibits EC development by suppressing MEST, which is of great benefit to EC therapy.

MicroRNAs and Long Non-Coding RNAs in Adrenocortical Carcinoma

Non-coding RNAs (ncRNAs) are a type of genetic material that do not encode proteins but regulate the gene expression at an epigenetic level, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). The role played by ncRNAs in many physiological and pathological processes has gained attention during the last few decades, as they might be useful in the diagnosis, treatment and management of several human disorders, including endocrine and oncological diseases. Adrenocortical carcinoma (ACC) is a rare and aggressive endocrine cancer, still characterized by high mortality and morbidity due to both endocrine and oncological complications. Despite the rarity of this disease, recently, the role of ncRNA has been quite extensively evaluated in ACC. In order to better explore the role of the ncRNA in human ACC, this review summarizes the current knowledge on ncRNA dysregulation in ACC and its potential role in the diagnosis, treatment, and management of this tumor.

JMJD2C-mediated long non-coding RNA MALAT1/microRNA-503-5p/SEPT2 axis worsens non-small cell lung cancer

Jumonji domain containing protein 2C (JMJD2C) could epigenetically regulate cancer cells. We specifically explored the downstream mechanism of JMJD2C in non-small cell lung cancer (NSCLC) from the long non-coding RNA metastasis associated with lung adenocarcinoma transcript 1/microRNA-503-5p/septin 2 (MALAT1/miR-503-5p/SEPT2) axis. NSCLC clinical tissues were utilized to assess JMJD2C, MALAT1, miR-503-5p and SEPT2 levels. NSCLC cell lines (A549 and H1299) were applied for loss-of-function and gain-of-function tests to identify the functional roles of JMJD2C, MALAT1, miR-503-5p, and SEPT2. The interactions among JMJD2C, MALAT1, miR-503-5p, and SEPT2 were assessed. Augmented JMJD2C, MALAT1, and SEPT2 and reduced miR-503-5p levels were found in NSCLC. Depleting JMJD2C or MALAT1, or restoring miR-503-5p exerted anti-tumor effects on NSCLC cells in vitro and in vivo. JMJD2C is bound to the promoter of MALAT1. MALAT1 bound to miR-503-5p and miR-503-5p targeted SEPT2. Knocking down MALAT1 or SEPT2, or elevating miR-503-5p mitigated the pro-tumor effects of upregulated JMJD2C on NSCLC. It is evident that the JMJD2C-mediated MALAT1/miR-503-5p/SEPT2 axis takes part in the process of NSCLC and even worsens NSCLC.

MiRNA-221-5p suppressed the Th17/Treg ratio in asthma via RORγt/Foxp3 by targeting SOCS1

Background

This study was designed to investigate the mechanism and effects of miRNA-221-5p on the T-helper 17 (Th17)/T-regulatory (Treg) ratio in asthma.

Methods

BALB/c mice were intranasally challenged with 100 µg OVA on 14 and 21 day. Mice were rechallenged with 2.5% OVA-PBS on 22 and 28 day. Mice were sacrificed using on day 30 under 35 mg/kg pentobarbital sodium. PBMCs were induced vitro model of asthma using 500 ng of lipopolysaccharides (LPS) for 4 h.

Results

The expression of miRNA-221-5p was reduced in in vivo model, compared sham group. The vitro model of asthma treated with miRNA-221-5p mimic resulted in the reduction of IL-6, IL-17, IL-21 and IL-22 levels, and induction of IL-10, IL-35 and TGF-β levels. In addition, down-regulation of miRNA-221-5p induced the protein expression of suppressor of cytokine signaling 1 (SOCS1) and receptor-related orphan receptor-gamma-t (RORγt) and suppressed that of FOXP3 in in vitro model of asthma. Over-expression of miRNA-221-5p induced the protein expression of FOXP3, and suppressed that of SOCS1 and RORγt in in vitro model of asthma. The inhibition of SOCS1 or RORγt attenuated the effects of anti-miRNA-221-5p on Th17/Treg ratio in asthma.

Conclusion

miRNA-221-5p may play critical roles in driving the differentiation of Th17/Treg ratio via RORγt/Foxp3 by Targeting SOCS1, reduced the function of Th17 cells by directly inhibiting RORγt/SOCS1 and promoted the function of Treg cells via Foxp3/ SOCS1 in asthma.

Extracellular vesicles derived from radioresistant oral squamous cell carcinoma cells contribute to the acquisition of radioresistance via the miR-503-3p-BAK axis

Despite advancements in treatments, oral squamous cell carcinoma (OSCC) has not significantly improved in prognosis or survival rate primarily due to the presence of treatment-resistant OSCC. The intercellular communication between tumour cells is a molecular mechanism involved in acquiring OSCC treatment resistance. Extracellular vesicles (EVs) and encapsulated miRNAs are important mediators of intercellular communication. Here, we focused on EVs released from clinically relevant radioresistant (CRR) OSCC cells. Additionally, we evaluated the correlation between miRNA expression in the serum samples of patients who showed resistance to radiotherapy and in EVs released from CRR OSCC cells. We found that EVs released from CRR OSCC cells conferred radioresistance to radiosensitive OSCC cells via miR-503-3p contained in EVs. This miR-503-3p inhibited BAK and impaired the caspase cascade to suppress radiation-induced apoptosis. Furthermore, OSCC cells with BAK knockdown had increased radioresistance. Additionally, the expression of circulating miR-503-3p in patients with OSCC was correlated with a poor treatment response and prognosis of radiotherapy. Our results provide new insights into the relationship between EVs and the radioresistance of OSCC and suggest that the miR-503-3p-BAK axis may be a therapeutic target and that circulating miR-503-3p is a useful prognostic biomarker in the radiotherapy of OSCC.

CircDLGAP4 overexpression relieves oxygen-glucose deprivation-induced neuronal injury by elevating NEGR1 through sponging miR-503-3p

Circular RNAs (circRNAs) have been reported to play vital regulatory roles in human diseases. However, the functions of circRNAs in ischemic stroke (IS) are limited. In this study, we aimed to explore the functions and mechanisms of circRNA DLG associated protein 4 (circDLGAP4) in IS development. Oxygen-glucose deprivation (OGD)-treated HCN-2 cells were used to mimic IS environment in vitro. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to detect the levels of circDLGAP4, microRNA-503-3p (miR-503-3p) and neuronal growth regulator 1 (NEGR1) mRNA. RNase R assay was conducted to analyze the stability of circDLGAP4. Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis were adopted for cell viability and death, respectively. Western blot assay was performed for protein levels. Enzyme-linked immunosorbent assay (ELISA) kits were used to examine the concentrations of inflammatory cytokines. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay were employed to analyze the relationships among circDLGAP4, miR-503-3p and NEGR1. CircDLGAP4 level was declined in HCN-2 cells after OGD treatment. CircDLGAP4 overexpression promoted cell viability and suppressed cell death and inflammatory cytokine concentrations in OGD-treated HCN-2 cells. CircDLGAP4 acted as the sponge for miR-503-3p and the impacts of circDLGAP4 overexpression on cell viability, death and inflammation in OGD-treated HCN-2 cells were reversed by miR-503-3p elevation. Furthermore, NEGR1 was the target gene of miR-503-3p. MiR-503-3p inhibition ameliorated OGD-induced HCN-2 cell impairments, but NEGR1 knockdown abolished the effects. CircDLGAP4 alleviated OGD-induced HCN-2 cell damage by regulating miR-503-3p/NEGR1 axis.

Clinical Significance and Biological Function of miR-1274a in Non-small Cell Lung Cancer

Since the discovery of microRNAs (miRNAs) as a class of important regulatory molecules, miRNAs are involved in the occurrence and development of tumors. In this paper, we aimed to identify the role of miR-1274a in non-small cell lung cancer (NSCLC). The miR-1274a expression levels in four NSCLC cells and tissues from 125 patients were determined by qRT-PCR assays. Kaplan-Meier survival curves and Cox regression analysis were used to examine the prognostic significance of miR-1274a in NSCLC patients. The CCK-8 and Transwell assays were performed to evaluate the cell proliferation, invasion, and migration ability of NSCLC cells. The miR-1274a expression levels were significantly higher in NSCLC tissues than in adjacent normal tissues, and overexpression of miR-1274a had a poor prognosis in NSCLC patients. Functional studies in two NSCLC cell lines have shown that overexpression of miR-1274a could promote cell proliferation, migration, and invasion. miR-1274a expression levels are upregulated in NSCLC tissues, and a high expression is associated with a poor prognosis in patients with NSCLC. Moreover, miR-1274a promotes cell proliferation, migration, and invasion. Based on our findings, miR-1274a may act as a tumor miRNA in the occurrence and development of NSCLC.

The Impact of lncRNAs and miRNAs on Apoptosis in Lung Cancer

Apoptosis is a coordinated cellular process that occurs in several physiological situations. Dysregulation of apoptosis has been documented in numerous pathological situations, particularly cancer. Non-coding RNAs regulate apoptosis via different mechanisms. Lung cancer is among neoplastic conditions in which the role of non-coding RNAs in the regulation of apoptosis has been investigated. Non-coding RNAs that regulate apoptosis in lung cancer have functional interactions with PI3K/Akt, PTEN, GSK-3β, NF-κB, Bcl-2, Bax, p53, mTOR and other important cancer-related pathways. Globally, over-expression of apoptosis-blocking non-coding RNAs has been associated with poor prognosis of patients, while apoptosis-promoting ones have the opposite effect. In the current paper, we describe the impact of lncRNAs and miRNAs on cell apoptosis in lung cancer.

Echinacoside exerts anti-tumor activity via the miR-503-3p/TGF-β1/Smad aixs in liver cancer

Background

Echinacoside (ECH) is the main active ingredient of Cistanches Herba, which is known to have therapeutic effects on metastatic tumors. However, the effects of ECH on liver cancer are still unclear. This study was to investigate the effects of ECH on the aggression of liver cancer cells.

Methods

Two types of liver cancer cells Huh7 and HepG2 were treated with different doses of ECH at different times and gradients. MTT and colony formation assays were used to determine the effects of ECH on the viability of Huh7 and HepG2 cells. Transwell assays and flow cytometry assays were used to detect the effects of ECH treatment on the invasion, migration, apoptosis and cell cycle of Huh7 and HepG2 cells. Western blot analysis was used to detect the effects of ECH on the expression levels of TGF-β1, smad3, smad7, apoptosis-related proteins (Caspase-3, Caspase-8), and Cyto C in liver cancer cells. The relationship between miR-503-3p and TGF-β1 was detected using bioinformatics analysis and Luciferase reporter assay.

Results

The results showed that ECH inhibited the proliferation, invasion and migration of Huh7 and HepG2 cells in a dose- and time-dependent manner. Moreover, we found that ECH caused Huh7 and HepG2 cell apoptosis by blocking cells in S phase. Furthermore, the expression of miR-503-3p was found to be reduced in liver tumor tissues, but ECH treatment increased the expression of miR-503-3p in Huh7 and HepG2 cells. In addition, we found that TGF-β1 was identified as a potential target of miR-503-3p. ECH promoted the activation of the TGF-β1/Smad signaling pathway and increased the expression levels of Bax/Bcl-2. Moreover, ECH could trigger the release of mitochondrial Cyto C, and cause the reaction Caspases grade.

Conclusions

This study demonstrates that ECH exerts anti-tumor activity via the miR-503-3p/TGF-β1/Smad aixs in liver cancer, and provides a safe and effective anti-tumor agent for liver cancer.

HDAC2 interacts with microRNA-503-5p to regulate SGK1 in osteoarthritis

Background

Osteoarthritis (OA) is a disabling joint disease that causes articular cartilage degeneration. It has been implicated that altered expression of histone deacetylase 2 (HDAC2) is found in patients with OA. However, the specific role of HDAC2 in the development of OA still remains enigmatic. Hence, we sought to characterize the functional relevance of HDAC2 in the development of OA.

Methods

Anterior cruciate ligament surgery was performed to generate the rat model of OA. Luciferase assay was performed to evaluate the relationship between microRNA-503-5p (miR-503-5p) and serum- and glucocorticoid-inducible kinase-1 (SGK1). Functional experiments were conducted to examine the functional significance of miR-503-5p, histone deacetylase 2 (HDAC2), and SGK1 on the progression of OA by determining proliferation, apoptosis, and expression of apoptosis-associated proteins and inflammatory cytokines.

Results

HDAC2 could inhibit miR-503-5p expression. SGK1 was the target gene of miR-503-5p. Upregulation of miR-503-5p or silencing of HDAC2 contributed to enhanced proliferation, suppressed apoptosis (reduced expression of Caspase-3 and Bax but elevated expression of Bcl2), and promoted inflammation in chondrocytes of OA rats.

Conclusion

In conclusion, our study demonstrated that HDAC2 could promote OA through miR-503-5p/SGK1 axis, which might function as a therapeutic target for OA treatment.

The Causes and Consequences of miR-503 Dysregulation and Its Impact on Cardiovascular Disease and Cancer

microRNAs (miRs) are short, non-coding RNAs that regulate gene expression by mRNA degradation or translational repression. Accumulated studies have demonstrated that miRs participate in various biological processes including cell differentiation, proliferation, apoptosis, metabolism and development, and the dysregulation of miRs expression are involved in different human diseases, such as neurological, cardiovascular disease and cancer. microRNA-503 (miR-503), one member of miR-16 family, has been studied widely in cardiovascular disease and cancer. In this review, we summarize and discuss the studies of miR-503 in vitro and in vivo, and how miR-503 regulates gene expression from different aspects of pathological processes of diseases, including carcinogenesis, angiogenesis, tissue fibrosis and oxidative stress; We will also discuss the mechanisms of dysregulation of miR-503, and whether miR-503 could be applied as a diagnostic marker or therapeutic target in cardiovascular disease or cancer.

circNRIP1 facilitates keloid progression via FXR1‑mediated upregulation of miR‑503‑3p and miR‑503‑5p

Circular nuclear receptor interacting protein 1 (circNRIP1) is implicated in tumor initiation and progression; however, the underlying mechanism of keloid progression is unclear. To the best of our knowledge, the present study is the first to characterize the contribution of circNRIP1 to keloid progression and evaluate the potential underlying molecular mechanisms using keloid-derived fibroblasts. The expression profile of circNRIP1 was confirmed in keloid tissue. The contribution of circNRIP1 to keloid progression was investigated via loss-of-function assays. Furthermore, the molecular mechanism by which circNRIP1 contributes to pre-microRNA (miR)-503 maturation through blocking Fbxo4-mediated Fragile-X mental retardation 1 (FXR1) ubiquitination was verified. Finally, the biological functions of FXR1, miR-503-3p, and miR-503-5p in keloid-derived fibroblast proliferation, apoptosis and extracellular matrix accumulation were confirmed. circNRIP1 was highly expressed in keloid tissue and keloid-derived fibroblasts. Functional analysis showed that circNRIP1 knockdown successfully blocked the proliferation and expression of extracellular matrix-associated proteins while increasing the rate of apoptosis in keloid-derived fibroblasts. Mechanistically, circNRIP1 maintained FXR1 stability by impeding Fbxo4-mediated FXR1 ubiquitination and degradation. Additionally, FXR1 increased the abundance of miR-503-3p and miR-503-5p by contributing to pre-miR-503 maturation. Knockdown of FXR1, miR-503-3p and miR-503-5p also inhibited proliferation and extracellular matrix accumulation in keloid-derived fibroblasts and increased levels of cell apoptosis. Collectively, the present study confirmed that circNRIP1 contributed to pre-miR-503 maturation via blocking Fbxo4-mediated FXR1 ubiquitination and degradation, which facilitates keloid progression. These results indicate that circNRIP1 has potential as a novel therapeutic target for the control and/or treatment of keloids.

lncRNA RAET1K Promotes the Progression of Acute Myeloid Leukemia by Targeting miR-503-5p/INPP4B Axis

Background

Although long non-coding RNA (lncRNA) RAET1K has been observed to be abnormally expressed in patients with various cancers, its role and molecular mechanism in acute myeloid leukemia (AML) remain unclear.

Methods

The expression of RAET1K and miR-503-5p in bone marrow tissues and cell lines was detected by qRT-PCR. Cell proliferation was evaluated by cell counting kit-8 and 5-ethynyl-20-deoxyuridine (EdU) staining assay. Cell invasion and migration were detected by transwell assay. Cell apoptosis was evaluated by flow cytometry. The relationship between RAET1K and miR-503-5p, as well as miR-503-5p and INPP4B, was determined by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. In addition, the tumorigenesis of leukemia cells was evaluated by using a xenograft mouse model in vivo.

Results

RAET1K was significantly upregulated and miR-503-5p was markedly downregulated in bone marrow tissues and cell lines (HL-60 and THP-1). Silencing of RAET1K (si-RAET1K) and overexpression of miR-503-5p inhibited cell proliferation, migration, and invasion but promoted apoptosis of HL-60 and THP-1 cells. RAET1K functioned as a sponge of miR-503-5p, and miR-503-5p inhibitor obviously attenuated the effect of si-RAET1K on AML progression in vitro. INPP4B was identified as a target of miR-503-5p, and INPP4B overexpression obviously reversed the effect of miR-503-5p mimics on cell proliferation, migration, invasion, and apoptosis of HL-60 and THP-1 cells in vitro. Knockdown of RAET1K effectively inhibited the tumorigenesis of leukemia cells in vivo.

Conclusion

Our results demonstrated that RAET1K/miR-503-5p/INPP4B axis contributed to AML progression, suggesting that RAET1K might be a potential target for the treatment of AML.

The microRNA-424/503 cluster: A master regulator of tumorigenesis and tumor progression with paradoxical roles in cancer

MicroRNAs (miRNAs) are a group of non-coding RNAs that play a crucial role in post-transcriptional gene regulation and act as indispensable mediators in several critical biological processes, including tumorigenesis, tissue homeostasis, and regeneration. MiR-424 and miR-503 are intragenic miRNAs that are clustered on human chromosome Xq26.3. Previous studies have reported that both miRNAs are dysregulated and play crucial but paradoxical roles in tumor initiation and progression, involving different target genes and molecular pathways. Moreover, these two miRNAs are concomitantly expressed in several cancer cells, indicating a coordinating function as a cluster. In this review, the roles and regulatory mechanisms of miR-424, miR-503, and miR-424/503 cluster are summarized in different types of cancers.

Long non-coding RNA LINC00460 promotes proliferation and inhibits apoptosis of cervical cancer cells by targeting microRNA-503-5p

Long non-coding RNAs are associated with the pathogenesis of cancers. Moreover, LINC00460 is involved in the development of multiple cancers. However, the function of LINC00460 in cervical cancer (CC) remains inconclusive. Herein, CC tissues and tumor-adjacent tissues were collected from patients. The effect of LINC00460 silencing in cell proliferation and apoptosis in CC was explored in vitro and in vivo. Additionally, the interaction between LINC00460 and miR-503-5p was analyzed using dual luciferase reporter assay. The expression of genes and proteins was assayed using quantitative real-time PCR, western blotting and immunohistochemistry, cell viability using MTT assay, cell cycle distribution using flow cytometry, cell apoptosis using Annexin V staining, Hoechst staining and TUNEL assay. LINC00460 levels in CC tissues were higher than tumor-adjacent tissues. LINC00460 silencing suppressed proliferation and promoted apoptosis of CC cells as evidenced by decreased cell viability, inhibited proliferation-related protein and cell cycle protein expressions and G1/S transition, increased apoptotic cells and Hoechst-positive cells, and enhanced apoptosis-related protein expressions. LINC00460 could bind to miR-503-5p and LINC00460 silencing enhanced miR-503-5p expression and inhibited its target gene expressions in CC cells. MiR-503-5p inhibition reversed LINC00460 silencing-caused inhibition of cell proliferation and miR-503-5p target gene expressions, and promotion of cell apoptosis. LINC00460 silencing also attenuated tumor growth, promoted miR-503-5p levels and cell apoptosis, and inhibited cell proliferation and miR-503-5p target gene expressions in tumor tissues. Hence, LINC00460 functioned as an oncogene in CC that affected cell proliferation and apoptosis via sponging miR-503-5p. This study provides a novel therapeutic target for CC.

MicroRNA-503-3p affects osteogenic differentiation of human adipose-derived stem cells by regulation of Wnt2 and Wnt7b under cyclic strain

BACKGROUND

MicroRNAs (miRNAs) play a role in regulating osteogenic differentiation (OD) of mesenchymal stem cells by inhibiting mRNAs translation under cyclic strain. miR-503-3p was downregulated in OD of human adipose-derived stem cells (hASCs) in vivo under cyclic strain in our previous study, while it might target the Wnt/β-catenin (W-β) pathway. In this study, we explored miR-503-3p's role in OD of hASCs under cyclic strain.

METHODS

OD of hASCs was induced by cyclic strain. Bioinformatic and dual luciferase analyses were used to confirm the relationship between Wnt2/Wnt7b and miR-503-3p. Immunofluorescence was used to detect the effect of miR-503-3p on Wnt2/Wnt7b and β-catenin in hASCs transfected with miR-503-3p mimic and inhibitor. Mimic, inhibitor, and small interfering RNA (siRNA) transfected in hASCs to against Wnt2 and Wnt7b. Quantitative real-time PCR (RT-PCR) and western blot were used to examine the OD and W-β pathway at the mRNA and protein levels, respectively. Immunofluorescence was performed to locate β-catenin. ALP activity and calcium were detected by colorimetric assay.

RESULTS

Results of immunophenotypes by flow cytometry and multi-lineage potential confirmed that the cultured cells were hASCs. Results of luciferase reporter assay indicated that miR-503-3p could regulate the expression levels of Wnt2 and Wnt7b by targeting their respective 3'-untranslated region (UTR). Under cyclic strain, gain- or loss-function of miR-503-3p studies by mimic and inhibitor revealed that decreasing expression of miR-503-3p could significantly bring about promotion of OD of hASCs, whereas increased expression of miR-503-3p inhibited OD. Furthermore, miR-503-3p high-expression reduced the activity of the W-β pathway, as indicated by lowering expression of Wnt2 and Wnt7b, inactive β-catenin in miR-503-3p-treated hASCs. By contrast, miR-503-3p inhibition activated the W-β pathway.

CONCLUSIONS

Collectively, our findings indicate that miR-503-3p is a negative factor in regulating W-β pathway by Wnt2 and Wnt7b, which inhibit the OD of hASCs under cyclic strain.

miR-503-5p inhibits colon cancer tumorigenesis, angiogenesis, and lymphangiogenesis by directly downregulating VEGF-A

MicroRNAs (miRNAs) are considered important in the pathogenesis of colon cancer. But the mechanism of their role in colon cancer is still largely unknown. Here, we aimed to explore the function of miR-503-5p in the pathogenesis of colon cancer. This study analyzed miRNA microarray of colon cancer. Then, we performed EdU, CCK-8, flow cytometry, Transwell invasion assays and in vivo assays to explore the exact role of miR-503-5p in colon cancer. We observed considerable downregulation of miR-503-5p expression in colon cancer cells and tissues and significant correlation with the TNM stage, differentiation grade and lymph node metastasis of colon cancer. Overexpression of miR-503-5p promoted the apoptosis and G1 arrest of colon cancer cells, and inhibited migration, proliferation, invasion and colony formation. Interestingly, ectopic miR-503-5p overexpression could significantly inhibit vascular endothelial growth factor (VEGF)-A expression and reduce the activity of a luciferase reporter containing the VEGF-A 3'-untranslated region. Furthermore, overexpressed miR-503-5p in human umbilical vein endothelial cells (HUVECs) and colon cancer cells resulted in lower expression levels of VEGFR-2, and subsequently inhibited AKT signaling pathway. Additionally, overexpression of miR-503-5p suppressed both lymphangiogenesis and angiogenesis in vivo and significantly inhibited the tumorigenicity of HT-29 cells in nude mice. In summary, our study shows downregulation of miR-503-5p at least partially contributes to the tumorigenesis of colon cancer through modulating the angiogenesis and lymphangiogenesis by targeting VEGF-A while stimulating AKT signaling pathways. Therapeutic strategies to restore miR-503-5p in colon cancer could be useful to inhibit tumor progression.

MiR-503-5p functions as an oncogene in oral squamous cell carcinoma by targeting Smad7

BACKGROND

Oral squamous cell carcinoma (OSCC) is a common oral malignancy. Previous studies indicated that the level of miR-503-5p was upregulated in OSCC tissues. However, the mechanism by which miR-503-5p regulates the proliferation and invasion of OSCC cells remains unclear. Therefore, this study aimed to investigate the role of miR-503-5p during the progression of OSCC.

METHODS

The level of miR-503-5p in Tca8113 cells was detected using RT-qPCR assay. In addition, CCK-8, transwell assays and flow cytometry assays were conducted to detect cell viability, migration, invasion and apoptosis, respectively. Meanwhile, the dual luciferase reporter assay was applied to explore the interaction between miR-503-5p and Smad7 in Tca8113 cells.

RESULTS

Overexpression of miR-503-5p significantly promoted the proliferation, migration and invasion of Tca8113 cells, while downregulation of miR-503-5p markedly inhibited proliferation, migration and invasion of cells. In addition, knockdown of miR-503-5p obviously induced the apoptosis of Tca8113 cells via increasing the levels of Bax and cleaved caspase 3, and decreased the expression of Bcl-2. Moreover, SMAD family member 7 (Smad7) was identified as a direct binding target of miR-503-5p in Tca8113 cells. Overexpression of miR-503-5p significantly downregulated the levels of Smad7 and E-cadherin, but upregulated the levels of N-cadherin and MMP-9 in Tca8113 cells.

CONCLUSION

These results indicated that miR-503-5p might act as an oncogene in OSCC cells by targeting Smad7. Therefore, miR-503-5p might act as a novel and potential therapeutic target for the treatment of OSCC.

MIR210HG promotes cell proliferation and invasion by regulating miR-503-5p/TRAF4 axis in cervical cancer

Long non-coding RNAs (lncRNAs) play important roles in the progression of cervical cancer (CC). However, the roles and underlying molecular mechanisms of lncRNAs in CC remain unclear. In the current study, we discovered a new lncRNA MIR210HG which was upregulated in CC tissues through microarray. The upregulation of MIR210HG was associated with advanced FIGO stage, metastasis, and poor prognosis in CC patients. Function assays showed that MIR210HG inhibition significantly suppressed the proliferation, invasion, and epithelial-mesenchymal transition (EMT) processes in CC and reduced tumor growth in vivo. Mechanistically, we identified that MIR210HG might serve as a competing endogenous RNA (ceRNA) of miR-503-5p to relieve the repressive effect of miR-503-5p on TRAF4 expression in CC cells. In conclusion, we demonstrated that MIR210HG promoted CC progression through regulating the MIR210HG/miR-503-5p/TRAF4 axis, indicating that MIR210HG might act as a novel insight into CC treatment.

Circ_0000267 promotes gastric cancer progression via sponging MiR-503-5p and regulating HMGA2 expression

Background

Circular RNAs (circRNAs) are a class of newly discovered RNAs that attach great importance to modulate gene expression and biological function. Nonetheless, in gastric cancer (GC), the expression and function of circRNA are much less explored. In this study, circ_0000267 expression in GC was investigated and the function and mechanism of circ_0000267 was probed.

Materials and Methods

Quantitative real‐time PCR (qRT‐PCR) was employed to detect circ_0000267, miR‐503‐5p, and HMGA2 expression. Immunohistochemistry and western blot were adopted to detect HMGA2 and epithelial–mesenchymal transition (EMT)‐related proteins (E‐cadherin and N‐cadherin) expression in GC tissues and cells, respectively. GC cell lines with circ_0000267 overexpressed and knocked down were constructed, and CCK‐8 assay, BrdU assay, scratch healing assay, and transwell assay were employed to assess the effect of circ_0000267 on the proliferation and metastasis of GC cells. Besides, dual‐luciferase reporter gene assay was adopted to verify the targeting relationship between circ_0000267 and miR‐503‐5p.

Results

Circ_0000267 showed a significant upregulation in GC tissues and cell lines, and its high expression level was extremely linked to the increased tumor diameter and local lymph node metastasis. Circ_0000267 overexpression accelerated GC cell proliferation, metastasis, and EMT processes, while knocking down circ_0000267 led to the opposite effect. From the perspective of mechanism, circ_0000267 promoted the progression of GC through adsorbing miR‐503‐5p and upregulating HMGA2 expression.

Conclusion

Circ_0000267 is an oncogenic circRNA that affects the progression of GC, which participates in promotion of GC proliferation, migration, invasion, and EMT via modulating the miR‐503‐5p/HMGA2 axis.

MicroRNA-503 contributes to podocyte injury via targeting E2F3 in diabetic nephropathy

Diabetic nephropathy (DN) is serious diabetic complication with capillary injury. Podocyte injury exerts a crucial effect on DN pathogenesis. MicroRNA-503 (miR-503) has been reported in various diseases including DN. Here, we investigated the detailed mechanism of miR-503 in the podocyte injury of DN. The functional role of miR-503 was investigated in cultured podocytes and diabetic rats. Podocyte injury was evaluated by migration and apoptosis experiments in podocytes and we observed that high glucose elevated miR-503 in a time and dose-dependent manner. Meanwhile, E2F transcription factor 3 (E2F3), as a crucial regulator in multiple diseases, was predicted as a potential target of miR-503 here. It was shown that E2F3 was greatly decreased in podocytes incubated with high glucose and miR-503 modulated its expression negatively. In addition, downregulation of E2F3 contributed to podocyte injury, which was reversed by miR-503 inhibitors in vitro. Furthermore, we proved that increase of miR-503 resulted in an unfavorable renal function in diabetic rats via targeting E2F3. These revealed for the first time that the overexpression of miR-503 promoted podocyte injury via targeting E2F3 in diabetic nephropathy and miR-503/E2F3 axis might represent a pathological mechanism of diabetic nephropathy progression.

The Role of MicroRNAs in the Pathogenesis of Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the most common microvascular complications in diabetic patients; it is also an important cause of renal dysfunction, renal fibrosis, and end-stage renal disease. Unfortunately, the pathogenesis of DN is complex and has not yet been fully elucidated; hence, the pathogenesis of DN to determine effective treatments of crucial importance is deeply explored. Early DN research focuses on hemodynamic changes and metabolic disorders, and recent studies have shown the regulatory role of microRNAs (miRNAs) in genes, which may be a new diagnostic marker and therapeutic target for diabetic nephropathy. In this review, we summarize the recent advances in the clinical value and molecular mechanisms of miRNAs in DN, providing new ideas for the diagnosis and treatment of DN.

CircRNA circ-BANP-mediated miR-503/LARP1 signaling contributes to lung cancer progression

Recently, circular RNAs (circRNAs) attract much attention due to their potential vital functions in multiple human diseases, including cancer. circ-BANP has been reported to modulate colorectal cancer growth. Nevertheless, the relationship between circ-BANP and lung cancer requires to be investigated. In this study, we found circ-BANP was overexpressed in lung cancer tissues. Higher circ-BANP expression was associated with lower survival rate. Moreover, silencing circ-BANP markedly inhibited proliferation, migration and invasion of lung cancer cells in vitro and impaired tumor propagation in vivo. In mechanism, circ-BANP was identified as the sponge of miR-503 while miR-503 targets LARP1. Circ-BANP-induced inhibition of miR-503 led to increased expression of LARP1 in lung cancer. Finally, rescue assays indicated that LARP1 restoration partially reversed the effects of circ-BANP knockdown in lung cancer. In sum, our study illustrated that circ-BANP-mediated miR-503/LARP1 signaling promoted lung cancer growth, migration and invasion, providing a novel insight on the mechanism underlying lung cancer progression.

miR-577 suppresses cell proliferation and epithelial-mesenchymal transition by regulating the WNT2B mediated Wnt/β-catenin pathway in non-small cell lung cancer

MicroRNAs (miRNAs/miRs) serve important roles in regulating malignant phenotype in numerous cancers, such as non-small cell lung cancer (NSCLC); however, the role and function of miR-577 in NSCLC remains unknown. In the present study, miR-577 expression levels were observed to be downregulated in NSCLC via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay, and inhibited cell proliferation, cell migration and invasion and epithelial-mesenchymal transition progress in NSCLC cells. The predicted target genes of miR-577 were determined by enhanced green fluorescent protein reporter assay, RT-qPCR and western blot analyses. miR-577 was demonstrated to suppress the expression of WNT2B by targeting the 3′-untranslated region of WNT2B mRNA in H522 and A549 cells. WNT2B was upregulated in NSCLC cells as observed via RT-qPCR analysis, and the malignant phenotype of H522 and A549 cells were promoted by WNT2B overexpression. In addition, miR-577 inactivated the Wnt/β-catenin pathway by targeting WNT2B in NSCLC cells. Collectively, miR-577 may function as a suppressor gene by directly downregulatingWNT2B mRNA and protein expression levels in H522 and A549 cells, and may serve important roles in the malignancy of NSCLC.

Stemness-Attenuating miR-503-3p as a Paracrine Factor to Regulate Growth of Cancer Stem Cells

Cancer stem cells (CSCs) with self-renewal abilities endorse cellular heterogeneity, resulting in metastasis and recurrence. However, there are no promising therapeutics directed against CSCs. Herein, we found that miR-503-3p inhibited tumor growth via the regulation of CSC proliferation and self-renewal. miR-503-3p, isolated from human adipose stem cell- (ASC-) derived exosomes, suppressed initiation and progression of CSCs as determined by anchorage-dependent (colony formation) and anchorage-independent (tumorsphere formation) assays. The expression of pluripotency genes was significantly decreased in miR-503-3p-treated CSCs. Furthermore, xenografts, which received miR-503-3p, exhibited remarkably reduced tumor growth in vivo. Thus, miR-503-3p may function as a stemness-attenuating factor via cell-to-cell communications.

miR-503 suppresses the proliferation and metastasis of esophageal squamous cell carcinoma by triggering autophagy via PKA/mTOR signaling

MicroRNA (miR)-503 is involved in the regulation of the malignant phenotype in multiple tumor types, and has been proven to be a novel diagnostic and therapeutic target; however, its function and mechanisms of action have not yet been fully elucidated in esophageal squamous cell carcinoma (ESCC). In the current study, we detected miR‑503 expression by RT‑qPCR and found that miR‑503 expression was increased in ESCC, but negatively correlated with lymph node metastasis, TNM stage and tumor differentiation. Functionally, we confirmed that miR‑503 inhibited the proliferation and metastasis of ESCC cells by triggering cellular autophagy. Mechanistically, we confirmed that miR‑503 exerted its biological effects by targeting protein kinase CAMP‑activated catalytic subunit alpha (PRKACA) in ESCC by dual luciferase reporter assay. Moreover, miR‑503 was found to trigger autophagy in ESCC cells through the protein kinase A (PKA)/mammalian target of rapamycin (mTOR) pathway. Taken together, our results demonstrate that miR‑503 suppresses the proliferation and metastasis of ESCC via the activation of autophagy, mediated by the PKA/mTOR signaling pathway.

HOXC13 promotes proliferation of esophageal squamous cell carcinoma via repressing transcription of CASP3

Esophageal squamous cell carcinoma (ESCC), the dominant subtype of esophageal cancer, is one of the most common digestive tumors worldwide. In this study, we confirmed that HOXC13, a member of the homeobox HOXC gene family, was significantly upregulated in ESCC and its overexpression was associated with poorer clinical characteristics and worse prognosis. Moreover, knockdown of HOXC13 inhibited proliferation and induced apoptosis of ESCC through upregulating CASP3. ChIP analysis revealed that HOXC13 repressed transcription of CASP3 through directly targeting the promotor region of CASP3. We also found that miR‐503 downregulated HOXC13, by directly targeting its 3′UTR, and inhibited proliferation of ESCC. In conclusion, our study demonstrates that HOXC13, which is directly targeted by miR‐503, promotes proliferation and inhibits apoptosis of ESCC through repressing transcription of CASP3.