miR-203 Suppresses Bladder Cancer Cell Growth and Targets Twist1

Bladder cancer: non-coding RNAs and exosomal non-coding RNAs

Bladder cancer (BCa) is a highly prevalent type of cancer worldwide, and it is responsible for numerous deaths and cases of disease. Due to the diverse nature of this disease, it is necessary to conduct significant research that delves deeper into the molecular aspects, to potentially discover novel diagnostic and therapeutic approaches. Lately, there has been a significant increase in the focus on non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), due to their growing recognition for their involvement in the progression and manifestation of BCa. The interest in exosomes has greatly grown due to their potential for transporting a diverse array of active substances, including proteins, nucleic acids, carbohydrates, and lipids. The combination of these components differs based on the specific cell and its condition. Research indicates that using exosomes could have considerable advantages in identifying and forecasting BCa, offering a less invasive alternative. The distinctive arrangement of the lipid bilayer membrane found in exosomes is what makes them particularly effective for administering treatments aimed at managing cancer. In this review, we have tried to summarize different ncRNAs that are involved in BCa pathogenesis. Moreover, we highlighted the role of exosomal ncRNAs in BCa.

miRNA/epithelial-mesenchymal axis (EMT) axis as a key player in cancer progression and metastasis: A focus on gastric and bladder cancers

The metastasis a major hallmark of tumors that its significant is not only related to the basic research, but clinical investigations have revealed that majority of cancer deaths are due to the metastasis. The metastasis of tumor cells is significantly increased due to EMT mechanism and therefore, inhibition of EMT can reduce biological behaviors of tumor cells and improve the survival rate of patients. One of the gaps related to cancer metastasis is lack of specific focus on the EMT regulation in certain types of tumor cells. The gastric and bladder cancers are considered as two main reasons of death among patients in clinical level. Herein, the role of EMT in regulation of their progression is evaluated with a focus on the function of miRNAs. The inhibition/induction of EMT in these cancers and their ability in modulation of EMT-related factors including ZEB1/2 proteins, TGF-β, Snail and cadherin proteins are discussed. Moreover, lncRNAs and circRNAs in crosstalk of miRNA/EMT regulation in these tumors are discussed and final impact on cancer metastasis and response of tumor cells to the chemotherapy is evaluated. Moreover, the impact of miRNAs transferred by exosomes in regulation of EMT in these cancers are discussed.

CREB1 activation promotes human papillomavirus oncogene expression and cervical cancer cell transformation

Human papillomaviruses (HPVs) infect the oral and anogenital mucosa and can cause cancer. The high-risk (HR)-HPV oncoproteins, E6 and E7, hijack cellular factors to promote cell proliferation, delay differentiation and induce genomic instability, thus predisposing infected cells to malignant transformation. cAMP response element (CRE)-binding protein 1 (CREB1) is a master transcription factor that can function as a proto-oncogene, the abnormal activity of which is associated with multiple cancers. However, little is known about the interplay between HPV and CREB1 activity in cervical cancer or the productive HPV lifecycle. We show that CREB is activated in productively infected primary keratinocytes and that CREB1 expression and phosphorylation is associated with the progression of HPV+ cervical disease. The depletion of CREB1 or inhibition of CREB1 activity results in decreased cell proliferation and reduced expression of markers of epithelial to mesenchymal transition, coupled with reduced migration in HPV+ cervical cancer cell lines. CREB1 expression is negatively regulated by the tumor suppressor microRNA, miR-203a, and CREB1 phosphorylation is controlled through the MAPK/MSK pathway. Crucially, CREB1 directly binds the viral promoter to upregulate transcription of the E6/E7 oncogenes, establishing a positive feedback loop between the HPV oncoproteins and CREB1. Our findings demonstrate the oncogenic function of CREB1 in HPV+ cervical cancer and its relationship with the HPV oncogenes.

Epigenetic regulation of epithelial-mesenchymal transition during cancer development

Epithelial-mesenchymal transition (EMT) plays essential roles in promoting malignant transformation of epithelial cells, leading to cancer progression and metastasis. During EMT-induced cancer development, a wide variety of genes are dramatically modified, especially down-regulation of epithelial-related genes and up-regulation of mesenchymal-related genes. Expression of other EMT-related genes is also modified during the carcinogenic process. Especially, epigenetic modifications are observed in the EMT-related genes, indicating their involvement in cancer development. Mechanically, epigenetic modifications of histone, DNA, mRNA and non-coding RNA stably change the EMT-related gene expression at transcription and translation levels. Herein, we summarize current knowledge on epigenetic regulatory mechanisms observed in EMT process relate to cancer development in humans. The better understanding of epigenetic regulation of EMT during cancer development may lead to improvement of drug design and preventive strategies in cancer therapy.

Circular RNAs: pivotal role in the leukemogenesis and novel indicators for the diagnosis and prognosis of acute myeloid leukemia

Acute myeloid leukemia (AML) is an aggressive hematological malignancy and affected patients have poor overall survival (OS) rates. Circular RNAs (circRNAs) are a novel class of non-coding RNAs (ncRNAs) with a unique loop structure. In recent years, with the development of high-throughput RNA sequencing, many circRNAs have been identified exhibiting either up-regulation or down-regulation in AML patients compared with healthy controls. Recent studies have reported that circRNAs regulate leukemia cell proliferation, stemness, and apoptosis, both positively and negatively. Additionally, circRNAs could be promising biomarkers and therapeutic targets in AML. In this study, we present a comprehensive review of the regulatory roles and potentials of a number of dysregulated circRNAs in AML.

The Role of MicroRNA in the Regulation of Tumor Epithelial–Mesenchymal Transition

Consistently, the high metastasis of cancer cells is the bottleneck in the process of tumor treatment. In this process of metastasis, a pivotal role is executed by epithelial–mesenchymal transition (EMT). The epithelial-to-mesenchymal transformation was first proposed to occur during embryonic development. Later, its important role in explaining embryonic developmental processes was widely reported. Recently, EMT and its intermediate state were also identified as crucial drivers in tumor progression with the gradual deepening of research. To gain insights into the potential mechanism, increasing attention has been focused on the EMT-related transcription factors. Correspondingly, miRNAs target transcription factors to control the EMT process of tumor cells in different types of cancers, while there are still many exciting and challenging questions about the phenomenon of microRNA regulation of cancer EMT. We describe the relevant mechanisms of miRNAs regulating EMT, and trace the regulatory roles and functions of major EMT-related transcription factors, including Snail, Twist, zinc finger E-box-binding homeobox (ZEB), and other families. In addition, on the basis of the complex regulatory network, we hope that the exploration of the regulatory relationship of non-transcription factors will provide a better understanding of EMT and cancer metastasis. The identification of the mechanism leading to the activation of EMT programs during diverse disease processes also provides a new protocol for the plasticity of distinct cellular phenotypes and possible therapeutic interventions. Here, we summarize the recent progress in this direction, with a promising path for further insight into this fast-moving field.

Non-invasive diagnostic potential of microRNA-203 in liquid biopsy of urothelial carcinoma of bladder

Increased CD44 antigen activity has been reported in recurrent cases of UBC. To date, no reliable biomarker is available with high significance and specificity for non-invasive detection of UBC. This study aimed to identify a CD44-linked microRNAs (miRNAs) (miR-9, miR-34a, miR-203) for non-invasive diagnosis of bladder cancer from other urinary tract malignancies. The expression of CD44-linked miRNAs was examined in serum, urine, and tissue specimens of Indian UBC patients (N = 25). For this purpose, healthy subjects (N = 25) and benign prostatic hyperplasia (BPH) (N = 10) patients were taken as controls. The relative expression of miRNAs was analyzed in serum, urine, and tissue samples using real-time quantitative reverse transcription PCR (qRT-PCR). The diagnostic potential of these miRNAs was accessed by plotting ROC curve. Increased miR-9 expression was observed in serum of UBC patients than healthy and BPH controls. In UBC patients, miR-34a expression was lower than healthy controls but non-significant as compared to BPH. miR-203 expression was considerably higher in serum of UBC patients but non-significant as compared to BPH controls. miR-203 was found to be considerably higher in urine samples from UBC patients as compared to BPH and healthy controls. The diagnostic potential of these miRNAs was evaluated using the ROC curve. Higher miR-203 levels in the urine of Indian UBC patients demonstrate its non-invasive diagnostic ability out of the three miRNAs studied. Our results characterize the non-invasive diagnostic potential of CD44-linked miR-203 in the urine of Indian UBC patients, which could be utilized in clinical settings in future after validation in larger patient cohort.

Exosome-mediated miR-25/miR-203 as a potential biomarker for esophageal squamous cell carcinoma: improving early diagnosis and revealing malignancy

Background

Esophageal squamous cell carcinoma (ESCC) is the leading cause of cancer death in men and women worldwide. The poor prognosis and rapid increase in ESCC incidence highlight the need to promote early detection and prediction. Identifying key molecular targets involved in ESCC monitoring and progression is critical for ESCC patients.

Methods

This study examined miR-25/miR-203 as a biomarker for ESCC patients. Real-time quantitative polymerase chain reaction (PCR) was used to detect miR-25/miR-203 expression levels in tissues and serum exosomes, and MiR-25/miR-203 upregulation was confirmed in ESCC.

Results

We found that the miR-25/miR-203 ratio in cancer tissues from 36 ESCC patients was significantly enhanced compared with that in adjacent tissues. Moreover, the serum level of miR-25/miR-203 in 57 ESCC patients was higher than that in 31 healthy volunteers. Intriguingly, in 38 ESCC patients, the level of miR-25/miR-203 decreased significantly after surgery. Using ROC curve statistical analysis, we found that each group of miR-25/miR-203 had obvious sensitivity and high specificity. The miR-25/miR-203 relationship with the clinicopathological features of ESCC patients was also analyzed. MiR-25/miR-203 was significantly associated with the ESCC TNM-stage and lymph node metastasis, which predicts the prognosis of ESCC and reflects tumor progression.

Conclusions

This study highlights the feasibility of using exosome-mediated miR-25/miR-203 as a vital noninvasive biomarker for the detection and treatment monitoring of ESCC.

Long non-coding RNA UCA1 enhances cervical cancer cell proliferation and invasion by regulating microRNA-299-3p expression

The long non-coding RNA, urothelial cancer-associated 1 (UCA1) is an important regulator in several tumors. However, to the best of our knowledge, the clinical roles of UCA1 in cervical cancer remain unclear. Thus, the present study aimed to investigate the function and mechanism of UCA1 in cervical cancer. Reverse transcription-quantitative PCR analysis was performed to detect UCA1 and microRNA (miR)-299-3p expression in cervical cancer tissues and cell lines. The Cell Counting Kit-8 and Transwell assays were performed to assess cell proliferation and invasion, respectively. Furthermore, the dual-luciferase reporter assay was performed to confirm the association between UCA1 and miR-299-3p. Rescue experiments were performed to determine the mechanism of the UCA1/miR-299-3p axis. The results demonstrated that UCA1 expression was upregulated in cervical cancer tissues and cell lines. Furthermore, overexpression of UCA1 enhanced the proliferation and invasion of cervical cancer cells, the effects of which were reversed following UCA1 knockdown. Notably, UCA1 interacted with miR-299-3p and negatively regulated miR-299-3p expression. In addition, miR-299-3p expression was downregulated in cervical cancer tissues and cell lines. Overexpression of miR-299-3p suppressed the proliferation and invasion of cervical cancer cells, reversing the effects of UCA1 knockdown on cervical cancer cell proliferation. Taken together, the results of the present study suggest that UCA1 promotes cell proliferation and invasion by regulating miR-299-3p expression in cervical cancer.

HOTAIR Contributes to Stemness Acquisition of Cervical Cancer through Regulating miR-203 Interaction with ZEB1 on Epithelial-Mesenchymal Transition

Cervical cancer stem cells contribute respond to considerable recurrence and metastasis of patients with cervical cancer. The stemness properties were partly regulated by the interaction of lncRNAs and miRNAs. HOTAIR functions as an oncogenic lncRNA. Previous research studies revealed its role in regulating stemness properties in various cancers. However, the role of HOTAIR in cervical cancer stem cells is still unknown. Here, cisplatin-resistant and serum-free cultured cells exhibited stem cells properties. Cervical cancer stem cells exhibited greater invasion and migration compared with their parental cells, which was similar to cells overexpressing HOTAIR. HOTAIR was significantly overexpressed in cervical cancer stem cells, and knockdown of HOTAIR generated statistical downregulation of stemness markers. Additionally, HOTAIR expression was negatively correlated with the level of miR-203, which was found to be an inhibitory miRNA in regulating the expressions of stemness markers. Also, miR-203 expression was negatively correlated with ZEB1. These findings suggested that HOTAIR should be a positive contributor in stemness acquisition of cervical cancer cells, and this effect should correlate with the interaction with miR-203, which can be suppressed by ZEB1.

Nanoliposomal Delivery of MicroRNA-203 Suppresses Migration of Triple-Negative Breast Cancer through Distinct Target Suppression

Triple-negative breast cancers affect thousands of women in the United States and disproportionately drive mortality from breast cancer. MicroRNAs are small, non-coding RNAs that negatively regulate gene expression post-transcriptionally by inhibiting target mRNA translation or by promoting mRNA degradation. We have identified that miRNA-203, silenced by epithelial-mesenchymal transition (EMT), is a tumor suppressor and can promote differentiation of breast cancer stem cells. In this study, we tested the ability of liposomal delivery of miR-203 to reverse aspects of breast cancer pathogenesis using breast cancer and EMT cell lines. We show that translationally relevant methods for increasing miR-203 abundance within a target tissue affects cellular properties associated with cancer progression. While stable miR-203 expression suppresses LASP1 and survivin, nanoliposomal delivery suppresses BMI1, indicating that suppression of distinct mRNA target profiles can lead to loss of cancer cell migration.

MicroRNA-203-3p inhibits the proliferation, invasion and migration of pancreatic cancer cells by downregulating fibroblast growth factor 2

Aberrant expression of fibroblast growth factor 2 (FGF2) is a major cause of poor prognosis in patients with pancreatic cancer. MicroRNA (miRNA/miR) miR-203-3p is a newly identified miRNA that can affect the biological behavior of tumors. The present study investigated the function of miR-203-3p on the regulation of FGF2 expression, and its role in pancreatic cancer cell proliferation, apoptosis, invasion and migration. Reverse transcription-quantitative PCR was used to determine the mRNA expression levels of miR-203-3p and FGF2 in vitro. Cell Counting Kit-8, Annexin V-APC/7-AAD double-staining Apoptosis Detection kit, wound healing and Transwell assays were used to determine the proliferation, apoptosis, migration and invasion of pancreatic cancer cells. The binding of miR-203-3p to FGF2 was assessed by a luciferase reporter assay. The results demonstrated that miR-203-3p expression was downregulated in pancreatic cancer cells. Gain- and loss-of-function experiments indicated that miR-203-3p inhibited the proliferation, migration and invasion, and promoted the apoptosis of pancreatic cancer cells in vitro. In addition, it was found that alteration of miR-203-3p abolished the promoting effects of FGF2 on pancreatic cancer cells. The present study demonstrated that FGF2 significantly promoted the proliferation, invasion and migration of pancreatic cancer cells. The mechanism involved the binding of miR-203-3p to the 3′-untranslated region of FGF2 mRNA, resulting in the downregulation of FGF2. In conclusion, miR-203-3p inhibited FGF2 expression, regulated the proliferation and inhibited the invasion and migration of pancreatic cancer cells.

Overexpressing microRNA-203 alleviates myocardial infarction via interacting with long non-coding RNA MIAT and mitochondrial coupling factor 6

Myocardial infarction (MI) is one of the leading causes of high mortality worldwide. Long non-coding RNA myocardial infarction associated transcript (MIAT) and mitochondrial coupling factor 6 (CF6) aggravate MI. This study aimed to elucidate whether miR-203 interacted with MIAT and CF6 in MI. Results revealed that MIAT and CF6 expressions were upregulated and that miR-203 was downregulated in mouse myocardial tissues after MI, as well as in hypoxic mouse cardiomyocytes. The overexpression of MIAT in mouse cardiomyocytes raised CF6 expression, whereas the knockdown of MIAT had the opposite effect. Mechanistically, the luciferase reporter and RNA pull-down assays corroborated the binding between miR-203 and CF6 3'UTR and between miR-203 and MIAT. The simultaneous overexpression of miR-203 and MIAT restored the reduction of CF6 caused by miR-203 overexpression alone, and the overexpression of miR-203 diminished the percentage of infarct area and the apoptosis of cardiomyocytes in vivo. Our findings corroborate that overexpressing miR-203 alleviates MI via interacting with MIAT and CF6.

Identification of the transcription factor, AFF4, as a new target of miR-203 in CNS

MiR-203 was identified as a hub of a potential regulatory miRNA network in central nervous system. Overexpressing of miR-203 in the frontal cortex of C57BL/6J wild type mouse induced neurodegeneration by increasing the apoptotic pathway and neuron death. AFF4, a transcription factor, was identified as a new bona fida protein target of miR-203 in CNS. The miRNA:mRNA interaction of miR-203 and AFF4 was verified using Dural-luciferase assay. Down-regulated expression of AFF4 was induced by overexpressing miR-203 both in vitro and in vivo. Open field test, Y maze and Morris water maze test were conducted for the behavioral assessment of the mice with stereotactic injection of lentiviral vector overexpressing miR-203 in the hippocampus. No anxiety-like behavior or impaired cognition was noticed in these mice. Consistent with the results of the behavioral assessment, the electron micrograph and Nissl staining revealed no significant change in the synaptic density and no neuron injuries in the hippocampus of mice overexpressing miR-203, respectively. Our results indicated that instead of promoting neurodegenerative phenotype, a more profound function should be ascribed to miR-203 in regulating neuron behavioral activities and cognition. Neuron-type specific functions of miR-203 are likely to be executed via its various downstream protein interactors.

CircRNA circTRAF3 promotes nasopharyngeal carcinoma metastasis through targeting miR-203a-3p/AKT3 axis

Distant metastasis is still the main cause of death in patients with nasopharyngeal carcinoma (NPC), and its mechanism is not fully understood. In this study, we studied the biological function and molecular mechanism of circular RNA circTRAF3 in NPC metastasis. We found that the increase in circTRAF3 is associated with the metastasis and survival of NPC patients. Knockdown of circTRAF3 could inhibit NPC cell proliferation and cell invasion, and induce apoptosis in vitro and in vivo. Further mechanism studies demonstrated that circTRAF3 eliminated the inhibitory effect of miR-203a-3p on AKT3 by adsorbing miR-203a-3p, and finally played the role of oncogene in NPC. Our findings reveal a new type of circRNA, circTRAF3, which acts as an oncogene in NPC and targets miR-203a-3p/AKT3 pathway. The circTRAF3/miR-203a-3p/AKT3 pathway may be a potential therapeutic target for metastatic NPC.

Knockdown of microRNA-203 reduces cisplatin chemo-sensitivity to osteosarcoma cell lines MG63 and U2OS in vitro by targeting RUNX2

Clinical studies have reported that miRNAs abnormal expression are associated with the generation of cisplatin-resistant to osteosarcoma. Our previous research found that miR-203 is downregulated in osteosarcoma cells and overexpressed miR-203 exerts antitumor properties on osteosarcoma cells. However, the role and mechanism of miR-203 in regulating the sensitivity of cisplatin in osteosarcoma cells remains unclear. This study aimed to investigate the effects of miR-203 in cisplatin therapy for osteosarcoma cells in vitro and determined the underlying mechanism. In this study, we found that miR-203 was significantly upregulated in osteosarcoma cells after exposure to cisplatin. miR-203 knockdown reduced the sensitivity of osteosarcoma cells to cisplatin by suppressing cell apoptosis, cell cycle arrest, and inducing invasion. Meanwhile, we found that miR-203 knockdown reduces the therapeutic sensitivity of osteosarcoma cells by upregulating RUNX2. Moreover, we found that RUNX2 silencing sensitizes osteosarcoma cells to chemotherapy treatment of cisplatin. In summary, our findings demonstrated that miR-203 knockdown reduces cisplatin chemo-sensitivity to osteosarcoma cells in vitro by targeting RUNX2, and speculated that miR-203 may be a target for drug resistance of osteosarcoma to cisplatin.

Targeting of FK506 binding protein 5 by miR-203 affects the progression of breast cancer via regulating the fatty acid degradation pathway and potential drug-repurposing

Increasing number of studies have suggested that microRNA (miR)-203 is a potential prognostic marker for breast cancer. However, the specific molecular mechanism underlying the effects of miR-203 remains unknown. The present study aimed to explore the molecular target and underlying mechanisms of action of miR-203 in breast cancer via bioinformatics analysis and cellular assays, such as wound healing assay and western blotting. In the present study, 17 candidate target genes of miR-203 were identified in the downregulated differentially expressed genes from Affymetrix microarray and TargetScan 7.2 database. Subsequently, FK506 binding protein 5 (FKBP5) was considered as the miR-203 target by 3 different hub gene analysis methods (EcCentricity, Betweenness and Stress). FKBP5 protein expression was significantly downregulated in SUM159 cells transfected with miR-203 mimics compared with SUM159 cells transfected with miR-203 negative control (NC) in western blot analysis. High expression of FKBP5 was associated with poor prognosis in breast cancer based on the results obtained from the Kaplan-Meier Plotter database. In addition, the wound healing assay indicated that the inhibition of migration due to miR-203 overexpression in SUM159 cells was reversed by FKBP5 overexpression. These results suggested that miR-203 may directly target FKBP5. In addition, Gene Set Enrichment Analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that miR-203 might play a role in breast cancer via the 'fatty acid degradation' KEGG pathway. Notably, the levels of fatty acids were significantly reduced in SUM159 cells transfected with miR-203 mimics compared with SUM159 cells transfected with miR-203 NC when assessed by the fatty acid content assay. Finally, virtual screening analysis revealed that ZINC000003944422 may be a potential inhibitor of FKBP5. In summary, the present study demonstrated that miR-203 may directly target FKBP5 in breast cancer via fatty acid degradation and potential drugs, hence providing a novel treatment approach for breast cancer.

MicroRNAs: Their Role in Metastasis, Angiogenesis, and the Potential for Biomarker Utility in Bladder Carcinomas

Angiogenesis is the process of generating new capillaries from pre-existing blood vessels with a vital role in tumor growth and metastasis. MicroRNAs (miRNAs) are noncoding RNAs that exert post-transcriptional control of protein regulation. They participate in the development and progression of several cancers including bladder cancer (BLCA). In cancer tissue, changes in microRNA expression exhibit tissue specificity with high levels of stability and detectability. miRNAs are less vulnerable to degradation, making them novel targets for therapeutic approaches. A suitable means of targeting aberrant activated signal transduction pathways in carcinogenesis of BLCA is possibly through altering the expression of key miRNAs that regulate them, exerting a strong effect on signal transduction. Precaution must be taken, as the complexity of miRNA regulation might result in targeting several downstream tumor suppressors or oncogenes, enhancing the effect further. Since exosomes contain both mRNA and miRNA, they could therefore possibly be more effective in targeting a recipient cell if they deliver a specific miRNA to modify the recipient cell protein production and gene expression. In this review, we discuss the molecules that have been shown to play a significant role in BLCA tumor development. We also discuss the roles of various miRNAs in BLCA angiogenesis and metastasis. Advances in the management of metastatic BLCA have been limited; miRNA mimics and molecules targeted at miRNAs (anti-miRs) as well as exosomes could serve as therapeutic modalities or as diagnostic biomarkers.

The miR-203a Regulatory Network Affects the Proliferation of Chronic Myeloid Leukemia K562 Cells

To study the molecular mechanism by which miR-203a affects the development of CML, bioinformatics software was used to predict the upstream transcription factors and downstream target genes of miR-203a. A 5’-rapid amplification of cDNA ends assay was performed to detect gene transcription initiation sites. A chromatin immunoprecipitation assay was used to verify the binding of transcription factors and promoter regions. A double luciferase reporter gene vector was constructed to demonstrate the regulatory effect of miR-203a on target genes. Real-time PCR and western blotting were used to detect the relative expression levels of genes and proteins, respectively. The results showed that there was a binding site for the transcription factor EGR1 in the upstream promoter region of miR-203a. WT1, BMI1, and XIAP were identified as target genes regulated by miR-203a. EGR1 and miR-203a were downregulated in human peripheral blood mononuclear cells and the CML K562 cell line, while WT1, BMI1, and XIAP were upregulated. The transcription initiation site of miR-203a was identified in the upstream promoter region (G nucleotide at −339 bp), and the transcription factor EGR1 could bind to the promoter region (at −268 bp) of miR-203a and increase its expression. Over expression of miR-203a inhibited the proliferation of K562 cells. A rescue assay showed that overexpression of WT1, BMI1, and XIAP offset the antitumor effect of miR-203a. Conclusion, EGR1 positively regulated the expression of miR-203a, thus relieving the inhibition of miR-203a on the translation of its target genes (WT1, BMI1, and XIAP) and affecting the proliferation of K562 cells.

Importance of microRNAs in Skin Oncogenesis and Their Suitability as Agents and Targets for Topical Therapy

Skin cancer is the most common cancer worldwide, with rapidly increasing incidence and consistent mortality. Skin cancer encompasses melanoma and non-melanoma skin cancer, which in turn is mainly divided into cutaneous squamous cell carcinoma and basal cell carcinoma. Small noncoding micro-RNAs (miRNAs) regulate protein expression after transcription and play a role in the development and progression of skin cancer. Deregulated expression of miRNAs in skin cancer is associated with cell proliferation, angiogenesis, metastasis, apoptosis, immune response, and drug resistance. Specific patterns of miRNAs in specific skin cancer types can be used as diagnostic markers. For therapeutic purposes, both miRNA and chemically modified variants thereof as well as miRNA antagonists (antagomiRs) or RNA inhibitors may be applied topically. Due to their specific physicochemical properties, physical or chemical diffusion promoters are used with varying degrees of success. There is no question by now that such preparations have a high potential for the treatment of epithelial skin tumors in particular.

circ-ZUFSP regulates trophoblasts migration and invasion through sponging miR-203 to regulate STOX1 expression

Recurrent spontaneous abortion (RSA), defined as two or more consecutive pregnancy losses before 12 weeks of gestation with or without previous live births. Circular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs that play important roles in gene expression regulation and trophoblasts function during embryo development. This study aimed to evaluate the function mechanism of circRNAs regulating trophoblasts function in the occurrence and progression RSA. Through overexpression and down-regulation of circ-ZUFSP, we investigated the effect of circ-ZUFSP on the function of trophoblasts and found loss of circ-ZUFSP suppressed trophoblasts migration and invasion in vitro. Moreover, loss of circ-ZUFSP regulated trophoblasts migration and invasion via regulation of miR-203. Furthermore, STOX1 was revealed to a target of miR-203, and down-regulation of STOX1 reversed circ-ZUFSP enhanced cell invasion, suggesting that circ-ZUFSP might regulate STOX1 expression through sponging miR-203 in HTR-8/SVneo cells. In addition, low expression of circ-ZUFSP, STOX1 and high expression of miR-203 were testified in placental tissues of RSA mice. Our study demonstrated a molecular mechanism of circ-ZUFSP regulating trophoblasts migration and invasion, which might provide a novel indicator for early diagnosis and potential treatment of RSA.

Role of microRNA/Epithelial-to-Mesenchymal Transition Axis in the Metastasis of Bladder Cancer

Bladder cancer (BC) is the 11th most common diagnosed cancer, and a number of factors including environmental and genetic ones participate in BC development. Metastasis of BC cells into neighboring and distant tissues significantly reduces overall survival of patients with this life-threatening disorder. Recently, studies have focused on revealing molecular pathways involved in metastasis of BC cells, and in this review, we focus on microRNAs (miRNAs) and their regulatory effect on epithelial-to-mesenchymal transition (EMT) mechanisms that can regulate metastasis. EMT is a vital process for migration of BC cells, and inhibition of this mechanism restricts invasion of BC cells. MiRNAs are endogenous non-coding RNAs with 19-24 nucleotides capable of regulating different cellular events, and EMT is one of them. In BC cells, miRNAs are able to both induce and/or inhibit EMT. For regulation of EMT, miRNAs affect different molecular pathways such as transforming growth factor-beta (TGF-β), Snail, Slug, ZEB1/2, CD44, NSBP1, which are, discussed in detail this review. Besides, miRNA/EMT axis can also be regulated by upstream mediators such as lncRNAs, circRNAs and targeted by diverse anti-tumor agents. These topics are also discussed here to reveal diverse molecular pathways involved in migration of BC cells and strategies to target them to develop effective therapeutics.

Targeting deubiquitinating enzyme USP26 by microRNA-203 regulates Snail1's pro-metastatic functions in esophageal cancer

Background

Esophageal cancer is one of the most common cancers worldwide with poor prognosis and high mortality. The transcription factor SNAI1, encoding Snail1, is important for metastatic progression in esophageal cancer whereas the microRNA (miRNA)-203 has been shown to function as an inhibitor of metastasis in EC. The Snail1 protein is stabilized in EC partially by the deubiquitinating enzyme USP26; however, how USP26 is regulated is not completely known.

Methods

Expression of SNAI1 and USP26 messenger RNA (mRNA) and miR-203 was performed in datasets within The Cancer Genome Atlas and Gene Expression Omnibus, respectively. Expression of Snail1 and USP26 protein and miR-203 was determined in the normal esophageal cell line HET-1A and EC cell lines Kyse150 and TE-1 using western blot and quantitative polymerase chain reaction, respectively. TargetScan was used for in situ prediction of miR-203 targets and in vitro heterologous reporter assays using the wild-type and miR-203 seed mutant of the 3′ Untranslated region (UTR) of USP26 were used to investigate whether USP26 is a target of miR-203. Effects of increasing miR-203 using MIR203A/5P mimic on USP26 and Snail1 in the HET-1A, Kyse150 and TE-1 cell lines were performed using western blot and cycloheximide-based protein stability analysis. Effects of modulating miR-203 in Kyse150 and TE-1 cell lines on in vitro pro-metastatic effects were analyzed by invasion assay, scratch wound-healing assay, and chemosensitivity to 5-fluoruracil (5-FU). In vivo lung metastasis assay was used to study the effect of modulating miR-203 in Kyse150 cells.

Results

SNAI1 mRNA and HSA/MIR203 was higher and lower, respectively, in EC patients compared to tumor-adjacent normal tissues. No changes in expression of USP26 mRNA were observed in these datasets. MIR/203 expression was downregulated whereas protein expression of both Snail1 and USP26 were higher in EC cell lines Kyse150 and TE-1 compared to normal esophageal cell line HET-1A. USP26 was predicted as a potential target of miR-203 by TargetScan Release 2.0. Reporter assays confirmed USP26 as a target of miR-203 in the EC cell lines. Transfection of EC cell lines with MIR203 mimic decreased USP26 protein expression and Snail1 protein stability indicating the ability of miR-203 to regulate Snail1 protein levels via USP26. Exogenous increase in miR-203 in the EC cell lines significantly inhibited Snail-1 mediated in vitro pro-metastatic function of invasion, wound-healing, and increased chemosensitivity to 5-FU. Finally, overexpression of miR-203 inhibited in vivo lung metastasis of Kyse150 cells, which was reversed following overexpression of USP26, indicating a direct role of miR-203-mediated regulation of USP26 in metastatic progression of EC.

Conclusions

Cumulatively, these results establish an important mechanism by which decrease in miR-203 expression potentiates metastatic progression in EC via USP26-mediated stabilization of Snail1. Hence, miR-203 can serve as a biomarker of metastasis in EC and is a potential target for therapeutic intervention in EC.

Novel long noncoding RNA LINC01385 promotes nasopharyngeal carcinoma proliferation via the miR-140-3p/Twist1 signaling pathway

Long non-coding RNAs (lncRNAs) have been verified as a key modulator in tumor progression. However, the functions of lncRNAs in nasopharyngeal carcinoma (NPC) remain unclear. In the present study, we explored lncRNAs expression patterns in NPC tissues by GEO dataset and selected the high expression lncRNA (LINC01385) to further study. Our data showed that LINC01385 expression was significantly increased NPC and correlated with advanced clinical features and poor prognosis. Function assays showed that knockdown of LINC01385 expression reduced the proliferation and invasion abilities of NPC cells in vitro. In mechanism, LINC01385 acted as a molecular sponge of miR-140-3p in NPC cells, Twist1 mRNA was validated as a direct target of miR-140-3p in NPC cells. The effects of the LINC01385 knockdown on malignant characteristics of NPC cells were greatly attenuated by miR-140-3p inhibition or Twist1 overexpression. Thus, we illustrated that LINC01385 aggravated the progression of NPC by sponging miR-140-3p and upregulating Twist1 expression, which implied LINC01385 might serve as a new potential therapeutic target for NPC treatment.

miR-203 affects esophageal cancer cell proliferation, apoptosis and invasion by targeting MAP3K1

miR-203 has been indicated to be a tumor suppressor in esophageal cancer, however, the underlying molecular mechanisms by which it functions are not fully understood. The present study aimed to investigate the molecular mechanisms underlying the regulatory activities of microRNA (miR)-203 in esophageal cancer. The miR-203 mimic/inhibitor, Mitogen-Activated Protein Kinase Kinase Kinase 1 (MAP3K1) overexpression plasmid and MAP3K1 small interfering (si)RNA were transfected into TE-1 cells. miR-203 and MAP3K1 mRNA expression were detected via reverse transcription-quantitative PCR analysis, while MAP3K1 protein expression was detected via western blot analysis. Dual-luciferase reporter assay was used to determine whether MAP3K1 was a direct target of miR-203. Cell proliferation and invasion abilities were assessed via MTT and Matrigel assays, respectively. Cell apoptosis was analyzed via flow cytometry, Caspase 8/3 Assay kits and western blot analysis. The results demonstrated that MAP3K1 was a direct target of miR-203. Overexpression of MAP3K1 reversed the suppressed cell proliferation and invasion abilities induced by miR-203 mimic, as well as the inhibitory effect of miR-203 mimic on cell apoptosis. Furthermore, MAP3K1 siRNA weakened the effect of miR-203 inhibitor on cell proliferation, apoptosis and invasion.

MicroRNA-203 restrains epithelial-mesenchymal transition, invasion and migration of papillary thyroid cancer by downregulating AKT3

MicroRNAs (miRNAs) have been reported to serve pivotal roles in the regulation of papillary thyroid cancer (PTC) development; thus, the aim of this study is to identify the impact of miR-203 and AKT3 on the epithelial-mesenchymal transition (EMT), migration and invasion of PTC. MiR-203 and AKT3 expression in PTC tissues and cells were tested. TPC-1 cells and K1 cells were screened for follow-up experiments. Apoptosis-related proteins (Bcl-2 and Bax), EMT-related proteins (Vimentin and E-cadherin), proliferation-associated proteins (Ki67 and CDK4), invasion- and migration-related protein (MMP-2 and MMP-9) were verified. The effects of upregulated miR-203 and downregulated AKT3 on the biological characteristics of PTC cells in each group were detected via the gain- and loss-of-function assays. The targeting relationship between miR-203 and AKT3 was verified.MiR-203 expression declined and AKT3 heightened in PTC tissues and cells. Upregulated miR-203 and downregulated AKT3 reduced the tumor volume and weight, suppressed cell migration, colony formation, proliferation, invasion, proliferation-associated proteins (Ki67 and CDK4), invasion- and migration-related protein (MMP-2 and MMP-9) and promoted cell apoptosis, raised E-cadherin and decreased Vimentin protein expression in TPC-1 cells. On the contrary, the K1 cells with the downregulated miR-203 or upregulated AKT3 exhibited an opposite result. This study suggests that upregulated miR-203 suppresses EMT, invasion, proliferation and migration as well as induces apoptosis of PTC cells via downregulated AKT3.

Downregulated hsa_circ_0077837 and hsa_circ_0004826, facilitate bladder cancer progression and predict poor prognosis for bladder cancer patients

Growing evidence has indicated that circular RNAs (circRNAs) play crucial roles in multiple biological processes. However, alterations in circRNA profiles during bladder cancer progression and the clinical significance thereof remain unclear. Therefore, high‐throughput RNA sequencing was conducted to identify circRNA and mRNA profiles in five pairs of bladder cancer tissues and adjacent noncancerous tissues. A total of 87 differentially expressed circRNAs and 2756 mRNAs were detected in above bladder cancer samples compared with paired noncancerous samples. Functional enrichment analyses, circRNA‐microRNA‐mRNA, and protein‐protein interaction networks revealed that these dysregulated circRNAs were potentially involved in carcinogenesis and evolution of bladder cancer. Subsequently, the differential expression of eight circRNAs was detected by real‐time qPCR. Hsa_circ_0003141 and hsa_circ_0008039 were significantly upregulated as well as hsa_circ_0026782, hsa_circ_0077837, hsa_circ_0004826, and hsa_circ_0001946 were significantly downregulated among validation of 70 matched bladder cancer tissues (≥75%). Moreover, hsa_circ_0077837 and hsa_circ_0004826 were also verified as markedly downregulated in four bladder cancer cells (100%). Naturally, hsa_circ_0077837 and hsa_circ_0004826 were also demonstrated using RNase‐R+ resistance experiments. In addition, Fisherʹs exact test, Kaplan‐Meier plots, Cox regression analyses, and receiver operating characteristic curve was performed to assess their clinical value. Downregulation of hsa_circ_0077837 and hsa_circ_0004826 all was significantly correlated with worse clinicopathological features and poor prognosis of bladder cancer patients. The area under the receiver operating characteristic curve of them was 0.775 (P < .0001) and 0.790 (P < .0001), respectively. Not surprisingly, in vitro functional experiments also demonstrated that the overexpression of hsa_circ_0077837 and hsa_circ_0004826 significantly weakened the proliferation, migration, and invasion of bladder cancer cells. Overall, hsa_circ_0077837 and hsa_circ_0004826 might act as tumor suppressors in the bladder cancer progression and serve as a potential biomarker for the diagnosis, prognosis, and therapy of bladder cancer.

Reduced miR-203 predicts metastasis and poor survival in esophageal carcinoma

We analyzed data from two non-coding RNA profiling arrays made available by the Gene Expression Omnibus (GEO) and found 17 miRNAs with remarkable differential expression between malignant and normal esophageal tissue. Correlation analysis between expression of these 17 miRNAs and patients’ clinicopathological characteristics showed that miR-203 was down-regulated in esophageal carcinoma (EC) tissues and was significantly associated with lymph node metastasis and poor overall survival. Overexpression of miR-203 significantly attenuated cellular proliferation, migration and invasion by EC cells in culture. Additionally, gene expression profiles and bioinformatics analysis revealed KIF5C to be a direct target of miR-203, and KIF5C overexpression partially counteracted the tumor inhibitory effects of miR-203 on EC cells. We also observed that miR-203, reduced KIFC5 protein levels, promoted cytoplasmic accumulation of Axin2, and reversed the invasive phenotype of EC cells. Taken together, these data demonstrate that miR-203 is a tumor suppressor in EC cells and its expression level could potentially be used as a prognostic indicator for EC patient outcomes.

LncRNA RHPN1-AS1 Targeting miR-625/REG3A Promotes Cell Proliferation And Invasion Of Glioma Cells

Introduction

Glioma arises from the proliferation of neuroglial cells differentiated from the ectoderm. Evidence has confirmed that differentially expressed long non-coding RNAs (lncRNAs) may be involved in the development and progression of various tumors. The present study aimed to explore the biological function of lncRNA RHPN1-AS1 in glioma.

Materials and methods

The expressions of RHPN1-AS1 in glioma tissues and cells were examined using RT-PCR. Colony formation assay, MTT assay, wound healing assay and transwell assay were performed to detect cell cloning efficiency, proliferation, migration and invasion of glioma cells, respectively. Western blot was applied to assess the expression levels of migration-related and invasion-related proteins. Online bioinformatic tools and luciferase reporter assay were, respectively, employed to predict and verify the downstream target microRNA/gene of RHPN1-AS1.

Results

RHPN1-AS1 was up-regulated in glioma tissues and cells. The cell proliferation, migration and invasion of glioma were inhibited when the expression of RHPN1-AS1 was down-regulated in glioma cells. The expressions of migration-related and invasion-related proteins were also suppressed in siRHPN1-AS1 groups. Furthermore, we predicted and verified that RHPN1-AS1 was directly targeted to miR-625-5p/REG3A. Our study demonstrated that the knockdown of RHPN1-AS1 inhibited the proliferation, migration and invasion activity of glioma cells via regulating miR-625-5p/REG3A expression.

Conclusion

The results revealed that the lncRNA RHPN1-AS1 may be a molecular target in glioma therapy.

MicroRNA-203 reinforces stemness properties in melanoma and augments tumorigenesis in vivo

One of the challenges encountered in microRNA (miRNA) studies is to observe their dual role in different conditions and cells. This leads to a tougher prediction of their behavior as gene expression regulators. miR-203 has been identified to play a negative role in the progression of malignant melanoma; however, it has been reported, with dual effect, as both an oncomiR and tumor suppressor miRNA in some malignancies, such as breast cancer, meanwhile, the role of miR-203 in melanoma stem cells or even metastatic cells is unclear. In the present study, after observation of upregulation of miR-203 in melanoma patient's serum and also melanospheres as cancer stem cells model, we examined its overexpression on the stemness potential and migration ability of melanoma cells. Our data demonstrated that the increased miR-203 level was significantly associated with significant increase in the ability of proliferation, colony and spheres formation, migration, and tumorigenesis in A375 and NA8 cells. All of these changes were associated with enhancement of BRAF, several epithelial to mesenchymal transition factors, and stemness genes. In conclusion, our results clearly determined that miR-203 could be down-regulateddownregulated in melanoma tissues but be overexpressed in melanoma stem cells. It has an important role as oncomiR and promote repopulation, tumorigenicity, self-renewal, and migration. Therefore, we suggested overexpression of miR-203 as biomarker for early detection of metastasis. However, more studies are needed to validate our data.

Epigenetic Mechanisms Influencing Epithelial to Mesenchymal Transition in Bladder Cancer

Bladder cancer is one of the most incident neoplasms worldwide, and its treatment remains a significant challenge, since the mechanisms underlying disease progression are still poorly understood. The epithelial to mesenchymal transition (EMT) has been proven to play an important role in the tumorigenic process, particularly in cancer cell invasiveness and metastatic potential. Several studies have reported the importance of epigenetic mechanisms and enzymes, which orchestrate them in several features of cancer cells and, specifically, in EMT. In this paper, we discuss the epigenetic enzymes, protein-coding and non-coding genes, and mechanisms altered in the EMT process occurring in bladder cancer cells, as well as its implications, which allows for improved understanding of bladder cancer biology and for the development of novel targeted therapies.

miR-181a and miR-203 inhibit migration and invasion of laryngeal carcinoma cells by interacting with ATF2

MicroRNAs (miRNAs) have been recognized to modulate the progression of tumorigenesis by serving as oncogenes or tumor suppressors. Despite the involvement of miR-181a and miR-203 in several cancers as has been substantiated, their roles in laryngeal carcinoma (LC) remain unclear. In this study, the abundances of miR-181a, miR-203 and activating transcription factor 2 (ATF2) mRNA in LC cell lines were detected by RT-qPCR. Western blot was performed to detect the protein levels of N-cadherin, E-cadherin and ATF2. Cell migration and invasion ability were assessed by Trans-well assay. The putative binding sites between miR-181a or miR-203 and ATF2 were predicted using Bioinformatics software and further validated by Dual-Luciferase reporter and RNA immunoprecipitation (RIP) assays. Results showed reduced abundances of miR-181a and miR-203 in LC cell lines. Introduction of miR-181a or miR-203 reduced cell migration and invasion, which was further confirmed by the reduction of N-cadherin and increase of E-cadherin in LC cells. ATF2 was identified to be a potential target of miR-181a and miR-203. Absence of ATF2 overturned the stimulatory effects of anti-miR-181a and anti-miR-203 on cell migration and invasion in LC cells. Our findings suggested that miR-181a and miR-203 attenuated cell migration and invasion ability by directly targeting ATF2 in LC, providing novel insight into the regulatory mechanisms of miR-181a and miR-203 in LC.

miR-203 inhibits ovarian tumor metastasis by targeting BIRC5 and attenuating the TGFβ pathway

BACKGROUND

We previously reported that miR-203 functions as a tumor suppressor in ovarian cancer cells by directly targeting transcription factor Snai2 and inhibiting epithelial to mesenchymal transition (EMT), whereas BIRC5/survivin promotes EMT. In this study, we tested our hypothesis that miR-203 inhibits ovarian tumor metastasis by suppressing EMT through targeting BIRC5, using an orthotopic ovarian cancer mouse model.

METHODS

We overexpressed miR-203 in ovarian cancer SKOV3 and OVCAR3 cells using a lentiviral vector and examined cell migration and invasion using transwell plates. The small molecule inhibitor, YM155, was used to inhibit survivin expression. miR-203-expressing and control SKOV3 cells were intrabursally injected into immunocompromised NSG female mice. Primary tumors in ovaries and metastatic tumors were collected to determine the expression of survivin and EMT markers using Western blot and immunostaining.

RESULTS

Overexpression of miR-203 inhibits EMT by targeting BIRC5 in ovarian cancer SKOV3 and OVCAR3 cells. miR-203 expression enhances the ability of the survivin inhibitor YM155 to reduce tumor cell migration and invasion in vitro. We further showed that miR-203 expression attenuated the TGFβ pathway in both SKOV3 and OVCAR3 cells. miR-203 expression also inhibited primary tumor growth in ovaries and metastatic tumors in multiple peritoneal organs including liver and spleen.

CONCLUSION

miR-203 inhibits ovarian tumor metastasis by targeting BIRC5/survivin and attenuating the TGFβ pathway.

Tumor-suppressing effects of microRNA-612 in bladder cancer cells by targeting malic enzyme 1 expression

The present study investigated the possible tumor-suppressing function of microRNA (miR)-612 and the underlying molecular mechanism of its action in bladder cancer in vitro and in vivo. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was carried out to quantify the expression levels of miR-612 in bladder cancer tissues and cell lines. The data demonstrated that the level of miR-612 expression was significantly reduced in bladder cancer tissues and cell lines, as compared with that in non-cancerous tissues and cells. Reduced miR-612 expression was associated with advanced tumor, lymph node and metastasis stages, and with distant metastasis of bladder cancer. A functional study revealed that transfection of cells with an miR-612 mimic suppressed bladder cancer cell growth, colony formation, migration, invasion and epithelial-mesenchymal transition. Bioinformatics analysis identified that miR-612 targeted the expression of malic enzyme 1 (ME1), and this was confirmed by western blot and luciferase reporter assay results. Furthermore, the ME1 expression levels were inversely associated with miR-612 expression in bladder cancer tissue specimens. In addition, knockdown of ME1 expression using ME1 siRNA mimicked the effect of ectopic miR-612 overexpression in bladder cancer cells in terms of tumor cell growth, migration and invasion. By contrast, ME1 overexpression weakened the inhibitory effect of the miR-612 mimic in bladder cancer cells. In conclusion, the present study demonstrated that miR-612 may function as a tumor suppressor in bladder cancer by targeting ME1 expression.