[Retracted] MicroRNA‑203 inhibits the proliferation and invasion of U251 glioblastoma cells by directly targeting PLD2

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that the PLD2 western blotting data shown in Fig. 3A and the Transwell invasion assay data shown in Fig. 6 were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes that had either already been published elsewhere prior to the submission of this paper to Molecular Medicine Reports, or were under consideration for publication at around the same time. In view of the fact that certain of these data had already apparently been published previously, the Editor of Molecular Medicine Reports has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 9: 503‑508, 2014; 10.3892/mmr.2013.1814].

microRNA-203 inhibits migration and invasion of canine tonsillar squamous cell carcinoma cells by targeting SLUG

Objective

Squamous cell carcinoma (SCC) occurring in the tonsils (TSCC) has a poorer prognosis than SCC occurring in other regions of the oral cavity (non-tonsillar SCC [NTSCC]) because it easily metastasizes to distant organs. This study aimed to elucidate the molecular mechanisms underlying the migration and invasion of TSCC cells in vitro.

Materials and methods

This study focused on differential microRNA (miRNA) expression using microRNA microarrays and quantitative polymerase chain reaction in canine TSCC and NTSCC tissues and cell lines. A target gene of the miRNA involved in cell migration and invasion was validated by wound healing, transwell, and luciferase assays.

Results

miR-203 expression was lower in TSCC tissues than in the normal oral mucosa and NTSCC tissues. Transfection of the miR-203 mimic resulted in the downregulation of mesenchymal marker protein expression and attenuation of cell migration and invasion in TSCC cells, but not in NTSCC cells. A dual-luciferase assay revealed that miR-203 directly targeted the mesenchymal transcription factor SLUG. SLUG overexpression enhances the migration of TSCC cells.

Conclusion

Our study indicates that the miR-203/SLUG axis may be involved in the metastatic mechanisms of TSCC.

Hepatitis B Virus X Protein Inhibits the Expression of Barrier To Autointegration factor1 via Upregulating miR-203 Expression in Hepatic Cells

Hepatitis B virus (HBV) infection targets host restriction factors that inhibit its replication and survival. Previous studies have shown that barriers to autointegration factor1 (BANF1) inhibited the replication of herpes simplex virus and vaccinia virus by binding to phosphate backbone of dsDNA. To date, no reports are available for the interplay between BANF1 and HBV. In this study, we elucidated the mechanisms by which HBV inhibit BANF1. First, the effect of HBV on BANF1 was observed in Huh-7, Hep G2, and Hep G2.2.15 cells. Huh-7 cells were transfected with pHBV_1.3 or HBx plasmids. The results showed that there was a decreased expression of BANF1 in Hep G2.2.15 cells (P ≤ 0.005) or in HBV/HBx expressing Huh-7 cells (P ≤ 0.005), whereas BANF1 overexpression decreased viral replication (P ≤ 0.05). To study whether phosphorylation/dephosphorylation of BANF1 was responsible for antiviral activity, mutants were created, and it was found that inhibition due to mutants was less significant compared to BANF1 wild type. Previous studies have shown that HBV, at least in part, could regulate the expression of host miRNAs via HBx. It was found that miR-203 expression was high in Hep G2.2.15 cells (P ≤ 0.005) compared to Hep G2 cells. Next, the effect of HBx on miR-203 expression was studied and result showed that HBx upregulated miR-203 expression (P ≤ 0.005). Overexpression of miR-203 downregulated BANF1 expression (P ≤ 0.05) and viral titer was upregulated (P ≤ 0.05), while inhibition of miR-203, reversed these changes. In conclusion, BANF1 downregulated HBV, whereas HBV inhibited BANF1, at least in part, via HBx-mediated miR-203 upregulation in hepatic cells. IMPORTANCE In this study, for the first time, we found that BANF1 inhibited HBV replication and restricted the viral load. However, as previously reported for other viruses, the results in this study showed that BAF1 phosphorylation/dephosphorylation is not involved in its antiviral activity against HBV. HBV infection inhibited the intracellular expression of BANF1, via HBx-mediated upregulation of miR-203 expression. Overexpression of miR-203 downregulated BANF1 and increased the viral titer, while inhibition of miR-203 reversed these changes. This study helped us to understand the molecular mechanisms by which HBV survives and replicates in the host cells.

microRNA-203 functions as a natural Ras inhibitor in hepatocellular carcinoma

microRNA-203 (miR203) plays an important role in the formation and development of multiple types of cancers. However, its role in hepatic carcinogenesis has not been well studied. Mitogen-activated protein kinase signaling is known to be activated in hepatocellular carcinoma (HCC), but there is a lack of effective drugs targeting this pathway for HCC treatment. In this study, we investigated the role of miR203 in HCC and the underlying mechanism. We found that miR203 was significantly downregulated in HCC cell lines and patient tissues compared with a hepatocyte cell line (L02) or normal liver tissues. Restoration of miR203 inhibited HCC cell growth and induced cell cycle arrest and apoptosis. In primary and xenograft HCC mouse models, miR203 also significantly blocked HCC growth. Bioinformatic analysis indicated that miR203 directly binds to the 3'UTR of NRas mRNA, resulting in decreased expression of NRas and inactivation of mitogen-activated protein kinase (MAPK) signaling. Activation of MAPK signaling by ectopic NRas expression rescued the cell proliferation blocked by miR203. Together, our findings illustrate the fundamental role of miR203 as a natural inhibitor of RAS/MAPK signaling in hepatic carcinogenesis in vitro and in vivo. In light of the critical and universal activation of the MAPK pathway in HCC, miR203 has the potential to serve as a nucleotide drug for the treatment of HCC with activated MAPK signaling.

gingivalis LPS-induced inflammation and differentiation of periodontal ligament cells

AIM

In this study, we aimed to explore the effects of microRNA-203 (miR-203) on P. gingivalis lipopolysaccharide (P.g. LPS)-stimulated periodontal ligament cells (PDLCs) and identify potential molecular targets for periodontitis treatment.

METHODS

PDLCs were stimulated by P.g. LPS, followed by quantification of miR-203 and AP-1 expression. Next, loss- and gain-of-function experiments were applied in P.g. LPS-induced PDLCs. The proliferation, apoptosis, and differentiation of PDLCs were determined and mineralized nodule numbers were counted. Functional assays were used to identify interactions among miR-203, activator protein 1 (AP-1), and intercellular adhesion molecule 1 (ICAM-1). In addition, expression of osteogenesis-related genes and release of proinflammatory factors were analyzed.

RESULTS

miR-203 was found to be downregulated while AP-1 was upregulated in PDLCs stimulated by P.g. LPS. The overexpression of miR-203 promoted P.g. LPS-stimulated PDLC proliferation and differentiation, inhibited apoptosis, and increased the number of mineralized nodules. miR-203 was verified to downregulate AP-1/ICAM-1 axis. miR-203 overexpression reduced the secretion of proinflammatory factors while increasing expression of osteogenesis-related genes in P.g. LPS-stimulated PDLCs, which was reversed by overexpressing AP-1 and ICAM-1.

CONCLUSION

These experimental data demonstrated the potential inhibitory effects of overexpressed miR-203 on periodontitis development by promoting PDLC differentiation and suppressing inflammatory responses through AP-1/ICAM-1 axis.

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.

Biomarker exploration of microRNA-203 as a promising substrate for predicting poor survival outcome in colorectal cancer

Background

Increasing studies indicated that microRNA-203 (miR-203) may play an important part in the prognosis of CRC. Nevertheless, the prognostic and influential mechanism of miR-203 expression in CRC remains to be inconclusive. Accordingly, we conducted the current study to investigate the biomarker performance of miR-203 in CRC.

Methods

In the present study, we conducted an evidence synthesis of the published literatures to identify the prognostic roles of miR-203 in patients with CRC. Moreover, several bioinformatics methods were applied for exploring the biomarker roles of miR-203.

Results

It was demonstrated that elevated miR-203 expression was clearly related to worse overall survival (HR: 1.55, 95% CI: 1.07–2.24, P = 0.021) for CRC. The gene Ontology (GO) analysis indicated that miR-203 targets were primarily involved in a series of GO items closely associated with the molecular pathogenesis of CRC. The pathway analysis exhibited the potential signal pathways of miR-203 involved in CRC including pathways in cancer, wnt pathway, prolactin signaling pathway, proteoglycans in cancer, FoxO pathway, focal adhesion and Ras pathway. By constructing a protein-protein interaction (PPI) network of the targets of miR-203, ten crucial proteins and a significant network module were retrieved and found to serve important roles in the molecular pathogenesis of CRC.

Conclusions

Our results indicated that miR-203 may function as a promising biomarker to monitor CRC survival outcomes and progression. Notably, large-scale prospective cohort studies and biological experiments are required to confirm our conclusions.

MicroRNA-203-mediated inhibition of doublecortin underpins cardioprotection conferred by sevoflurane in rats after myocardial ischaemia-reperfusion injury

Myocardial ischaemia‐reperfusion (I/R) injury is a serious illness with high morbidity and mortality. Mounting evidence indicates the utility of sevoflurane (SEV) in the treatment of myocardial I/R injury. This study aimed to explore the molecular mechanisms underlying the protective action of SEV against myocardial I/R injury. A rat model of myocardial I/R injury was established, and I/R rats were treated with different concentrations of SEV. MicroRNA‐203 (miR‐203) and doublecortin (DCX) expression levels were determined using reverse transcription‐quantitative polymerase chain reaction. Putative target relationship between miR‐203 and DCX was explored using dual‐luciferase reporter gene assay and RNA‐binding protein immunoprecipitation assay. Ischaemia‐reperfusion rats were treated with SEV, miR‐203 antagomir or sh‐DCX, followed by determination of oxidative stress‐ and inflammation‐related factor levels using nitrite and enzyme‐linked immunosorbent assays, and that of apoptosis‐related factors using Western blot analysis. The apoptotic rate of myocardial tissues was determined using TdT‐mediated dUTP‐biotin nick end labeling (TUNEL) staining, and the infract area was evaluated using triphenyltetrazolium chloride staining. The results showed miR‐203 was poorly expressed and DCX was highly expressed in myocardial tissues of I/R rats. Sevoflurane was found to elevate miR‐203, and miR‐203, in turn, could target and reduce DCX expression. Sevoflurane, miR‐203 overexpression or DCX silencing resulted in declined oxidative stress, inflammation, apoptosis and infarct area, ultimately alleviating myocardial I/R injury. Collectively, these findings showed that SEV‐activated miR‐203 exhibited suppressive effects on myocardial I/R injury in rats and highlighted the SEV/miR‐203/DCX axis as a promising therapeutic target for myocardial I/R injury management.

Diagnostic and mechanistic values of microRNA-130a and microRNA-203 in patients with papillary thyroid carcinoma

This research was determined to unearth the diagnostic values and the effects of microRNA (miR)-130a and miR-203 on cell proliferation and apoptosis of papillary thyroid carcinoma (PTC). Expression of miR-130a and miR-203 were evaluated and were subjected to correlation analysis. The diagnostic values of miR-130a and miR-203 and their associations with clinicopathological characteristics of patients with PTC were measured. The expression levels of miR-130a and miR-203 in K1, IHH4, TPC-1, and BCPAP cells together with Nthy-ori 3-1 cells were measured. Cells were transfected with miR-130a mimics, miR-203 mimics, and coordinate of miR-130a mimics and miR-203 mimics. Cell growth, colony formation, and apoptosis were detected by cell counting kit-8 (CCK-8) assay, colony formation assay, and flow cytometry. PTC tissues had decreased miR-130a and miR-203 relative to adjacent normal tissues and normal thyroid tissue (both P < .05). miR-130a was in positive correlation with miR-203 (r = 0.754, P < .01). miR-130a was related with tumor infiltration and tumor stage while miR-203 was implicated in tumor stage and lymph-node metastasis. The area under the curve (AUC), sensitivity, as well as specificity for miR-130 in predicting PTC was 0.839, 74.5%, and 85.0% and those for miR-203 were 0.818, 73.7%, and 84.0%, respectively. PTC cells had lower expression of miR-130a and miR-203 than that in Nthy-ori 3-1 cells. After transfected miR-130a and miR-203 mimics in BCPAP and TPC-1 cells, both cells had increased miR-130a and miR-203, promoted cell apoptosis rate and decreased cell growth rate, and colony formation ability. After coordinately transfected with miR-130a mimics and miR-203 mimics, the cell growth and colony formation ability of PTC cells were restrained, and apoptosis of PTC cells was elevated (all P < .05). This study highlights that miR-130a and miR-203 have satisfactory diagnostic value in PTC and upregulated miR-130a and miR-203 can inhibit PTC cell growth and promote cell apoptosis.

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.

Overexpression of microRNA-203 Suppresses Proliferation, Invasion, and Migration while Accelerating Apoptosis of CSCC Cell Line SCL-1

Cutaneous squamous cell carcinoma (CSCC) is a malignant proliferation of cutaneous epithelium that has been observed to have an alarming rise in incidence. Numerous studies have demonstrated microRNAs (miRNAs or miRs) as important biomarkers in the diagnosis, prognosis, and treatment of CSCC. This study aims to investigate the effects of miR-203 on the behaviors of CSCC cells and possible mechanisms associated with protein regulator of cytokinesis-1 (PRC1) and Wnt/β-catenin signaling pathway. PRC1 was suggested as a target of miR-203 in squamous cell carcinoma cell line 1 (SCL-1) cells by dual-luciferase reporter gene assay. Based on the immunohistochemical staining and qRT-PCR, PRC1 was abundantly expressed while miR-203 was poorly expressed in CSCC tissues. miR-203 mimic or inhibitor was transfected into SCL-1 cells to upregulate or downregulate its expression. Upregulation of miR-203 downregulated PRC1 expression to block the Wnt/β-catenin signaling pathway. By conducting 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), scratch test, and Transwell and flow cytometric analyses, miR-203 was witnessed to restrain SCL-1 cell proliferation, migration, and invasion while accelerating their apoptosis. The rescue experiments addressed that inhibition of the Wnt/β-catenin signaling pathway conferred the anti-tumor effect of miR-203. These results establish a tumor-suppressive role for miR-203 in CSCC cell line SCL-1. Hence, miR-203 has promising potential as a therapeutic target for CSCC.

Inhibitory role of miR-203 in the angiogenesis of mice with pathological retinal neovascularization disease through downregulation of SNAI2

BACKGROUND

Pathological retinal neovascularization is a disease characterized by abnormal angiogenesis in retina that is a major cause of blindness in humans. Previous reports have highlighted the involvement of microRNAs (miRNAs) in retinal angiogenesis. Therefore, we aimed at exploring the mechanism underlying miR-203 regulating the progression of pathological retinal neovascularization.

METHODS

Initially, the mouse model of pathological retinal neovascularization disease was established and the hypoxia-induced human retinal microvascular endothelial cells (HRMECs) were generated. Then, miR-203 and SNAI2 expression in HRMECs and retinal tissues was examined. Subsequently, the effects of miR-203 and SNAI2 on viability, migration, apoptosis and angiogenesis of HRMECs were investigated, with the expression of Bax, Ki-67, MMP-2, MMP-9, VEGF and CD34 measured. Finally, the regulation of miR-203 or SNAI2 on GSK-3β/β-catenin pathway was determined through examining the levels of phosphorylated p-GSK-3β and β-catenin.

RESULTS

Poorly expressed miR-203 and highly expressed SNAI2 were found in HRMECs and retinal tissues of pathological retinal neovascularization. Importantly, overexpressed miR-203 or silencing SNAI2 inhibited viability, migration and angiogenesis but promoted apoptosis of HRMECs, evidenced by elevated Bax expression but reduced expression of Ki-67, MMP-2, MMP-9, VEGF and CD34. Moreover, overexpression of miR-203 was found to repress the GSK-3β/β-catenin pathway by downregulating SNAI2.

CONCLUSION

Collectively, this study demonstrated that overexpression of miR-203 suppressed the angiogenesis in mice with pathological retinal neovascularization disease via the inactivation of GSK-3β/β-catenin pathway by inhibiting SNAI2, which provided a novel therapeutic insight for pathological retinal neovascularization disease.

Overexpression of microRNA-203 can downregulate survivin and function as a potential therapeutic target in papillary thyroid cancer

Papillary thyroid cancer (PTC) is the most common type of thyroid carcinoma. PTC has a considerably high five-year survival rate; however, the possibility of recurrence is also high. Therefore, there is a requirement to clarify the molecular mechanism of PTC to promote understanding regarding the development of the disease and further improve prognosis. A number of studies have demonstrated that microRNAs (miRNAs or miRs) contribute to the progression of PTC. The present study revealed that the expression level of miR-203 was significantly lower in PTC tissues and cell lines compared with in the normal controls. In addition, inhibition of miR-203 was identified to be associated with an overexpression of survivin, which was observed in PTC samples. miR-203 regulates the expression of Bcl-2 via its downstream regulator survivin. Furthermore, the present study identified that inhibition of miR-203 histone acetylation was associated with high expression levels of miR-203 in PTC tissue samples. In summary, the results indicate that miR-203 functions as a biomarker and may serve as a candidate target for the development of novel therapeutic strategies to treat PTC.

LncRNA BANCR promotes tumorigenesis and enhances adriamycin resistance in colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy in the United States. Chemotherapeutic resistance is a massive obstacle for cancer treatment. The roles and molecular basis of long non-coding RNA BRAF-activated noncoding RNA (BANCR) in CRC progression and adriamycin (ADR) resistance have not been extensively identified. In this study, we found that BANCR and CSE1L expressions were upregulated in CRC tumor tissues. Meanwhile, CSE1L expression was correlated with depth of CRC. BANCR silencing suppressed cell proliferation and invasion capacity, increased apoptotic rate and potentiated cell sensitivity to ADR. CSE1L downregulation triggered a reduction of cell proliferation and invasion ability, and an increase of apoptosis rate and cell sensitivity to ADR. CSE1L overexpression attenuated si-BANCR-mediated anti-proliferation, anti-invasion and pro-apoptosis effects in CRC cells. BANCR acted as a molecular sponge of miR-203 to sequester miR-203 away from CSE1L in CRC cells, resulting in the upregulation of CSE1L expression. CSE1L knockdown inhibited expressions of DNA-repair-related proteins (53BP1 and FEN1) in HCT116 cells. BANCR knockdown also inhibited tumor growth and enhanced ADR sensitivity in CRC mice model. In conclusion, BANCR knockdown suppressed CRC progression and strengthened chemosensitization of CRC cells to ADR possibly by regulating miR-203/CSE1L axis, indicating that BANCR might be a promising target for CRC treatment.

Targeting Exosomal EBV-LMP1 Transfer and miR-203 Expression via the NF-κB Pathway: The Therapeutic Role of Aspirin in NPC

Nasopharyngeal carcinoma (NPC) is an invasive head-and-neck tumor with Epstein-Barr virus (EBV) as an important etiological cause. The EBV oncoprotein Latent membrane protein 1 (LMP1) can be trafficked into exosomes with unclear roles, and this trafficking is a potential problem in NPC control. MicroRNA-203 (miR-203) was found by us to be downregulated by LMP1, and it functions as a tumor suppressor in NPC. In this study, aspirin reversed the epithelial-mesenchymal transition (EMT) by promoting miR-203 expression in cells, and, remarkably, it repressed exosomal LMP1 (exo-LMP1) secretion from EBV-positive cells. Nuclear factor κB (NF-κB) activation was required for the exo-LMP1 production. The exo-LMP1 uptake influenced the EMT potential of EBV-negative recipient NPC cells. The exo-LMP1 level was upregulated in clinical NPC plasma samples. Aspirin treatment observably inhibited NPC lung metastasis in nude mice. The study revealed that aspirin is a promising drug for NPC therapy via its targeting of exo-LMP1 transfer and the regulatory effect of LMP1 on miR-203 expression. EBV can regulate its own tumorigenesis via the LMP1/NF-κB/exo-LMP1 axis, opening a new avenue for understanding the pathogenesis of this tumor virus. Our study also provides a rationale for the use of exo-LMP1 or exosomal miR-203 (exo-miR203) in EBV-targeted therapy by aspirin in invasive NPC.

[Study on the effects of microRNA-203 on the invasion and apoptosis of laryngeal cancer cells via targeting LASP1]

Objective: To explore the role of microRNA-203 in laryngeal cancer and its underlying mechanism and clarify the relationship between microRNA-203 and LASP1.Method: microRNA-203 expression in laryngeal cancer tissues and paracancerous tissues was detected by quantitative real time-polymerase chain reaction（qRT-PCR）. The regulatory effects of microRNA-203 on invasion and apoptosis of laryngeal cancer cells were detected by Transwell assay and flow cytometry, respectively. Dual-luciferase reporter gene assay was performed to access the binding condition of microRNA-203 and LASP1. Both mRNA and protein levels of LASP1 in laryngeal cancer cells were detected after transfection with microRNA-203 mimic or microRNA-203 inhibitor by qRT-PCR and Western blot. Rescue experiments were finally performed to detect whether microRNA-203 regulates laryngeal cancer development via targeting LASP1. Result: microRNA-203 was lowly expressed in laryngeal cancer tissues and cell lines.Knockdown of microRNA-203 in Hep-2 cells can promote the invasiveness and inhibit apoptosis of laryngeal cancer cells. Subsequently,LASP1 was predicted to be the target gene of microRNA-203，which was further verified by dual-luciferase reporter gene assay.LASP1 expression was negatively regulated by microRNA-203. Furthermore，rescue experiments showed that microRNA-203 regulates invasion and apoptosis of laryngeal cancer cells via targeting LASP1. Conclusion： Low expression of microRNA-203 could promote the invasion and inhibit apoptosis of laryngeal cancer cells viainhibiting LASP1. microRNA-203 and LASP1 both play a very important role in the development of laryngeal cancer..

microRNA-203 suppresses invasion of gastric cancer cells by targeting ERK1/2/Slug/ E-cadherin signaling

BACKGROUND AND AIMS

Growing evidence suggests that microRNA plays an essential role in the development and metastasis of many tumors, including gastric cancer (GC). Expression of microRNA-203 (miR-203) has been reported to decrease in GC. In addition, overexpression of miR-203 inhibits grow of GC cells in vitro and in vivo. However, whether miR-203 affects cell migration and invasion of GC remains unclear. This study aimed to reveal the role of miR-203 on migration and invasion of GC, and its potential mechanisms.

METHODS

Synthetic pre-miR-203 (miR-203), anti-miR-203 and scrambled negative control RNAs was transfected into the gastric cancer SGC7901 cells to generate miR-203 or anti-miR-203-transfected stable clones. The roles of miR-203 on cell invasion and motility were then analyzed by Transwell migration assay and Wound healing assay in vitro. Using siRNA to targeting ERK1/2, Slug, and E-cadherin or Slug cDNA transfection (to increase Slug expression) to examine the miR-203 signaling pathway. We also examined the efficacies of miR-203 or anti-miR-203 on peritoneal metastasis of SGC7901 cells in the nude mouse model.

RESULTS

Overexpression of miR-203 inhibits SGC7901 cell invasion and motility, followed by decreased phospho-ERK1/2 (pERK1/2) and Slug expression, as well as increased E-cadherin expression. Re-expression of Slug in miR-203/SGC7901cells decreased E-cadherin expression and restored the invasive phenotypes. Targeting E-cadherin in miR-203/SGC7901cells also restored the invasive phenotypes. Inhibition of miR-203 promotes SGC7901 cell invasion and motility, followed by increased phospho-ERK1/2 (pERK1/2) and Slug expression, as well as decreased E-cadherin expression. Targeting ERK1/2 or Slug in anti-miR-203/SGC7901cells increased E-cadherin expression and reversed the invasive phenotypes. In addition, targeting ERK1/2 decreased Slug and increased the E-cadherin expression. Significantly, we found that miR-203 could exert marked inhibition of the peritoneal metastasis of SGC7901 in nude mice in vivo. Targeting miR-203 could exert marked promotion of the peritoneal metastasis of SGC7901 in nude mice in vivo.

CONCLUSIONS

miR-203/ERK1/2/Slug/E-cadherin signaling pathway plays an essential role on SGC7901 cell invasion and motility. miR-203 can be novel modalities to prevent peritoneal metastasis of invasive cancers such as gastric cancer.

The inducible microRNA-203 in fish represses the inflammatory responses to Gram-negative bacteria by targeting IL-1 receptor-associated kinase 4

Innate immune responses are the first defense against pathogenic invaders. Activation and termination of these immune responses are regulated by several mechanisms. MicroRNAs (miRNAs), a group of small non-coding RNAs, have been implicated in the regulation of a spectrum of both physiological and pathological conditions, including immune responses. Although the immune regulatory miRNA networks in higher vertebrates have been well described, regulation of these responses in fish species is poorly understood. In the present study, we investigated the role of the miRNA miR-203 involved in inflammatory responses in miiuy croaker (Miichthys miiuy). We found that the Gram-negative bacterium Vibrio anguillarum and lipopolysaccharide significantly up-regulated host miR-203 expression. The increased miR-203 expression suppressed the production of inflammatory cytokines and thereby prevented mounting of a full immune response. Mechanistically, we identified and validated IL-1 receptor-associated kinase 4 (IRAK4) as a target of miR-203. We observed that miR-203 post-transcriptionally controls IRAK4 expression and thereby inhibits the activation of nuclear factor κB (NF-κB) signaling. In summary, our findings reveal that miR-203 in fish is a critical suppressor of innate immune responses to bacterial infection by suppressing a feedback to IRAK4-NF-κB-mediated signaling.

Development and validation of nomogram based on miR-203 and clinicopathological characteristics predicting survival after neoadjuvant chemotherapy and surgery for patients with non-metastatic osteosarcoma

Background

Recently, nomograms have been used as models for risk prediction in malignant tumor because they can predict the outcome of interest for a certain individual based on many variables. This study aimed to establish an effective prognostic nomogram for osteosarcoma based on the clinicopathological factors and microRNA-203.

Results

The results showed that miR-203 expression was significantly lower in osteosarcoma tissues compared with the corresponding adjacent tissues (P < 0.001). Patients with low miR-203 expression had poor overall survival (OS) in osteosarcoma. The histological type, tumor size, AJCC stage and miR-203 expression were integrated in the nomogram. The nomogram showed significantly better prediction of OS than for patients with non-metastatic osteosarcoma. The ROC curve also showed higher specificity and sensitivity for predicting 3- and 5-year osteosarcoma patients’ survival compared with AJCC stage. The decision curve analysis also indicated more potential of clinical application of the nomogram compared with AJCC staging system. Moreover, our findings were supported by the validation cohort.

Materials and Methods

We retrospectively investigated 301 patients with non-metastatic osteosarcoma. Data from primary cohort (n = 198) were used to develop multivariate nomograms. This nomogram was internally validated for discrimination and calibration with bootstrap samples and was externally validated with an independent patient cohort (n = 103).

Conclusions

Our proposed nomogram showed more accurate prognostic prediction for patients with non-metastatic osteosarcoma.

Low folate levels are associated with methylation-mediated transcriptional repression of miR-203 and miR-375 during cervical carcinogenesis

The aim of the present study was to investigate the correlation between a lack of folic acid and the abnormal expression of microRNA (miR)-203 and miR-375 in cervical cancer. In total, 60 tissue samples of cervical intraepithelial neoplasia (CIN) or stage IA-IIA cervical cancer (study group), and 30 samples without soluble interleukin or malignancy (control group) were examined. The expression of miR-203 and miR-375 was detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and the difference in expression levels was quantified using the 2^-ΔΔCq method. In addition, CaSki cervical cancer cells were cultured in vitro and treated with various concentrations of folic acid. The DNA methylation states of miR-203 and miR-375 were subsequently detected by methylation-specific PCR, and the expression levels were evaluated using RT-PCR. miR-203 and miR-375 were significantly downregulated in CIN and cervical cancer tissues, compared with the control group. There was a marked difference in terms of the expression levels of miR-375 between the two groups (P<0.05). In CaSki cells, as the concentration of folic acid increased, the positive rate of DNA methylation of miR-203 and miR-375 decreased, while the expression levels of miR-203 and miR-375 demonstrated a gradual increase, which indicated that the latter two parameters were negatively correlated (P<0.05). Compared with normal cervical tissue, the expression levels of miR-203 and miR-375 were downregulated in CIN and cervical cancer. Methylation of these two miRs was apparent in CaSki cells, and was associated with a lack of folic acid. Therefore, reduced levels of folic acid, leading to increased methylation of miR-203 and miR-375, may be significant events during cervical carcinogenesis.

Analysis of microRNA-203 function in CREB/MITF/RAB27a pathway: comparison between canine and human melanoma cells

MicroRNA (miR)-203 is downregulated and acts as an anti-oncomir in melanoma cells. Here, using human and canine melanoma cells, we elucidated the effects of miR-203 on cyclic adenosine monophosphate response element binding protein (CREB)/microphthalmia-associated transcription factor (MITF)/RAB27a pathway, which is known to be important for the development and progression of human melanoma. In this study, we showed that miR-203 directly targeted CREB1 and regulated its downstream targets, MITF and RAB27a. miR-203 significantly suppressed the growth of human and canine melanoma cells and inhibited melanosome transport through the suppression of the signalling pathway. In conclusion, miR-203 was shown to be a common tumour-suppressive miRNA in human and canine melanoma and thus to play a crucial role in the biological mechanisms of melanoma development.

MicroRNA-203 inhibits malignant melanoma cell migration by targeting versican

MicroRNA (miR)-203 has been demonstrated to function as a suppressor in tumorigenesis. Recently, miR-203 was reported to play a role in malignant melanoma (MM); however, the detailed function of miR-203 in MM remains unclear. In the present study, the expression of miR-203 was shown to be significantly downregulated in MM tissues when compared with normal adjacent tissues. Based on a bioinformatic prediction, versican was further identified as a novel target of miR-203, and the expression of versican was markedly increased in MM tissues. Inhibition of miR-203 increased the protein expression of versican, while upregulation of miR-203 inhibited the protein expression of versican in MM A375 cells. In addition, the upregulation of versican significantly promoted A375 cell migration; however, upregulation of miR-203 suppressed A375 cell migration. The present study further investigated whether miR-203 was involved in versican-mediated A375 cell migration, and the results indicated that upregulation of miR-203 significantly inhibited A375 cell migration, which was impaired by overexpression of versican. These observations indicated that versican functions as a downstream effector in miR-203-mediated MM cell migration. Therefore, the results demonstrated that miR-203 exhibited an inhibitory effect on MM cell migration via directly targeting versican, thus, may become an effective inhibitor for MM metastasis.

MicroRNA-203 down-regulation is associated with unfavorable prognosis in human glioma

BACKGROUND AND OBJECTIVES

MicroRNA-203 (miR-203) serves as a tumor suppressor or a tumor promoter in different human malignancies. However, its involvement in human gliomas is still unclear. The aim of this study was to investigate the clinical significance of miR-203 expression in gliomas.

METHODS

Real-time quantitative PCR was employed to measure the expression level of miR-203 in clinical glioma tissues.

RESULTS

The expression of miR-203 was reduced in high WHO grade glioma tissues compared with that in low WHO grade and normal brain tissues, and decreased with ascending tumor WHO grades (P < 0.001). The reduced miR-203 expression in gliomas was significantly associated with higher WHO grade (P < 0.001), lower KPS score (P = 0.008) and poorer disease-specific survival of patients (P = 0.001). More importantly, subgroup analyses according to tumor WHO grade revealed that the disease-specific survival of patients with low miR-203 expression in high WHO grades (III-IV) subgroup was significantly shorter than those with high miR-203 expression (P < 0.001), but no significant difference was found for patients in WHO grades I-II subgroup (P = 0.08).

CONCLUSION

Our data validate an important clinical significance of miR-203 in gliomas, and reveal that it might be an intrinsic regulator of tumor progression and a potential prognostic factor for this dismal disease.