MicroRNA-378 regulates epithelial-mesenchymal transition and metastasis of melanoma by inhibiting FOXN3 expression through the Wnt/β-catenin pathway

FOXN Transcription Factors: Regulation and Significant Role in Cancer

A growing number of studies have demonstrated that cancer development is closely linked to abnormal gene expression, including alterations in the transcriptional activity of transcription factors. The Forkhead box class N (FOXN) proteins FOXN1-6 form a highly conserved class of transcription factors, which have been shown in recent years to be involved in the regulation of malignant progression in a variety of cancers. FOXNs mediate cell proliferation, cell-cycle progression, cell differentiation, metabolic homeostasis, embryonic development, DNA damage repair, tumor angiogenesis, and other critical biological processes. Therefore, transcriptional dysregulation of FOXNs can directly affect cellular physiology and promote cancer development. Numerous studies have demonstrated that the transcriptional activity of FOXNs is regulated by protein-protein interactions, microRNAs (miRNA), and posttranslational modifications (PTM). However, the mechanisms underlying the molecular regulation of FOXNs in cancer development are unclear. Here, we reviewed the molecular regulatory mechanisms of FOXNs expression and activity, their role in the malignant progression of tumors, and their value for clinical applications in cancer therapy. This review may help design experimental studies involving FOXN transcription factors, and enhance their therapeutic potential as antitumor targets.

MicroRNA as a Diagnostic Tool, Therapeutic Target and Potential Biomarker in Cutaneous Malignant Melanoma Detection—Narrative Review

Melanoma is the most serious type of skin cancer, causing a large majority of deaths but accounting for only ~1% of all skin cancer cases. The worldwide incidence of malignant melanoma is increasing, causing a serious socio-economic problem. Melanoma is diagnosed mainly in young and middle-aged people, which distinguishes it from other solid tumors detected mainly in mature people. The early detection of cutaneous malignant melanoma (CMM) remains a priority and it is a key factor limiting mortality. Doctors and scientists around the world want to improve the quality of diagnosis and treatment, and are constantly looking for new, promising opportunities, including the use of microRNAs (miRNAs), to fight melanoma cancer. This article reviews miRNA as a potential biomarker and diagnostics tool as a therapeutic drugs in CMM treatment. We also present a review of the current clinical trials being carried out worldwide, in which miRNAs are a target for melanoma treatment.

Comprehensive Analysis of microRNA Expression During the Progression of Colorectal Tumors

BACKGROUND

No effective early diagnostic biomarkers are available for colorectal cancer (CRC). Therefore, we sought to identify new biomarkers that could identify CRC from progression as a pre-cancerous lesion to its invasive form. Recent studies have shown that microRNAs (miRs) are associated with the onset of cancer invasion and progression.

AIMS

We hypothesized that the identification of miRs associated with CRC might be useful to detect this disease at early stages.

METHODS

We conducted an integrated analysis of 79 isolated colorectal tumor glands, including adenomas, intramucosal cancers, and invasive CRCs that showed a microsatellite stable phenotype using GeneChip miRNA 4.0 microarray assays. The colorectal tumors we examined were divided into 2 cohorts (42 in the first cohort and 37 in the second cohort).

RESULTS

First, cluster analysis was performed to stratify expression patterns of multiple miRs that were pooled according to the following criteria: fold change in expression (< -2.0 or > 2.0), p < 0.05, and mature miRs. As a result, the expression patterns of pooled miRs were subdivided into 3 subgroups that were correlated with tumor grade. Each subgroup was characterized by specific miRs. In addition, we found that specific miRs, including miR-140-3p and miR-378i, were closely associated with cancer invasion. Finally, we analyzed paired dysregulated miRs between adenomatous and cancerous components present within the same tumor.

DISCUSSION

We showed that several miRs were dysregulated during progression from adenoma to intramucosal cancer. Specific miRs may have key roles in progression from intramucosal tumor to invasive CRC.

Depicting the Implication of miR-378a in Cancers

MicroRNA-378a (miR-378a), including miR-378a-3p and miR-378a-5p, are encoded in PPARGC1B gene. miR-378a is essential for tumorigenesis and is an independent prognostic biomarker for various malignant tumors. Aberrant expression of miR-378a affects several physiological and pathological processes, including proliferation, apoptosis, tumorigenesis, cancer invasion, metastasis, and therapeutic resistance. Interestingly, miR-378a has a dual functional role in either promoting or inhibiting tumorigenesis, independent of the cancer type. In this review, we comprehensively summarized the role and regulatory mechanisms of miR-378a in cancer development, hoping to provide a direction for its potential use in cancer therapy.

FOXN3 inhibits cell proliferation and invasion via modulating the AKT/MDM2/p53 axis in human glioma

This study aimed to evaluate the biological role of forkhead box N3 (FOXN3) in human glioma and clarify the possible molecular mechanisms. FOXN3 expression patterns in clinical tissue specimens were characterized via qPCR and Western blotting. Kaplan-Meier survival curve was applied to assess the correlation between FOXN3 expression and overall survival. Effects of FOXN3 over-expression and depletion on glioma cell proliferation, apoptosis, migration and invasion were assessed by CCK8, colony formation assay, flow cytometry, scratch wound healing assay and Transwell invasion assay, respectively. Moreover, the involvement of AKT/murine double minute 2 (MDM2)/p53 pathway was evaluated. Additionally, tumor transplantation model assay was performed to determine the effects of FOXN3 over-expression on glioma cell growth in vivo. Results showed that FOXN3 was significantly down-regulated in glioma tissues compared with normal tissues. Patients with lower FOXN3 expression exhibited a shorter overall survival time. Gain- and loss-of-function analyses demonstrated that FOXN3 over-expression significantly suppressed proliferation, survival and motility of glioma cells, whereas FOXN3 knockdown remarkably promoted glioma cell proliferation, survival and motility. Furthermore, FOXN3 over-expression inhibited the activation of AKT/MDM2/p53 signaling pathway in glioma cells, while FOXN3 depletion facilitated its activation. Additionally, tumor xenograft assays revealed that FOXN3 over-expression retarded glioma cell growth in vivo. Collectively, these findings indicate that FOXN3 inhibits cell growth and invasion through inactivating the AKT/MDM2/p53 signaling pathway and that FOXN3-AKT/MDM2/p53 axis may represent a novel therapeutic target for glioma patients.

Micro RNAs Promoting Growth and Metastasis in Preclinical In Vivo Models of Subcutaneous Melanoma

During the last years a considerable therapeutic progress in melanoma patients with the RAF V600E mutation via RAF/MEK pathway inhibition and immuno-therapeutic modalities has been witnessed. However, the majority of patients relapse after therapy. Therefore, a deeper understanding of the pathways driving oncogenicity and metastasis of melanoma is of paramount importance. In this review, we summarize microRNAs modulating tumor growth, metastasis, or both, in preclinical melanoma-related in vivo models and possible clinical impact in melanoma patients as modalities and targets for treatment of melanoma. We have identified miR-199a (ApoE, DNAJ4), miR-7-5p (RelA), miR-98a (IL6), miR-219-5p (BCL2) and miR-365 (NRP1) as possible targets to be scrutinized in further target validation studies.

MicroRNA Signature in Melanoma: Biomarkers and Therapeutic Targets

Melanoma is the utmost fatal kind of skin neoplasms. Molecular changes occurring during the pathogenic processes of initiation and progression of melanoma are diverse and include activating mutations in BRAF and NRAS genes, hyper-activation of PI3K/AKT pathway, inactivation of p53 and alterations in CDK4/CDKN2A axis. Moreover, several miRNAs have been identified to be implicated in the biology of melanoma through modulation of expression of genes being involved in these pathways. In the current review, we provide a summary of the bulk of information about the role of miRNAs in the pathobiology of melanoma, their possible application as biomarkers and their emerging role as therapeutic targets for this kind of skin cancer.

miR-574-5p Targets FOXN3 to Regulate the Invasion of Nasopharyngeal Carcinoma Cells via Wnt/β-Catenin Pathway

MicroRNAs (miR) are a class of non-coding endogenous RNA molecules that suppress the translation of protein-coding genes by destabilizing target mRNAs. The MiR-574-5p has been reported to be involved in the several types of cancer. However, the expression of miR-574-5p and its mechanism in nasopharyngeal carcinoma (NPC) remain unclear. We found that the expression level of miR-574-5p was significantly increased in the NPC cell lines. We further demonstrated that Forkhead box N3 (FOXN3) was a target gene of miR-574-5p. FOXN3 overexpression and inhibition reversed the promoting or suppressing effect, respectively, of NPC cell proliferation, migration and invasion caused by miR-574-5p. Furthermore, miR-574-5p enhanced the β-catenin and TCF4 protein expression by repressing FOXN3 expression, resulting in the activation of the Wnt/β-catenin signaling pathway, but the activity of the Wnt/β-catenin signaling pathway was inhibited by a miR-574-5p inhibitor or FOXN3 overexpression, which reversed the effect of miR-574-5p. Wound-healing and Transwell assays also showed that miR-574-5p promotes the cell migration and invasion of NPC cells, whereas the promoting effect of miR-574-5p was also reversed by a miR-574-5p inhibitor or FOXN3 overexpression. Collectively, these data suggested that miR-574-5p promotes NPC cell proliferation, migration, and invasion at least partly by targeting the FOXN3/Wnt/β-Catenin signaling pathway.

FOXN3 suppresses the growth and invasion of papillary thyroid cancer through the inactivation of Wnt/β-catenin pathway

Forkhead box N3 (FOXN3) is a subtype of FOX family that has been demonstrated to be implicated in several cancers. However, the role of FOXN3 in papillary thyroid carcinoma (PTC) and its mechanisms have not yet been investigated. Our results showed that FOXN3 was markedly down regulated in PTC tissues and cell lines. Overexpression of FOXN3 suppressed the proliferation, colony formation, migration, and invasion in PTC cells. Overexpression of FOXN3 also prevented EMT process in PTC cells, as shown by the increased E-cadherin expression level and decreased expression levels of N-cadherin and vimentin. In addition, overexpression of FOXN3 inhibited tumor growth of PTC in vivo. Furthermore, overexpression of FOXN3 caused significant decreases in expression levels of β-catenin, c-Myc, and cyclin D1. Additionally, activation of Wnt/β-catenin pathway reversed the effects of FOXN3 on PTC cells. In conclusion, these findings indicated that FOXN3 exerted a tumor suppressive activity in PTC, which was mediated by Wnt/β-catenin pathway.

MicroRNA-574-5p directly targets FOXN3 to mediate thyroid cancer progression via Wnt/β-catenin signaling pathway

OBJECTIVE

Thyroid cancer is the most common endocrine tumor. A large number of thyroid cancer-related miRNAs have been studied and identified. However, the detailed roles of miR-574-5p in thyroid cancer remain poorly understood. This work mainly aimed to investigate the role of miR-574-5p/FOXN3 axis and its mechanism in the thyroid cancer progression.

METHODS

MiR-574-5p, FOXN3, Wnt/β-catenin pathway, and apoptosis-related markers were measured by quantitative real-time PCR (qRT-PCR) and western blotting analysis, respectively. Luciferase reporter assay was employed to validate the direct targeting of FOXN3 by miR-574-5p. MTT, flow cytometry, wound healing and transwell experiments were applied to analyze the functions of FOXN3 and miR-574-5p in thyroid cancer cells.

RESULTS

Knockdown of miR-574-5p up-regulated FOXN3 expression and miR-574-5p directly targeted FOXN3 in thyroid cancer cells. Biological function experiments showed that knockdown of miR-574-5p inhibited proliferation, migration, invasion and promoted apoptosis of thyroid cancer cells. The activation of Wnt/β-catenin pathway was suppressed by MiR-574-5p silencing. FOXN3 silencing reversed the effects of miR-574-5p inhibitor on FOXN3 level and Wnt/β-catenin singling pathway, also reversed the effects on cell migration, proliferation, invasion and apoptosis.

CONCLUSION

The miR-574-5p/FOXN3 axis is a novel molecular mechanism that promotes thyroid cancer progression, suggesting their potential for clinical therapy of thyroid cancer.

Serum exosomal miR-378 upregulation is associated with poor prognosis in non-small-cell lung cancer patients

Background

Deregulated circulating microRNAs (miRNAs) are potential biomarkers for the early detection and prognosis prediction of non–small‐cell lung cancer (NSCLC). The aim of the present study was to investigate the expression pattern of serum exosomal miR‐378 in NSCLC and its correlation with clinical variables.

Methods

Quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR) was performed to detect serum exosomal miR‐378 levels in 103 patients with NSCLC and 60 control subjects.

Results

Our results showed that serum exosomal miR‐378 was significantly overexpressed in NSCLC patients, and serum exosomal miR‐378 upregulation was clearly associated with positive lymph node metastasis and advanced TNM stage. In addition, receiver operating characteristic (ROC) analysis demonstrated that combination of serum exosomal miR‐378 expression and carcinoembryonic antigen (CEA) had a high discriminating power to differentiate NSCLC subjects from controls. Moreover, serum exosomal miR‐378 levels in 73 NSCLC cases were significantly decreased after radiotherapy and could be used as an indicator of radiotherapeutic response in NSCLC. Furthermore, survival analyses revealed that patients with higher serum exosomal miR‐378 expression had poor overall survival. Multivariate analysis showed that serum exosomal miR‐378 expression was independently associated with overall survival.

Conclusions

Collectively, serum exosomal miR‐378 has strong potential as a promising non‐invasive biomarker for screening and monitoring NSCLC.

microRNA-378a-5p iS a novel positive regulator of melanoma progression

Evaluating the expression levels of miR-378a-5p both in a large melanoma patient cohort from The Cancer Genome Atlas database and in melanoma patients from our Institute, we found that miR-378a-5p is upregulated in metastatic melanoma specimens. miR-378a-5p expression was also increased in melanoma cells resistant to target therapy, and decreased in response to drug treatment. We also demonstrated that overexpression of miR-378a-5p enhances in vitro cell invasion and migration, and facilitates the ability of melanoma cells to form de novo vasculogenic structures. While performing downstream targeting studies, we confirmed the ability of miR-378a-5p to modulate the expression of known target genes, such as SUFU, FUS-1, and KLF9. Luciferase-3′UTR experiments also identified STAMBP and HOXD10 as new miR-378a-5p target genes. MMP2 and uPAR, two HOXD10 target genes, were positively regulated by miR-378a-5p. Genetic and pharmacologic approaches inhibiting uPAR expression and activity evidenced that the in vitro tumor-promoting functions of miR-378a-5p, were in part mediated by uPAR. Of note miR-378a-5p was also able to increase VEGF, as well as in vitro and in vivo angiogenesis. Finally, genetic and pharmacologic modulation of Bcl-2 evidenced Bcl-2 ability to regulate miR-378a-5p expression. In conclusion, to the best of our knowledge, this is the first study demonstrating that miR-378a-5p acts as an oncogenic microRNA in melanoma.

MicroRNA-127 Inhibits the Progression of Melanoma by Downregulating Delta-Like Homologue 1

Objective

Melanoma is the most common form of skin cancer with low survival rate and poor prognosis. MicroRNAs (miRNAs) have been reported to play essential roles in progression of melanoma. However, the role and mechanism of miR-127 in the process of melanoma remain poorly understood.

Methods

The expressions of miR-127 and delta-like homologue 1 (DLK1) were measured in melanoma tissues and cells by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Cell proliferation and apoptosis were measured by MTT assay, flow cytometry, and Western blot. The interaction between miR-127 and DLK1 was investigated by bioinformatics analysis, luciferase activity assay, and RNA immunoprecipitation (RIP). Murine xenograft model was conducted to investigate the effect of miR-127 on tumor growth in vivo.

Results

miR-127 was inhibited and DLK1 mRNA was enhanced in melanoma tissues and cells. Low abundance of miR-127 in melanoma tissues predicted a poor prognosis and was associated with the malignant clinicopathological features. Overexpression of miR-127 inhibited cell proliferation and induced apoptosis in melanoma cells. Moreover, DLK1 was targeted by miR-127 and its restoration reversed the regulatory effect of miR-127 on the process of melanoma. Besides, the addition of miR-127 suppressed xenograft tumor growth via suppressing DLK1 protein level in nude mice.

Conclusion

miR-127 blocked the development of melanoma by targeting DLK1, providing a novel biomarker for the treatment of melanoma.

miR-378 serves as a prognostic biomarker in cholangiocarcinoma and promotes tumor proliferation, migration, and invasion

MicroRNAs (miRNAs) have been demonstrated that play a critical role in tumorigenesis. The aim of this study is to identify the functional role of miR-378 in cholangiocarcinoma (CCA). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression levels of miR-378 in human CCA tissue samples and CCA cell lines. The receiver operating characteristic (ROC) curve was established, and the area under the ROC curve (AUC) was calculated to estimate the capacity of miR-378 in distinguishing CCA patients with different TNM stages. Kaplan-Meier survival analysis and Cox regression assay were performed to explore the prognostic value of miR-378. Cell proliferation capacity was assessed by MTT assay. Cell migration and invasion were identified by Transwell assays. miR-378 was significantly elevated in CCA tissues when compared with adjacent normal tissues, and in CCA cell lines compared to HIBEC cells. And we found that the expression of miR-378 was significantly associated with TNM stage (P= 0.030) and lymph node metastasis (P= 0.018). ROC curve analysis result showed miR-378 could distinguish CCA patients with TNM stages III and IV from those with stages I and II, with the AUC was 0.816. Patients with high expression of miR-378 had a shorter overall survival rate (Log-rank P= 0.030). The miR-378 was proven to be an independent prognostic predictor for the CCA patients (HR = 1.735, 95% CI = 1.007-2.988, P= 0.041). Downregulation of miR-378 could inhibit cell proliferation, migration, and invasion. These results indicated that miR-378 function as an oncogene and promote CCA cells proliferation, migration, and invasion. The miR-378 could be a novel prognostic marker for CCA.