The Interplay of MicroRNA-34a, LGR4, EMT-Associated Factors, and MMP2 in Regulating Uveal Melanoma Cells

Recent approaches for the treatment of uveal melanoma: Opportunities and challenges

Uveal melanoma (UM) is the most prevalent primary intraocular cancer in adult population. Primary methods for treatment of UM involves surgery Proton Beam Therapy (PBT), Plaque Brachytherapy, phototherapy, and Charged Particle Radiation Therapy (CPT). It has been found that approximately 50 % of patients diagnosed with UM ultimately experience development of metastatic disease. Furthermore, it has been identified that majority of the patient experience metastasis in liver with a prevalence of 95 %. Management of metastatic UM (MUM) involves various therapeutic modalities, including systemic chemotherapy, molecular targeted therapy, immunotherapy and liver directed interventions. We outline gene mutation in UM and addresses various treatment modalities, including molecular targeted therapy, miRNA-based therapy, and immunotherapy. Additionally, inclusion of ongoing clinical trials aimed at developing novel therapeutic options for management of UM are also mentioned.

Genetic and Epigenetic Features of Uveal Melanoma-An Overview and Clinical Implications

Uveal melanoma (UM) is rare, but it is the most common primary intraocular malignancy among adults. This review represents the molecular, genetic, and immunobiological mechanisms involved in UM carcinogenesis and progression, as well as data about the association of chromosomal changes, genetic mutations, selective proteins, and biochemical biomarkers with the clinical implications of UM. Genetic analysis has the potential to identify patients with a high risk of UM metastasis, enabling management that is more effective and allowing for the follow-up of patients. Advancements in molecular characterization of UM offer opportunities to develop targeted therapeutic strategies by focusing on relevant signaling pathways. Changes in miRNA expression could be useful in the diagnosis and prognosis of UM, due to unique miRNA profiles in melanoma cells or tissue and its association with metastasis. Although liver function tests do not provide enough data on the prognosis of UM, due to the high frequency of liver metastasis, liver function tests (LFTs) might be useful indicators; however, the absence of rising LFT values cannot lead to the exclusion of liver metastases. Molecular analysis of tumor tissue will allow us to identify patients with the added benefit of new therapeutic agents and provide a better insight into melanoma pathogenesis and its biological behavior.

Elevated ZNF704 expression is associated with poor prognosis of uveal melanoma and promotes cancer cell growth by regulating AKT/mTOR signaling

BACKGROUND

Uveal melanoma (UM) is the most common intraocular malignancy in adults, with a poor survival prognosis. To date, limited understanding of UM's molecular mechanisms constitutes an obstacle to developing effective therapy. In this study, we examined key regulators mediating UM progression and their clinical relevance.

METHODS

Transcriptomics of UM patients and cells were analyzed via RNA sequencing and bioinformatic analysis. Zinc finger protein 704 (ZNF704) was identified as prognosis-related biomarker for UM based on clinical characteristics and RNA-seq data from The Cancer Genome Atlas (TCGA). Gene expression was knocked down by specific shRNAs/siRNAs and overexpressed by transfection with plasmids inserted with investigated gene cDNA. Cell proliferation, viability and invasion abilities were determined by CCK8, colony formation and transwell assays, respectively. For cell cycle and apoptosis, cells were PI or PI/Annexin V-APC stained and analyzed by flow cytometry. Standard immunoblotting and quantitative RT-PCR were employed to assess the mRNA and protein abundance. To determine tumor growth in vivo, 4-week-old BALB/c-nu immune-deficient nude mice were inoculated with tumor cells.

RESULTS

Analysis of differential expressed genes (DEGs) and survival analysis identified ZNF704 as a novel biomarker of UM. Prognostic analysis indicated ZNF704 as an independent predictor of UM overall survival. Expression of ZNF704 is elevated in UM tissues relative to adjacent normal choroid tissues. Knockdown of ZNF704 suppressed the growth and migration of UM cells and vice versa. In addition, expression of ZNF704 arrest UM cells at G0/G1 phase and inhibit cell apoptosis. RNA sequencing analysis indicated that SORBS3 were dysregulated after ZNF704 downregulation. Gene Set Enrichment Analysis (GSEA) revealed that upon ZNF704 knowndown, genes related with PI3K/AKT/mTOR, EMT and metastasis are enriched. Mechanistically, ZNF704 activates AKT/mTOR/glycolysis signaling pathway in UM cells. Moreover, expression of SORBS3 is downregulated by ZNF704 and knockdown of SORBS3 restored tumor cell viability in ZNF704 silenced cells.

CONCLUSIONS

ZNF704 predicts poor prognosis of UM and exhibit pro-oncogenic effect in UM progression in vivo and in vitro, mediated through AKT/mTOR signaling pathway and suppression of SORBS3 expression.

Genetics and RNA Regulation of Uveal Melanoma

Uveal melanoma (UM) is the most common intraocular malignant tumor and the most frequent melanoma not affecting the skin. While the rate of UM occurrence is relatively low, about 50% of patients develop metastasis, primarily to the liver, with lethal outcome despite medical treatment. Notwithstanding that UM etiopathogenesis is still under investigation, a set of known mutations and chromosomal aberrations are associated with its pathogenesis and have a relevant prognostic value. The most frequently mutated genes are BAP1, EIF1AX, GNA11, GNAQ, and SF3B1, with mutually exclusive mutations occurring in GNAQ and GNA11, and almost mutually exclusive ones in BAP1 and SF3B1, and BAP1 and EIF1AX. Among chromosomal aberrations, monosomy of chromosome 3 is the most frequent, followed by gain of chromosome 8q, and full or partial loss of chromosomes 1 and 6. In addition, epigenetic mechanisms regulated by non-coding RNAs (ncRNA), namely microRNAs and long non-coding RNAs, have also been investigated. Several papers investigating the role of ncRNAs in UM have reported that their dysregulated expression affects cancer-related processes in both in vitro and in vivo models. This review will summarize current findings about genetic mutations, chromosomal aberrations, and ncRNA dysregulation establishing UM biology.

PTK6 inhibits autophagy to promote uveal melanoma tumorigenesis by binding to SOCS3 and regulating mTOR phosphorylation

Autophagy dysfunction is one of the common causes of tumor formation and plays an important role in uveal melanoma (UM). However, little is known about the regulatory mechanisms of autophagy in UM. Here, we show that PTK6 can promote the proliferation, migration, and invasion of UM cells by inhibiting autophagy. SOCS3 can inhibit the proliferation, migration, and invasion of UM cells. Overexpression of SOCS3 can partially rescue the PTK6-induced promotion of UM cell proliferation, migration, and invasion. Mechanistically, PTK6 can bind to SOCS3, and SOCS3 can downregulate the expression of PTK6. Furthermore, PTK6 can upregulate the phosphorylation of mTOR to inhibit autophagy. Taken together, our findings demonstrate the functions of PTK6 and SOCS3 in UM cells and targeting the SOCS3-PTK6 signaling axis might be a novel and promising therapeutic strategy for patients with UM.

Palmitic Acid Promotes Lung Metastasis of Melanomas via the TLR4/TRIF-Peli1-pNF-κB Pathway

A high-fat diet plays an important role in aggravating cancers. Palmitic acid (PA) is one of the components of saturated fatty acids; it has been reported to promote tumor proliferation in melanomas, but the signal transduction pathway mediated by palmitic acid remains unclear. This study showed that palmitic acid can promote the lung metastasis of melanomas. Moreover, the interaction between palmitic acid and toll-like receptor 4 (TLR4) was predicted by molecular docking. The experimental results proved that palmitic acid could promote the TLR4 and Toll/IL-1 receptor domain-containing adaptor-inducing IFN-β (TRIF) expression. The expression of Pellino1 (Peli1) and the phosphorylation of NF-kappa B (pNF-κB) were downregulated after the suppression of TLR4 and the silencing of Peli1 also inhibited the phosphorylation of NF-κB. Therefore, we concluded that palmitic acid promoted the lung metastasis of melanomas through the TLR4/TRIF-Peli1-pNF-κB pathway.

EMT-Related Gene Signature Predicts the Prognosis in Uveal Melanoma Patients

Background. Uveal melanoma (UVM) is the most common primary intraocular malignancy in adults. Epithelial-mesenchymal transition (EMT) is an essential regulator of the UVM’s immune microenvironment. However, the precise role of EMT in UVM remains to be explored and the development of a related treatment strategy is urgently needed. Methods. Multiomics data and clinical information for TCGA-UVM were used to identify the EMT subtypes and analyze their regulatory role in the immune microenvironment in UVM. A machine-learning method based on the identified subtypes was utilized to construct the EMT feature-based prognostic model. External validation cohorts GSE84976 and GSE22138 were employed to validate the model’s robustness. Immunotherapy cohort IMvigor210 was used to explore the model’s potential to predict immunotherapy responsiveness. Results. Two EMT subtypes were identified in UVM. The role of EMT in shaping the immune microenvironment and regulating cancer-immunity circle of UVM was analyzed. A robust prognostic model was presented and validated to predict patient prognosis. The model also predicted patient’s immune features and immunotherapy responsiveness. Conclusion. The EMT-mediated immune features in UVM were illustrated, providing a reliable model to facilitate precise UVM treatment. This research may assist in decision-making during clinical UVM therapy.

Sclerostin Suppression Facilitates Uveal Melanoma Progression Through Activating Wnt/β-Catenin Signaling Via Binding to Membrane Receptors LRP5/LRP6

Objective

Uveal melanoma (UM) is the most frequent primary eye cancer in adults with a 50% mortality rate. Characterizing the fundamental signaling pathways that drive UM is of importance for the development of targeted therapy. This study aims to probe the impact of sclerostin (SOST) on malignant progression of UM and regulation of Wnt/β-catenin signaling.

Methods

Epithelial-type (n=20) and spindle-type (n=16) UM tissues were collected for immunohistochemical staining of SOST, Wnt-1, and β-catenin expressions. SOST was silenced in three UM cell lines (primary spindle-type OCM-1 cells, metastatic epithelial Mum-2B cells, and metastatic spindle-type Mum-2C cells) through transfecting specific siRNA. RT-qPCR and Western blot were presented for examining the levels of SOST, and markers in Wnt/β-catenin signaling. Flow cytometry, MTT, EdU, transwell, and tube formation assays were conducted, respectively. By implanting BALB/c nude murine models in situ, the function of SOST on tumor growth was investigated, followed by immunofluorescence double staining of SOST and LRP5/6.

Results

Low SOST expression as well as high Wnt-1 and β-catenin expressions were found in epithelial-type (high malignancy) than spindle-type (low malignancy) UM tissues. Silencing SOST activated the markers in Wnt/β-catenin signaling as well as accelerated cell cycle progression, migration, invasion, angiogenesis, and reduced apoptosis in UM cells. In situ tumor formation in murine eyes showed that SOST knockdown promoted tumor growth. Moreover, SOST interacted with LRP5/LRP6.

Conclusion

SOST silencing may facilitate the malignant progression of UM cells through activating Wnt/β-catenin signaling. Mechanistically, SOST may exert this function by interacting with LRP5/LRP6 membrane receptors.

The Role of Metalloproteinases and Their Tissue Inhibitors on Ocular Diseases: Focusing on Potential Mechanisms

Eye diseases are associated with visual impairment, reduced quality of life, and may even lead to vision loss. The efficacy of available treatment of eye diseases is not satisfactory. The unique environment of the eye related to anatomical and physiological barriers and constraints limits the bioavailability of existing agents. In turn, complex ethiopathogenesis of ocular disorders that used drugs generally are non-disease specific and do not act causally. Therefore, there is a need for the development of a new therapeutic and preventive approach. It seems that matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have a significant role in the development and progression of eye diseases and could be used in the therapy of these disorders as pharmacological targets. MMPs and TIMPs play an important role in the angiogenesis, epithelial-mesenchymal transition, cell invasion, and migration, which occur in ocular diseases. In this review, we aim to describe the participation of MMPs and TIMPs in the eye diseases, such as age-related macular degeneration, cataract, diabetic retinopathy, dry eye syndrome, glaucoma, and ocular cancers, posterior capsule opacification focusing on potential mechanisms.

NEAT1 in bone marrow mesenchymal stem cell-derived extracellular vesicles promotes melanoma by inducing M2 macrophage polarization

Bone marrow mesenchymal stem cells (BMSCs)-derived extracellular vesicles (EVs) reportedly play an important role in melanoma pathogenesis. This study aimed to explore the mechanisms of EVs-carried long non-coding RNA (lncRNA) NEAT1 involvement in melanoma. Gain- and loss-of-function experiments were performed to determine biological characteristics of A-375 melanoma cells. Bioinfomatic prediction, RNA immunoprecipitation (RIP), and dual luciferase reporter gene experiments were applied to investigate the roles of NEAT1 and microRNA-374a-5p (miR-374a-5p), and leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4). A subcutaneous tumor model was constructed using nude mice, and in vivo fluorescence imaging was used to observe the effect of NEAT1 on the growth and metastasis of melanoma cells in vivo. The results indicated that BMSC-EVs could be internalized by macrophages to promote the expression of macrophages M2 markers. M2 type macrophages promoted malignancy of melanoma cells. NEAT1 derived from BMSC-EVs promoted the progression of melanoma by promoting M2 polarization of macrophages. NEAT1 inhibits miR-374 expression, while miR-374 could upregulate LGR4-dependent IQGAP1 expression. The tumor-inhibiting effect of NEAT1 silencing was validated in the nude mouse xenograft model. Collectively, the results demonstrated that BMSC-EVs carrying NEAT1 can promote the progression of melanoma by inducing M2 polarization of macrophages, and thus may be considered as a potential target for melanoma therapeutics.

Emerging Roles for LGR4 in Organ Development, Energy Metabolism and Carcinogenesis

The leucine-rich repeats containing G protein-coupled receptor 4 (LGR4) belonging to G protein-coupled receptors (GPCRs) family, had various regulatory roles at multiple cellular types and numerous targeting sites, and aberrant LGR4 signaling played crucial roles in diseases and carcinogenesis. On the basis of these facts, LGR4 may become an appealing therapeutic target for the treatment of diseases and tumors. However, a comprehensive investigation of its functions and applications was still lacking. Hence, this paper provided an overview of the molecular characteristics and signaling mechanisms of LGR4, its involvement in multiple organ development and participation in the modulation of immunology related diseases, metabolic diseases, and oxidative stress damage along with cancer progression. Given that GPCRs accounted for almost a third of current clinical drug targets, the in-depth understanding of the sophisticated connections of LGR4 and its ligands would not only enrich their regulatory networks, but also shed new light on designing novel molecular targeted drugs and small molecule blockers for revolutionizing the treatment of various diseases and tumors.

Circular RNA circFLNA inhibits the development of bladder carcinoma through microRNA miR-216a-3p/BTG2 axis

Recent studies have shown that circular RNA circFLNA is abnormally expressed in a variety of malignant tumors, but its role and mechanism in bladder carcinoma (BCa) are still unclear. The present paper aims to contribute to research on the effects and mechanism of circFLNA on the malignant phenotype of BCa. In this study, the expressions of circFLNA, miR-216a-3p and BTG2 in BCa and BCa cells (EJ, T24, 5637, TCC-SUP) were detected by qRT-PCR. EdU staining, colony formation, Transwell assay, wound healing assays, and sphere formation assay were used to measure the cell proliferation, viability, invasion, migration, and cell stemness of BCa cells after circFLNA overexpression. In addition, the correlation existed between miR-216a-3p and circFLNA or BTG2 was confirmed by Dual-Luciferase Reporter assay and RNA pull-down. Western blot was utilized to determine the expression of BTG2, MMP2, epithelial-mesenchymal transition (EMT)-related proteins (vimentin, E-cadherin) and stem cell-specific proteins (CD34, OCT4, SOX2). Our study confirmed that downregulated circFLNA and BTG2 expression and upregulated miR-216a-3p were found in both BCa tissues and cell lines. Meanwhile, upregulated circFLNA inhibited proliferation, invasion and migration, EMT and stemness of BCa cells. MiR-216a-3p was a target gene of circFLNA and could target BTG2. Further analysis finally demonstrated that circFLNA sponged miR-216a-3p and indirectly promoted BTG2 expression, ultimately regulating proliferation, migration, invasion and EMT of BCa cells. In conclusion, circFLNA inhibits the malignant phenotype of BCa cells and their stemness through miR-216a-3p/BTG2, thus suppressing BCa progression.

Regulation of epigenetic homeostasis in uveal melanoma and retinoblastoma

Uveal melanoma (UM) and retinoblastoma (RB), which cause blindness and even death, are the most frequently observed primary intraocular malignancies in adults and children, respectively. Epigenetic studies have shown that changes in the epigenome contribute to the rapid progression of both UM and RB following classic genetic changes. The loss of epigenetic homeostasis plays an important role in oncogenesis by disrupting the normal patterns of gene expression. The targetable nature of epigenetic modifications provides a unique opportunity to optimize treatment paradigms and establish new therapeutic options for both UM and RB with these aberrant epigenetic modifications. We aimed to review the research findings regarding relevant epigenetic changes in UM and RB. Herein, we 1) summarize the literature, with an emphasis on epigenetic alterations, including DNA methylation, histone modifications, RNA modifications, noncoding RNAs and an abnormal chromosomal architecture; 2) elaborate on the regulatory role of epigenetic modifications in biological processes during tumorigenesis; and 3) propose promising therapeutic candidates for epigenetic targets and update the list of epigenetic drugs for the treatment of UM and RB. In summary, we endeavour to depict the epigenetic landscape of primary intraocular malignancy tumorigenesis and provide potential epigenetic targets in the treatment of these tumours.

Runs of homozygosity analysis reveals population characteristics of yellow-feathered chickens using re-sequencing data

1. To evaluate the inbreeding of yellow-feathered chickens (YFCs) and identify genes related to their unique characteristics, whole-genome re-sequencing data were applied to detect runs of homozygosity (ROH) in the genomes of ten YFC breeds. The number, length, distribution of ROH, and inbreeding coefficient in different YFC populations were calculated. Genomic regions with high frequency in ROH were annotated.2. In total, 25,547 ROH with an average length of 335 kb were detected, with most being <1 Mb. The domination of short ROH reflected the long breeding history of this chicken. The number, length, frequency, and distribution of ROH varied among chicken populations, and high genetic diversity was maintained.3. Numerous genes related to YFC characteristics were identified in the high-frequency ROH regions. Among these, IFNA, IFNB, IL11RA, IL22RA1, IFNLR1, and TRIF genes were involved in disease resistance. The AMY, G6PC, SDHB, GCNT4, and ACO genes were associated with energy material metabolism; and FABPL, AQP7, ACAA2, and RYR2 were related to meat quality and flavour. The KITLG, CREB3, RYR2, and LGR4 genes, related to pigmentation, were detected.4. This ROH-based inbreeding evaluation laid the foundation for breeding and conservation of YFC populations, and the candidate genes identified can be used for marker-assisted selection.

Curcumin-Alleviated Osteoarthritic Progression in Rats Fed a High-Fat Diet by Inhibiting Apoptosis and Activating Autophagy via Modulation of MicroRNA-34a

Purpose

The mechanism underlying curcumin’s protective effect on osteoarthritis (OA) has not been clarified. This study aimed to determine whether curcumin exerts a chondroprotective effect by inhibiting apoptosis via upregulation of E2F1/PITX1 and activation of autophagy via the Akt/mTOR pathway by targeting microRNA-34a (miR-34a).

Methods

Male Sprague–Dawley rats were fed a normal diet (ND) or high-fat diet (HFD) for 28 weeks. Five rats from each diet group were selected randomly for histological analysis of OA characteristics. Rats fed a HFD were given a single intra-stifle joint injection of the miR-34a mimic agomir-34a or negative control agomir (NC), followed by weekly low-dose (200 μg/kg body weight) or high-dose (400 μg/kg body weight) curcumin intra-joint injections from weeks 29 to 32. The rats’ stifle joints were submitted to histological analysis and to an apoptotic assay. Expression of miR-34a was detected using a real-time RT-PCR. E2F1 and PITX1 protein levels were determined by Western blot analysis, and the expressions of Beclin1, LC3B, p62, phosphorylated (p)-Akt, and p-mTOR were measured using immunofluorescence analysis.

Results

We found that rats fed a HFD had OA-like lesions in their articular cartilage and had increased apoptosis of chondrocytes and decreased autophagy compared to rats fed a ND. Curcumin treatment alleviated OA changes, inhibited apoptosis, and upregulated autophagy. Agomir-34a treatment reduced E2F1, PITX1, Beclin1, and LC3B expression and increased p62, p-Akt, and p-mTOR expression in HFD-fed rats given low- or high-dose curcumin. Greater numbers of apoptotic cells, lesser expression of p62, p-Akt, and p-mTOR, and greater expression of E2F1, PITX1, and LC3B were observed in the agomir-34a and high-dose curcumin-treated group than in agomir-34a and low-dose curcumin-treated group.

Conclusion

Curcumin’s chondroprotective effect was mediated by its suppression of miR-34a, apparently by reducing apoptosis, via upregulation of E2F1/PITX1, and by augmenting autophagy, likely via the Akt/mTOR pathway.

The Role of LGR4 (GPR48) in Normal and Cancer Processes

Leucine-rich repeats containing G protein-coupled receptor 4 (LGR4) is a receptor that belongs to the superfamily of G protein-coupled receptors that can be activated by R-spondins (RSPOs), Norrin, circLGR4, and the ligand of the receptor activator of nuclear factor kappa-B (RANKL) ligands to regulate signaling pathways in normal and pathological processes. LGR4 is widely expressed in different tissues where it has multiple functions such as tissue development and maintenance. LGR4 mainly acts through the Wnt/β-catenin pathway to regulate proliferation, survival, and differentiation. In cancer, LGR4 participates in tumor progression, invasion, and metastasis. Furthermore, recent evidence reveals that LGR4 is essential for the regulation of the cancer stem cell population by controlling self-renewal and regulating stem cell properties. This review summarizes the function of LGR4 and its ligands in normal and malignant processes.

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.

Curcumol inhibits the viability and invasion of colorectal cancer cells via miR-30a-5p and Hippo signaling pathway

MicroRNA-30a-5p (miR-30a-5p), which functions as a tumor suppressor, has been reported to be downregulated in colorectal cancer (CRC) tissues and to be associated with cancer invasion. However, the detailed regulatory mechanism of curcumol in the malignant progression of CRC remains unknown. MTT, Transwell, scratch, western blotting and reverse transcription-quantitative PCR assays were performed to examine how curcumol inhibited CRC cell viability, invasion and migration, and to detect the role of miR-30a-5p and curcumol in the invasion and Hippo signaling pathways of CRC cells. The present study revealed that miR-30a-5p expression was downregulated in human CRC tissues and cells. The results demonstrated that miR-30a-5p downregulation was accompanied by the inactivation of the Hippo signaling pathway, which was demonstrated to promote CRC cell viability, invasion and migration. Curcumol treatment was identified to increase miR-30a-5p expression and to activate the Hippo signaling pathway, which in turn inhibited the invasion and migration of CRC cells. Overexpression of miR-30a-5p enhanced the effects of curcumol on cell invasion and migration, and the Hippo signaling pathway in CRC cells. Furthermore, downregulation of miR-30a-5p reversed the effects of curcumol on cell invasion and migration, and the Hippo signaling pathway in CRC cells. These findings identified novel signaling pathways associated with miR-30a-5p and revealed the effects of curcumol on miR-30a-5p expression. Therefore, curcumol may serve as a potential therapeutic strategy to delay CRC progression.

Emerging roles of microRNAs and their implications in uveal melanoma

Uveal melanoma (UM) is the most common intraocular malignant tumor in adults with an extremely high mortality rate. Genetic and epigenetic dysregulation contribute to the development of UM. Recent discoveries have revealed dysregulation of the expression levels of microRNAs (miRNAs) as one of the epigenetic mechanisms underlying UM tumorigenesis. Based on their roles, miRNAs are characterized as either oncogenic or tumor suppressive. This review focuses on the roles of miRNAs in UM tumorigenesis, diagnosis, and prognosis, as well as their therapeutic potentials. Particularly, the actions of collective miRNAs are summarized with respect to their involvement in major, aberrant signaling pathways that are implicated in the development and progression of UM. Elucidation of the underlying functional mechanisms and biological aspects of miRNA dysregulation in UM is invaluable in the development of miRNA-based therapeutics, which may be used in combination with conventional treatments to improve therapeutic outcomes. In addition, the expression levels of some miRNAs are correlated with UM initiation and progression and, therefore, may be used as biomarkers for diagnosis and prognosis.

MicroRNA-633 enhances melanoma cell proliferation and migration by suppressing KAI1

The aim of the present study was to determine the impact of microRNA (miRNA/miR)-633 on the biological properties of malignant melanoma cells. Kang-Ai 1 (KAI1), also known as cluster of differentiation 82, is an important transcriptional regulator and tumor suppressor gene present in different types of tumors. miRNAs that potentially bind with KAI1 were predicted via bioinformatics analyses. In total, six putative miRNA regulators of KAI1 were identified in the present analysis, among which miR-633 was upregulated the most in melanoma tissues compared with the control group. The expression levels of miR-633 and KAI1 in melanoma tissues compared with adjacent normal tissues were then assessed. It was found that miR-633 was significantly upregulated in melanoma cells compared with the control group, whereas the expression levels of KAI1 showed the opposite results. miR-633 was predicted to target the 3'-untranslated region of KAI1 using predictive online tools, and results from luciferase reporter assays confirmed the direct regulation of KAI1 promoter activity by miR-633. Furthermore, miR-633 mimics over expression was shown to suppress both mRNA and protein expression of KAI1, while miR-633 inhibition resulted in decreased viability and migrationin melanoma cells in vitro. Taken together, the present study demonstrated, to the best of the authors' knowledge for the first time, that miR-633 exerts an important role in melanoma through targeting KAI1.

The Role of Non-Coding RNAs in Uveal Melanoma

Simple Summary

The development of uveal melanoma is a multifactorial and multi-step process, in which abnormal gene expression plays a key role. Recently, several studies have highlighted the role of non-coding RNAs in the progression of uveal melanoma by affecting different signaling pathways. As important agents in the regulation of genes, non-coding RNAs have enormous potential to open up therapeutic pathways, predict response to treatment, and anticipate patient outcome for uveal melanoma. This review aims to provide a comprehensive view of what we know about ncRNAs in uveal melanoma currently.

Abstract

Uveal melanoma (UM) is the most common primary intraocular tumor in adulthood. Approximately 50% of patients develop metastatic disease, which typically affects the liver and is usually fatal within one year. This type of cancer is heterogeneous in nature and is divided into two broad groups of tumors according to their susceptibility to develop metastasis. In the last decade, chromosomal abnormalities and the aberrant expression of several signaling pathways and oncogenes in uveal melanomas have been described. Recently, importance has been given to the association of the mentioned deregulation with the expression of non-coding RNAs (ncRNAs). Here, we review the different classes of ncRNAs—such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs)—and their contribution to the development of UM. Special attention is given to miRNAs and their regulatory role in physiopathology and their potential as biomarkers. As important agents in gene regulation, ncRNAs have a huge potential for opening up therapeutic pathways, predicting response to treatment, and anticipating patient outcome for UM.

MicroRNAs and Uveal Melanoma: Understanding the Diverse Role of These Small Molecular Regulators

Uveal melanoma (UM) is a rare tumour of the eye, characterised by a high propensity to metastasise in half of all patients, most frequently to the liver. Although there are effective treatment options for the primary tumour, once metastasis has occurred prognosis is poor, with overall survival limited to months. Currently, there are no effective treatments for metastatic UM, despite the tumour having a well-defined signalling pathway to which many therapies have been directed. In an effort to develop novel treatment approaches, understanding the role of other signalling molecules, such as microRNAs, is fundamental. MicroRNAs (miRNAs) are small non-coding RNA molecules involved in posttranscriptional gene regulation, resulting in reduced target gene expression and subsequent protein translation. In UM, several dysregulated miRNAs have been proposed to play a functional role in disease progression, whereas others have been put forward as clinical biomarkers of high-risk disease following isolation from blood, plasma and exosomes. Most recently, analyses of large datasets have identified promising prognostic miRNA signatures and panels. This review navigates the plethora of aberrant miRNAs disclosed so far in UM, and maps these to signalling pathways, which could be targeted in future therapies for the disseminated disease.

Inhibition of Lnc-OC1 Induced Cell Apoptosis and Decreased Cell Viability by Releasing miR-34a and Inhibiting PD-L1 in Endometrial Carcinoma

Now, there is a growing awareness of the role to long non-coding RNAs (lncRNAs) in tumorigenesis and progression of a variety of malignancies including endometrial carcinoma (EC). Here, we explored the potential molecular mechanism of Lnc-OC1, a novel lncRNA, in the development of EC. Our results suggested that Lnc-OC1 was significantly upregulated in EC tissues comparing with normal tissues. Besides, Lnc-OC1 was higher expressed in the more advanced stage of EC. Therefore, Lnc-OC1 might be a crucial regulator in the progress of EC. Moreover, knockdown of Lnc-OC1 leaded to an inhibition of cell viability and a raise of cell apoptosis. In addition, Lnc-OC1 could sponge miR-34a and thus decrease its expression. miR-34a was proved to be a tumor suppressor in different malignance, hence downregulating Lnc-OC1 helped to alleviate EC by releasing miR-34a. Furthermore, rescue experiments significantly indicated that knockdown of Lnc-OC1 inhibited cell growth through repressing PD-L1 expression at least partially. Concisely, our results proved that Lnc-OC1/miR-34a/PD-L1 axis might serve as a therapeutic target of EC.