The promyelocytic leukemia zinc finger-microRNA-221/-222 pathway controls melanoma progression through multiple oncogenic mechanisms

Therapeutic modulation of KIT ligand in melanocytic disorders with implications for mast cell diseases

KIT ligand and its associated receptor KIT serve as a master regulatory system for both melanocytes and mast cells controlling survival, migration, proliferation and activation. Blockade of this pathway results in cell depletion, while overactivation leads to mastocytosis or melanoma. Expression defects are associated with pigmentary and mast cell disorders. KIT ligand regulation is complex but efficient targeting of this system would be of significant benefit to those suffering from melanocytic or mast cell disorders. Herein, we review the known associations of this pathway with cutaneous diseases and the regulators of this system both in skin and in the more well-studied germ cell system. Exogenous agents modulating this pathway will also be presented. Ultimately, we will review potential therapeutic opportunities to help our patients with melanocytic and mast cell disease processes potentially including vitiligo, hair greying, melasma, urticaria, mastocytosis and melanoma.

Extracellular vesicle-derived non-coding RNAs in remodeling melanoma

Melanoma is one of the most lethal cutaneous malignancies. Despite great advances in radiotherapy, chemotherapy, and immunotherapy, the survival rate and prognosis of patients with melanoma remain poor. The abundant and sophisticated reciprocal communication network between melanoma cells and non-tumor cells contributes to the high heterogeneity of the melanoma microenvironment and is intimately related to varying treatment responses and clinical courses. Extracellular vesicles (EVs) are membrane structures generated by nearly all cell types. EVs contain biologically active molecules, mainly comprising proteins, lipids, and RNAs, and undoubtedly play multifaceted roles in numerous diseases, represented by melanoma. Non-coding RNAs (ncRNAs) mainly encompass long non-coding RNAs, microRNAs, and circular RNAs and constitute the majority of the human transcriptome. Multiple ncRNAs encapsulated in EVs coordinate various pathophysiological processes in melanoma. This review summarizes the mechanisms by which EV-ncRNAs modulate biological behaviors and immunity, and their potential diagnostic and therapeutic applications in melanoma. Undoubtedly, further insight into EV-ncRNAs and their functions in melanoma will contribute to the clinical treatment of melanoma and the implementation of precision medicine.

Resveratrol: Targeting Cancer Stem Cells and ncRNAs to Overcome Cancer Drug Resistance

A major challenge in treating cancer is the development of drug resistance, which can result in treatment failure and tumor recurrence. Targeting cancer stem cells (CSCs) and non-coding RNAs (ncRNAs) with a polyphenolic substance called resveratrol has the ability to combat this problem by lowering cancer resistance to drugs and opening up new therapeutic options. Resveratrol alters the expression of genes related to self-renewal, modulating important signaling pathways involved in cancer initiation and CSC control. Additionally, resveratrol affects non-coding RNAs (ncRNAs), including Micro-RNAs (miRNAs) and long non-coding RNAs (lncRNAs which are essential for stemness, drug resistance, and other cancer-related activities. Numerous studies have shown that resveratrol has the potential to be an effective anticancer drug when used in combination therapy, but issues with absorption and pharmacokinetics still need to be resolved before it can be used in clinical applications. Reducing chemotherapy resistance by better understanding the intricate mechanisms by which resveratrol affects cancer cells and CSCs, as well as its impact on ncRNA expression, could eventually contribute to more effective cancer treatments. To completely understand these pathways and optimize the utilization of resveratrol in combination treatments, additional study is necessary.

Determination of Common microRNA Biomarker Candidates in Stage IV Melanoma Patients and a Human Melanoma Cell Line: A Potential Anti-Melanoma Agent Screening Model

MicroRNAs (miRNAs) are small, non-coding RNAs that play an important role in regulating gene expression. Dysregulation of miRNA expression is commonly observed in cancer, and it can contribute to malignant cell growth. Melanoma is the most fatal type of skin malignant neoplasia. Some microRNAs can be prospective biomarkers for melanoma in stage IV (advanced) at higher risk of relapses and require validation for diagnostic purposes. This work aimed to (1) determine the most significant microRNA biomarker candidates in melanoma using content analysis of the scientific literature, (2) to show microRNA biomarker candidates' diagnostic efficacy between melanoma patients and healthy control groups in a small-scale preliminary study by blood plasma PCR analysis, (3) to determine significant microRNA markers of the MelCher human melanoma cell line, which are also detected in patients with melanoma, that can be used as markers of drug anti-melanoma activity, and (4) test anti-melanoma activity of humic substances and chitosan by their ability to reduce level of marker microRNAs. The content analysis of the scientific literature showed that hsa-miR-149-3p, hsa-miR-150-5p, hsa-miR-193a-3p, hsa-miR-21-5p, and hsa-miR-155-5p are promising microRNA biomarker candidates for diagnosing melanoma. Estimating microRNA in plasma samples showed that hsa-miR-150-5p and hsa-miR-155-5p may have a diagnostic value for melanoma in stage IV (advanced). When comparing ΔCt hsa-miR-150-5p and ΔCt hsa-miR-155-5p levels in melanoma patients and healthy donors, statistically significant differences were found (p = 0.001 and p = 0.001 respectively). Rates ΔCt were significantly higher among melanoma patients (medians concerning the reference gene miR-320a were 1.63 (1.435; 2.975) and 6.345 (4.45; 6.98), respectively). Therefore, they persist only in plasma from the melanoma patients group but not in the healthy donors group. In human wild-type stage IV melanoma (MelCher) cell culture, the presence of hsa-miR-150-5p and hsa-miR-155-5p in supernatant was detected. The ability of humic substance fractions and chitosan to reduce levels of hsa-miR-150-5p and hsa-miR-155-5p was tested on MelCher cultures, which is associated with anti-melanoma activity. It was found that the hymatomelanic acid (HMA) fraction and its subfraction UPLC-HMA statistically significantly reduced the expression of miR-150-5p and miR-155-5p (p ≤ 0.05). For the humic acid (HA) fraction, this activity was determined only to reduce miR-155-5p (p ≤ 0.05). Ability to reduce miR-150-5p and miR-155-5p expression on MelCher cultures was not determined for chitosan fractions with a molecular weight of 10 kDa, 120 kDa, or 500 kDa. Anti-melanoma activity was also determined in the MTT test on MelCher cultures for explored substances. The median toxic concentration (TC50) was determined for HA, HMA and UPLC-HMA (39.3, 39.7 and 52.0 μg/mL, respectively). For 10 kDa, 120 kDa, or 500 kDa chitosan fractions TC50 was much higher compared to humic substances (508.9, 6615.9, 11352.3 μg/mL, respectively). Thus, our pilot study identified significant microRNAs for testing the in vitro anti-melanoma activity of promising drugs and melanoma diagnostics in patients. Using human melanoma cell cultures gives opportunities to test new drugs on a culture that has a microRNA profile similar to that of patients with melanoma, unlike, for example, murine melanoma cell cultures. It is necessary to conduct further studies with a large number of volunteers, which will make it possible to correlate the profile of individual microRNAs with specific patient data, including the correlation of the microRNA profile with the stage of melanoma.

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.

Suppression of exosomal hsa_circ_0001005 eliminates the Vemurafenib resistance of melanoma

OBJECTIVES

More and more evidences show that circular RNAs (circRNAs) can be used as miRNA sponge to regulate the drug resistance of malignancies, including melanoma. However, how exosomal circRNAs participate in the therapeutic resistance of melanoma remains ambiguous.

METHODS

Vemurafenib-resistant A375 cells were cultured and then the circRNA profile of exosomes from the parental A375 and A375-resistant cells were sequenced. Transmission electron microscopy (TEM), exogenous nanoparticle tracking analysis (NTA) and Western Blot assays were leveraged to confirm the successful collection of exosomes from A375 and A375R cells. Another five published RNA-seq data and microRNA-seq data, and seven miRNA databases were collected to construct a competing endogenous RNA (ceRNA) network. Comprehensive bioinformatic analysis was adopted to identify key molecules related to the drug resistance, including multiscale embedded gene co-expression network analysis (MEGENA). Then, qRT-PCR, cell viability and colony formation were used to estimate the function of hub circRNAs. The role of has_circ_0001005 in vivo was verified via xenograft assay. The Tumor online Prognostic analyses Platform (ToPP) was leveraged to develop the has_circ_0001005-related prognostic models for melanoma patients based on TCGA data.

RESULTS

Compared with parental cells, hsa_circ_0001005 expression was significantly increased in resistant cells and their exosomes. The elevated level of hsa_circ_0001005 was related to the poor clinical prognosis of melanoma patients. Hsa_circ_0001005 found in melanoma was mainly secreted by drug-resistant cells as exosomes. Exosomal hsa_circ_0001005 activated multiple canonical pathways related to drug resistance through sponging four miRNAs, thus suppressing the drug sensitivity of melanoma. Knocking down hsa_circ_0001005 in vitro, we found that the inhibition of hsa_circ_0001005 could hinder the clone formation of melanoma. Further in vivo animal experiments suggested that suppression of hsa_circ_0001005 can increase the sensitivity to Vemurafenib of melanoma cells. Finally, we also constructed the functional regulatory ceRNA network and prognostic risk models for hsa_circ_0001005, and further survival analysis reveals that the regulatory network and prognostic risk models obviously affected the prognosis of melanoma patients.

CONCLUSIONS

This study confirmed that the level of hsa_circ_0001005 in exosomes is the key factor affecting drug resistance of melanoma, which provides a new potential therapeutic target for melanoma patients.

Comparative transcriptome and miRNA analysis of skin pigmentation during embryonic development of Chinese soft-shelled turtle (Pelodiscus sinensis)

BACKGROUND

Aquatic animals show diverse body coloration, and the formation of animal body colour is a complicated process. Increasing evidence has shown that microRNAs (miRNAs) play important regulatory roles in many life processes. The role of miRNAs in pigmentation has been investigated in some species. However, the regulatory patterns of miRNAs in reptile pigmentation remain to be elucidated. In this study, we performed an integrated analysis of miRNA and mRNA expression profiles to explore corresponding regulatory patterns in embryonic body colour formation in the soft-shelled turtle Pelodiscus sinensis.

RESULTS

We identified 8 866 novel genes and 9 061 mature miRNAs in the skin of Chinese soft-shelled turtles in three embryonic stages (initial period: IP, middle period: MP, final period: FP). A total of 16 563 target genes of the miRNAs were identified. Furthermore, we identified 2 867, 1 840 and 4 290 different expression genes (DEGs) and 227, 158 and 678 different expression miRNAs (DEMs) in IP vs. MP, MP vs. FP, and IP vs. FP, respectively. Among which 72 genes and 25 miRNAs may be related to turtle pigmentation in embryonic development. Further analysis of the novel miRNA families revealed that some novel miRNAs related to pigmentation belong to the miR-7386, miR-138, miR-19 and miR-129 families. Novel_miR_2622 and novel_miR_2173 belong to the miR-19 family and target Kit and Gpnmb, respectively. The quantification of novel_miR_2622 and Kit revealed negative regulation, indicating that novel_miR_2622 may participate in embryonic pigmentation in P. sinensis by negatively regulating the expression of Kit.

CONCLUSIONS

miRNA act as master regulators of biological processes by controlling the expression of mRNAs. Considering their importance, the identified miRNAs and their target genes in Chinese soft-shelled turtle might be useful for investigating the molecular processes involved in pigmentation. All the results of this study may aid in the improvement of P. sinensis breeding traits for aquaculture.

Targeting the epigenome in malignant melanoma: Facts, challenges and therapeutic promises

Malignant melanoma is the most lethal type of skin cancer with high rates of mortality. Although current treatment options provide a short-clinical benefit, acquired-drug resistance highlights the low 5-year survival rate among patients with advanced stage of the disease. In parallel, the involvement of an aberrant epigenetic landscape, (e.g., alterations in DNA methylation patterns, histone modifications marks and expression of non-coding RNAs), in addition to the genetic background, has been also associated with the onset and progression of melanoma. In this review article, we report on current therapeutic options in melanoma treatment with a focus on distinct epigenetic alterations and how their reversal, by specific drug compounds, can restore a normal phenotype. In particular, we concentrate on how single and/or combinatorial therapeutic approaches have utilized epigenetic drug compounds in being effective against malignant melanoma. Finally, the role of deregulated epigenetic mechanisms in promoting drug resistance to targeted therapies and immune checkpoint inhibitors is presented leading to the development of newly synthesized and/or improved drug compounds capable of targeting the epigenome of malignant melanoma.

Regulatory function of DNA methylation mediated lncRNAs in gastric cancer

As one of the most common malignancies worldwide, gastric cancer contributes to cancer death with a high mortality rate partly responsible for its out-of-control progression as well as limited diagnosis. DNA methylation, one of the epigenetic events, plays an essential role in the carcinogenesis of many cancers, including gastric cancer. Long non-coding RNAs have emerged as the significant factors in the cancer progression functioned as the oncogene genes, the suppressor genes and regulators of signaling pathways over the decade. Intriguingly, increasing reports, recently, have claimed that abnormal DNA methylation regulates the expression of lncRNAs as tumor suppressor genes in gastric cancer and lncRNAs as regulators could exert the critical influence on tumor progression through acting on DNA methylation of other cancer-related genes. In this review, we summarized the DNA methylation-associated lncRNAs in gastric cancer which play a large impact on tumor progression, such as proliferation, invasion, metastasis and so on. Furthermore, the underlying molecular mechanism and signaling pathway might be developed as key points of gastric cancer range from diagnosis to prognosis and treatment in the future.

Implications of Decreased Expression of miR-125a with Respect to Its Variant Allele in the Pathogenesis of Recurrent Pregnancy Loss: A Study in a High Incidence Zone

Pregnancy is controlled by several types of genes and the regulation of their expression is tightly controlled by miRNAs. The present study was carried out to explore the association between miR-125a polymorphic sequence variation and its expression and recurrent pregnancy loss (RPL) compared to full-term healthy controls. A total of 150 women that had experienced two or more RPLs and 180 healthy controls (two or more full-term pregnancies) were recruited, along with 50 product of conception (POC) samples from the corresponding RPL patients, and evaluated for miR-125a SNPs by the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP), which was confirmed by high resolution melting (HRM)/DNA sequencing. Additionally, the expression of miR-125a was quantified with q−PCR in the maternal plasma of 40 corresponding RPL patients against healthy controls. The frequency of variant genotype CC was significantly higher in RPL cases (19.3%) than controls (10.5%), with an odds ratio of >2 (p = 0.025). The expression levels of miR-125a were markedly decreased in RPL cases compared to healthy controls (p < 0.05). Variant genotype CC was found significantly more often in RPL cases than controls (0.34 vs. 0.20; p < 0.05).In this study, miR-125a rs12976445 C/T revealed that the homozygous CC genotype and C allele were associated with the risk of RPL and significant expression indicates that miR-125a has an important role in RPL etiopathogenesis.

The Role of Extracellular Vesicles in Melanoma Progression

Cutaneous melanoma arises from a malignant transformation of the melanocytes in the skin. It is the deadliest form of skin cancer owing to its potential to metastasize. While recent advances in immuno-oncology have been successful in melanoma treatment, not all the patients respond to the treatment equally, thus individual pre-screening and personalized combination therapies are essential to stratify and monitor patients. Extracellular vesicles (EVs) have emerged as promising biomarker candidates to tackle these challenges. EVs are ~50-1000-nm-sized, lipid bilayer-enclosed spheres, which are secreted by almost all cell types, including cancer cells. Their cargo, such as nucleic acids, proteins, lipids, amino acids, and metabolites, can be transferred to target cells. Thanks to these properties, EVs can both provide a multiplexed molecular fingerprint of the cell of origin and thus serve as potential biomarkers, or reveal pathways important for cancer progression that can be targeted pharmaceutically. In this review we give a general overview of EVs and focus on their impact on melanoma progression. In particular, we shed light on the role of EVs in shaping the tumor-stroma interactions that facilitate metastasis and summarize the latest findings on molecular profiling of EV-derived miRNAs and proteins that can serve as potential biomarkers for melanoma progression.

Loss of full-length pumilio 1 abrogates miRNA-221-induced gene p27 silencing-mediated cell proliferation in the heart

Upregulated expression of microRNA (miR)-221 is associated with downregulation of p27 and subsequent increased cell proliferation in a variety of human cancers. It is unknown whether miR-221 mimics could trigger neoplastic cellular proliferation. In vitro, we demonstrated miR-221 significantly downregulates the expression of P27 and increases proliferation of H9c2 and cardiac fibroblasts. The knockdown of PUM1 but not PUM2 abolished such effects by miR-221, as verified by RT-qPCR and western blot, direct binding of p27 3′ UTR by luciferase reporter assay and cell proliferation by Ki67. In vivo expression of P27 in the rat liver, heart, kidney, spleen, and muscle were not affected by miR-221 at 1 and 4 mg/kg and concurrently full-length (FL) PUM1 (140 kDa) was not detected. Instead, isoforms of 105 and 90 kDa were observed and generated through alternative RNA slicing verified by cDNA cloning and sequencing and cathepsin K cleavage confirmed by studies with the inhibitor odanacatib. This is the first study to address the possible pro-proliferative effects of miR-221 mimic therapeutics in cardiovascular applications. Loss of FL PUM1 expression is a key factor abrogating miR-221-mediated p27 regulation, although other concurrent mechanisms cannot be excluded. Our findings provide essential insights into the context-dependent nature of miRNA functionality.

MicroRNA Isoforms Contribution to Melanoma Pathogenesis

Cutaneous melanoma (CM) is the most lethal tumor among skin cancers, and its incidence is constantly increasing. A deeper understanding of the molecular processes guiding melanoma pathogenesis could improve diagnosis, treatment and prognosis. MicroRNAs play a key role in melanoma biology. Recently, next generation sequencing (NGS) experiments, designed to assess small-RNA expression, revealed the existence of microRNA variants with different length and sequence. These microRNA isoforms are known as isomiRs and provide an additional layer to the complex non-coding RNA world. Here, we collected data from NGS experiments to provide a comprehensive characterization of miRNA and isomiR dysregulation in benign nevi (BN) and early-stage melanomas. We observed that melanoma and BN express different and specific isomiRs and have a different isomiR abundance distribution. Moreover, isomiRs from the same microRNA can have opposite expression trends between groups. Using The Cancer Genome Atlas (TCGA) dataset of skin cancers, we analyzed isomiR expression in primary melanoma and melanoma metastasis and tested their association with NF1, BRAF and NRAS mutations. IsomiRs differentially expressed were identified and catalogued with reference to the canonical form. The reported non-random dysregulation of specific isomiRs contributes to the understanding of the complex melanoma pathogenesis and serves as the basis for further functional studies.

Overexpression of miR-221 stimulates proliferation of rat neural stem cell with activating Phosphatase and tensin homolog/protein kinase B signaling pathway

Neural stem cells (NSCs) are self-renewing, multipotent cells, and remain in our brains throughout life. They could be activated by brain damage and involved in the central nervous system (CNS) repair and motor functional recovery. Previous research demonstrated that miR-221 could regulate proliferation, differentiation, and survival. However, the effect of miR-221 on NSCs remains unknown. In this study, we showed that overexpression of miR-221 inhibited the expression of phosphatase and tensin homolog (PTEN) protein and increased the phosphorylation level of protein kinase B (AKT). More importantly, an AKT-specific inhibitor abolished the effect of miR-221 on the phosphorylation level of AKT. 5-Bromo-2-deoxyUridine (BrdU) incorporation assay and Cyclin D1 expression showed that miR-221 overexpression further promoted the NSCs proliferation. However, knocking down miR-221 inhibited cell proliferation. The AKT-specific inhibitor also blocked the proliferative efficiency of miR-221. These results demonstrated that miR-221 overexpression promoted the proliferation of cultured rat NSCs, for which the PTEN/AKT pathway activation was one possible mechanism. Our research may provide a novel investigating strategy to improve stem cell treatment for CNS diseases.

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.

Melanoma genomics: a state-of-the-art review of practical clinical applications

Our collective understanding of melanoma genomics has rapidly expanded in the past decade, bringing great promise to patients affected with the most severe and aggressive cases of melanoma. In this review, we present the practical clinical impact of genetics and genomics on modern melanoma diagnosis and treatment. Characterization of somatic driver mutations, which can be used to distinguish different subtypes of melanoma such as nonacral cutaneous melanoma (NACM), desmoplastic melanoma (DM), acral melanoma (AM), mucosal melanoma (MM) and uveal melanoma (UM), has led to the development of many targeted therapies against these tumours. Although targeted therapies exist for certain mutations, such as BRAF and KIT, other genotypes respond to newer-generation immune therapies such as immune checkpoint inhibitors. Epigenetics also plays a critical role in melanoma pathogenesis and drug resistance, holding promise for new treatment avenues. In this review, special attention is placed on clinical trials and translational research, especially novel genomic tests aimed to benefit patients on an individualized level in the current emerging era of personalized therapy.

Bioinformatics analysis of the expression and role of microRNA-221-3p in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, associated with a high rate of morbidity and mortality. However, the target genes of miR-221-3p and the underlying mechanism involved in HNSCC are still not clear. Therefore, in the current study, we studied the role of miR-221-3p in the HNSCC.

METHODS

Tissues collected from 48 control and 21 HNSCC patients were processed to check the differential expression of miR-221-3p by RT-qPCR. Overexpression of microRNA-221-3p (miR-221-3p) is significantly correlated to the onset and progression of HNSCC. We also conducted the meta-analysis of the cancer literature from the cancer genome atlas (TCGA) and the Gene Expression Omnibus (GEO) database to estimate the expression of miR-221-3p in HNSCC. The miR-221-3p target genes in the HNSCC were predicted with the miRWalk and TCGA databases, and functionally annotated via the Gene Ontology. Finally, Spearman's analysis was used to determine the role of the related target genes in important pathways involved in the development of HNSCC.

RESULTS

We observed a significantly higher expression of miR-221-3p in HNSCC compared to the normal with a summary receiver operating characteristic (sROC) of 0.86(95% Cl: 0.83,0.89). The KEGG and GO comprehensive analysis predicted that miR-221-3p might be involved in the development of HNSCC through the following metabolic pathways, viz. Drug metabolism - cytochrome P450 UGT1A7 and MAOB may be important genes for the role of miR-221-3p.

CONCLUSION

Based on bioinformatics analysis, our results indicate that miR-221-3p may be used as a non-invasive and hypersensitive biomarker in the diagnosis. Thus, it can be concluded that miR-221-3p may be an extremely important gene locus involved in the process of the deterioration and eventual tumorigenesis of HNSCC. Hopefully, additional work will validate its usefulness as a target for future clinical research.

The role of CAF derived exosomal microRNAs in the tumour microenvironment of melanoma

Exosomes play a crucial role in the crosstalk between cancer associated fibroblasts (CAFs) and cancer cells, contributing to carcinogenesis and the tumour microenvironment. Recent studies have revealed that CAFs, normal fibroblasts and cancer cells all secrete exosomes that contain miRNA, establishing a cell-cell communication network within the tumour microenvironment. For example, miRNA dysregulation in melanoma has been shown to promote CAF activation via induction of epithelial-mesenchymal transition (EMT), which in turn alters the secretory phenotype of CAFs in the stroma. This review assesses the roles of melanoma exosomal miRNAs in CAF formation and how CAF exosome-mediated feedback signalling to melanoma lead to tumour progression and metastasis. Moreover, efforts to exploit exosomal miRNA-mediated network communication between tumour cells and their microenvironment, and their potential as prognostic biomarkers or novel therapeutic targets in melanoma will also be considered.

Silencing of long noncoding RNA TUG1 inhibits viability and promotes apoptosis of acute myeloid leukemia cells by targeting microRNA-221-3p/KIT axis

OBJECTIVE: Acute myeloid leukemia (AML) is a hematological malignancy. This study was attempted to uncover the effects of long noncoding RNA taurine-upregulated gene1 (TUG1) on the viability and apoptosis of AML cells. METHODS: QRT-PCR was implemented to examine the expression of TUG1, miR-221-3p and KIT in AML. The correlation between TUG1 and clinicopathological features of AML patients was evaluated. The effect of TUG1 on AML cells were studied by RNA interference approach. AML cells were transfected with miR-221-3p mimic and miR-221-3p inhibitor, respectively. Then the viability and apoptosis of AML cells were examined by MTT and flow cytometry assay, respectively. Additionally, dual-luciferase reporter assay was used to confirm the interactions among TUG1, miR-221-3p and KIT. Western blot was applied to analyze protein expression of KIT. RESULTS: The expression of TUG1 and KIT was up-regulated in AML, but miR-221-3p was down-regulated. TUG1 expression had obviously correlation with World Health Organization (WHO) grade in AML patients. The functional experiment stated that TUG1 silencing suppressed the viability and accelerated the apoptosis of AML cells. Moreover, the mechanical experiment demonstrated that TUG1 and KIT were both targeted by miR-221-3p with the complementary binding sites at 3’UTR. Up-regulation of miR-221-3p inhibited the protein expression of KIT. Furthermore, in the feedback experiment, miR-221-3p inhibition or KIT overexpression reversed the repression of tumor behavior induced by TUG1 silencing. CONCLUSIONS: TUG1 silencing retarded viability and promoted apoptosis of AML cells via regulating miR-221-3p/KIT axis, providing a potential therapeutic target for AML.

Vitamin D and IFN-β Modulate the Inflammatory Gene Expression Program of Primary Human T Lymphocytes

IFN-β treatment is a commonly used therapy for relapsing-remitting multiple sclerosis (MS), while vitamin D deficiency correlates with an increased risk of MS and/or its activity. MS is a demyelinating chronic inflammatory disease of the central nervous system, in which activated T lymphocytes play a major role, and may represent direct targets of IFN-β and vitamin D activities. However, the underlying mechanism of action of vitamin D and IFN-β, alone or in combination, remains incompletely understood, especially when considering their direct effects on the ability of T lymphocytes to produce inflammatory cytokines. We profiled the expression of immune-related genes and microRNAs in primary human T lymphocytes in response to vitamin D and IFN-β, and we dissected the impact of these treatments on cytokine production and T cell proliferation. We found that the treatments influenced primarily memory T cell plasticity, rather than polarization toward a stable phenotype. Moreover, our data revealed extensive reprogramming of the transcriptional output of primary T cells in response to vitamin D and IFN-β and provide the bases for further mechanistic insights into these commonly used treatments.

MicroRNAs at the Crossroad of the Dichotomic Pathway Cell Death vs. Stemness in Neural Somatic and Cancer Stem Cells: Implications and Therapeutic Strategies

Stemness and apoptosis may highlight the dichotomy between regeneration and demise in the complex pathway proceeding from ontogenesis to the end of life. In the last few years, the concept has emerged that the same microRNAs (miRNAs) can be concurrently implicated in both apoptosis-related mechanisms and cell differentiation. Whether the differentiation process gives rise to the architecture of brain areas, any long-lasting perturbation of miRNA expression can be related to the occurrence of neurodevelopmental/neuropathological conditions. Moreover, as a consequence of neural stem cell (NSC) transformation to cancer stem cells (CSCs), the fine modulation of distinct miRNAs becomes necessary. This event implies controlling the expression of pro/anti-apoptotic target genes, which is crucial for the management of neural/neural crest-derived CSCs in brain tumors, neuroblastoma, and melanoma. From a translational point of view, the current progress on the emerging miRNA-based neuropathology therapeutic applications and antitumor strategies will be disclosed and their advantages and shortcomings discussed.

Signaling of Tumor-Derived sEV Impacts Melanoma Progression

Small extracellular vesicles (sEV or exosomes) are nanovesicles (30–150 nm) released both in vivo and in vitro by most cell types. Tumor cells produce sEV called TEX and disperse them throughout all body fluids. TEX contain a cargo of proteins, lipids, and RNA that is similar but not identical to that of the “parent” producer cell (i.e., the cargo of exosomes released by melanoma cells is similar but not identical to exosomes released by melanocytes), possibly due to selective endosomal packaging. TEX and their role in cancer biology have been intensively investigated largely due to the possibility that TEX might serve as key component of a “liquid tumor biopsy.” TEX are also involved in the crosstalk between cancer and immune cells and play a key role in the suppression of anti-tumor immune responses, thus contributing to the tumor progression. Most of the available information about the TEX molecular composition and functions has been gained using sEV isolated from supernatants of cancer cell lines. However, newer data linking plasma levels of TEX with cancer progression have focused attention on TEX in the patients’ peripheral circulation as potential biomarkers of cancer diagnosis, development, activity, and response to therapy. Here, we consider the molecular cargo and functions of TEX as potential biomarkers of one of the most fatal malignancies—melanoma. Studies of TEX in plasma of patients with melanoma offer the possibility of an in-depth understanding of the melanoma biology and response to immune therapies. This review features melanoma cell-derived exosomes (MTEX) with special emphasis on exosome-mediated signaling between melanoma cells and the host immune system.

Sex and Gender Disparities in Melanoma

Worldwide, the total incidence of cutaneous melanoma is higher in men than in women, with some differences related to ethnicity and age and, above all, sex and gender. Differences exist in respect to the anatomic localization of melanoma, in that it is more frequent on the trunk in men and on the lower limbs in women. A debated issue is if-and to what extent-melanoma development can be attributed to gender-specific behaviors or to biologically intrinsic differences. In the search for factors responsible for the divergences, a pivotal role of sex hormones has been observed, although conflicting results indicate the involvement of other mechanisms. The presence on the X chromosome of numerous miRNAs and coding genes playing immunological roles represents another important factor, whose relevance can be even increased by the incomplete X chromosome random inactivation. Considering the known advantages of the female immune system, a different cancer immune surveillance efficacy was suggested to explain some sex disparities. Indeed, the complexity of this picture emerged when the recently developed immunotherapies unexpectedly showed better improvements in men than in women. Altogether, these data support the necessity of further studies, which consider enrolling a balanced number of men and women in clinical trials to better understand the differences and obtain actual gender-equitable healthcare.

KIT and Melanoma: Biological Insights and Clinical Implications

Melanoma, originating from epidermal melanocytes, is a heterogeneous disease that has the highest mortality rate among all types of skin cancers. Numerous studies have revealed the cause of this cancer as related to various somatic driver mutations, including alterations in KIT-a proto-oncogene encoding for a transmembrane receptor tyrosine kinase. Although accounting for only 3% of all melanomas, mutations in c-KIT are mostly derived from acral, mucosal, and chronically sun-damaged melanomas. As an important factor for cell differentiation, proliferation, and survival, inhibition of c-KIT has been exploited for clinical trials in advanced melanoma. Here, apart from the molecular background of c-KIT and its cellular functions, we will review the wide distribution of alterations in KIT with a catalogue of more than 40 mutations reported in various articles and case studies. Additionally, we will summarize the association of KIT mutations with clinicopathologic features (age, sex, melanoma subtypes, anatomic location, etc.), and the differences of mutation rate among subgroups. Finally, several therapeutic trials of c-KIT inhibitors, including imatinib, dasatinib, nilotinib, and sunitinib, will be analyzed for their success rates and limitations in advanced melanoma treatment. These not only emphasize c-KIT as an attractive target for personalized melanoma therapy but also propose the requirement for additional investigational studies to develop novel therapeutic trials co-targeting c-KIT and other cytokines such as members of signaling pathways and immune systems.

Potential Onco-Suppressive Role of miR122 and miR144 in Uveal Melanoma through ADAM10 and C-Met Inhibition

Uveal melanoma (UM) is a rare tumor of the eye that leads to deadly metastases in about half of the patients. ADAM10 correlates with c-Met expression in UM and high levels of both molecules are related to the development of metastases. MiR122 and miR144 modulate ADAM10 and c-Met expression in different settings. We hypothesized a potential onco-suppressive role for miR122 and miR144 through modulation of ADAM10 and c-Met in UM. We analyzed the UM Cancer Genome Atlas data portal (TCGA) dataset, two other cohorts of primary tumors and five human UM cell lines for miR122 and miR144 expression by miR microarray, RT-qPCR, Western blotting, miR transfection and luciferase reporter assay. Our results indicate that miR122 and miR144 are expressed at low levels in the UM cell lines and in the TCGA UM dataset and were down-modulated in a cohort of seven UM samples, compared to normal choroid. Both miR122 and miR144 directly targeted ADAM10 and c-Met. Overexpression of miR122 and miR144 led to reduced expression of ADAM10 and c-Met in the UM cell lines and impaired cell proliferation, migration, cell cycle and shedding of c-Met ecto-domain. Our results show that miR122 and miR144 display an onco-suppressive role in UM through ADAM10 and c-Met modulation.

Placental exosomes isolated from urine of patients with gestational diabetes exhibit a differential profile expression of microRNAs across gestation

Placenta‑derived exosomes play an important role in cellular communication both in the mother and the fetus. Their concentration and composition are altered in several pregnancy disorders, such as gestational diabetes mellitus (GDM). The isolation and characterization of placental exosomes from serum, plasma and tissues from patients with GDM have been previously described; however, to the best of our knowledge, to date, there is no study available on placental exosomes isolated from urine of patients with GDM. In the present study, placental exosomes were purified from urine the 1st, 2nd and 3rd trimester of gestation. Placental exosomes were characterized by transmission electron microscopy in cryogenic mode and by western blot analysis, confirming the presence of exosomal vesicles. The expression profile of five microRNAs (miR‑516‑5p, miR‑517‑3p, miR‑518‑5p, miR‑222‑3p and miR‑16‑5p) was determined by RT‑qPCR. In healthy pregnant women, the expression of the miRNAs increased across gestation, apart from miR‑516‑5p, which was not expressed at the 2nd trimester. All the miRNAs examined were downregulated in patients with GDM at the 3rd trimester of gestation. The downregulated miRNAs affected several metabolic pathways closely associated with the pathophysiology of GDM. This provides further evidence of the regulatory role of miRNAs in the GDM. This also suggests that the of urinary exosomes may be an excellent source of biomarkers and therapeutic targets.

The miRNAs Role in Melanoma and in Its Resistance to Therapy

Melanoma is the less common but the most malignant skin cancer. Since the survival rate of melanoma metastasis is about 10–15%, many different studies have been carried out in order to find a more effective treatment. Although the development of target-based therapies and immunotherapeutic strategies has improved chances for patient survival, melanoma treatment still remains a big challenge for oncologists. Here, we collect recent data about the emerging role of melanoma-associated microRNAs (miRNAs) currently available treatments, and their involvement in drug resistance. We also reviewed miRNAs as prognostic factors, because of their chemical stability and resistance to RNase activity, in melanoma progression. Moreover, despite miRNAs being considered small conserved regulators with the limitation of target specificity, we outline the dual role of melanoma-associated miRNAs, as oncogenic and/or tumor suppressive factors, compared to other tumors.

MicroRNA-221 and MicroRNA-222 in Common Human Cancers: Expression, Function, and Triggering of Tumor Progression as a Key Modulator

MicroRNAs (miRNAs) are a class of short (~22 nucleotides [nt]), single-stranded RNA oligonucleotides that are regulatory in nature and are often dysregulated in various diseases, including cancer. miRNAs can act as oncomiRs (miRNAs associated with cancer) or tumor suppressor miRNAs and have the potential to be a diagnostic, prognostic, noninvasive biomarker for these diseases. MicroRNA-221 (miR-221) and microRNA-222 (miR-222) are homologous miRNAs, located on the human chromosome Xp11.3, which factored significantly in impairment in the regulation of a wide range of cancers. In this review, we have highlighted the most consistently reported dysregulated miRNAs that trigger human tissues to express cancerous features and surveyed the role of those miRNAs in metastasis, apoptosis, angiogenesis, and tumor prognosis. Also, we applied the causes of drug resistance and the role of coordinated actions of these miRNAs to epigenetic changes and selected miRNAs as a potential type of cancer treatment.

Therapeutic potential of antagomiRs in haematological and oncological neoplasms

BACKGROUND

The importance of the role of MicroRNAs (or miRNAs) has been emphasised by the large number of studies in human tumour cells, underlining the high impact of post-transcriptional processes in cancer onset, progression, invasion and metastatisation. Currently known as oncomiR, real databases are collecting all the smaller fragments of RNA capable of participating in the oncogenesis.

AIMS

With the aim to collect for the first time the most important acquisitions in literature about antagomiRs in oncology, our narrative review is born with the purpose of showing that specific antisense oligonucleotides, capable to bind and antagonise single or multiple miRNAs, are effective as therapeutic compounds.

RESULTS

Peptide or locked nucleic acids, miRNA sponges or antagomiRs attached to plasmid or lentiviral vectors carrying miRNA sequences to its target are objects of our analysis, demonstrating their effectiveness in a large number and types of tumours. We have also tried how to overcome their high immunogenicity, which remains its greatest limit for clinical use.

CONCLUSIONS

They are ambitious but fascinating promise to alter the promotion of the tumour growth by binding specific molecular targets, with high precision and low toxicity, leaving the scientists the chance of development as anti-cancer drugs and not just.

Dissimilar Appearances Are Deceptive-Common microRNAs and Therapeutic Strategies in Liver Cancer and Melanoma

: In this review, we summarize the current knowledge on miRNAs as therapeutic targets in two cancer types that were frequently described to be driven by miRNAs-melanoma and hepatocellular carcinoma (HCC). By focusing on common microRNAs and associated pathways in these-at first sight-dissimilar cancer types, we aim at revealing similar molecular mechanisms that are evolved in microRNA-biology to drive cancer progression. Thereby, we also want to outlay potential novel therapeutic strategies. After providing a brief introduction to general miRNA biology and basic information about HCC and melanoma, this review depicts prominent examples of potent oncomiRs and tumor-suppressor miRNAs, which have been proven to drive diverse cancer types including melanoma and HCC. To develop and apply miRNA-based therapeutics for cancer treatment in the future, it is essential to understand how miRNA dysregulation evolves during malignant transformation. Therefore, we highlight important aspects such as genetic alterations, miRNA editing and transcriptional regulation based on concrete examples. Furthermore, we expand our illustration by focusing on miRNA-associated proteins as well as other regulators of miRNAs which could also provide therapeutic targets. Finally, design and delivery strategies of miRNA-associated therapeutic agents as well as potential drawbacks are discussed to address the question of how miRNAs might contribute to cancer therapy in the future.

Tumor-derived extracellular vesicles and microRNAs: Functional roles, diagnostic, prognostic and therapeutic options

In the last few years cancer research more and more highlighted the importance of cell to cell communication in tumor progression. Among many other functional mechanisms, results evidenced the importance of miRNAs loaded into exosomes and their actions as mediators in intercellular communication, either in the tumor microenvironment or at distant sites. Deregulation of miRNA levels is a prerogative of cancer cells and is reflected in the miRNA cargo of tumor derived exosomes. Thus, learning of circulating miRNA activities add the missing piece we need to understand some unclear aspects of cancer biology. Here we summarized the current knowledge on exosome transfer capabilities between cancer cells and all the cells constituting tumor microenvironment with a particular focus on their miRNA cargos and regulatory functions. The clinical relevance of these molecular aspects is emphasized by numerous cell interactions that ultimately result in normal cell function defeat, relevant to increase tumor malignancy. The quantitative and qualitative evaluation of circulating miRNAs offers new perspective for better diagnosis and prognosis of cancer patients, eventually improving their management.

Role of miR-221/222 in Tumor Development and the Underlying Mechanism

MicroRNA-221/222 (miRNA-221/222, miR-221/222) is a noncoding microRNA which is widely distributed in eukaryotic organisms and deeply involved in the posttranscriptional regulation of gene expressions. According to recent studies, abnormal expressions of miR-221/222 are closely related to the occurrence and development of various kinds of malignant tumors. The role of miR-221/222 in tumor development and their potential molecular mechanism in various cancers, including liver cancer, colorectal cancer, cervical cancer, ovarian cancer, and endometrial carcinoma, are summarized and reviewed in this paper. Moreover, the potential translational biomarker role of abnormal miR-221/222 level in tumor or blood circulation for tumor diagnosis is also discussed.

Circulating microRNAs as biomarkers for early diagnosis of cutaneous melanoma

Introduction: Cutaneous melanoma is the deadliest form of skin cancer, with a dramatic increase in the incidence rate worldwide over the past decade. Early detection has been shown to improve the outcome of melanoma patients. The identification of noninvasive biomarkers able to identify melanoma at an early stage remains an unmet clinical need. Circulating miRNAs (c-miRNAs), small non-coding RNAs, appear as potential ideal candidate biomarkers due to their stability in biological fluids and easy detectability. Moreover, c-miRNAs are reported to be heavily deregulated in cancer patients.Areas covered: This review examines evidence of the specific c-miRNAs or panels of c-miRNAs reported to be useful in discriminating melanoma from benign cutaneous lesions.Expert opinion: Although the interesting reported by published studies, the non-homogeneity of detection and normalization methods prevents the individuation of single c-miRNA or panel of c-miRNAs that are specific for early detection of cutaneous melanoma. In the future, prospective wide and well-designed clinical trials will be needed to validate the diagnostic potential of some of the c-miRNA candidates in clinical practice.

The risk of melanoma in patients with chronic lymphocytic leukemia; a population-based study

INTRODUCTION

Melanoma is a highly malignant tumor that has been repeatedly reported in chronic lymphocytic leukemia (CLL) patients. We aim to assess the epidemiologic characteristics of this association and emphasize the importance of carefully approaching such cases.

METHODS

Patients who were diagnosed with CLL between 2000 and 2015 and registered in the Surveillance, Epidemiology and End Results (SEER) database of the US National Cancer Institute were identified using the SEER*stat software (version 8.3.5). The Multiple Primary Standardized Incidence Ratios session of the SEER*stat software (version 8.3.5) was used to calculate the observed/expected (O/E) ratios of melanoma.

RESULTS

48,876 CLL cases were reviewed, of which 474 developed a second primary melanoma of the skin. O/E ratio was 2.07 (95% CI 1.89-2.27), and excess risk was 9.7 per 10,000. The increase in melanoma risk was higher within the first 5 years following CLL diagnosis; O/E = 2.22 (95% CI 1.56-2.14) and excess risk was 10.43 per 10,000. It was higher in males compared to females O/E was 2.10 (95% CI 1.89-2.33) and 1.98 (95% CI 1.62-2.40) in males and females, respectively, and in people aged 45-64; O/E = 2.30 (95% CI 1.95-2.70). Out of 7827 CLL patients receiving chemotherapy, 70 later developed melanoma with a significant O/E of 2.28 (95% CI 1.77-2.88) and an excess risk of 10.66 per 10,000.

CONCLUSION

CLL increases the risk of developing melanoma, especially within 5 years of the diagnosis, and in white males aged between 45-64 years. It is crucial to keep rigorous screening, high-suspicion and close follow-up for recurrence in consideration while managing these patients.

Exosomal miR-221 derived from hydroquinone-transformed malignant human bronchial epithelial cells is involved in cell viability of recipient cells

miR-221, an oncogenic microRNA, can promote cell proliferation and is highly expressed in various types of tumors. However, the role of exosomal miR-221 in benzene-caused carcinogenesis remains elusive. Our study was designed to investigate whether exosomes secreted by the hydroquinone (HQ; an active metabolite of benzene)-transformed malignant cells can transmit miR-221 to normal recipient cells and its possible effects on cell viability. Our investigation revealed that expression levels of miR-221 were significantly increased in HQ-transformed malignant cells relative to normal controls. Furthermore, exposure of control cells to exosomes that were derived from HQ-transformed malignant cells increased miR-221 levels and promoted their proliferation. Analyses of the biological potency of exosomes derived from HQ-transformed malignant cells in which miR-221 levels were decreased using an inhibitor, showed that both miR-221 levels and proliferation of recipient cells were decreased, but still were higher than those of normal 16HBE cells. Our study indicates that exosomal miR-221 derived from HQ-transformed malignant human bronchial epithelial cells is involved in the proliferation of recipient cells.

The "-OMICS" facet of melanoma: Heterogeneity of genomic, proteomic and metabolomic biomarkers

In the recent decade, cutting edge molecular and proteomic analysis platforms revolutionized biomarkers discovery in cancers. Melanoma is the prototype with over 51,100 biomarkers discovered and investigated thus far. These biomarkers include tissue based tumor cell and tumor microenvironment biomarkers and circulating biomarkers including tumor DNA (cf-DNA), mir-RNA, proteins and metabolites. These biomarkers provide invaluable information for diagnosis, prognosis and play an important role in prediction of treatment response. In this review, we summarize the most recent discoveries in each of these biomarker categories. We will discuss the challenges in their implementation and standardization and conclude with some perspectives in melanoma biomarker research.

Circulating cell-free microRNAs in cutaneous melanoma staging and recurrence or survival prognosis

Cutaneous melanoma is a skin cancer with increasing incidence. Identification of novel clinical biomarkers able to detect the stage of disease and suggest prognosis could improve treatment and outcome for melanoma patients. Cell-free microRNAs (cf-miRNAs) are the circulating copies of short non-coding RNAs involved in gene expression regulation. They are released into the interstitial fluid, are detectable in blood and other body fluids and have interesting features of ideal biomarker candidates. They are stable outside the cell, tissue specific, vary along with cancer development and are sensitive to change in the disease course such as progression or therapeutic response. Moreover, they are accessible by non-invasive methods or venipuncture. Some articles have reported different cf-miRNAs with the potential of diagnostic tools for melanoma staging, recurrence and survival prediction. Although some concordance of results is already emerging, differences in analytical methods, normalization strategies and tumour staging still will require further research and standardization prior to clinical usage of cf-miRNA analysis. This article reviews this literature with the aim of contributing to a shared focusing on these new promising tools for melanoma treatment and care.

Clustered microRNAs hsa-miR-221-3p/hsa-miR-222-3p and their targeted genes might be prognostic predictors for hepatocellular carcinoma

Objective: MicroRNAs (miRNAs) have been explored in malignancies. We investigated the functions of clustered miRNAs hsa-miR-221/222-3p in hepatocellular carcinoma (HCC). Methods: Human miRNA tissue atlas website was determined expression levels in liver tissue. Four databases, TarBase, miRTarBase, miRecords and miRPathDB, were found experimentally validated target genes of clustered miRNAs. TargetScanHuman was predicted target genes. The STRING website was depicted protein-protein interaction (PPI) networks. The OncoLnc website analyzed prognostic values for hsa-miR-221/222-3p and their target genes. The MCODE plugin calculated modules of PPI networks. Receiver operating characteristic (ROC) curves were predicted 1, 3, and 5 years prognostic values. Results: Expression of clustered miRNAs was high in liver tissues. A total of 1577 target genes were identified. Enrichment analysis showed that target genes were enriched mainly in cancer, Wnt signaling and ErbB signaling pathways. Two modules were calculated using PPI networks. Has-miR-221-3p was not associated with prognosis (P = 0.401). Has-miR-222-3p and target genes ESR1, TMED7, CBFB, ETS2, UBE2J1 and UBE2N of the clustered miRNAs were associated with HCC survival (all P < 0.05). Has-miR-222-3p, CBFB, and UBE2N showed good performance of ROC in prognosis prediction at 1, 3, and 5 years (all area under curves > 0.600). Conclusion: Has-miR-222-3p and target genes, especially CBFB, UBE2N, may serve as prognostic predictors for HCC.

Expression of the PTEN/FOXO3a/PLZF signalling pathway in pancreatic cancer and its significance in tumourigenesis and progression

Pancreatic cancer (PC) is one of the most lethal gastrointestinal malignancies. The PTEN/AKT signalling pathway is closely related to the tumourigenesis and progression of PC. The downstream effectors, FOXO3a, PLZF and VEGF, are reported to be involved in angiogenesis, lymph node metastasis and poor survival in PC. By using tissue microarrays and immunohistochemistry, we found, that PTEN, FOXO3a and PLZF expression was significantly decreased in PC specimens compared with that in chronic pancreatitis (CP) specimens, while VEGF expression was significantly increased. Furthermore, the expression of PTEN was positively correlated with that of FOXO3a and PLZF but negatively correlated with that of VEGF. Our results suggest that the PTEN/FOXO3a/PLZF signalling pathway may negatively regulate VEGF expression in PC. Through clinical analysis of 69 PC patients, PTEN, FOXO3a and PLZF expression was found to be significantly decreased in specimens from PC patients with lymph node metastasis and poor prognosis, while VEGF expression was significantly increased. Taken together, these reaults suggest that the PTEN/FOXO3a/PLZF signalling pathway may be capable of inhibiting growth and metastasis in PC by regulating VEGF-mediated angiogenesis, which requires further in vivo and in vitro studies and can potentially be a therapeutic target for PC.

New Insights into the Implication of Epigenetic Alterations in the EMT of Triple Negative Breast Cancer

Breast cancer is the most common cancer and leading cause of cancer death among women worldwide, encompassing a wide heterogeneity of subtypes with different clinical features. During the last two decades, the use of targeted therapies has emerged in clinical research in order to increase treatment efficiency, improve prognosis and reduce recurrence. However, the triple negative breast cancer (TNBC) subtype remains a clinical challenge, with poor prognosis since no therapeutic targets have been identified. This aggressive breast cancer entity lacks expression of oestrogen receptor (ER) and progesterone receptor (PR), and it does not overexpress human epidermal growth factor receptor 2 (HER2). The major reason for TNBC poor prognosis is early therapeutic escape from conventional treatments, leading to aggressive metastatic relapse. Metastases occur after an epithelial-mesenchymal transition EMT of epithelial cells, allowing them to break free from the primary tumour site and to colonize distant organs. Cancer-associated EMT consists not only of acquired migration and invasion ability, but involves complex and comprehensive reprogramming, including changes in metabolism, expression levels and epigenetic. Recently, many studies have considered epigenetic alterations as the primary initiator of cancer development and metastasis. This review builds a picture of the epigenetic modifications implicated in the EMT of breast cancer. It focuses on TNBC and allows comparisons with other subtypes. It emphasizes the role of the main epigenetic modifications lncRNAs, miRNAs, histone and DNA- modifications in tumour invasion and appearance of metastases. These epigenetic alterations can be considered biomarkers representing potential diagnostic and prognostic factors in order to define a global metastatic signature for TNBC.

The rs17084733 variant in the KIT 3' UTR disrupts a miR-221/222 binding site in gastrointestinal stromal tumour: a sponge-like mechanism conferring disease susceptibility

Several miRNAs are dysregulated in gastrointestinal stromal tumours (GIST), and miR-221/222 appear to have a prominent role in GIST biology. Therefore, we investigated the role of DNA variants located in miR-221/222 precursor sequences and their target KIT 3'UTR. Ninety-five polymorphisms were analysed in 115 GIST cases and 88 healthy controls. KIT 3'UTR rs17084733 and pri-miR-222 rs75246947 were found significantly associated with GIST susceptibility. Specifically, KIT rs17084733 A allele was more common in GIST, particularly in KIT wild-type (WT) patients (Padj = 0.017). rs17084733 variant is located within one of the three miR-221/222 binding sites in the KIT 3'UTR, resulting in a mismatch in this seed region. Conversely, KIT mRNA levels were lower in patients carrying the variant allele, except for KIT mutant GIST. Luciferase assay data in GIST cells, generated using a construct containing all the three miR-221/222 binding sites, are consistent with KIT mRNA levels in GIST patients. Reporter assay data, generated using a construct containing only the site encompassing rs17084733, confirmed that this is a functional variant disrupting the miR-221/222 binding site. In conclusion, this is the first study investigating the role of SNPs on miR-221/222 precursor sequences and their binding region on KIT 3'UTR in GIST. We identified the KIT variant rs17084733 as a possible novel genetic biomarker for risk of developing KIT-WT GIST. Moreover, our findings suggest the role of one of the three miR-221/222 binding sites on KIT 3'UTR as endogenous sponge, soaking up and subtracting miR-221/222 to the other two sites characterized by a higher affinity.

Role of miRNAs in Melanoma Metastasis

Tumour metastasis is a multistep process. Melanoma is a highly aggressive cancer and metastasis accounts for the majority of patient deaths. microRNAs (miRNAs) are non-coding RNAs that affect the expression of their target genes. When aberrantly expressed they contribute to the development of melanoma. While miRNAs can act locally in the cell where they are synthesized, they can also influence the phenotype of neighboring melanoma cells or execute their function in the direct tumour microenvironment by modulating ECM (extracellular matrix) and the activity of fibroblasts, endothelial cells, and immune cells. miRNAs are involved in all stages of melanoma metastasis, including intravasation into the lumina of vessels, survival during circulation in cardiovascular or lymphatic systems, extravasation, and formation of the pre-metastatic niche in distant organs. miRNAs contribute to metabolic alterations that provide a selective advantage during melanoma progression. They play an important role in the development of drug resistance, including resistance to targeted therapies and immunotherapies. Distinct profiles of miRNA expression are detected at each step of melanoma development. Since miRNAs can be detected in liquid biopsies, they are considered biomarkers of early disease stages or response to treatment. This review summarizes recent findings regarding the role of miRNAs in melanoma metastasis.

miR-221/222-Mediated Inhibition of Autophagy Promotes Dexamethasone Resistance in Multiple Myeloma

Inherent or acquired resistance to chemotherapeutic drugs is still an obstacle for the treatment of multiple myeloma (MM). MicroRNA dysregulation is related to the development of chemoresistance in cancers. However, its role in chemoresistance of MM is largely unknown. Here we demonstrated that miR-221/222 were upregulated in plasma cells from patients with MM, especially those with relapsed or refractory disease. Moreover, expression levels of miR-221/222 were inversely correlated with dexamethasone (Dex) sensitivity of human MM cell lines. Importantly, we found that Dex induced pro-death autophagy in MM cells and the inhibition of autophagy significantly decreased Dex-induced cell death. Mechanistically, autophagy-related gene 12 (ATG12) was identified as a novel target gene of miR-221/222, and miR-221/222 overexpression inhibited autophagy by directly targeting ATG12 and the p27^kip (p27)-mammalian target of rapamycin (mTOR) pathway. Indeed, Dex treatment decreased the expression of miR-221/222, thereby activating the ATG12/p27-mTOR autophagy-regulatory axis and inducing cell death in Dex-sensitive MM cells. Furthermore, both in vitro and in vivo results showed that the inhibitions of miR-221/222 increased the expression of ATG12 and p27 and functionally induced extended autophagy and cell death of MM cells. In conclusion, our findings demonstrated the crucial role of the miR-221/222-ATG12/p27-mTOR autophagy-regulatory axis in Dex resistance of MM, and they suggest potential prediction and treatment strategies for glucocorticoid resistance.

Interplay between small and long non-coding RNAs in cutaneous melanoma: a complex jigsaw puzzle with missing pieces

The incidence of cutaneous melanoma (CM) has increased in the past few decades. The biology of melanoma is characterized by a complex interaction between genetic, environmental and phenotypic factors. A greater understanding of the molecular mechanisms that promote melanoma cell growth and dissemination is crucial to improve diagnosis, prognostication, and treatment of CM. Both small and long non-coding RNAs (lncRNAs) have been identified to play a role in melanoma biology; microRNA and lncRNA expression is altered in transformed melanocytes and this in turn has functional effects on cell proliferation, apoptosis, invasion, metastasis, and immune response. Moreover, specific dysregulated ncRNAs were shown to have a diagnostic or prognostic role in melanoma and to drive the establishment of drug resistance. Here, we review the current literature on small and lncRNAs with a role in melanoma, with the aim of putting into some order this complex jigsaw puzzle.

Identification of dysregulated microRNAs in canine malignant melanoma

Inhibiting aberrantly upregulated microRNAs (miR/miRNAs) has emerged as a novel focus for therapeutic intervention in human melanoma. Thus, identifying upregulated miRNAs is essential for identifying additional melanoma-associated therapeutic targets. In the present study, microarray-based miRNA profiling of canine malignant melanoma (CMM) tissue obtained from the oral cavity was performed and differential expression was confirmed by a reverse transcription-quantitative polymerase chain reaction (RT-qPCR). An analysis of the microarray data revealed 17 dysregulated miRNAs; 5 were upregulated and 12 were downregulated. RT-qPCR analysis was performed for 2 upregulated (miR-204 and miR-383), 3 downregulated (miR-122, miR-143 and miR-205) and 6 additional oncogenic miRNAs (oncomiRs; miR-16, miR-21, miR-29b, miR-92a, miR-125b and miR-222). The expression levels of seven of the miRNAs, miR-16, miR-21, miR-29b, miR-122, miR-125b, miR-204 and miR-383 were significantly upregulated; however, the expression of miR-205 was downregulated in CMM tissues compared with normal oral tissues. The microarray and RT-qPCR analyses validated the upregulation of two potential oncomiRs miR-204 and miR-383. The present study additionally constructed a protein interaction network and a miRNA-target regulatory interaction network using STRING and Cytoscape. In the proposed network, cyclin dependent kinase 2 was a target for miR-383, sirtuin 1 and tumor protein p53 were targets for miR-204 and ATR serine/threonine kinase was a target for both. It was concluded that miR-383 and miR-204 were potential oncomiRs that may be involved in regulating melanoma development by evading DNA repair and apoptosis.

Melanoma: Where we are and where we go

Melanoma is known as an aggressive tumor which shows an increasing incidence and poor prognosis in the metastatic phase. Hence, it seems that diagnosis and effective management (including early diagnosis, choosing of the effective therapeutic platform, caring, and training of patients for early detection) are major aspects of melanoma therapy. Early detection of melanoma is a key point for melanoma therapy. There are various diagnosis options such as assessing of biopsy, imaging techniques, and biomarkers (i.e., several proteins, polymorphism, and liquid biopsy). Among the various biomarkers, assessing circulating tumor cells, cell-free DNAs, cell-free RNAs, and microRNAs (miRNAs) have emerged as powerful diagnosis tools for melanoma patients. Deregulations of these molecules are associated with melanoma pathogenesis. After detection of melanoma, choosing of effective therapeutic regimen is a key step for recovery of melanoma patients. Several studies indicated that various therapeutic approaches including surgery, immunotherapy, systematic therapy, radiation therapy and antibodies therapy could be used as potential therapeutic candidates for melanoma therapy. Caring for melanoma patients is one of the important components of melanoma therapy. Caring and training for melanoma patients could contribute to better monitoring of patients in response to various therapeutic options. Here, we summarized various diagnosis approaches such as assessing biopsy, imaging techniques, and utilization of various biomarkers (i.e., proteins, CTCs, cfDNAs, and miRNAs) as a diagnostic biomarker for detection and monitoring patients with melanoma. Moreover, we highlighted various therapeutic options and caring aspects in patients with melanoma.

Promyelocytic leukemia zinc finger triggers ATP-binding cassette subfamily E member 1-mediated growth inhibition in breast cancer cells

The promyelocytic leukemia zinc finger (PLZF) protein is a transcription factor that is involved in a number of biological processes, including those regulating cellular growth; however, little is known regarding how it achieves its inhibitory effect in different cell and tissue types. It has previously been demonstrated that PLZF expression levels become diminished during the oncogenic transformation of certain tissue types and thus, may serve as a hallmark for tumor aggressiveness. To examine this in breast cancer, survival curves from available oncology databases were analyzed and demonstrated that PLZF expression was positively associated with increased survival in patients with breast cancer. The mRNA and protein levels of PLZF were also revealed to be associated with the tumorigenicity of four breast cancer cell lines. Since ATP-binding cassette subfamily E member 1 (ABCE1), also known as RNase L inhibitor, has been determined to be a target gene of PLZF, the present study also investigated whether the tumor suppressive effect of PLZF was associated with ABCE1 expression. PLZF was revealed to downregulate the expression of ABCE1 in vitro, which relieved the inhibitory effect of ABCE1 on the ribonuclease L enzyme. Finally, it was concluded that PLZF expression caused an ABCE1-mediated increase in cellular cytotoxicity, as demonstrated by a reduction in the proliferation rate of breast cancer cell lines. The results of the present study are important for understanding how PLZF exerts its final inhibitory actions in breast cancer cells, and potentially in other solid tumors, through the modulation of immunological pathways.

Negative correlation of cytoplasm TIMP3 with miR-222 indicates a good prognosis for NSCLC

Background

The aim of this study was to observe the expression of microRNA-222 (miR-222) and matrix metalloproteinase inhibitor 3 (TIMP3) in non-small cell lung cancer (NSCLC) and discuss their significance.

Methods

A total of 230 patients with NSCLC were enrolled in the observation group during the operation. Ninety-eight normal adjacent tissues were used as the control group. Two groups of miR-222 and TIMP3 were detected by in situ hybridization and immunohistochemistry. The distribution of miR-222 and TIMP3 in A549/H358/PC9 cells was observed by immunofluorescence. Chi-squared and Spearman correlation tests were used to analyze the relationship among miR-222, TIMP3 expression, and clinicopathological parameters of NSCLC. Kaplan-Meier and Cox proportional hazards regression were used to analyze the prognostic impact of miR-222 and TIMP3.

Results

Immunohistochemistry showed that the expression of miR-222 in lung cancer tissue was significantly higher, but TIMP3 was lower than that in normal lung tissue (P = 0.0001 for the former and P = 0.0002 for the latter). Meanwhile, miR-222 and TIMP3 were mainly distributed in the cytoplasm. Among them, cTIMP3 accounted for 70.29% (72/101), cmiR-222 for 59.35% (92/155), 14.85% for nTIMP3 (15/101), and 18.06% for nmiR-222 (28/155). There was a significant difference in distribution (both P < 0.0001). The expression of miR-222 and TIMP3 were negatively correlated in lung cancer tissues (r = -0.43, P = 0.0219). With the progression of clinical stage, the positive intensity of cTIMP3 showed a decreasing trend, while the cmiR-222 showed a reverse trend (the former P = 0.0024 and the latter P < 0.0001). In the Kaplan-Meier prognostic analysis, we found that the high expression of cTIMP3 could predict a better prognosis (P = 0.0040), whereas cmiR-222 was the opposite (P = 0.0016). Multivariate analysis shows that both can be used as independent factors.

Conclusion

TIMP3 expression in lung cancer is relatively low and has a negative correlation with lung cancer staging and prognosis, suggesting that it may play a defensive function in the development of lung cancer, while miR-222 has the opposite effect, and the expression of both proteins is negatively correlated, suggesting that in lung cancer progresses, both proteins may play some role together.

Levels of MicroRNA Heterogeneity in Cancer Biology

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression, involved in the silencing of messenger RNA (mRNA) translation. The importance of miRNA signatures in disease screening, prognosis, and progression of different tumor types and subtypes is increasing. miRNA expression levels change depending on numerous factors. In this review, we are describing the circumstances under which miRNA levels can change, these are named 'levels' of heterogeneity of miRNAs. miRNAs can have oncogenic, tumor suppressive, or both roles depending on tumor type and target mRNA whose translation they silence. The expression levels of a single miRNA may vary across different cancer types and subtypes, indicating that a miRNA signature may be tissue specific. miRNA levels of expression also vary during disease formation and propagation, indicating the presence of a time profile for their expression. The complexity of the miRNA-mRNA interference network mirrors different genetic and epigenetic changes that influence miRNA and mRNA availability to each other, and hence, their binding ability. The potential role of miRNAs as biomarkers is two-fold; first, for monitoring of the phases of cancer pathogenesis, and second, to characterize the particular type/subtype of cancer. It is important that a particular miRNA should be characterized by examining as many types and subtypes of cancers as are available, as well as being extracted from different types of samples, in order to obtain a complete picture of its behavior and importance in the disease pathology.