MicroRNAs as potential diagnostic and prognostic biomarkers in melanoma

Pathogenic role of exosomes and microRNAs in HPV-mediated inflammation and cervical cancer: A review

Cervical cancer (CC) is the fourth most common cause of cancer death in women. The most important risk factor for the development of CC is cervical infection with human papilloma virus (HPV). Inflammation is a protective strategy that is triggered by the host against pathogens such as viral infections that acts rapidly to activate the innate immune response. Inflammation is beneficial if it is brief and well controlled; however, if the inflammation is excessive or it becomes of chronic duration, it can produce detrimental effects. HPV proteins are involved, both directly and indirectly, in the development of chronic inflammation, which is a causal factor in the development of CC. However, other factors may also have a potential role in stimulating chronic inflammation. MicroRNAs (miRNAs) (a class of noncoding RNAs) are strong regulators of gene expression. They have emerged as key players in several biological processes, including inflammatory pathways. Abnormal expression of miRNAs may be linked to the induction of inflammation that occurs in CC. Exosomes are a subset of extracellular vesicles shed by almost all types of cells, which can function as cargo transfer vehicles. Exosomes contain proteins and genetic material (including miRNAs) derived from their parent cells and can potentially affect recipient cells. Exosomes have recently been recognized to be involved in inflammatory processes and can also affect the immune response. In this review, we discuss the role of HPV proteins, miRNAs and exosomes in the inflammation associated with CC.

Circulating microRNA expression profiling and bioinformatics analysis of patients with coronary artery disease by RNA sequencing

BACKGROUND

MicroRNAs play a vital role in coronary artery disease. Abnormal expression of microRNAs has been found to be associated with the occurrence of CAD.

METHODS

We identified significantly differentially expressed microRNAs in plasma between 40 patients with CAD and 10 controls with NCA using RNA sequencing. The differentially expressed microRNAs were analyzed for Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment.

RESULTS

Fifty cDNA libraries were constructed and sequenced, and a total of 1871.82 M raw reads were obtained, and 2135 microRNAs were found. Compared to the expressed microRNAs of NCA controls, 159 microRNAs were differentially expressed in CAD patients, including 119 upregulated microRNAs and 40 downregulated microRNAs. The top 10 upregulated miRNAs were miR-144-3p, miR-34a-5p, miR-15b-3p, miR-22-3p, miR-29b-3p, miR-1270, miR-6891-5p, miR-106a-5p, miR-15b-5p, and hsa-miR-499b-3p. The top ten downregulated miRNAs were miR-4437, miR-6842-3p, miR-4664-3p, miR-671-3p, miR-219a-1-3p, miR-7848-3p, miR-664a-3p, miR-1284, miR-361-3p, and miR-6780a-5p. The target genes of differentially expressed microRNAs were related to many basic biological terms, such as biological process, cellular component, and molecular function. According to the KEGG pathway analysis, the most enriched pathways of the differentially expressed microRNAs were endocytosis, focal adhesion, axon guidance, and so on. Furthermore, six upregulated and two downregulated microRNAs were detected by qRT-PCR (Quantitative Real-time PCR) and ROC analysis for diagnosing CAD.

CONCLUSION

The results suggest that the expression levels of some microRNAs may play a vital role in the physiological and pathological course of CAD. Our study may provide useful information for the diagnosis and treatment of CAD.

Mir-5100 Mediates Proliferation, Migration and Invasion of Oral Squamous Cell Carcinoma Cells Via Targeting SCAI

PURPOSE

We aimed to investigate the role of microRNA-5100 (miRNA-5100) in oral squamous cell carcinoma (OSCC) and its underlying mechanisms.Material/Methods: The expression of miR-5100 and suppressor of cancer cell invasion (SCAI) in OSCC cell lines were examined. A luciferase reporter assay was applied to confirm the combination between miR-5100 and SCAI. Then, miR-5100 inhibitor or small hairpin RNA (shRNA)-SCAI were transfected into cells. Cell Counting Kit-8 assay was executed for testing cell proliferation ability. Flow cytometry assay was exploited for measuring cell cycle. Invasion and migration of OSCC cells were assessed using Transwell assay and wound healing assay. The expression of proteins were detected using western blotting.

RESULTS

The results demonstrated that the level of miR-5100 was upregulated while SCAI was downregulated in OSCC cells. SCAI was verified as a direct target of miR-5100. MiR-5100 silencing suppressed proliferation of OSCC cells, increased cells in the G1 and G2 phases, and reduced those in the S phase, which was reversed after transfection with shRNA-SCAI. Moreover, miR-5100 inhibitor downregulated the expression of cyclin-dependent kinase-2 (CDK-2) and cyclinD1, accompanied by upregulation in p27 expression, whereas SCAI silencing had the opposite results. The invasion and migration abilities of OSCC cells were reduced after treatment with miR-5100 inhibitor, whereas SCAI silencing suppressed the effects of miR-5100 inhibitor on OSCC cell behaviors.

CONCLUSION

These findings suggested that miR-5100 silencing inhibit proliferation, invasion and migration of OSCC cells via upregulating the expression of SCAI, which provides theoretical basis and treatment strategies for the treatment of OSCC.

Cancer stem cells as therapeutic targets of pancreatic cancer

The discovery of stem cells and their potential abilities in self-renewal and differentiation has opened a new horizon in medicine. Scientists have found a small population of stem cells in some types of cancers with the same functions as normal stem cells. There are two models for tumor progression: clonal (stochastic) and cancer stem cell (CSCs) models. According to the first model, all transformed cells in the tumor have carcinogenic potential and are able to proliferate and produce the same cells. The latter model, which has received more attention recently, considers the role of CSCs in drug resistance and tumor metastasis. Following the model, researchers have found that targeting CSCs may be a promising way in cancer therapy. This review describes CSC characteristics in general, while also focusing on CSC properties in the context of pancreatic cancer.

Prognostic and clinical significance of long non-coding RNA HNF1A-AS1 in solid cancers: A systematic review and meta-analysis

BACKGROUND

LncRNA HNF1A Antisense RNA 1 (HNF1A-AS1) is often dysregulated in cancer. We performed this meta-analysis to clarify the usefulness of HNF1A-AS1 as a prognostic marker in malignant tumors.

METHODS

The PubMed, OVID, and Web of Science databases were searched from inception to January 11, 2018. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to explore the relationship between HNF1A-AS1 expression and survival. Odds ratios (OR) were calculated to assess the association between HNF1A-AS1 expression and pathological parameters.

RESULTS

Eight studies with a total of 802 patients were included in the study. The pooled hazard ratio (HR) suggested high HNF1A-AS1 expression correlated with poor overall survival (OS) (HR = 4.85, 95% confidence interval (CI): 2.43-9.68), and disease-free survival (DFS) (HR = 6.34, 95% CI: 1.03-39.12) in cancer patients. High HNF1A-AS1 expression also correlated with poor histological grade (OR = 1.88, 95% CI: 1.27-2.79), high tumor stage (OR = 4.04, 95% CI: 2.53-6.47), lymph node metastasis (LNM) (OR = 4.53, 95% CI: 2.30-8.92), and distant metastasis (OR = 5.99, 95% CI: 2.88-12.48). Begg funnel plot did not show any evidence of obvious asymmetry for high tumor stage (Pr > |z| = 0.368) and LNM (Pr > |z| = 1.000).

CONCLUSIONS

Thus high HNF1A-AS1 expression is predictive of poor OS, DFS, lymph node metastasis, distant metastasis, histological grade, and larger tumor stage, which suggests high HNF1A-AS1 expression may serve as a novel biomarker of poor prognosis in cancer.

Micro RNA Transcriptome Profile in Canine Oral Melanoma

MicroRNAs (miRNAs) dysregulation contribute the cancer pathogenesis. However, the miRNA profile of canine oral melanoma (COM), one of the frequent malignant melanoma in dogs is still unrevealed. The aim of this study is to reveal the miRNA profile in canine oral melanoma. MiRNAs profile of oral tissues from normal healthy dogs and COM patients were compared by next-generation sequencing. Along with tumour suppressor miRNAs, we report 30 oncogenic miRNAs in COM. The expressions of miRNAs were further confirmed by quantitative real-time PCR (qPCR). Pathway analysis showed that deregulated miRNAs impact on cancer and signalling pathways. Three oncogenic miRNAs targets (miR-450b, 301a, and 223) from human study also were down-regulated in COM and had a significant negative correlation with their respective miRNA. Furthermore, we found that miR-450b expression is higher in metastatic cells and regulated MMP9 expression through a PAX9-BMP4-MMP9 axis. In silico analysis indicated that miR-126, miR-20b, and miR-106a regulated the highest numbers of differentially expressed transcription factors with respect to human melanoma. Chromosomal enrichment analysis revealed the X chromosome was enriched with oncogenic miRNAs. We comprehensively analyzed the miRNA's profile in COM which will be a useful resource for developing therapeutic interventions in both species.

Overexpression of microRNA‑21 inhibits the growth and metastasis of melanoma cells by targeting MKK3

Melanoma is an aggressive skin carcinoma with poor prognosis, and is prevalent worldwide. It was demonstrated that microRNA (miR)‑21 and mitogen‑activated protein kinase kinase 3 (MKK3) both participated in the occurrence and development of various tumors; however, their detailed roles in the progression of melanoma remain unclear. Reverse transcription‑quantitative PCR (RT‑qPCR) and western blot analyses were conducted to examine the expression levels of miR‑21 and MKK3 in clinical specimens of patients with melanoma and melanoma cell lines. A dual‑luciferase reporter assay was performed to verify the target interaction between miR‑21 and MKK3. The mRNA and protein expressions of MKK3 were measured using RT‑qPCR and western blot analysis, respectively, following transfection with miR‑21 mimics and inhibitor. Subsequently, Cell Counting Kit‑8 and colony formation assays, and flow cytometry were conducted to assess the effects of miR‑21 and MKK3 on the cell growth of melanoma. Cell migration and invasion experiments were performed to evaluate the effects of miR‑21 and MKK3 on the cell metastasis of melanoma. It was revealed that MKK3 was upregulated, and miR‑21 was downregulated in patients with melanoma and melanoma cell lines. MKK3 was demonstrated to be a direct target of miR‑21. Furthermore, it was demonstrated that upregulated miR‑21 expression and downregulated MKK3 expression suppressed cell proliferation and colony formation, promoted apoptosis, delayed the cell cycle, and inhibited cell migration and invasion. The present findings suggested that miR‑21 could inhibit the cell growth and metastasis of melanoma by negatively regulating MKK3.

Exosomes: Diagnostic Biomarkers and Therapeutic Delivery Vehicles for Cancer

Exosomes are described as nanoscale extracellular vesicles (EVs) secreted by multiple cell types and extensively distributed in various biological fluids. They contain multifarious bioactive molecules and transfer them to adjoining or distal cells through systemic circulation, participating in intracellular and intercellular communication, and modulating host-tumor cell interactions. Recent research has indicated that exosomes obtained from different biological fluids and their contents (proteins, nucleic acids, glycoconjugates, and lipids) can serve as biomarkers for cancer diagnosis, prognosis, and therapeutic response. Furthermore, the discovery of exosomes as therapeutic delivery vehicles has drawn much attention in antineoplastic drug delivery. They can be utilized for therapeutic delivery of proteins, genetic drugs, and chemotherapeutic drugs. Herein, this review summarizes the biogenesis, structure, and components of exosomes, focusing primarily on their two possible applications as diagnostic biomarkers and therapeutic delivery vehicles for cancers.

MicroRNA and exosome: Key players in rheumatoid arthritis

Rheumatoid arthritis (RA) is known as one of important autoimmune disorders which can lead to joint pain and damage throughout body. Given that internal (ie, genetic and epigenetic alterations) and external factors (ie, lifestyle changes, age, hormones, smoking, stress, and obesity) involved in RA pathogenesis. Increasing evidence indicated that cellular and molecular alterations play critical roles in the initiation and progression of RA. Among various targets and molecular signaling pathways, microRNAs (miRNAs) and their regulatory networks have key roles in the RA pathogenesis. It has been showed that deregulation of many miRNAs involved in different stages of RA. Hence, identification of miRNAs and their signaling pathways in RA, could contribute to new knowledge which help to better treatment of patients with RA. Besides miRNAs, exosomes have been emerged as key messengers in RA pathogenesis. Exsosomes are nanocarriers which could be released from various cells and lead to changing of behaviors recipient cells via targeting their cargos (eg, proteins, messenger RNAs, miRNAs, long noncoding RNAs, DNAs). Here, we summarized several miRNAs involved in RA pathogenesis. Moreover, we highlighted the roles of exosomes in RA pathogenesis.

PPAR-γ: Its ligand and its regulation by microRNAs

Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear receptor superfamily. PPARs are categorized into three subtypes, PPARα, β/δ, and γ, encoded by different genes, expressed in diverse tissues and participate in various biological functions and can be activated by their metabolic derivatives in the body or dietary fatty acids. The PPAR-γ also takes parts in the regulation of energy balance, lipoprotein metabolism, insulin sensitivity, oxidative stress, and inflammatory signaling. It has been implicated in the pathology of numerous diseases including obesity, diabetes, atherosclerosis, and cancers. Among various cellular and molecular targets that are able to regulate PPAR-γ and its underlying pathways, microRNAs (miRNAs) appeared as important regulators. Given that the deregulation of these molecules via targeting PPAR-γ could affect initiation and progression of various diseases, identification of miRNAs that affects PPAR-γ could contribute to the better understanding of roles of PPAR-γ in various biological and pathological conditions. Here, we have summarized the function and various ligands of PPAR-γ and have highlighted various miRNAs involved in the regulation of PPAR-γ.

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.

Exosomal microRNA and stroke: A review

Blood vessels rupture or occlusion in brain results in stroke. Stroke is the major reason for mortality and dysfunction worldwide. Despite several attempts, there are no any approved therapeutic approaches for stroke subjects. The most neuroprotective agents showed the positive effects in preclinical reports, while there are no significant therapeutic impacts in the clinical trials. MicroRNAs (miRNAs) are small noncoding RNAs which involved in the modulation of a variety of cellular and molecular pathways. Given that deregulation of these molecules is related to initiation and progression of stroke. Exosomes are nano-carriers which are able to transfer different cargos such as miRNAs to recipient cells. Increasing evidence revealed that exosomal miRNAs are one of very important factors which are involved in the pathogenesis of stroke. Hence, more understanding about the role of exosomal miRNAs in stroke pathogenesis could contribute in discovering and developing new therapeutic approaches. Moreover, it has been proved the exosomal miRNAs could be used as noninvasive biomarkers in diagnosis and monitoring response to therapy in subjects with stroke. Herein for first time, we summarized different exosomal miRNAs involved in pathogenesis of stroke.

MicroRNA-329 upregulation impairs the HMGB2/β-catenin pathway and regulates cell biological behaviors in melanoma

Melanoma is responsible for the majority of deaths caused by skin cancer. Antitumor activity of microRNA-329 (miR-329) has been seen in several human cancers. In this study, we identify whether miR-329 serves as a candidate regulator in melanoma. Melanoma-related differentially expressed genes were screened with its potential molecular mechanism predicted. Melanoma tissues and pigmented nevus tissues were collected, where the levels of miR-329 and high-mobility group box 2 (HMGB2) were determined. To characterize the regulatory role of miR-329 on HMGB2 and the β-catenin pathway in melanoma cell activities, miR-329 mimics, miR-329 inhibitors, and siRNA-HMGB2 were transfected into melanoma cells. Cell viability, migration, invasion, cell cycle, and apoptosis were assessed. miR-329 was predicted to influence melanoma by targeting HMGB2 via the β-catenin pathway. High level of HMGB2 and low miR-329 expression were observed in melanoma tissues. HMGB2 was targeted and negatively regulated by miR-329. In melanoma cells transfected with miR-329 mimics or siRNA-HMGB2, cell proliferation, migration, and invasion were impeded, yet cell cycle arrest and apoptosis were promoted, corresponding to decreased levels of β-catenin, cyclin D1, and vimentin and increased levels of GSK3β and E-cadherin. Collectively, our results show that miR-329 can suppress the melanoma progression by downregulating HMGB2 via the β-catenin pathway.

MicroRNA heterogeneity in melanoma progression

The altered expression of miRNAs has been linked with neocarcinogenesis or the development of human malignancies including melanoma. Of significance, multiple clinical studies have documented that distinct sets of microRNAs (miRNAs) could be utilized as prognostic biomarkers for cancer development or predict the outcomes of treatment responses. To that end, an in-depth validation of such differentially expressed miRNAs is necessary in diverse settings of cancer patients in order to devise novel approaches to control tumor growth and/or enhance the efficacy of clinically-relevant therapeutic options. Moreover, considering the heterogeneity and sophisticated regulation of miRNAs, the precise delineation of their cellular targets could also be explored to design personalized medicine. Given the significance of miRNAs in regulating several key cellular processes of tumor cells including cell cycle progression and apoptosis, we review the findings of such miRNAs implicated in melanoma tumorigenesis. Understanding the novel mechanistic insights of such miRNAs will be useful for developing diagnostic or prognostic biomarkers or devising future therapeutic intervention for malignant melanoma.

Melanoma-Derived Extracellular Vesicles: Focus on Their Proteome

Malignant melanoma is one of the most aggressive types of cancer, and its incidence is increasing rapidly each year. Despite the extensive research into improved diagnostic and treatment methods, early detection and disease constraint still present significant challenges. As successful isolation protocols have been developed, extracellular vesicles (EVs) have become the subject of extensive investigation in terms of their role in cancer progression and as a possible source of disease biomarkers. Besides functional studies, quantitative and qualitative proteomics have recently emerged as promising tools for the advancement of melanoma biomarkers. Nevertheless, the amount of data concerning the proteome of melanoma-derived EVs is still very limited. In this review we cover the current knowledge on protein content of melanoma-derived EVs, with a focus on their potential role in the development and progression of melanomas.

MicroRNAs and response to therapy in leukemia

A variety of epigenetic factors involved in leukemia pathogenesis. Among various epigenetic factors, microRNAs (miRNAs) have emerged as important players, which affect a sequence of cellular and molecular signaling pathways. Leukemia is known as progressive cancer, which is related to many health problems in the world. It has been shown that the destruction of the blood-forming organs could lead to abnormal effects on the proliferation and development of leukocytes and their precursors. Despite many attempts for approved effective and powerful therapies for patients with leukemia, finding and developing new therapeutic approaches are required. One of the important aspects of leukemia therapy, identification of underlying cellular and molecular mechanisms involved in the pathogenesis of leukemia. Several miRNAs (ie, miR-103, miR-101, mit-7, let-7i, miR-424, miR-27a, and miR-29c) and play major roles in response to therapy in patients with leukemia. miRNAs exert their effects by targeting a variety of targets, which are associated with response to therapy in patients with leukemia. It seems that more understanding about the roles of miRNAs in response to therapy in patients with leukemia could contribute to better treatment of patients with leukemia. Here, for the first time, we summarized various miRNAs, which are involved in response to therapy in the treatment patients with leukemia.

Pancreatic β-cell regeneration: From molecular mechanisms to therapy

Pancreatic β cells are a type of cells that are present in the islets of Langerhans. These cells are highly specialized for the secretion of insulin in response to low increasing of blood glucose levels. Hence, pancreatic β cells could contribute to maintaining systemic glucose homeostasis. Increasing evidence has revealed that a variety of internal (ie, genetic and epigenetic factors) and external factors (ie, radical-oxidative stress) are involved in the protection and/or regeneration of pancreatic β cells. The pathways regulating β-cell replication have been intensely investigated. Glucose has an important role in cell cycle entry of quiescent β cells, which exerts its effect via glucose metabolism and unfolded proteins. A variety of growth factors, hormones, and signaling pathways (ie, calcium-calcineurin nuclear factor of activated T cells) are others factors that could affect β-cell replication under different conditions. Therefore, a greater understanding of the underlying pathways involved in the regeneration and protection of pancreatic β cells could lead to finding and developing new therapeutic approaches. Utilization of stem cells and various phytochemical agents have provided new aspects for preventing β-cell degeneration and stimulating the endogenous regeneration of islets. Thus, these therapeutic platforms could be used as potential therapies in the treatment of insulin-dependent diabetes mellitus. Here, we summarized the various mechanisms involved in pancreatic β-cell regeneration. Moreover, we highlighted different therapeutic approaches which could be used for the regeneration of pancreatic β cells.

Prognostic value of long noncoding RNA ROR in patients with cancer in China: A systematic review and meta-analysis

BACKGROUND

For cancer, it is common that there is usually a dysregulation of the long noncoding RNA regulator of reprogramming (LncRNA ROR). To illustrate the application of LncRNA ROR, which serves as the prognostic marker for the malignant tumors, it is of great importance to conduct a meta-analysis.

METHODS

There were 3 databases being applied. The data used were collected before January 5, 2018. These 3 databases include the OVID, PubMed, and Science databse. To further explore the association between the expression and survival of LncRNA ROR, it calculated the 95% confidence intervals (CIs) and hazard ratios (HRs). Meanwhile, the odds ratios (ORs) have been calculated for the evaluation of the correlation between the pathological and expression parameters of LncRNA ROR.

RESULTS

There were 8 researches participated by 720 patients. According to the HR, it has been implied that there was a high LncRNA ROR expression related with the weak disease-free survival (DFS) (HR = 3.48, 95% CI, 2.24-5.41) and overall survival (OS) (HR = 2.47, 95% CI, 1.76-3.47) among the cancer patients with none dramatic heterogeneity. There was also a correlation among lymph node metastasis (OR = 5.38, 95% CI, 2.21-13.12), high tumor stage (OR = 3.80, 95% CI, 1.95-7.41), and larger tumor size (OR = 4.43, 95% CI, 1.26-15.51).

CONCLUSIONS

Thus, it can be predicted about the lymph node metastasis and high tumor stage, larger tumor size, DFS, and poor OS based on the high LncRNA ROR. This suggests that high LncRNA ROR can be used as a new indicator of poor prognosis in cancer.

Curcumin: A new candidate for retinal disease therapy?

The retina is the neural portion and light-sensitive layer of the eye, which has been observed in most of the vertebrates. The retina is composed of light-sensitive cells that absorb light and convert it into neural signals. These signals are sent to the brain for visual recognition. It has been shown that many pathogenesis conditions, including inflammation, angiogenesis, oxidative stress, and imbalanced histone modifications in the retina are associated with initiation and progression of retinal diseases (ie, glaucoma, diabetic retinopathy, and age-related macular degeneration). Currently available treatments include laser surgery, freezing, stem-cell therapy, shrinking abnormal blood vessels. It has some limitations, such as invasive methods, high costs, and many side effects. Hence, finding a new therapeutic platform for stopping or slowing of the disease progression is required. Curcumin is a natural product, which is associated with a wide range of properties, such as antioxidant, anti-inflammatory, antiangiogenic, and antitumor activates. It exerts therapeutic effects via activation/inhibition cellular and molecular targets involved in various diseases, such as retinal diseases. Increasing evidence revealed that curcumin can be used as a therapeutic option in the treatment of different retinal diseases. Here, we summarized various clinical and preclinical studies that used curcumin as a therapeutic agent in the treatment of retinal disorders.

Prognostic value of long non-coding RNA ZEB1-AS1 in Chinese cancer patients: A Meta-analysis

BACKGROUND

Aberrant expression of long non-coding RNA Zinc finger E-box binding homeobox 1 antisense 1 (lncRNA ZEB1-AS1) can be detected in numerous malignancies. Therefore, a meta-analysis had been carried out in this study, aiming to examine the prognostic value of lncRNA ZEB1-AS1 in malignancies.

METHODS

Electronic databases, such as PubMed, OVID as well as Web of Science, had been systemically retrieved from inception to February 14th, 2019. Besides, the hazard ratios (HRs), together with the corresponding 95% confidence intervals (CIs), had also been analyzed for determining the association of lncRNA ZEB1-AS1 expression with the overall survival (OS) and recurrence-free survival (RFS). In addition, the pooled odds ratios (ORs) would also be computed using the Stata SE12.0 software for evaluating the relationship of lncRNA ZEB1-AS1 expression with pathological factors.

RESULTS

A total of 21 original studies involving 1801 cancer patients had been enrolled into the current meta-analysis. As suggested by the pooled HR, high expression of lncRNA ZEB1-AS1 had displayed marked correlation with OS (HR = 2.16, 95% CI: 1.89-2.47) among cancer patients, and no significant heterogeneity was detected. Additionally, high expression of lncRNA ZEB1-AS1 was also markedly associated with RFS among cancer patients (pooled HR = 2.55, 95% CI: 1.61-4.03). Besides, the expression of lncRNA ZEB1-AS1 had displayed marked correlation with poor histological grade (PHG) (OR = 2.86, 95% CI: 2.11-3.87), high tumor stage (HTS) (OR = 3.81, 95% CI: 2.72-5.34) as well as lymph node metastasis (LNM) (OR = 3.33, 95% CI: 2.47-4.49). Additionally, no distinct asymmetry had been detected for RFS, PHG as well as HTS based on Begg funnel plot.

CONCLUSIONS

Taken together, high expression of lncRNA ZEB1-AS1 can predict the dismal OS, RFS, LNM, PHG, and HTS, indicating that lncRNA ZEB1-AS1 can be potentially used as a new biomarker to predict the dismal prognosis for cancer patients.

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.

Circulating Exosomal miR-20b-5p Is Elevated in Type 2 Diabetes and Could Impair Insulin Action in Human Skeletal Muscle

miRNAs are noncoding RNAs representing an important class of gene expression modulators. Extracellular circulating miRNAs are both candidate biomarkers for disease pathogenesis and mediators of cell-to-cell communication. We examined the miRNA expression profile of total serum and serum-derived exosome-enriched extracellular vesicles in people with normal glucose tolerance or type 2 diabetes. In contrast to total serum miRNA, which did not reveal any differences in miRNA expression, we identified differentially abundant miRNAs in patients with type 2 diabetes using miRNA expression profiles of exosome RNA (exoRNA). To validate the role of these differentially abundant miRNAs on glucose metabolism, we transfected miR-20b-5p, a highly abundant exoRNA in patients with type 2 diabetes, into primary human skeletal muscle cells. miR-20b-5p overexpression increased basal glycogen synthesis in human skeletal muscle cells. We identified AKTIP and STAT3 as miR-20b-5p targets. miR-20b-5p overexpression reduced AKTIP abundance and insulin-stimulated glycogen accumulation. In conclusion, exosome-derived extracellular miR-20b-5p is a circulating biomarker associated with type 2 diabetes that plays an intracellular role in modulating insulin-stimulated glucose metabolism via AKT signaling.

Loss of exosomal miR-148b from cancer-associated fibroblasts promotes endometrial cancer cell invasion and cancer metastasis

Cancer-associated fibroblasts (CAFs) play crucial roles in tumor progression, given the dependence of cancer cells on stromal support. Therefore, understanding how CAFs communicate with endometrial cancer cell in tumor environment is important for endometrial cancer therapy. Exosomes, which contain proteins and noncoding RNA, are identified as an important mediator of cell-cell communication. However, the function of exosomes in endometrial cancer metastasis remains poorly understood. In the current study we found that CAF-derived exosomes significantly promoted endometrial cancer cell invasion comparing to those from normal fibroblasts (NFs). We identified a significant decrease of miR-148b in CAFs and CAFs-derived exosomes. By exogenously transfect microRNAs, we demonstrated that miR-148b could be transferred from CAFs to endometrial cancer cell through exosomes. In vitro and in vivo studies further revealed that miR-148b functioned as a tumor suppressor by directly binding to its downstream target gene, DNMT1 to suppress endometrial cancer metastasis. In endometrial cancer DNMT1 presented a potential role in enhancing cancer cell metastasis by inducing epithelial-mesenchymal transition (EMT). Therefore, downregulated miR-148b induced EMT of endometrial cancer cell as a result of relieving the suppression of DNMT1. Taken together, these results suggest that CAFs-mediated endometrial cancer progression is partially related to the loss of miR-148b in the exosomes of CAFs and promoting the transfer of stromal cell-derived miR-148b might be a potential treatment to prevent endometrial cancer progression.

Serum exosomal microRNAs as potent circulating biomarkers for melanoma

Exosomes are small homogenous membrane vesicles that derive from the exocytosis process of cells and can contain DNA, microRNAs (miRNAs), and/or proteins. Characterization of the content profile of exosomes may reflect the state of the cells that release them, and this could be predictive of disease. In this study, to explore the potential biomarkers for melanoma, we isolated serous exosomes from 30 patients with melanoma and 30 healthy individuals using the ultracentrifugation method. Five miRNAs were subsequently detected in each sample by quantitative reverse transcription-PCR: miRNA-532-5p, miRNA-106b, miRNA-200c, miRNA-199a-5p, and miRNA-210. Only the levels of exo-miRNA-532-5p and exo-miRNA-106b differed between the two groups (Z=-4.17 and -4.57, respectively, P<0.0001). When these two miRNAs were evaluated individually and in combination in 95 melanoma patients and 95 healthy individuals serum samples, the area under the receiver operating characteristic curve values were 0.867, 0.820, and 0.936, respectively. Furthermore, in blinded tests of samples from 25 melanoma patients and 25 healthy individuals, this panel of miRNAs identified 23/25 patients with melanoma (92.0% sensitivity) and 22/25 healthy individuals (88.0% sensitivity). Our exo-miRNA panel also distinguished patients with metastasis from those without metastasis, patients with stage I-II disease from those with stage III-IV disease, and patients who had received pembrolizumab treatment from those who were untreated. Overall, these results indicate that serum exosomal miRNAs, especially exo-miRNA-532-5p and exo-miRNA-106b, have the potential to be used for monitoring and/or a diagnosis of melanoma in a clinical setting.

Vaccines for colorectal cancer: an update

Colorectal cancer (CRC) is known as the third most common and fourth leading cancer associated death worldwide. The occurrence of metastasis has remained as a critical challenge in CRC, so that distant metastasis (mostly to the liver) has been manifested in about 20%-25% of patients. Several screening approaches have introduced for detecting CRC in different stages particularly in early stages. The standard treatments for CRC are surgery, chemotherapy and radiotherapy, in alone or combination. Immunotherapy is a set of novel approaches with the aim of remodeling the immune system battle with metastatic cancer cells, such as immunomodulatory monoclonal antibodies (immune checkpoint inhibitors), adoptive cell transfer (ACT) and cancer vaccine. Cancer vaccines are designed to trigger the intense response of immune system to tumor-specific antigens. In two last decades, introduction of new cancer vaccines and designing several clinical trials with vaccine therapy, have been taken into consideration in colon cancer patients. This review will describe the treatment approaches with the special attention to vaccines applied to treat colorectal cancer.

microRNAs: Key players in virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as one of the major health problems worldwide. Pathological analysis indicated that a variety of risk factors including genetical (i.e., alteration of tumor suppressors and oncogenes) and environmental factors (i.e., viruses) are involved in beginning and development of HCC. The understanding of these risk factors could guide scientists and clinicians to design effective therapeutic options in HCC treatment. Various viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) via targeting several cellular and molecular pathways involved in HCC pathogenesis. Among various cellular and molecular targets, microRNAs (miRNAs) have appeared as key players in HCC progression. miRNAs are short noncoding RNAs which could play important roles as oncogenes or tumor suppressors in several malignancies such as HCC. Deregulation of many miRNAs (i.e., miR-222, miR-25, miR-92a, miR-1, let-7f, and miR-21) could be associated with different stages of HCC. Besides miRNAs, exosomes are other particles which are involved in HCC pathogenesis via targeting different cargos, such as DNAs, RNAs, miRNAs, and proteins. In this review, we summarize the current knowledge of the role of miRNAs and exosomes as important players in HCC pathogenesis. Moreover, we highlighted HCV- and HBV-related miRNAs which led to HCC progression.

MicroRNA in leukemia: Tumor suppressors and oncogenes with prognostic potential

Leukemia is known as a progressive malignant disease, which destroys the blood-forming organs and results in adverse effects on the proliferation and development of leukocytes and their precursors in the blood and bone marrow. There are four main classes of leukemia including acute leukemia, chronic leukemia, myelogenous leukemia, and lymphocytic leukemia. Given that a variety of internal and external factors could be associated with the initiation and progression of different types of leukemia. One of the important factors is epigenetic regulators such as microRNAs (miRNAs) and long noncoding RNAs (ncRNA). MiRNAs are short ncRNAs which act as tumor suppressor (i.e., miR-15, miR-16, let-7, and miR-127) or oncogene (i.e., miR-155, miR-17-92, miR-21, miR-125b, miR-93, miR-143-p3, miR-196b, and miR-223) in leukemia. It has been shown that deregulation of these molecules are associated with the initiation and progression of leukemia. Hence, miRNAs could be used as potential therapeutic candidates in the treatment of patients with leukemia. Moreover, increasing evidence revealed that miRNAs could be used as diagnostic and prognostic biomarkers in monitoring patients in early stages of disease or after received chemotherapy regimen. It seems that identification and development of new miRNAs could pave to the way to the development new therapeutic platforms for patients with leukemia. Here, we summarized various miRNAs as tumor suppressor and oncogene which could be introduced as therapeutic targets in treatment of leukemia.

Genetic and epigenetic contribution to astrocytic gliomas pathogenesis

Astrocytic gliomas are the most common and lethal form of intracranial tumors. These tumors are characterized by a significant heterogeneity in terms of cytopathological, transcriptional, and (epi)genomic features. This heterogeneity has made these cancers one of the most challenging types of cancers to study and treat. To uncover these complexities and to have better understanding of the disease initiation and progression, identification, and characterization of underlying cellular and molecular pathways related to (epi)genetics of astrocytic gliomas is crucial. Here, we discuss and summarize molecular and (epi)genetic mechanisms that provide clues as to the pathogenesis of astrocytic gliomas.

Meta-analysis of the prognostic value of long non-coding RNA PVT1 for cancer patients

BACKGROUND

Plasmacytoma variant translocation 1 (PVT1) is reported to be dysregulated in various cancers. Therefore, this meta-analysis was performed to clarify its utility as a prognosis marker in malignant tumors.

METHODS

Electronic databases, including PubMed, OVID, Cochrane Library, and Web of Science databases, were retrieved from inception to December 16, 2017. Typically, hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were calculated, so as to explore the relationship between PVT1 expression and patient survival. In addition, odds ratios (OR) were calculated to assess the association of PVT1 expression with pathological parameters.

RESULTS

A total of 23 studies involving 2350 patients were included in this meta-analysis. The pooled HR suggested that high PVT1 expression levels were correlated with poor overall survival (OS, HR = 1.99, 95% CI: 1.73-2.28), disease-free survival (DFS, HR = 1.76, 95% CI: 1.45-2.14), and recurrence-free survival (RFS, HR = 1.74, 95% CI: 1.26-2.39) in cancer patients without obvious heterogeneity. Moreover, high PVT1 expression levels were also correlated with larger tumor size (OR = 1.47, 95% CI: 1.02-2.11), poor differentiation grade (OR = 1.79, 95% CI: 1.39-2.30), advanced tumor stage (pooled OR = 3.28, 95% CI: 2.46-4.38), lymph node metastasis (OR = 2.67, 95% CI: 1.66-4.29) and distant metastasis (OR = 4.00, 95% CI: 1.39-11.50) in cancer patients.

CONCLUSIONS

Findings of this meta-analysis suggest that a high PVT1 expression level may serve as a novel biomarker of poor prognosis in cancers.

Molecular aspects of pancreatic β-cell dysfunction: Oxidative stress, microRNA, and long noncoding RNA

Metabolic syndrome is known as a frequent precursor of type 2 diabetes mellitus (T2D). This disease could affect 8% of the people worldwide. Given that pancreatic β-cell dysfunction and loss have central roles in the initiation and progression of the disease, the understanding of cellular and molecular pathways associated with pancreatic β-cell dysfunction can provide more information about the underlying pathways involved in T2D. Multiple lines evidence indicated that oxidative stress, microRNA, and long noncoding RNA play significant roles in various steps of diseases. Oxidative stress is one of the important factors involved in T2D pathogenesis. This could affect the function and survival of the β cell via activation or inhibition of several processes and targets, such as receptor-signal transduction, enzyme activity, gene expression, ion channel transport, and apoptosis. Besides oxidative stress, microRNAs and noncoding RNAs have emerged as epigenetic regulators that could affect pancreatic β-cell dysfunction. These molecules exert their effects via targeting a variety of cellular and molecular pathways involved in T2D pathogenesis. Here, we summarized the molecular aspects of pancreatic β-cell dysfunction. Moreover, we highlighted the roles of oxidative stress, microRNAs, and noncoding RNAs in pancreatic β-cell dysfunction.

Downregulation of intratumoral expression of miR-205, miR-200c and miR-125b in primary human cutaneous melanomas predicts shorter survival

While only 15–25 percent of melanoma patients develop distant metastasis and die, this disease is still responsible for the majority of skin cancer-related deaths. The availability of adjuvant therapies makes the selection of high-risk patients essential. We evaluated the intratumoral expression of ten miRNAs in primary melanomas in relation to its ability to predict melanoma survival. To this end, we correlated miRNA expression in 132 cryopreserved primary and metastatic tumors with clinicopathological factors and clinical outcome. We found sequential downregulation of intratumoral expression of miR-125b, miR-182, miR-200c and miR-205 over the full spectrum of melanoma progression. Moreover, downregulation of these miRNAs occurred in primary melanomas that further disseminated to distant sites. Furthermore, miR-125b, miR-200c and miR-205 correlated as independent factors with shorter survival. Our in vitro findings demonstrate that loss of miR-205 potentiates the invasive ability of melanoma cells. We conclude that the downregulation of miR-205 in primary melanomas is an intrinsic property that might contribute to distant metastasis. In particular, the interaction of melanoma cells with the extracellular matrix is one of the key mechanisms by which miR-205 influences melanoma metastasis. In conclusion, miR-125b, miR-200c and miR-205 are useful prognostic biomarkers at the time of diagnosis to select high-risk patients.

Chemopreventive and therapeutic potential of curcumin in esophageal cancer: Current and future status

Esophageal cancer is a common malignant tumor with an increasing trend during the past three decades. Currently, esophagectomy, often in combination with neoadjuvant chemo- and radiotherapy, is the cornerstone of curative treatment for esophageal cancer. However, esophagostomy is related to significant risks of perioperative mortality and morbidity, as well as lengthy recovery. Moreover, the adjuvant therapies including chemotherapy and radiotherapy are associated with numerous side effects, limiting compliance and outcome. The dietary agent curcumin has been extensively studied over the past few decades and is known to have many biological activities especially in regard to the prevention and potential treatment of cancer. This review summarizes the chemo-preventive and chemotherapeutic potential of curcumin in esophageal cancer in both preclinical and clinical settings.

Influenza vaccine: Where are we and where do we go?

The alarming rise of morbidity and mortality caused by influenza pandemics and epidemics has drawn attention worldwide since the last few decades. This life-threatening problem necessitates the development of a safe and effective vaccine to protect against incoming pandemics. The currently available flu vaccines rely on inactivated viral particles, M2e-based vaccine, live attenuated influenza vaccine (LAIV) and virus like particle (VLP). While inactivated vaccines can only induce systemic humoral responses, LAIV and VLP vaccines stimulate both humoral and cellular immune responses. Yet, these vaccines have limited protection against newly emerging viral strains. These strains, however, can be targeted by universal vaccines consisting of conserved viral proteins such as M2e and capable of inducing cross-reactive immune response. The lack of viral genome in VLP and M2e-based vaccines addresses safety concern associated with existing attenuated vaccines. With the emergence of new recombinant viral strains each year, additional effort towards developing improved universal vaccine is warranted. Besides various types of vaccines, microRNA and exosome-based vaccines have been emerged as new types of influenza vaccines which are associated with new and effective properties. Hence, development of a new generation of vaccines could contribute to better treatment of influenza.

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.

A miRNA signature suggestive of nodal metastases from laryngeal carcinoma

The discovery that miRNAs are frequently deregulated in tumours offers the opportunity to identify them as prognostic and diagnostic markers. The aim of this multicentric study is to identify a miRNA expression profile specific for laryngeal cancer. The secondary endpoint was to identify specific deregulated miRNAs with potential as prognostic biomarkers for tumour spread and nodal involvement, and specifically to search for a miRNA pattern pathognomonic for N+ laryngeal cancer and for N- tissues. We identified 20 miRNAs specific for laryngeal cancer and a tissue-specific miRNA signature that is predictive of lymph node metastases in laryngeal carcinoma characterised by 11 miRNAs, seven of which are overexpressed (upregulated) and four downregulated. These results allow the identification of a group of potential specific tumour biomarkers for laryngeal carcinoma that can be used to improve its diagnosis, particularly in early stages, as well as its prognosis.

Micro-RNAs as critical regulators of matrix metalloproteinases in cancer

Metastasis is known to be one of the important factors associated with cancer-related deaths worldwide. Several cellular and molecular targets are involved in the metastasis process. Among these targets, matrix metalloproteinases (MMPs) play central roles in promoting cancer metastasis. MMPs could contribute toward tumor growth, angiogenesis, migration, and invasion via degradation of the extracellular matrix and activation of pre-pro-growth factors. Therefore, identification of various cellular and molecular pathways that affect MMPs could contribute toward a better understanding of the metastatic pathways involved in various tumors. Micro-RNAs are important targets that could affect MMPs. Multiple lines of evidence have indicated that deregulation of various micro-RNAs, including miR-9, Let-7, miR-10b, and miR-15b, affects metastasis of tumor cells via targeting MMPs.

MicroRNA-143-3p inhibits growth and invasiveness of melanoma cells by targeting cyclooxygenase-2 and inversely correlates with malignant melanoma progression

Malignant melanoma is one of the most leading form of skin cancer associated with a low patient survival rate. Increasing evidence revealed that microRNAs (miRNAs) play a crucial role in the occurrence and development of several form of cancer including melanoma. In this study, we aimed at investigating the expression and role of miR-143-3p in human malignant melanoma. Our results showed that the expression of miR-143-3p was lower in human melanoma cells, as well as human biopsy specimens, when compared to normal human melanocytes. Ectopic expression of miR-143-3p in human melanoma cells inhibited proliferation, migration, invasion and promoted apoptosis acting through a molecular mechanism that, at least in part, is dependent on inhibition of cyclooxygenase-2 (COX-2) gene. Collectively, these results demonstrate that miR-143-3p could represent at the same time, a new early diagnostic marker and therapeutic target acting as tumor suppressor in melanoma cancer.

Regulation of tumor angiogenesis by microRNAs: State of the art

MicroRNAs (miRNAs, miRs) are small (21-25 nucleotides) endogenous and noncoding RNAs involved in many cellular processes such as apoptosis, development, proliferation, and differentiation via binding to the 3'-untranslated region of the target mRNA and inhibiting its translation. Angiogenesis is a hallmark of cancer, which provides oxygen and nutrition for tumor growth while removing deposits and wastes from the tumor microenvironment. There are many angiogenesis stimulators, among which vascular endothelial growth factor (VEGF) is the most well known. VEGF has three tyrosine kinase receptors, which, following VEGF binding, initiate proliferation, invasion, migration, and angiogenesis of endothelial cells in the tumor environment. One of the tumor microenvironment conditions that induce angiogenesis through increasing VEGF and its receptors expression is hypoxia. Several miRNAs have been identified that affect different targets in the tumor angiogenesis pathway. Most of these miRNAs affect VEGF and its tyrosine kinase receptors expression downstream of the hypoxia-inducible Factor 1 (HIF-1). This review focuses on tumor angiogenesis regulation by miRNAs and the mechanism underlying this regulation.

Endometrial pinopode biomarkers: Molecules and microRNAs

Ultrastructural changes on the apical surface of the luminal epithelium of the uterus are known as pinopodes. Their morphology in species and in special species is associated with different results about size, duration, and percentage of surface area covered by pinopodes. The content of pinopodes is different in rodents and humans. In mice and rats pinopodes have many vacuoles and no organelle that extends to the actin stalk above the microvilli. Human pinopodes do not have a large vacuole and contain the golgi complex, a rough endoplasmic reticulum, secretory vesicles, and mitochondria that extend from the entire cell surface. It has been suggested that pinopodes are good markers of endometrial receptivity and implantation window. There are several molecular markers related to the presence of pinopodes, including integrins, leukemia inhibiting factor (LIF), l-selectin, HOXA10, glutaredoxin, glycodelinA, heparin-binding epidermal growth factor, mucins, and microRNAs (miRNAs). Multiple lines of evidence have indicated that miRNAs could affect the expression of LIF and pinopodes in the endometrium and these molecules play key roles in implantation window processes. Here, we have summarized the morphology and function of pinopodes. Moreover, we have highlighted several molecules in relation to pinopodes that could be used as biomarkers.

MicroRNAs in cutaneous melanoma: Role as diagnostic and prognostic biomarkers

Melanoma is the leading cause of skin cancer deaths in the United States, and its incidence has been rising steadily for the past 30 years (Aftab, Dinger, & Perera, 2014). A more complete understanding of the molecular mechanisms that drive melanomagenesis is crucial to improve diagnosis, prognostication, and treatment of this disease. Given that melanoma survival rates are better when the disease is detected early, precise diagnostic tests for early melanoma detection would be extremely useful. In addition, as survival rates decrease drastically when the disease becomes metastatic, improved tools to more precisely identify high-risk patients as well as to predict treatment response are necessary. The role of microRNAs (miRNAs) in melanoma biology could be the key. miRNA expression profiling has identified several miRNAs that play a crucial role in melanoma cell proliferation, migration, and invasion, as well as miRNAs involved in apoptosis and in the immune response. Here we review the most current data on the miRNAs involved in melanoma as well as their potential roles as diagnostic and prognostic biomarkers of this disease.

miR-150 Suppresses Tumor Growth in Melanoma Through Downregulation of MYB

miR-150 has been demonstrated to inhibit tumor progression in various human cancers, including colorectal cancer, ovarian cancer, and thyroid cancer. However, the role of miR-150 in melanoma remains to be determined. In this study, we found that miR-150 was underexpressed in melanoma tissues and cell lines. Through transfection of miR-150 mimics, we found that miR-150 significantly inhibited the proliferation, migration, and invasion of melanoma cells. In mechanism, we found that MYB was a target of miR-150 in melanoma cells. Overexpression of miR-150 significantly inhibited mRNA and protein levels of MYB in melanoma cells. Moreover, there was an inverse correlation between the expression of miR-150 and MYB in melanoma tissues. We also showed that MYB was upregulated in melanoma tissues and cell lines. Through functional experiments, we found that restoration of MYB in miR-150-overexpressed melanoma cells rescued the proliferation, migration, and invasion. Therefore, our findings demonstrated that miR-150 suppressed the proliferation, migration, and invasion of melanoma cell by downregulating MYB.

MicroRNA-622 is a novel mediator of tumorigenicity in melanoma by targeting Kirsten rat sarcoma

The network of molecular players is similar when comparing neural crest-derived, actively migrating melanoblasts to melanoma cells. However, melanoblasts are sensitive to differentiation-initiating signals at their target site (epidermis), while melanoma cells maintain migratory and undifferentiated features. We aimed at identifying downregulated genes in melanoma that are particularly upregulated in melanoblasts. Loss of such genes could contribute to stabilization of a dedifferentiated, malignant phenotype in melanoma. We determined that microRNA-622 (miR-622) expression was strongly downregulated in melanoma cells and tissues compared to melanocytes and melanoblast-related cells. miR-622 expression correlated with survival of patients with melanoma. miR-622 re-expression inhibited clonogenicity, proliferation, and migration in melanoma. Inhibition of miR-622 in melanocytes induced enhanced migration. Kirsten rat sarcoma (KRAS) was identified as a major functional target of miR-622 in melanoma. We conclude that miR-622 is a novel tumor suppressor in melanoma and identify the miR-622-KRAS axis as potential therapeutic target.

Liquid biopsy to monitor melanoma patients

During the last six years, several innovative, systemic therapies for the treatment of metastatic malignant melanoma (MM) have emerged. Conventional chemotherapy has been superseded by novel first-line therapies, including systemic immunotherapies (anti-CTLA4 and anti-PD1; authorization of anti-PDL1 is anticipated) and therapies targeting specific mutations (BRAF, NRAS, and c-KIT). Thus, treating physicians are confronted with new challenges, such as stratifying patients for appropriate treatments and monitoring long-term responders for progression. Consequently, reliable methods for monitoring disease progression or treatment resistance are necessary. Localized and advanced cancers may generate circulating tumor cells and circulating tumor DNA (ctDNA) that can be detected and quantified from peripheral blood samples (liquid biopsy). For melanoma patients, liquid biopsy results may be useful as novel predictive biomarkers to guide therapeutic decisions, particularly in the context of mutation-based targeted therapies. The challenges of using liquid biopsy include strict criteria for the phenotypic nature of circulating MM cells or their fragments and the instability of ctDNA in blood. The limitations of liquid biopsy in routine diagnostic testing are discussed in this review.

Deregulation of miR-183 promotes melanoma development via lncRNA MALAT1 regulation and ITGB1 signal activation

Dysregulation of miR-183 has been recently elucidated in several carcinomas. However, the expression patterns and mechanisms of miR-183 involved in malignant melanoma remain unidentified. Here, we found down-regulation of miR-183 in melanoma tissues and cells. Decreased level of miR-183 was relevant to poor overall survival, while miR-183 up-regulation resulted in a marked suppression of cell growth in vitro and in vivo. We further found that the expression and function of miR-183 were suppressed by MALAT1. Integrin β1 (ITGB1) was then speculated and confirmed as a direct target of miR-183. We also illustrated that MALAT1 may function as a sponge competitive endogenous RNA (ceRNA) for miR-183, and thus regulate the molecular expression of ITGB1. Collectively, we found a new signaling pathway promoting melanoma development by MALAT1-miR-183-ITGB1 axis, which may be clinically valuable as new targets for malignant melanoma therapy.

The BRAF activated non-coding RNA: A pivotal long non-coding RNA in human malignancies

Long non-coding RNAs (lncRNAs) participate in the complex network of cancer and play an important role in tumourigenesis and progression. BRAF activated non-coding RNA (BANCR), a 4-exon transcript of 693-bp, was first discovered as an oncogenic long non-coding RNA in BRAF^V600E melanomas cells in 2012 and was related to melanoma cell migration. Besides melanoma, increasing evidence has explored the potential role of BANCR in the development and progression of multiple other human malignancies, such as retinoblastoma, lung cancer, gastric cancer etc. since its discovery. The expression pattern of BANCR varies in different types of cancers, either as a tumour suppressor or as an accelerator. Functional BANCR may serve as a promising biomarker for cancer diagnosis as well as prognosis evaluation. BANCR-targeted intervention may also become a valuable novel therapeutic tool against human malignancies. This review summarized the advanced research progresses concerning the expression and role of BANCR in different human malignancies.