MicroRNA-610 inhibits tumor growth of melanoma by targeting LRP6

LINC00511 promotes melanoma progression by targeting miR-610/NUCB2

Long intergenic noncoding RNA 00511 (LINC00511) predicts poor prognosis in various malignancies and functions as an oncogene in distinct malignant tumors. The role of LINC00511 in melanoma progression was assessed. In our research, expression of LINC00511 in melanoma cells was detected by quantitative reverse transcription PCR. Colony formation and CCK8 assays were used to detect cell proliferation. Cell metastasis was evaluated by transwell and wound healing assays. Downstream target of LINC00511 was investigated by luciferase activity assay. As a results, LINC00511 was elevated in melanoma cells and tissues. Loss of LINC00511 decreased cell viability, reduced proliferation, invasion, and migration of melanoma. miR-610 was target of LINC00511, and miR-610 binds to 3'UTR of nucleobindin-2 (NUCB2). Inhibition of miR-610 attenuated LINC00511 deficiency-induced decrease of NUCB2 in melanoma cells. Loss of miR-610 weakened LINC00511 deficiency-induced decrease of cell viability, proliferation, invasion, and migration of melanoma. In conclusion, silence of LINC00511 reduced cell proliferation and metastasis of melanoma through down-regulation of miR-610-mediated NUCB2.

MicroRNA Signature in Melanoma: Biomarkers and Therapeutic Targets

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

MIR-520f Regulated Itch Expression and Promoted Cell Proliferation in Human Melanoma Cells

Accumulating evidence suggests that abnormal expression and dysfunction of microRNA is involved in development of cancers. However, the function of miR-520f especially in human melanoma remains elusive. In the current study, the underlying function of miR-520f in human melanoma was investigated. Our study demonstrated that the miR-520f level in human melanoma cell lines and clinical tissues was increased. Overexpression of miR-520f promoted cell proliferation by using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay, colony formation, anchorage-independent growth assay, and 5-bromo-2-deoxyuridine assays. Furthermore, we revealed that miR-520f could interact with circular RNA Itchy E3 ubiquitin protein ligase (ITCH) 3′-untranslated region and suppress ITCH expression in human melanoma cells. The inhibitory effect of miR-520f-in could be partially restored by knockdown of ITCH in human melanoma cells. In summary, this study provides novel insights into miR-520f act as a crucial role in the regulation of human melanoma cell growth via regulating ITCH, which might be a potential biomarker and therapeutic target of human melanoma.

Anti-angiogenic role of microRNA-23b in melanoma by disturbing NF-κB signaling pathway via targeted inhibition of NAMPT

Aim: Melanoma is the major cause of death in patients inflicting skin cancer. We identify miR-23b plays an anti-angiogenic role in melanoma. Materials & methods: We collected tumor tissues from melanoma patients. Experiments in vivo and in vitro were designed to evaluate the role of miR-23b in melanoma. Results & conclusion: miR-23b was found to be downregulated in melanoma tissues, and associated with poor patient survival. Elevating miR-23b inhibited cell viability and colony formation, reduced pro-angiogenetic ability, and accelerated apoptosis in SK-MEL-28 cells. miR-23b targeted NAMPT. Disturbing NF-κB signaling pathway with ammonium pyrrolidinedithiocarbamate (an inhibitor of NF-kB signaling pathway) impeded acquired pro-angiogenetic ability of nicotinamide phosphoribosyl transferase-overexpressed SK-MEL-28 cells. MiR-23b is a prognostic factor in melanoma. This study provides an enhanced understanding of microRNA-based targets for melanoma treatment.

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.

Targeting FER Kinase Inhibits Melanoma Growth and Metastasis

Melanoma is one of the most aggressive types of tumors and exhibits high metastatic potential. Fes-related (FER) kinase is a non-receptor tyrosine kinase that has been implicated in growth and metastasis of various epithelial tumors. In this study, we have examined the role that FER kinase plays in melanoma at the molecular level. FER-depleted melanoma cells exhibit impaired Wnt/β-catenin pathway activity, as well as multiple proteomic changes, which include decreased abundance of L1-cell adhesion molecule (L1-CAM). Consistent with the pro-metastatic functions of these pathways, we demonstrate that depletion of FER kinase decreases melanoma growth and formation of distant metastases in a xenograft model. These findings indicate that FER is an important positive regulator of melanoma metastasis and a potential target for innovative therapies.

Systematic Review and Meta-analysis of the Prognostic Significance of miRNAs in Melanoma Patients

BACKGROUND

Melanoma is the most aggressive and deadly form of skin cancer. The molecular variability involving microRNA (miRNA) expression plays a significant role in melanogenesis, which leads to poor prognostic effects in melanoma. Since there is a scarcity of comprehensive data on the prognostic role of miRNAs in melanoma patients, this study focuses on filling this knowledge gap through a systematic review and meta-analysis.

METHODS

The included studies were extracted from several bibliographic databases between 2012 and 2018 using multiple keywords according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The hazard ratios (HRs) and 95% confidence intervals (CIs) for different survival endpoints were compared to the high and low expression levels of miRNAs. The mean effect size of HR values was estimated using a random-effects model of meta-analysis. Inverted funnel plot symmetry was used to assess publication bias. Subgroup analysis was carried out individually for multiple miRNAs across different studies.

RESULTS

A total of 24 studies across eight countries were included, of which 16 studies were eligible for meta-analysis. Twenty-five miRNA expression levels were studied from 2669 melanoma patients to estimate the association between the prognostic role of miRNAs and survival outcome in these 16 studies. The overall pooled effect size (HR) for up- and downregulated miRNAs was 1.043 (95% CI 0.921-1.181; p = 0.506), indicating that the miRNA expression increased the likelihood of death in melanoma patients by 4.3%. Subgroup analysis for miRNA10b, miRNA16 and miRNA21 showed a poor prognosis. The quality assessment revealed that 16 studies were good quality and eight studies were of fair quality.

CONCLUSION

This is one of the first pooled meta-analysis studies on the role of miRNAs in the prognosis of melanoma. Our findings are inconclusive but suggest that miRNA expression could predict poor survival in melanoma patients. Therefore, miRNA expression could act as promising prognostic marker for melanoma.

microRNA-134 inhibits melanoma growth and metastasis by negatively regulating collagen triple helix repeat containing-1 (CTHRC1)

Melanoma, a malignant tumor of melanocytes, is considered to be the most aggressive of skin cancers and its incidence keeps increasing worldwide. miR-134 and CTHRC1 have been demonstrated to be involved in the occurrence and development of various tumors. However, their roles are still elusive in the progression of melanoma. qRT-PCR and western blot (WB) were used to examine the expressions of miR-134 and CTHRC1 in clinical specimens of melanoma patients and melanoma cell lines. Dual-luciferase reporter assay was applied to verify the target interaction between miR-134 and CTHRC1. The mRNA and protein expressions of CTHRC1 were measured by qRT-PCR and WB after treatment by miR-134 inhibitor and mimic. Subsequently, CCK8, colony formation assay, and flow cytometry were utilized to assess the influences of miR-134 and CTHRC1 on cell growth of melanoma. Cell migration and invasion experiments were performed to evaluate the effects of miR-134 and CTHRC1 on metastasis of melanoma. It was shown that CTHRC1 was up-regulated and miR-134 was down-regulated in melanoma patients and cell lines. CTHRC1 was demonstrated to be a direct target of miR-134. Ultimately, we also found that up-regulated miR-134 expression and down-regulated CTHRC1 expression could suppress cell proliferation and cell colony formation, promote apoptosis, delay the cell cycle, and hinder cell migration and invasion. Our findings suggest that miR-134 could inhibit the growth and metastasis of melanoma by negatively regulating CTHRC1.

MicroRNA‑539 inhibits cell proliferation, colony formation and invasion in pancreatic ductal adenocarcinoma by directly targeting IGF‑1R

MicroRNAs (miRNAs) possess oncogenic and tumour‑suppressive roles in the carcinogenesis and progression of pancreatic ductal adenocarcinoma (PDAC) by regulating the expression of numerous cancer‑related genes. Thus, the investigation on the expression and roles of miRNAs in PDAC may facilitate the identification of novel and effective targets for the clinical diagnosis and treatment of patients with PDAC. miRNA‑539 (miR‑539) has been studied in multiple types of human cancer. However, its expression and potential biological function in PDAC remain unclear. In the current study, the expression level, clinical significance, roles and underlying molecular mechanism of miR‑539 in PDAC. The present results demonstrated that miR‑539 expression was downregulated in PDAC tissues and cell lines. A low miR‑539 level was associated with TNM stage and lymph node metastasis of patients with PDAC. miR‑539 overexpression induced a significant reduction in the proliferation, colony formation and invasion of PDAC cells. Insulin‑like growth factor 1 receptor (IGF‑1R) was confirmed as a direct target gene of miR‑539 in PDAC. Further analysis indicated that IGF‑1R was overexpressed in PDAC tissues. Notably, the mRNA expression of IGF‑1R was negatively correlated with miR‑539 levels in PDAC tissues. In addition, the recovered IGF‑1R expression also partially counteracted the suppressive roles of miR‑539 overexpression in PDAC cells. Overall, miR‑539 may inhibit the aggressive behaviour of PDAC by directly targeting IGF‑1R and may serve as a novel therapeutic target for patients with this disease.