MiR-377 targets E2F3 and alters the NF-kB signaling pathway through MAP3K7 in malignant melanoma

Abstract

BackgroundThe incidence of cutaneous malignant melanoma continues to rise, and once the disease metastasizes it is almost inevitably fatal. We recently reported that a large miRNAs cluster on human chromosome 14q32, implicated in many types of cancers, is significantly down-regulated in melanoma. miR-377, one of the miRNAs located within this cluster, was studied here.MethodsqRT-pCR was used to quantify miR-377 levels in melanoma cell lines and samples. Melanoma cell lines ectopically expressing miR-377 were generated by stable transfection, mRNA expression was assessed using mRNA arrays and protein expression was assessed by Western blot analysis. Potential targets of miR-377 were identified through luciferase reporter assays. Cellular proliferation, migration and soft-agar colony formation were monitored in control and miR-377-expressing cells using cell biology techniques.ResultsmiR-377 is expressed in normal melanocytes but not in melanoma cell lines or samples. Its ectopic stable expression in melanoma cell lines decreased their proliferative and migratory capacity and their colony-forming capability. mRNA arrays of melanoma cells over-expressing miR-377 pointed to several down-regulated mRNAs that have putative binding sites for miR-377 in their 3′UTR, of which both E2F3 and MAP3K7 were found to be direct targets of miR-377.E2F3, a potent transcriptional inducer of cell-cycle progression, was found to be elevated in melanoma cell lines, but decreased following ectopic expression of miR-377. Ectopic miR-377 also led to a decrease in the activity of a reporter plasmid containing three E2F DNA-binding sites linked to a luciferase cDNA sequence, demonstrating that miR-377 down-regulates E2F3-induced transcription.MAP3K7 (known as TAK1), a serine/threonine kinase along the MAPK signaling pathway, was over-expressed in melanoma but decreased following ectopic expression of miR-377. MAP3K7 is involved in the activation of NF-κB. MiR-377 over-expression led to decreased activity of a reporter plasmid containing two NF-κB DNA-binding sites and to decreased output along the NF-kB signaling pathway.ConclusionOur results suggest that miR-377 is an important negative regulator of E2F and MAP3K7/NF-kB signaling pathway in melanoma cells; it is tempting to speculate that its silencing in melanoma promotes the tumorigenic and metastatic potential of the cells through activation of these pathways.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-015-0338-9) contains supplementary material, which is available to authorized users.

Long non-coding RNA NEAT1 promotes non-small cell lung cancer progression through regulation of miR-377-3p-E2F3 pathway

“…In our study, we investigated the effect of NEAT1 on NSCLC cells and discovered that NEAT1 involved in the ceRNA regulatory network and functioned as endogenous miRNA sponges to bind to miR-377-3p and regulated its function [71]. Recent studies indicated miR-377 showed tumor suppressive role on malignant melanoma [72], human clear cell renal cell carcinoma (CCRCC) [73], and hepatocellular carcinoma [74], while its role on NSCLC had not been investigated. In this study, we found miR-377-3p was down-expressed in NSCLC lung tissues and cell lines, and miR-377-3p suppressed cell growth, metastasis, and induced cell apoptosis in A549 and H1299 cells.…”

Potential therapeutic targets of epithelial–mesenchymal transition in melanoma

“…NFκB has been shown to induce EMT via induction of vascular endothelial growth factor (VEGF) expression and receptor translation, increase of MMP expression, and promotion of Snail [26,96]. In addition, overexpression of NFκB and increased localization of NFκB to the nucleus have been associated with faster migration of melanoma cells, and miRNA inhibition of targets directly upstream of NFκB has been shown to reduce melanoma cell migration [97,98]. Recent evidence suggests that NFκB promotes invasion by stabilizing favorable transcription factors.…”

Differential Expression of MicroRNAs in Uterine Cervical Cancer and Its Implications in Carcinogenesis; An Integrative Approach

“…Stable expression of miR-377 diminished the proliferative, migratory, and the colony-forming capability of melanoma cell lines. 33 Down-regulation of miR-1184 was stated in rectal cancer. 34 However, no other reports are available in cancer cases, suggesting the deregulation of miR-5587 and miR-4687.…”

“…More than 200 different HPV types are identified, which includes the carcinogenesis promoting high-risk HPV types (HR-HPV) such as HPV types 16,18,31,33,35,39,45,51,52,56,58,59, and 68. Among HR-HPV types, HPV type 16 is the common oncogenic type followed by HPV type 18.…”