Altered expression of selected microRNAs in melanoma: Antiproliferative and proapoptotic activity of miRNA-155

Abstract

Abstract. Altered expression of microRNAs (miRNAs) has been detected in cancer, suggesting that these small non-coding RNAs can act as oncogenes or tumor suppressor genes. In the present study, we investigated the expression of miRNA-17-5p, miRNA-18a, miRNA-20a, miRNA-92a, miRNA-146a, miRNA-146b and miRNA-155 by real-time quantitative RT-PCR in a panel of melanocyte cultures and melanoma cell lines and explored the possible role of miRNA-155 in melanoma cell proliferation and survival. The analyzed miRNAs were selected on the basis of previous studies strongly supporting their involvement in cancer development and/or progression. We found that miRNA-17-5p, miRNA18a, miRNA-20a, and miRNA-92a were overexpressed, whereas miRNA-146a, miRNA-146b and miRNA-155 were down-regulated in the majority of melanoma cell lines with respect to melanocytes. Ectopic expression of miRNA-155 significantly inhibited proliferation in 12 of 13 melanoma cell lines with reduced levels of this miRNA and induced apoptosis in 4 out of 4 cell lines analyzed. In conclusion, our data further support the finding of altered miRNA expression in melanoma cells and establish for the first time that miRNA-155 is a negative regulator of melanoma cell proliferation and survival.

Human TYRP1: Two functions for a single gene?

“…miR-155 promotes the degradation of the master gene involved in pigmentation and reduces the expression levels of TYRP1 Due to its role in several cancers, miR-155 is considered by the miRNA community as an oncomir, an miRNA involved in oncogenesis (Di Leva et al, 2014;Volinia et al, 2006). However, in melanoma, miR-155 likely acts as a tumor suppressor (Levati et al, 2009;Segura et al, 2010). The overexpression of synthetic miR-155 reduces the proliferation and viability of melanoma cells in culture (Gilot et al, 2017).…”

MicroRNA Signature in Melanoma: Biomarkers and Therapeutic Targets

“…The inhibitory effect of let-7a on expression of integrin beta 3 has been verified in another study (86). In addition, functional studies have shown the role of miR-155 in the suppression of proliferation of a number of melanoma cell lines and induction of apoptosis in these cells (16). Table 2 lists the down-regulated miRNAs in melanoma.…”

“…Two other miRNAs including miR-489 and miR-527 had the opposite pattern of expression (15). Levati et al have demonstrated up-regulation of miR-17-5p, miR-18a, miR-20a, and miR-92a while down-regulation of miR-146a, miR-146b and miR-155 in most of assessed melanoma cell lines compared with melanocytes (16).…”

MicroRNA as a Diagnostic Tool, Therapeutic Target and Potential Biomarker in Cutaneous Malignant Melanoma Detection—Narrative Review

“…It was found that expression of the receptor tyrosine kinase c-KIT decreased with melanoma progression [ 31 ], and that miR-221/222 expression increased with tumor progression and was inversely correlated with c-KIT expression [ 32 ]. Looking at the current results, we can also now include oncogenes determining the development of melanoma such as miR-21, miR-155, miR-182 and miR-214 [ 33 , 34 , 35 ].…”