Altered expression of selected microRNAs in melanoma: antiproliferative and proapoptotic activity of miRNA-155.
Levati L, Alvino E, Pagani E, Arcelli D, Caporaso P, Bondanza S, Di Leva G, Ferracin M, Volinia S, Bonmassar E, Croce CM, D'Atri S. Altered expression of selected microRNAs in melanoma: antiproliferative and proapoptotic activity of miRNA-155. Journal of Oncology 2009 Aug;35(2):393-400.
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, miRNA-18a, 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.

