ORIGINAL ARTICLES: SHORT COMMUNICATIONMicroRNA miR-125b induces senescence in human melanoma cellsGlud, Martina,b; Manfé, Valentinaa; Biskup, Edytaa; Holst, Linea; Dirksen, Anne Marie Ahlburga; Hastrup, Ninac; Nielsen, Finn C.d,e; Drzewiecki, Krzysztof T.b,e; Gniadecki, Roberta,eAuthor Information aDepartment of Dermatology, Bispebjerg Hospital bDepartment of Plastic Surgery and Burn Unit cDepartment of Pathology dClinical Biochemistry, Rigshospitalet eFaculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark Correspondence to Martin Glud, MD, Department of Plastic Surgery and Burn Unit, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, Copenhagen 2100, Denmark Tel: +45 2762215; fax: +45 35316010; e-mail: [email protected] Received August 26, 2010 Accepted January 31, 2011 Melanoma Research: June 2011 - Volume 21 - Issue 3 - p 253-256 doi: 10.1097/CMR.0b013e328345333b Buy Metrics Abstract MicroRNAs (miRNAs) are small noncoding RNA molecules involved in gene regulation. Aberrant expression of miRNA has been associated with the development or progression of several diseases, including cancer. In a previous study, we found that the expression of miRNA-125b (miR-125b) was two-fold lower in malignant melanoma producing lymph node micrometastases than in nonmetastasizing tumors. To get further insight into the functional role of miR-125b, we assessed whether its overexpression or silencing affects apoptosis, proliferation, or senescence in melanoma cell lines. We showed that overexpression of miR-125b induced typical senescent cell morphology, including increased cytoplasmatic/nucleus ratio and intensive cytoplasmatic β-galactosidase expression. In contrast, inhibition of miR-125b resulted in 30–35% decreased levels of spontaneous apoptosis. We propose that downregulation of miR-125b in an early cutaneous malignant melanoma can contribute to the increased metastatic capability of this tumor. © 2011 Lippincott Williams & Wilkins, Inc.