Cutaneous melanoma is an extremely heterogenous human cancer. The most aggressive melanoma may contain deregulated cells with undifferentiated/stem cell-like phenotype. A critical mechanism by which melanoma cells enhance their invasive capacity is the dissolution of the intercellular adhesion and the acquisition of mesenchymal features as a part of an epithelial-to-mesenchymal transition. The aim of this study was to clarify the role of a stem cell-like population in human melanomas by means of melanocytic cell culture analysis obtained from distinct histotypes of primary and metastatic malignant melanoma. Patients with advanced melanoma >2 cm in diameter and/or >300 mm2 surface were enrolled. The melanoma cells were isolated from skin biopsies of lentigo maligna melanoma, superficial spreading melanoma, nodular melanoma, and metastatic melanoma. The colony forming unit assay and alkaline phosphatase stain were evaluated. Cells were subsequently cultured and maintained in different media to evaluate their ability to differentiate into osteogenic and adipogenic lineages. Immunohistochemistry and flow cytometry analysis were performed to evaluate antigenic markers CD90, CD73, CD105, CD146, CD20, CD166, and Nestin. This study confirms that melanoma can include heterogenous cell populations with the ability both to self-renew and to a give rise to differentiated progeny. Melanoma cells displayed intratumoral heterogeneity and dynamic antigen phenotypes. Histologically, transitions from normal skin to melanoma were associated with a gradual increase in the expression of CD146, CD20, CD133, Nestin, and CD73. These molecular profiles could be further analyzed and, in the future, used for the development of novel biomolecular targeted-therapy approaches.
Departments of *Dermatology
‡Clinical and Diagnostic Medicine and Public Health, University Hospital of Modena and Reggio Emilia, University of Modena and Reggio Emilia, Modena
†1st Medical Department, Dermatology Unit, Arcispedale Santa Maria Nuova, Reggio Emilia
§Department of Odontostomatological and Maxillofacial Sciences, Oral Medicine Unit, School of Medicine and Surgery, Federico II University of Naples, Naples, Italy
Supported in part by a grant provided by Istituto Superiore di Sanità (Grant number: ISS 2011-527/TR1.a).
The authors declare no conflict of interest.
Reprints: Giovanni Ponti, MD, PhD, Department of Clinical and Diagnostic Medicine and Public Health, University Hospital of Modena and Reggio Emilia, University of Modena and Reggio Emilia; via del Pozzo, 71, Modena 41100, Italy (e-mail: firstname.lastname@example.org).
Received November 27, 2012
Accepted March 1, 2013