title: Novel MITF targets identified using a two-step DNA microarray strategy.
abstract: Malignant melanoma is a chemotherapy-resistant cancer with high mortality. Recent advances in our understanding of the disease at the molecular level have indicated that it shares many characteristics with developmental precursors to melanocytes, the mature pigment-producing cells of the skin and hair follicles. The development of melanocytes absolutely depends on the action of the microphthalmia-associated transcription factor (MITF). MITF has been shown to regulate a broad variety of genes, whose functions range from pigment production to cell-cycle regulation, migration and survival. However, the existing list of targets is not sufficient to explain the role of MITF in melanocyte development and melanoma progression. DNA microarray analysis of gene expression offers a straightforward approach to identify new target genes, but standard analytical procedures are susceptible to the generation of false positives and require additional experimental steps for validation. Here, we introduce a new strategy where two DNA microarray-based approaches for identifying transcription factor targets are combined in a cross-validation protocol designed to help control false-positive generation. We use this two-step approach to successfully re-identify thirteen previously recorded targets of MITF-mediated upregulation, as well as 71 novel targets. Many of these new targets have known relevance to pigmentation and melanoma biology, and further emphasize the critical role of MITF in these processes.
authors.affiliation: Department of Dermatology, University Hospital of Zürich, Zürich, Switzerland. keith.hoek@usz.ch
authors.forename: Keith S
authors.initials: KS
authors.lastname: Hoek
authors.forename: Natalie C
authors.initials: NC
authors.lastname: Schlegel
authors.forename: Ossia M
authors.initials: OM
authors.lastname: Eichhoff
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Widmer
authors.forename: Christian
authors.initials: C
authors.lastname: Praetorius
authors.forename: Steingrimur O
authors.initials: SO
authors.lastname: Einarsson
authors.forename: Sigridur
authors.initials: S
authors.lastname: Valgeirsdottir
authors.forename: Kristin
authors.initials: K
authors.lastname: Bergsteinsdottir
authors.forename: Alexander
authors.initials: A
authors.lastname: Schepsky
authors.forename: Reinhard
authors.initials: R
authors.lastname: Dummer
authors.forename: Eirikur
authors.initials: E
authors.lastname: Steingrimsson
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008545:Melanoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; C497234:MITF protein, human; D051739:Microphthalmia-Associated Transcription Factor