title: A novel role for microphthalmia-associated transcription factor-regulated pigment epithelium-derived factor during melanoma progression.
abstract: Microphthalmia-associated transcription factor (MITF) acts via pigment epithelium-derived factor (PEDF), an antiangiogenic protein, to regulate retinal pigment epithelium migration. PEDF expression and/or regulation during melanoma development have not been investigated previously. Using immunohistochemistry, we determined expression of PEDF in common and dysplastic melanocytic nevi, melanoma in situ, invasive melanoma, and metastatic melanoma (n = 102). PEDF expression was consistently decreased in invasive and metastatic melanoma, compared with nevi and melanoma in situ (P < 0.0001). PEDF was lost in thicker melanomas (P = 0.003), and correlated with depth of invasion (P = 0.003) and distant metastasis (P = 0.0331), but only marginally with mitotic index, AJCC stage, nodal metastasis, or blood vascular density (0.05 < P < 0.10). Quantitative real-time PCR and microarray analyses confirmed PEDF down-regulation at the mRNA level in several melanoma lines, compared with melanocytes. MITF positively correlated with PEDF expression in invasive melanomas (P = 0.0003). Searching for PEDF regulatory mechanisms revealed two occupied conserved E-boxes (DNA recognition elements) in the first intron of the human and mouse PEDF promoter regions, confirmed by binding assays. Dominant-negative and siRNA approaches in vivo demonstrated direct transcriptional influence of MITF on PEDF, establishing the PEDF gene (SERPINF1) as a MITF target in melanocytes and melanoma cells. These findings suggest that loss of PEDF expression promotes early invasive melanoma growth.
authors.affiliation: Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts. Electronic address: dadras@uchc.edu.
authors.forename: Soheil S
authors.initials: SS
authors.lastname: Dadras
authors.affiliation: Department of Pediatric Hematology/Oncology, Melanoma Program in Medical Oncology, Boston, Massachusetts.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Lin
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California.
authors.forename: Gita
authors.initials: G
authors.lastname: Razavi
authors.affiliation: Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts.
authors.forename: Akinori
authors.initials: A
authors.lastname: Kawakami
authors.affiliation: Merrimack Pharmaceuticals, Cambridge, Massachusetts.
authors.forename: Jinyan
authors.initials: J
authors.lastname: Du
authors.affiliation: Department of Pediatric Hematology/Oncology, Melanoma Program in Medical Oncology, Boston, Massachusetts.
authors.forename: Erez
authors.initials: E
authors.lastname: Feige
authors.affiliation: Department of Pediatric Hematology/Oncology, Melanoma Program in Medical Oncology, Boston, Massachusetts.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Milner
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts.
authors.forename: Massimo F
authors.initials: MF
authors.lastname: Loda
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Granter
authors.affiliation: Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts.
authors.forename: Michael
authors.initials: M
authors.lastname: Detmar
authors.affiliation: Department of Pediatric Hematology/Oncology, Melanoma Program in Medical Oncology, Boston, Massachusetts.
authors.forename: Hans R
authors.initials: HR
authors.lastname: Widlund
authors.affiliation: Research Institute and Clinic of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Horstmann
authors.affiliation: Cutaneous Biology Research Center and Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts; Department of Pediatric Hematology/Oncology, Melanoma Program in Medical Oncology, Boston, Massachusetts.
authors.forename: David E
authors.initials: DE
authors.lastname: Fisher
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008544:Melanocytes; D008545:Melanoma / Q000378:metabolism*; D051379:Mice; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D008969:Molecular Sequence Data; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009414:Nerve Growth Factors / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D034741:RNA, Small Interfering / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D015843:Serpins / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism*; D055815:Young Adult; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D005136:Eye Proteins; D051739:Microphthalmia-Associated Transcription Factor; D009414:Nerve Growth Factors; D034741:RNA, Small Interfering; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor; C497234:MITF protein, human