title: Expression of the wt1 Wilms' tumor gene by normal and malignant human melanocytes.
abstract: We report expression of the wt1 (Wilms' tumor) gene by cultured human melanoma cells. Using RNA polymerase chain reaction analysis, wt1 transcripts were detected in 7 of 9 melanoma cell lines but not in 5 normal melanocyte strains. In Northern blot analysis, steady-state wt1 mRNA levels were found in 2 of 4 melanoma lines but not in normal melanocytes. Sequence analysis of the wt1 cDNA expressed by melanoma cell line WM 902-B revealed the presence of 4 previously published splice variants but no evidence for mutations in the coding region. Previous work has shown that WT1 modulates transcription after binding to the early growth response (EGR)-1 sites present in the platelet-derived growth factor (PDGF)-A chain promoter; the PDGF-A chain gene is known to be expressed by various melanoma cell lines. Based on these findings, we studied the relationship of wt1 and PDGF-A chain gene expression in melanoma cell lines. Co-expression of the wt1 and the PDGF-A chain genes was observed in 2 melanoma cell lines with mutated p53 but not in 2 melanoma cell lines with wild-type p53; this result is consistent with a previous report showing that, in the context of absent or mutated p53, WT1 acts as a transcriptional activator, whereas in the presence of wild-type p53 it acts as a repressor.
authors.affiliation: Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104.
authors.forename: U
authors.initials: U
authors.lastname: Rodeck
authors.forename: A
authors.initials: A
authors.lastname: Bossler
authors.forename: C
authors.initials: C
authors.lastname: Kari
authors.forename: C W
authors.initials: CW
authors.lastname: Humphreys
authors.forename: T
authors.initials: T
authors.lastname: Györfi
authors.forename: J
authors.initials: J
authors.lastname: Maurer
authors.forename: E
authors.initials: E
authors.lastname: Thiel
authors.forename: H D
authors.initials: HD
authors.lastname: Menssen
mesh_terms: D001483:Base Sequence; D015152:Blotting, Northern; D018076:DNA, Complementary / Q000737:chemistry; D015870:Gene Expression; D016162:Genes, Wilms Tumor; D016158:Genes, p53; D006801:Humans; D008544:Melanocytes / Q000378:metabolism*; D008545:Melanoma / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010982:Platelet-Derived Growth Factor / Q000235:genetics; D016133:Polymerase Chain Reaction; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D018076:DNA, Complementary; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger