Ultraviolet B-induced melanoma in Monodelphis domestica occurs in the absence of alterations in the structure or expression of the p53 gene.
Monodelphis domestica, a South American opossum, has been established as a mammalian model for sporadic ultraviolet radiation (UVR)-induced melanoma. Using this model system, we investigated the role of changes in the p53 gene in the development of cutaneous melanocyte-derived lesions. Cutaneous melanocytic hyperplasias, benign melanomas and metastatic primary melanomas, plus affected lymph nodes and visceral organs, were screened for mutations in the Monodelphis p53 gene by single-strand conformation polymorphism analysis and direct sequencing. With the exception of a silent point mutation found in a single benign melanocytic hyperplasia sample, no p53 mutations were detected. Furthermore, a relative quantitative reverse transcriptase-polymerase chain reaction approach was used to analyse p53 gene expression at different stages of primary melanoma progression and revealed no substantial changes in p53 mRNA levels. These results suggest that, as in humans, UVR-induced melanoma in the Monodelphis model is initiated and progresses on the basis of predominantly p53-independent molecular pathways.
Wang
Z
Z
Department of Genetics, Southwest Foundation for Biomedical Research, PO Box 760549, San Antonio, TX 78227-5301, USA.
Atencio
J
J
Robinson
E S
ES
McCarrey
J R
JR
D000818:Animals; D017931:DNA Primers / Q000378:metabolism; D016158:Genes, p53 / Q000235:genetics*; D008545:Melanoma / Q000235:genetics*; D009374:Neoplasms, Experimental; D009381:Neoplasms, Radiation-Induced / Q000235:genetics*; D009893:Opossums; D017354:Point Mutation; D018807:Polymorphism, Single-Stranded Conformational; D012313:RNA / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012878:Skin Neoplasms / Q000235:genetics*; D013997:Time Factors; D014018:Tissue Distribution; D014466:Ultraviolet Rays
D017931:DNA Primers; D012313:RNA