Inactivating p53 mutations are found in many ultraviolet radiation (UVR)-induced skin tumors. We examined 12 UVR-induced corneal tumors of the marsupial Monodelphis domestica for mutations in exons 5-8 of p53 and compared their mutational spectrum with that of UVR-induced skin tumors of other species. First we cloned and characterized a cDNA extending from the middle of exon 4 through exon 11 of the Monodelphis p53 gene.
View Article and Find Full Text PDFDNA Cell Biol
November 1998
The tumor suppressor gene, CDKN2A (p16), encodes a cyclin-dependent kinase inhibitor and functions as a negative regulator in the retinoblastoma pathway that blocks cell cycle progression from the G1 phase. The gene has been found to be deleted, truncated, mutated, or silenced by promoter methylation in a wide range of tumor types. Where melanoma CDKN2A mutations have been characterized, C --> T and CC --> TT transitions were found, indicating a direct role for ultraviolet radiation (UVR)-induced pyrimidine dimers in the formation of some tumors.
View Article and Find Full Text PDFIn previously reported studies, we transfected repair-proficient murine fibroblasts with the denV gene of bacteriophage T4 and showed that expression of encoded endonuclease V markedly enhanced cyclobutane pyrimidine dimer (CPD) repair and reduced the frequency of ultraviolet radiation (UV)-induced mutations. In the present studies, we compared the spectra of UV-induced mutations at the hprt locus in denV-transfected and control cells. A significant difference in mutation types was observed.
View Article and Find Full Text PDFChronic exposure to ultraviolet radiation (UVR) induces corneal sarcomas in the South American opossum Monodelphis domestica. Cell lines are readily established from these tumors. Northern blotting of mRNA from six such cell lines revealed high expression of the H-ras oncogene.
View Article and Find Full Text PDFWe have isolated and characterized a 1,593-bp cDNA containing the coding region of the basic fibroblast growth factor (BFGF) gene of a marsupial, the opossum Monodelphis domestica. The encoded protein is 156 amino acids long. The BFGF gene of M.
View Article and Find Full Text PDF