QUT ePrints

CDKN2A/p16 is inactivated in most melanoma cell lines

Castellano, Marina, Pollock, Pamela M., Walters, Marilyn K., Sparrow, Louise E., Down, Louise M., Gabrielli, Brian G., Parsons, Peter G., & Hayward, Nicholas K. (1997) CDKN2A/p16 is inactivated in most melanoma cell lines. Cancer Research, 57(21), pp. 4868-4875.

[img] Published Version (PDF 1MB)
Administrators only | Request a copy from author

    View at publisher

    Abstract

    The CDKN2A gene maps to chromosome 9p21-22 and is responsible for melanoma susceptibility in some families. Its product, p16, binds specifically to CDK4 and CDK6 in vitro and in vivo, inhibiting their kinase activity. CDKN2A is homozygously deleted or mutated in a large proportion of tumor cell lines and some primary tumors, including melanomas. The aim of this study was to investigate the involvement of CDKN2A and elucidate the mechanisms of p16 inactivation in a panel of 60 cell lines derived from sporadic melanomas. Twenty-six (43%) of the melanoma lines were homozygously deleted for CDKN2A, and an additional 15 (25%) lines carried missense, nonsense, or frameshift mutations. All but one of the latter group were shown by microsatellite analysis to be hemizygous for the region of 9p surrounding CDKN2A. p16 was detected by Western blotting in only five of the cell lines carrying mutations. Immunoprecipitation of p16 in these lines, followed by Western blotting to detect the coprecipitation of CDK4 and CDK6, revealed that p16 was functionally compromised in all cell lines but the one that carried a heterozygous CDKN2A mutation. In the remaining 19 lines that carried wild-type CDKN2A alleles, Western blot analysis and immunoprecipitation indicated that 11 cell lines expressed a wild-type protein. Northern blotting was performed on the remaining eight cell lines and revealed that one cell line carried an aberrantly sized RNA transcript, and two other cell lines failed to express RNA. The promoter was found to be methylated in five cell lines that expressed CDKN2A transcript but not p16. Presumably, the message seen by Northern blotting in these cell lines is the result of cross-hybridization of the total cDNA probe with the exon 1beta transcript. Microsatellite analysis revealed that the majority of these cell lines were hemi/homozygous for the region surrounding CDKN2A, indicating that the wild-type allele had been lost. In the 11 cell lines that expressed functional p16, microsatellite analysis revealed loss of heterozygosity at the markers immediately surrounding CDKN2A in five cases, and the previously characterized R24C mutation of CDK4 was identified in one of the remaining 6 lines. These data indicate that 55 of 60 (92%) melanoma cell lines demonstrated some aberration of CDKN2A or CDK4, thus suggesting that this pathway is a primary genetic target in melanoma development.

    Impact and interest:

    101 citations in Scopus
    Search Google Scholar™
    99 citations in Web of Science®

    Citation countsare sourced monthly from Scopus and Web of Science® citation databases.

    These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

    Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

    ID Code: 45809
    Item Type: Journal Article
    Keywords: Blotting, Western, Chromosomes, Human, Pair 9/ genetics, Cyclin-Dependent Kinase Inhibitor p16/metabolism, Gene Deletion, Genes, p16/ genetics, Humans, Melanoma/ genetics, Neoplasm Proteins/metabolism, Sequence Deletion, Tumor Cells, Cultured
    ISSN: 0008-5472
    Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > ONCOLOGY AND CARCINOGENESIS (111200) > Cancer Cell Biology (111201)
    Divisions: Past > Schools > Cell & Molecular Biosciences
    Past > QUT Faculties & Divisions > Faculty of Science and Technology
    Current > Institutes > Institute of Health and Biomedical Innovation
    Copyright Owner: Copyright 1997 American Association for Cancer Research
    Deposited On: 09 Sep 2011 10:39
    Last Modified: 09 Sep 2011 10:39

    Export: EndNote | Dublin Core | BibTeX

    Repository Staff Only: item control page