Infrequent mutations of Archipelago (hAGO, hCDC4, Fbw7) in primary ovarian cancer

Gynecol Oncol. 2005 Jul;98(1):124-8. doi: 10.1016/j.ygyno.2005.04.007.

Abstract

Objective: Archipelago (AGO, also known as hCdc4, Fbw7, or Sel-10) is an F-box containing component of the SCF complex implicated in the ubiquitination and proteolysis of cyclin E and c-Myc, and found to be mutated in 16% of endometrial carcinomas. We have previously reported somatic mutations in AGO in 3/10 ovarian cancer cell lines, but the frequency of such mutations in primary ovarian cancer is unknown.

Methods: The coding sequence of AGO was analyzed in 95 primary sporadic ovarian tumors and 16 cases of familial ovarian cancer, and correlated with levels of cyclin E and c-Myc protein expression. Constructs encoding mutations in AGO were transfected into an AGO-null cell line to directly test their ability to regulate cyclin E and c-Myc levels.

Results: Mutations were present in only 2 of 95 sporadic cases: a premature stop within the WD domain (471 Ter) and a missense change near the F-box (S245T). Both primary tumor specimens containing these mutations showed high levels of cyclin E and c-Myc, but reconstitution of an AGO-null cell line with constructs encoding these mutations showed 471 Ter to be inactive in regulating endogenous cyclin E and c-Myc levels, while the S245T mutant was indistinguishable from wild-type. No germ-line mutations were found in familial cases of ovarian cancer.

Conclusion: Somatic AGO mutations are infrequent in primary ovarian cancers and are unlikely to contribute to familial ovarian cancer. Reconstitution experiments, rather than measuring tumor levels of cyclin E and c-Myc, provide an effective approach to determine the functional significance of AGO mutations identified in human cancers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Cycle Proteins / genetics*
  • Cyclin E / biosynthesis
  • Cyclin E / genetics
  • DNA Mutational Analysis
  • F-Box Proteins / genetics*
  • F-Box-WD Repeat-Containing Protein 7
  • Female
  • Gene Expression Regulation, Neoplastic
  • Genes, Tumor Suppressor
  • Humans
  • Mutation*
  • Ovarian Neoplasms / enzymology
  • Ovarian Neoplasms / genetics*
  • Ovarian Neoplasms / metabolism
  • Proto-Oncogene Proteins c-myc / biosynthesis
  • Proto-Oncogene Proteins c-myc / genetics
  • Transfection
  • Ubiquitin-Protein Ligases / genetics*

Substances

  • Cell Cycle Proteins
  • Cyclin E
  • F-Box Proteins
  • F-Box-WD Repeat-Containing Protein 7
  • FBXW7 protein, human
  • MYC protein, human
  • Proto-Oncogene Proteins c-myc
  • Ubiquitin-Protein Ligases