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


CONCLUSIONS
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.
Kwak
Eunice L
EL
Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149, CNY-7, 13th Street, Charlestown, MA 02129, USA.
Moberg
Kenneth H
KH
Wahrer
Doke C R
DC
Quinn
Jennifer E
JE
Gilmore
Paula M
PM
Graham
Colin A
CA
Hariharan
Iswar K
IK
Harkin
D Paul
DP
Haber
Daniel A
DA
Bell
Daphne W
DW
D018797:Cell Cycle Proteins / Q000235:genetics*; D019927:Cyclin E / Q000096:biosynthesis / Q000235:genetics; D004252:DNA Mutational Analysis; D044783:F-Box Proteins / Q000235:genetics*; D000073979:F-Box-WD Repeat-Containing Protein 7; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D009154:Mutation; D010051:Ovarian Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection; D044767:Ubiquitin-Protein Ligases / Q000235:genetics*
D018797:Cell Cycle Proteins; D019927:Cyclin E; D044783:F-Box Proteins; D000073979:F-Box-WD Repeat-Containing Protein 7; C513273:FBXW7 protein, human; C489427:MYC protein, human; D016271:Proto-Oncogene Proteins c-myc; D044767:Ubiquitin-Protein Ligases