Absence of the previously reported G protein oncogene (gip2) in ovarian granulosa cell tumors.
The molecular pathogenesis of granulosa cell tumors of the ovary is not understood, although recent studies have shown that authentic inhibin secretion by these tumors may be used as a tumor marker. G proteins are heterotrimeric membrane-based polypeptides that mediate signal transduction. Activating mutations of the alpha-subunit have been reported in several tumors in which the resulting constitutively activated signal transduction pathway may be involved in tumorigenesis. Activating mutations of the G protein, G alpha I-2, have been reported to be present in 30% of ovarian sex cord tumors and in adrenocortical tumors; this activated G alpha I-2 has been designated the gip2 oncogene. We sought to explore the frequency of this oncogene in granulosa cell tumors, the most common of the sex cord tumors. Genomic DNA was obtained from either fresh-frozen tumor tissue or paraffin-embedded sections. Using both allele-specific oligonucleotide hybridization and direct sequencing of a PCR-amplified region of the G alpha I-2 gene, we were unable to confirm the presence of the previously reported mutation in any of the 13 tumors examined. The gip2 oncogene does not appear to be present at high frequency in ovarian granulosa cell tumors.
Shen
Y
Y
Prince Henry's Institute of Medical Research, Clayton, Victoria, Australia.
Mamers
P
P
Jobling
T
T
Burger
H G
HG
Fuller
P J
PJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D019204:GTP-Binding Proteins / Q000235:genetics*; D006106:Granulosa Cell Tumor / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D009857:Oncogenes; D010051:Ovarian Neoplasms / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000235:genetics*
D017931:DNA Primers; D004273:DNA, Neoplasm; D011518:Proto-Oncogene Proteins; D019204:GTP-Binding Proteins; C498015:GNAI2 protein, human; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go