Current research shows that the main cause of GCT carcinogenesis is the FOXL2 mutation, but there are several other noteworthy mutations that contribute to the pathogenesis of this disease.
A virtually universal chromosomal anomaly in GCTs is increase in 12p copy number, often in the form of isochromosome 12p [i(12p)], but this aspect of sarcomatoid YSTs has not hitherto been studied.
These data suggested that hypermethylation of the CDH13, DKK3 and FOXL2 gene promoters, and overexpression of the EZH2 protein were involved in the development of GCT.
To identify the molecular basis of advanced stage disease we have used whole transcriptome analysis of FOXL2C134W mutation positive adult (a)GCT to identify genes that are differentially expressed between early (stage 1) and advanced (stage 3) aGCT.
Immunostaining and Western blot analyses confirmed FOXO1 and phosphatase and tensin homolog (PTEN) depletion, maintenance of globin transcription factor (GATA) 4 and nuclear localization of FOXL2 and phosphorylated small mothers against decapentaplegic (SMAD) 2/3 in the tumor cells, recapitulating results we observed in human adult GCTs.
Several studies have shown that a somatic mutation leading to a C134W substitution in the transcription factor FOXL2 appears in more than 95% of adult-type GCTs.
The common clonal origin of the AMKL and GCT was further confirmed with massively parallel sequencing, which identified somatic TP53 and PTEN mutations, as well as a rare germline ATM variant.
In summary, our data suggest that p63 regulates GCTSC proliferation by binding to the CDC2 and CDC25C p53-REs, which may inhibit the p53 tumor suppressor activity and contribute to GCT tumorigenesis.
Recently, it has been shown that a FOXL2 402C>G (C134W) mutation is present in 97% of human adult-type GCTs, suggesting an important role for this mutation in the development of GCTs.
The aim of this study was to investigate the role of Notch signaling in the proliferation, steroidogenesis, apoptosis, and phosphatidylinositol 3-kinase (PI3K)/AKT pathway in a FOXL2-mutated granulosa tumor cell line (KGN) representative of the adult form of GCTs.
The histogenesis of these tumours is unknown and, in view of the very strong association between the C134W (402 C>G) FOXL2 mutation and adult-type GCT, we analysed a series of gynandroblastomas for this mutation.
To our knowledge, this is the first case report of a patient with mediastinal GCT subsequently developing acute megakaryoblastic leukemia involving i(12p) in Korea.
Recently, FOXL2 c.402C>G, a new somatic mutation that leads to a p.C134W change, was found in the majority of adult-type ovarian granulosa cell tumors (GCTs).
The Mdm2 inhibitor nutlin-3 was evaluated alone and in combination with cisplatin in a panel of germ cell tumour (GCT)-derived cell lines (embryonal carcinomas, being the nonseminomatous stem-cell component) with wild-type (NT2 and 2102EP cells) and mutant (NCCIT cells) p53 status.