ABSTRACT
OBJECTIVE: To develop a rapid, sensitive and reliable method to detect FOXL2 C402G mutation in granulosa cell tumor (GCT) and to investigate the prevalence of FOXL2 mutation in granulose cell tumors among Israeli patients. METHODS: We designed and optimized a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) genotyping assay to detect FOXL2 C402G mutation in DNA isolated from formalin-fixed paraffin-embedded tissue samples. We examined 20 tumor samples obtained from Israeli patients diagnosed with granulose cell tumor. RESULTS: Eighteen out of 20 samples were found to harbor FOXL2 C402G mutation. Pathological review of the two tumors harboring wild type FOXL2 (C402) concluded that they were adenocarcinomas and has been misclassified at initial diagnosis. We found that the prevalence of FOXL2 mutations among Israeli patients with GCT (100%) is similar to previous reports. CONCLUSIONS: Our results indicate that the FOXL2 mutations can be reliably detected by MALDI-TOF-MS genotyping. MALDI-TOF-MS genotyping is a simple, robust and highly sensitive method to detect FOXL2 C402G mutation. Our results confirm previous studies reporting over 95% prevalence of FOXL2 mutation in GCT. Furthermore, we suggest that testing for the presence of the FOXL2 C402G mutation may improve diagnostic accuracy.
Subject(s)
DNA, Neoplasm/genetics , Forkhead Transcription Factors/genetics , Gene Deletion , Granulosa Cell Tumor/genetics , Ovarian Neoplasms/genetics , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Alleles , Female , Forkhead Box Protein L2 , Granulosa Cell Tumor/pathology , Humans , Israel , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/pathology , Ovarian Neoplasms/pathology , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methodsABSTRACT
The human 1-8 interferon inducible gene family consists of at least 3 functional genes; 9-27, 1-8D and 1-8U, which are all linked on an 18-kb fragment of chromosome 11 and are highly homologous. It has recently been shown by us and others that the 1-8D gene is overexpressed in colon carcinoma. Here, we show, by sequence comparison of the 1-8D in pairs of tumor/normal colon tissues, the existence of 6 different alleles, containing single-nucleotide polymorphisms with no mutations. Transformation assays revealed a possible role for the 1-8D gene as a transformation inhibitor. Further, transient expression of the human 1-8D gene in multiple mammalian cell lines showed accumulation of cells in the G1 phase followed by elevation in the subG1 phase. SubG1 elevation was confirmed as apoptosis by Annexin-V binding assays and transferase-mediated dUTP nick end labeling assays. Moreover, knock-down of 1-8D provided partial protection from Etoposide and UV-induced apoptosis. The induction of apoptosis by 1-8D is dependent on caspase activities but not on p53 expression. Although 1-8D induces apoptosis independently of p53, p53 expression downregulates 1-8D protein expression. Our data suggest a role for the 1-8D gene as a novel pro-apoptotic gene that will provide new insights into the regulated cellular pathways to death.
