FOXL2 Research Articles

A novel insertion in the FOXL2 gene in a Chilean patient with blepharophimosis ptosis epicanthus inversus syndrome type I

A novel insertion in the forkhead transcription factor 2 (FOXL2) was identified in a Chilean patient with blepharophimosis, ptosis, and epicanthus inversus syndrome associated with premature ovarian failure (BPES type I). A clinical and molecular characterization of a patient with BPES type I was performed. We present a 16-year-old adolescent girl with surgically treated blepharophimosis, ptosis, and epicanthus inversus that was associated with delayed puberty and secondary amenorrhea at the age of 15, indicators that suggested that the patient had BPES type I. The FOXL2 gene was analyzed by sequencing its coding region. The sequence analysis of the FOXL2 gene revealed a novel heterozygous mutation: an 11 bp duplication (c.901_911dup11) that was predicted to encode a truncated protein (p.Pro305Argfs*54). A novel out-of-frame duplication following the polyalanine domain in the FOXL2 gene was identified in a Chilean patient with BPES type I. This study characterized the molecular alterations in FOXL2 and confirmed the diagnosis, thereby providing information to allow for improved genetic counseling for the patient and her family.

Genetic changes in nonepithelial ovarian cancer

Nonepithelial ovarian cancers (OCs), including sex cord-stromal tumors (SCSTs) and germ cell tumors (GCTs), are an uncommon subset of OC, together accounting for 10% of all OCs. The etiology of these tumors remains largely unresolved. It is well established that tumorigenesis is the result of multiple genetic alterations driving a normal cell toward a malignant state. Much effort has been made into researching the molecular mechanisms underlying epithelial OC, but far less is known about the genetic changes in SCSTs and GCTs. Recently, a single point missense mutation (C134W) was found in the FOXL2 gene in approximately 95% of adult-type granulosa cell tumors, suggesting a key role for FOXL2 in these tumors. By contrast, the FOXL2 mutation was not found in the juvenile type. DICER1 somatic missense mutations were found in approximately 60% of Sertoli-Leydig tumors. Ovarian GCTs share many morphological features and a similar pattern of chromosomal alterations with testicular GCTs. In the latter, recent genome-wide association studies have identified seven susceptibility loci near KITLG, SPRY4, UKC2, BAK1, DMRT1, TERT and ATF7IP. All of the susceptibility loci detected thus far are all involved in primordial germ cell function or sex determination. TGF-β/BMP and Wnt/β-catenin signaling was absent in dysgerminomas, but present in yolk sac tumors, suggesting intertumoral heterogeneity. In this article, the authors aim to provide an overview of the current knowledge on the possible molecular changes in SCSTs and GCTs of the ovary.

Characterization of the inhibitor of kappaB kinase (IKK) complex in granulosa cell tumors of the ovary and granulosa cell tumor-derived cell lines.

Granulosa cell tumors of the ovary (GCT) are a distinct, hormonally active subset of ovarian cancers. Although it has recently been shown that ∼97% of all adult GCT harbor a novel somatic missense mutation in the FOXL2 gene, given its almost universal presence, it does not explain differences in tumor stage and/or recurrence. The nuclear factor kappaB (NFκB) transcription factor is constitutively active in two human GCT-derived cell lines, COV434 and KGN, which are useful in vitro models to investigate juvenile and adult GCT, respectively. This study aimed to determine the molecular basis and pathogenetic significance of this aberrant NFκB activity. Selective chemical inhibitors were used to target candidate components of the pathway. The constitutive activity was blocked by two independent inhibitors of IκBα phosphorylation, suggesting that aberrant activation occurs upstream of this point. NFκB inhibition resulted in a dose-dependent decrease in cell proliferation and viability and a dose-dependent increase in apoptosis. Inhibitors of earlier components of the pathway were without effect. Two independent inhibitors of inhibitor of kappaB kinase (IKK)β, a catalytic subunit of the NFκB activation complex, were unable to inhibit the constitutive activity, but surprisingly also ligand-induced activity. These findings suggest a central role for IKKβ; however, no mutations or altered expression of the IKKβ, IKKα, or IKKγ genes was observed in the cell lines or in a panel of human GCT samples. This study highlights unresolved issues in understanding the pathogenesis of GCT and in the use of the COV434 and KGN cells lines as model systems.

Embryonic Stem Cell—Derived Granulosa Cells Participate in Ovarian Follicle Formation In Vitro and In Vivo

Differentiating embryonic stem cells (ESCs) can form ovarian follicle-like structures in vitro, consisting of an oocyte-like cell surrounded by somatic cells capable of steroidogenesis. Using a dual-fluorescence reporter system in which mouse ESCs express green fluorescent protein (GFP) under the control of a germ cell-specific Pou5f1 gene promoter and red fluorescent protein (Discosoma sp red [DsRed]) driven by the granulosa cell-specific Forkhead box L2 (Foxl2) gene promoter, we first confirmed in vitro formation of follicle-like structures containing GFP-positive cells surrounded by DsRed-positive cells. Isolated DsRed-positive cells specified from ECSs exhibited a gene expression profile consistent with granulosa cells, as revealed by the detection of messenger RNAs (mRNAs) for Foxl2, follistatin (Fst), anti-Müllerian hormone (Amh), and follicle-stimulating hormone receptor (Fshr) as well as by production of both progesterone and estradiol. In addition, treatment of isolated DsRed-expressing cells with follicle-stimulating hormone (FSH) significantly increased estradiol production over basal levels, confirming the presence of functional FSH receptors in these cells. Last, ESC-derived DsRed-positive cells injected into neonatal mouse ovaries became incorporated within the granulosa cell layer of immature follicles. These studies demonstrate that Foxl2-expressing ovarian somatic cells derived in vitro from differentiating ESCs express granulosa cell markers, actively associate with germ cells in vitro, synthesize steroids, respond to FSH, and participate in folliculogenesis in vivo.

Clinical, Radiologic, and Genetic Features in Blepharophimosis, Ptosis, and Epicanthus Inversus Syndrome in the Indian Population

To study the clinical, radiologic, and genetic features in Indian Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) patients. A total of 33 clinically well characterized BPES cases who presented between 2009 to 2011 were recruited. Clinical evaluation consisted of ophthalmic and orthoptic examination. For orbital indices, computed tomography (CT) scan of orbits was performed. Genetic studies included cytogenetic analysis and molecular analysis of FOXL2 gene. Significant clinical findings included a high incidence of refractive error in 94%, amblyopia in 60%, and strabismus in 40% of BPES cases. Orbital radiologic indices on CT scan in BPES were found to be comparable to the control group. On karyotyping, 8 out of 33 (24%) cases harbored chromosomal abnormalities. These abnormalities included 46,XY;del(3qter), 46,XY;del(3q26.3), 46,XX;del(3q24-25), and 46,XY;del(3q26qter). On molecular analysis, a novel mutation consisting of heterozygous substitution at c1635 that replaced cytosine by thymidine was detected. To the best of our knowledge, this is the first study on clinical features in BPES patients of Indian origin. A high incidence of refractive error, strabismus, and amblyopia was found in BPES cases. Orbital imaging confirmed that clinical features are limited to soft tissue abnormalities, with no underlying bony changes. Cytogenetic studies showed that most chromosomal abnormalities in the Indian population are in the region of the long arm of chromosome 3. Results of molecular analysis indicate that there may be loci other than the FOXL2 gene, which are affected in BPES cases. Our study expands the existing mutation spectrum of FOXL2 gene.

The discovery of Foxl2 paralogs in chondrichthyan, coelacanth and tetrapod genomes reveals an ancient duplication in vertebrates

The Foxl2 (forkhead box L2) gene is an important member of the forkhead domain family, primarily responsible for the development of ovaries during female sex differentiation. The evolutionary studies conducted previously considered the presence of paralog Foxl2 copies only in teleosts. However, to search for possible paralog copies in other groups of vertebrates and ensure that all predicted copies were homolog to the Foxl2 gene, a broad evolutionary analysis was performed, based on the forkhead domain family. A total of 2464 sequences for the forkhead domain were recovered, and subsequently, 64 representative sequences for Foxl2 were used in the evolutionary analysis of this gene. The most important contribution of this study was the discovery of a new subgroup of Foxl2 copies (ortholog to Foxl2B) present in the chondrichthyan Callorhinchus milii, in the coelacanth Latimeria chalumnae, in the avian Taeniopygia guttata and in the marsupial Monodelphis domestica. This new scenario indicates a gene duplication event in an ancestor of gnathostomes. Furthermore, based on the analysis of the syntenic regions of both Foxl2 copies, the duplication event was not exclusive to Foxl2. Moreover, the duplicated copy distribution was shown to be complex across vertebrates, especially in tetrapods, and the results strongly support a loss of this copy in eutherian species. Finally, the scenario observed in this study suggests an update for Foxl2 gene nomenclature, extending the actual suggested teleost naming of Foxl2A and Foxl2B to all vertebrate sequences and contributing to the establishment of a new evolutionary context for the Foxl2 gene.

Microhomology-Mediated Mechanisms Underlie Non-Recurrent Disease-Causing Microdeletions of the FOXL2 Gene or Its Regulatory Domain

Genomic disorders are often caused by recurrent copy number variations (CNVs), with nonallelic homologous recombination (NAHR) as the underlying mechanism. Recently, several microhomology-mediated repair mechanisms—such as microhomology-mediated end-joining (MMEJ), fork stalling and template switching (FoSTeS), microhomology-mediated break-induced replication (MMBIR), serial replication slippage (SRS), and break-induced SRS (BISRS)—were described in the etiology of non-recurrent CNVs in human disease. In addition, their formation may be stimulated by genomic architectural features. It is, however, largely unexplored to what extent these mechanisms contribute to rare, locus-specific pathogenic CNVs. Here, fine-mapping of 42 microdeletions of the FOXL2 locus, encompassing FOXL2 (32) or its regulatory domain (10), serves as a model for rare, locus-specific CNVs implicated in genetic disease. These deletions lead to blepharophimosis syndrome (BPES), a developmental condition affecting the eyelids and the ovary. For breakpoint mapping we used targeted array-based comparative genomic hybridization (aCGH), quantitative PCR (qPCR), long-range PCR, and Sanger sequencing of the junction products. Microhomology, ranging from 1 bp to 66 bp, was found in 91.7% of 24 characterized breakpoint junctions, being significantly enriched in comparison with a random control sample. Our results show that microhomology-mediated repair mechanisms underlie at least 50% of these microdeletions. Moreover, genomic architectural features, like sequence motifs, non-B DNA conformations, and repetitive elements, were found in all breakpoint regions. In conclusion, the majority of these microdeletions result from microhomology-mediated mechanisms like MMEJ, FoSTeS, MMBIR, SRS, or BISRS. Moreover, we hypothesize that the genomic architecture might drive their formation by increasing the susceptibility for DNA breakage or promote replication fork stalling. Finally, our locus-centered study, elucidating the etiology of a large set of rare microdeletions involved in a monogenic disorder, can serve as a model for other clustered, non-recurrent microdeletions in genetic disease.

Mechanisms of Activin-Stimulated FSH Synthesis: The Story of a Pig and a FOX1

Activins were discovered and, in fact, named more than a quarter century ago based on their abilities to stimulate pituitary follicle-stimulating hormone (FSH) synthesis and secretion. However, it is only in the last decade that we have finally come to understand their underlying mechanisms of action in gonadotroph cells. In this minireview, we chronicle the research that led to the recent discovery of forkhead box L2 (FOXL2) as an essential mediator of activin-regulated FSH beta subunit (Fshb) transcription in vitro and in vivo.

The <i>FOXL2</i> Mutation (c.402C>G) in Adult-Type Ovarian Granulosa Cell Tumors of Three Japanese Patients: Clinical Report and Review of the Literature

Adult-type granulosa cell tumor (AGCT) is a rare class of malignant ovarian tumor with unique features, characterized by slow growth, late recurrence, relatively good prognosis and unified cause in almost all patients. The forkhead box L2 (FOXL2) gene encodes an essential transcription factor in the ovary. FOXL2 is important in female sex determination, follicle recruitment, and granulosa cell development. About 70-97% of AGCTs were reported to carry a somatic mutation c.402C>G (C134W) in the FOXL2 gene. However, it is unknown whether AGCTs of Japanese patients harbor the FOXL2 c.402C>G mutation. Here, we report a mutational analysis of the FOXL2 gene in four Japanese patients with AGCTs, and we review the literature to determine the precise incidence of FOXL2 mutations in AGCTs. All four patients were analyzed by immunohistochemistry for FOXL2. Genomic DNA was extracted from paraffin-embedded tissues, and was analyzed to detect the c.402C>G mutation in FOXL2 by direct sequencing. All tumors were stained with FOXL2. Three of the four tumors harbor the c.402C>G mutation. Based on the literature review, FOXL2 immunostaining is a highly specific marker for sex cord-stromal tumors (SCSTs), but it is not specific for AGCTs, one subtype of SCSTs. We identified 340 patients with the FOXL2 mutation (c.402C>G) and determined that the incidence of the mutation is 91.9% in AGCT patients. Therefore, this FOXL2 mutation is specific to AGCTs in the ovary and is useful for diagnosis of this disease.

Expression of Sex-Related Genes in Chicken Embryos During Male-to-Female Sex Reversal Exposure to Diethylstilbestrol

Sex emerges out of a delicate dance between a variety of promale, anti-male, and possibly profemale genes. To investigate the role that sex-related genes play in sex determination and gonadal differentiation of fowl, we constructed a male-to-female sex-reversal model of chick induced by diethylstilbestrol (DES) at onset of incubation (E0). The results of semiquantitative PCR showed that the expression of Sf1, the orphan nuclear receptor steroidogenic factor-1 gene, was put forward from E7d to E5d and up-regulated during E5-7d; the Dmrt1, the double sex and the Mab-3 related to transcription factor 1 gene, was down-regulated during E3-7d. Meanwhile, anti-Müllerian hormone gene (Amh) expressed at a similar level in the genetic females and sex-reversal females before E7d, while no expression products of the three female-specific genes Wpkci, Fet1 and Foxl2 were detected in male-to-female embryos. These findings suggest that the expression of some certain sex-related genes, induced by the exogenous estrogen during period of sex determination and gonadal differentiation, results in the male-to-female sex reversal. Moreover, high activity of Sf1 gene during E5-7d might be related to the profemale process, while low activity of Dmrt1 gene during E3-5d might be anti-male. The expression activity of Amh gene might only contribute to the promale process after E7d, however, it is possibly not an anti-female gene in chick embryos.

Comparative study of microRNA regulation on FOXL2 between adult-type and juvenile-type granulosa cell tumours in vitro

ObjectivesDespite their distinct biology, granulosa cell tumours (GCTs) are treated similarly to other ovarian tumours. Predominantly expressed in granulosa cells, the transcription factor Forkhead Box L2 (FOXL2) is near absent in juvenile-type GCTs. This research aimed to investigate miRNAs as a mechanism of suppression of FOXL2 expression in juvenile-type GCTs. MethodsThe miRNA abundance of two GCT cell lines COV434 and KGN was profiled using Affymetrix miRNA GeneChip arrays. Luciferase assays were used to confirm miRNA binding to the 3′UTR of FOXL2. Identified as promising candidates, the miR-17 miRNA family was targeted for knockdown with a miRNA sponge. Additionally, individual family members miR-17, miR-20b and miR-106a were knocked down using Anti-miR™ inhibitors. Subsequently, FOXL2 expression was analysed using RT-qPCR and Western blotting. ResultsThe profiling of COV434 and KGN cells revealed unique miRNA signatures, with COV434 expressing miR-17 family miRNAs whilst KGN expressed members of the let-7 miRNA gene family. Luciferase assays confirmed miRNA binding to FOXL2's 3′UTR. Reduction of miR-17 family miRNAs increased FOXL2 mRNA expression, however luciferase assays performed in combination with the sponge suggested this is an indirect effect. As no changes in protein were observed, we propose another miRNA is repressing the translation of FOXL2 mRNA. ConclusionThrough miRNA profiling we have begun to unravel the profiles of GCTs, showing that juvenile and adult derived-cell lines are biologically distinct. By expanding on this discovery we may further elucidate the miRNA–mRNA pathways involved in GCT initiation and progression with potential for novel therapeutics for these cancers.

Sexing Frogs by Real-Time PCR: Using Aromatase (cyp19) as an Early Ovarian Differentiation Marker

Most anurans have no identified sex-markers; therefore, alternative methods for identification of early changes in sex ratios are required. In this study, Lithobates sylvaticus and Silurana tropicalis tadpoles were sampled at different developmental stages covering the entire process of sex differentiation. Three candidate genes known to be involved in sex differentiation in other vertebrate species were selected to develop a method to identify phenotypic sex in frogs: cytochrome p450 aromatase (cyp19), forkhead box L2 (foxl2) and the cytochrome 17-alpha-hydroxylase/17,20 lyase (cyp17). Cloning of these genes revealed nucleotide identity values ranging between 75–97% when compared to other amphibian species. Gene expression of cyp17,cyp19 and foxl2 in L. sylvaticus adult gonads and gonad-mesonephros complex (GMC) of tadpoles was analyzed by real-time RT-PCR. Results showed clear sexually dimorphic patterns in the expression of the 3 genes. Our analysis reveals that GMC gene expression levels of cyp19 alone can be used as a robust predictor of phenotypic sex in L. sylvaticus tadpoles. In addition, we validated this method measuring cyp19 mRNA levels in S. tropicalis GMCs. We propose measuring cyp19 as a tool to study the effects of chemical contaminants (including endocrine disrupting compounds) on amphibian gonadal development and sex ratios in the future.

The Transcriptional Targets of Mutant FOXL2 in Granulosa Cell Tumours

BackgroundDespite their distinct biology, granulosa cell tumours (GCTs) are treated the same as other ovarian tumours. Intriguingly, a recurring somatic mutation in the transcription factor Forkhead Box L2 (FOXL2) 402C>G has been found in nearly all GCTs examined. This investigation aims to identify the pathogenicity of mutant FOXL2 by studying its altered transcriptional targets.MethodsThe expression of mutant FOXL2 was reduced in the GCT cell line KGN, and wildtype and mutant FOXL2 were overexpressed in the GCT cell line COV434. Total RNA was hybridised to Affymetrix U133 Plus 2 microarrays. Comparisons were made between the transcriptomes of control cells and cells altered by FOXL2 knockdown and overexpression, to detect potential transcriptional targets of mutant FOXL2.ResultsThe overexpression of wildtype and mutant FOXL2 in COV434, and the silencing of mutant FOXL2 expression in KGN, has shown that mutant FOXL2 is able to differentially regulate the expression of many genes, including two well known FOXL2 targets, StAR and CYP19A. We have shown that many of the genes regulated by mutant FOXL2 are clustered into functional annotations of cell death, proliferation, and tumourigenesis. Furthermore, TGF-β signalling was found to be enriched when using the gene annotation tools GATHER and GeneSetDB. This enrichment was still significant after performing a robust permutation analysis.ConclusionGiven that many of the transcriptional targets of mutant FOXL2 are known TGF-β signalling genes, we suggest that deregulation of this key antiproliferative pathway is one way mutant FOXL2 contributes to the pathogenesis of adult-type GCTs. We believe this pathway should be a target for future therapeutic interventions, if outcomes for women with GCTs are to improve.

Genome-wide in vivo identification of mouse FOXL2 binding sites from ChIP-seq data

Genome-wide in vivo identification of mouse FOXL2 binding sites from ChIP-seq data

The combination of polyalanine expansion mutation and a novel missense substitution in transcription factor FOXL2 leads to different ovarian phenotypes in blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) patients

What are the implications of multiple alterations of the forkhead box L2 (FOXL2) gene in blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) patients? A multi-mutation of FOXL2, consisting of the expansion of the polyalanine tract from 14 to 24 residues (FOXL2-Ala24), an novel Y186C substitution from c.557A>G, and a synonymous variant (c.505G>A), had a cumulative effect on ovarian phenotypes in BPES patients. Mutations in FOXL2, a gene encoding a forkhead transcription factor cause BPES. Overall, the expansion of the polyalanine tract of FOXL2 from 14 to 24 residues (FOXL2-Ala24) accounts for 30% of intragenic mutations. In this study, patients from seven BPES families and six sporadic cases were included. We conducted an extensive clinical, hormonal and functional study in 20 patients carrying the expansion of the polyalanine tract of FOXL2 associated with BPES. A multi-mutation of FOXL2 was detected in one BPES family that showed more severe BPES symptoms. Subcellular localization and transactivation studies were performed for the constructs of FOXL2-Ala24, Y186C and FOXL2-Ala24-Y186C. We described the first multi-mutation of FOXL2 (c. [672_701dup30; 557A>G]) that leads to the polyalanine expansion of +10 residues (FOXL2-Ala24) combined with an Y186C substitution and a synonymous variant in a Chinese BPES family. This multi-mutation genotype was associated with more serious BPES clinical manifestations and the development of esotropia in the right eye. In in vitro studies, the multi-mutation affected the function of FOKL2 on the StAR promoter and DK3, and induced more aggressive aggregation and mislocalization of FOXL2 protein. The synonymous variant, while not affecting amino acid coding, causes a change in the RNA stem-loop structure. The multi-mutation of FOXL2 was detected in one BPES family and it needs to be validated further by more BPES subjects. The results of our study contribute new insights into the research field of BPES caused by the multi-mutation of FOXL2. This study was supported by Shanghai Leading Academic Discipline Project (Grant number S30205) and Shanghai Jiao Tong University School of Medicine Doctor Innovation Fund (Grant number 201131). The authors have no competing interests to declare.

BPES with atypical premature ovarian insufficiency, and evidence of mitotic recombination, in a woman with trisomy X and a translocation t(3;11)(q22.3;q14.1)

Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is a rare autosomal dominant disorder characterized by a complex dysgenesis of the eyelids and premature ovarian insufficiency. FOXL2 located at 3q22.3, encoding a forkhead transcription factor, is the only gene known to be responsible for BPES. We describe a patient diagnosed with BPES with atypical ovarian failure, characterized by normal levels of gonadotropins, who was found to have trisomy X as well as a translocation (3;11)(q22.3;q14.1). The translocation breakpoint at 3q22.3 is located upstream of the FOXL2 gene and most likely causes BPES by separating the FOXL2 transcription unit from its cis-regulatory sequences. By array analysis we detected mosaicism for the balanced and an unbalanced form of the translocation in blood cells. We propose mitotic recombination as the likely mechanism of the mosaicism formation. Mitotic recombination is a common phenomenon in human cells. Thus, we hypothesize that it may be one of the mechanisms responsible for cryptic imbalances and possible abnormal phenotypes in some carriers of balanced rearrangements.

Blepharophimosis, ptosis, epicanthus inversus syndrome with translocation and deletion at chromosome 3q23 in a black African female

Blepharophimosis–ptosis–epicanthus inversus syndrome (BPES) is a rare autosomal dominant disorder whose main features are the abnormal shape, position and alignment of the eyelids. Type I refers to BPES with female infertility from premature ovarian failure while type II is limited to the ocular features. A causative gene, FOXL2, has been localized to 3q23. We report a black female who carried a de novo chromosomal translocation and 3.13 Mb deletion at 3q23, 1.2 Mb 5′ to FOXL2. This suggests the presence of distant cis regulatory elements at the extended FOXL2 locus. In spite of 21 protein coding genes in the 3.13 Mb deleted segment, the patient had no other malformation and a strictly normal psychomotor development at age 2.5 years. Our observation confirms panethnicity of BPES and adds to the knowledge of the complex cis regulation of human FOXL2 gene expression.

Mutational analysis of PIK3CA,JAK2,BRAF,FOXL2,IDH1,AKT1 and EZH2 oncogenes in sarcomas

Recent studies have revealed several recurrent mutations in oncogenes that could not only be underlying mechanisms of tumorigenesis, but also be potential targets for cancer therapies. Compared to carcinomas, genetic alterations of sarcomas are relatively unknown. To see whether recurrent oncogenes discovered in non-sarcomatous malignancies are present in sarcomas as well, we analyzed oncogenes with known mutations in various types of sarcomas. We performed mutational analysis of recurrent mutation sites of PIK3CA (exons 9 and 20), JAK2 (exon 14), BRAF (exon 15), FOXL2 (exon 1), IDH1 (exon 4), AKT1 (exon 3), and EZH2 (exon 16) genes in 108 sarcomas by single- strand conformation polymorphism and DNA sequencing. The sarcomas consisted of malignant fibrous histiocytomas, rhabdomyosarcomas, osteosarcomas, malignant peripheral nerve sheath tumors, leiomyosarcomas, synovial sarcomas, liposarcomas, angiosarcomas, chondrosarcomas, and Ewing sarcomas. Overall, we detected the two PIK3CA mutations and one JAK2 mutation (total: 3/108: 2.8%). Two rhabdomyosarcomas (16.7%) and one angiosarcoma (16.7%) harbored the mutations, whereas other sarcomas harbored none. The PIK3CA mutations were novel missense mutations that had not been detected in other cancers. The JAK2 mutation was an intron mutation. This study demonstrated that the somatic mutations of PIK3CA and JAK2 occurred in a small fraction of the sarcomas and that these mutations may not play a principal role in the development of sarcomas.

Bioinformatic analysis of coding regions of Foxl2 gene among species

Bioinformatic analysis of coding regions of Foxl2 gene among species

FOXL2 Is Involved in the Synergy between Activin and Progestins on the Follicle-Stimulating Hormone β-Subunit Promoter

Differential regulation of gonadotropin hormone production in the pituitary is critical for fertility. Activin and progesterone signaling in gonadotrope cells is important for Fshb gene expression. Previously, we reported that synergy between activin and progestins required the binding of SMAD proteins and the progesterone receptor (PR) to the murine Fshb promoter. In this study, we demonstrate that the FOXL2 transcription factor is also necessary for the full synergistic response between activin and progestins. We show that this synergy occurs in a species-specific manner and that multiple elements in the Fshb promoter that bind forkhead box L2 (FOXL2), SMA/mothers against decapentaplegic homologs (SMAD), and PR are required. Furthermore, we demonstrate that FOXL2 can physically interact with PR and SMAD3. Thus, it is likely that protein-protein interactions among FOXL2, SMAD, and PR recruited to the Fshb promoter play a key role in facilitating Fshb transcription before the secondary FSH surge in rodents.