FOXG1 is overexpressed in hepatoblastoma

Stephania tetrandra and Its Active Compound Coclaurine Sensitize NSCLC Cells to Cisplatin through EFHD2 Inhibition

BACKGROUND

Adjuvant chemotherapy, particularly cisplatin, is recommended for non-small cell lung carcinoma (NSCLC) patients at high risk of recurrence. EF-hand domain-containing protein D2 (EFHD2) has been recently shown to increase cisplatin resistance and is significantly associated with recurrence in early-stage NSCLC patients. Natural products, commonly used as phytonutrients, are also recognized for their potential as pharmaceutical anticancer agents.

RESULT

In this study, a range of Chinese herbs known for their antitumor or chemotherapy-enhancing properties were evaluated for their ability to inhibit EFHD2 expression in NSCLC cells. Among the herbs tested, Stephania tetrandra (S. tetrandra) exhibited the highest efficacy in inhibiting EFHD2 and sensitizing cells to cisplatin. Through LC-MS identification and functional assays, coclaurine was identified as a key molecule in S. tetrandra responsible for EFHD2 inhibition. Coclaurine not only downregulated EFHD2-related NOX4-ABCC1 signaling and enhanced cisplatin sensitivity, but also suppressed the stemness and metastatic properties of NSCLC cells. Mechanistically, coclaurine disrupted the interaction between the transcription factor FOXG1 and the EFHD2 promoter, leading to a reduction in EFHD2 transcription. Silencing FOXG1 further inhibited EFHD2 expression and sensitized NSCLC cells to cisplatin.

CONCLUSIONS

S. tetrandra and its active compound coclaurine may serve as effective adjuvant therapies to improve cisplatin efficacy in the treatment of NSCLC.

PLP1-Targeting Antisense Oligonucleotides Improve FOXG1 Syndrome Mice

FOXG1 syndrome is a rare neurodevelopmental disorder of the telencephalon, for which there is no cure. Underlying heterozygous pathogenic variants in the Forkhead Box G1 (FOXG1) gene with resulting impaired or loss of FOXG1 function lead to severe neurological impairments. Here, we report a patient with a de novo pathogenic single nucleotide deletion c.946del (p.Leu316Cysfs*10) of the FOXG1 gene that causes a premature protein truncation. To study this variant in vivo, we generated and characterized Foxg1 c946del mice that recapitulate hallmarks of the human disorder. Accordingly, heterozygous Foxg1 c946del mice display neurological symptoms with aberrant neuronal networks and increased seizure susceptibility. Gene expression profiling identified increased oligodendrocyte- and myelination-related gene clusters. Specifically, we showed that expression of the c946del mutant and of other pathogenic FOXG1 variants correlated with overexpression of proteolipid protein 1 (Plp1), a gene linked to white matter disorders. Postnatal administration of Plp1-targeting antisense oligonucleotides (ASOs) in Foxg1 c946del mice improved neurological deficits. Our data suggest Plp1 as a new target for therapeutic strategies mitigating disease phenotypes in FOXG1 syndrome patients.

The postnatal injection of AAV9-FOXG1 rescues corpus callosum agenesis and other brain deficits in the mouse model of FOXG1 syndrome

Heterozygous mutations in the FOXG1 gene manifest as FOXG1 syndrome, a severe neurodevelopmental disorder characterized by structural brain anomalies, including agenesis of the corpus callosum, hippocampal reduction, and myelination delays. Despite the well-defined genetic basis of FOXG1 syndrome, therapeutic interventions targeting the underlying cause of the disorder are nonexistent. In this study, we explore the therapeutic potential of adeno-associated virus 9 (AAV9)-mediated delivery of the FOXG1 gene. Remarkably, intracerebroventricular injection of AAV9-FOXG1 to Foxg1 heterozygous mouse model at the postnatal stage rescues a wide range of brain pathologies. This includes the amelioration of corpus callosum deficiencies, the restoration of dentate gyrus morphology in the hippocampus, the normalization of oligodendrocyte lineage cell numbers, and the rectification of myelination anomalies. Our findings highlight the efficacy of AAV9-based gene therapy as a viable treatment strategy for FOXG1 syndrome and potentially other neurodevelopmental disorders with similar brain malformations, asserting its therapeutic relevance in postnatal stages.

Saikosaponin-d mediates FOXG1 to reverse docetaxel resistance in prostate cancer through oxidative phosphorylation

BACKGROUND

Prostate cancer (PCa), a prevalent malignancy worldwide, is frequently identified in advanced stages due to the absence of distinctive early symptoms, thereby culminating in the development of chemotherapy-induced drug resistance. Exploring novel resistance mechanisms and identifying new therapeutic agents can facilitate the advancement of more efficacious strategies for PCa treatment.

METHODS

Bioinformatics analysis was employed to investigate the expression of FOXG1 in PCa tissues. Subsequently, qRT-PCR was utilized to validate FOXG1 mRNA expression levels in corresponding PCa cell lines. FOXG1 knockdown was performed, and cell proliferation was assessed using CCK-8 assays, while cell migration and invasion capabilities were evaluated through wound healing and Transwell assays. Western blot and Seahorse analyzer were used to measure oxidative phosphorylation (OXPHOS) levels. Additionally, to explore potential approaches to alleviate PCa drug resistance, this study assessed the impact of biologically active saikosaponin-d (SSd) on PCa malignant progression and resistance by regulating FOXG1 expression.

RESULTS

FOXG1 exhibited high expression in PCa tissues and cell lines. Knockdown of FOXG1 inhibited the proliferation, migration, and invasion of PCa cells, while FOXG1 overexpression had the opposite effect and promoted OXPHOS levels. The addition of an OXPHOS inhibitor prevented this outcome. Finally, SSd was shown to suppress FOXG1 expression and reverse docetaxel resistance in PCa cells through the OXPHOS pathway.

CONCLUSION

This work demonstrated that SSd mediated FOXG1 to reverse malignant progression and docetaxel resistance in PCa through OXPHOS.

FOXG1 improves mitochondrial function and promotes the progression of nasopharyngeal carcinoma

Forkhead‑box gene 1 (FOXG1) has been reported to serve an important role in various malignancies, but its effects on nasopharyngeal cancer (NPC) remain unknown. Thus, the present study aimed to investigate the specific regulatory relationship between FOXG1 and NPC progression. Tumor tissues and matching para‑carcinoma tissues were obtained from patients with NPC. Small interfering (si)RNA‑FOXG1 and pcDNA3.1‑FOXG1 were transfected into SUNE‑1 and C666‑1 cells to knockdown and overexpress FOXG1 expression, respectively. FOXG1 expression was detected using reverse transcription‑quantitative PCR and immunohistochemistry. Cell proliferation was detected using MTT and 5‑ethynyl‑20‑deoxyuridine assays. Transwell invasion assay, wound healing assay and flow cytometry were used to detect cell invasion, migration and apoptosis, respectively. Western blotting was conducted to detect the expression levels of mitochondrial markers (succinate dehydrogenase complex flavoprotein subunit A, heat shock protein 60 and pyruvate dehydrogenase), epithelial‑mesenchymal transition (EMT) related proteins (N‑cadherin, Snail and E‑cadherin) and apoptosis‑related proteins [Bax, Bcl‑2, poly(ADP‑ribose) polymerase 1 (PARP), cleaved PARP, cleaved caspase‑3, cleaved caspase‑8, cleaved caspase‑9, caspase‑3, caspase‑8 and caspase‑9]. The mitochondrial membrane potential was detected via flow cytometry, while the ATP/ADP ratio was determined using the ADP/ATP ratio assay kit. The present results demonstrated that FOXG1 expression was upregulated in NPC tissues and cells, and was associated with distant metastasis and TNM stage. Moreover, knockdown of FOXG1 inhibited the proliferation, migration, invasion, EMT and mitochondrial function of SUNE‑1 cells, as well as promoted cell apoptosis, while the opposite results were observed in C666‑1 cells. In conclusion, FOXG1 enhanced proliferation, migration and invasion, induced EMT and improved mitochondrial function in NPC cells. The current findings provide an adequate theoretical basis for the treatment of NPC.

FOXG1 Gene and Its Related Phenotypes

FOXG1 is an important transcriptional repressor found in cell precursor of the ventricular region and in neurons in the early stage of differentiation during the development of the nervous epithelium in the cerebrum and optical formation. Mutations involving FOXG1 gene have been described first in subjects with congenital Rett syndrome. They can cause seizure, delayed psychomotor development, language disorders, and autism. FOXG1 deletions or intragenic mutations also determinate reduction in head circumference, structural defects in the corpus callosum, abnormal movements, especially choreiform, and intellectual retardation with no speech. Patients with duplications of 14q12 present infantile spasms and have subsequent intellectual disability with autistic features, head circumference in the normal range, and regular aspect of corpus callosum. Clinical characteristics of patients with FOXG1 variants include growth deficit after birth associated with microcephaly, facial dysmorphisms, important delay with no language, deficit in social interaction like autism, sleep disorders, stereotypes, including dyskinesia, and seizures. In these patients, it is not characteristic a history of loss of acquired skills.

Transcription and Beyond: Delineating FOXG1 Function in Cortical Development and Disorders

Forkhead Box G1 (FOXG1) is a member of the Forkhead family of genes with non-redundant roles in brain development, where alteration of this gene's expression significantly affects the formation and function of the mammalian cerebral cortex. FOXG1 haploinsufficiency in humans is associated with prominent differences in brain size and impaired intellectual development noticeable in early childhood, while homozygous mutations are typically fatal. As such, FOXG1 has been implicated in a wide spectrum of congenital brain disorders, including the congenital variant of Rett syndrome, infantile spasms, microcephaly, autism spectrum disorder (ASD) and schizophrenia. Recent technological advances have yielded greater insight into phenotypic variations observed in FOXG1 syndrome, molecular mechanisms underlying pathogenesis of the disease, and multifaceted roles of FOXG1 expression. In this review, we explore the emerging mechanisms of FOXG1 in a range of transcriptional to posttranscriptional events in order to evolve our current view of how a single transcription factor governs the assembly of an elaborate cortical circuit responsible for higher cognitive functions and neurological disorders.

Forkhead box (FOX) G1 promotes hepatocellular carcinoma epithelial-Mesenchymal transition by activating Wnt signal through forming T-cell factor-4/Beta-catenin/FOXG1 complex

Background

Forkhead box G1 (FOXG1) is a member of the Fox transcription factor family involved in regulation of many cancers. However, the role of FOXG1 in hepatocellular carcinogenesisis largely unclear. The present study aimed at examining the biological function and underlying mechanism of FOXG1 on hepatocellular carcinoma (HCC) tumor metastasis as well as its clinical significance.

Methods

Levels of FOXG1 were determined by immunohistochemical and real-time PCR analysis in HCC cell lines and human HCC samples. The effect of FOXG1 on cancer cell invasion and metastasis was investigated in vitro and in vivo in either FOXG1-silenced or overexpressing human HCC cell lines. Immunoprecipitation and chromatin immunoprecipitation assays were performed to investigate the interaction of FOXG1, β-catenin, TCF4 and the effect on Wnt target-gene promoters.

Results

In human HCC, the level of FOXG1 progressively increased from surrounding non tumorous livers to HCC, reaching the highest levels in metastatic HCC. Furthermore, expression levels of FOXG1 directly correlated with cancer cell epithelial-mesenchymal transition (EMT) phenotype. In FOXG1-overexpressing cells, FOXG1 promotes the stabilization and nuclear accumulation of β-catenin by directly binding to β-catenin and it associates with the lymphoid enhancer factor/T cell factor proteins (LEF/TCFs) on Wnt responsive enhancers (WREs) in chromatin.

Conclusions

The results show that FOXG1 plays a key role in mediating cancer cell metastasis through the Wnt/β-catenin pathway in HCC cells and predicts HCC prognosis after surgery. Targeting FOXG1 may provide a new approach for therapeutic treatment in the future.

FOXG1-Related Syndrome: From Clinical to Molecular Genetics and Pathogenic Mechanisms

Individuals with mutations in forkhead box G1 (FOXG1) belong to a distinct clinical entity, termed “FOXG1-related encephalopathy”. There are two clinical phenotypes/syndromes identified in FOXG1-related encephalopathy, duplications and deletions/intragenic mutations. In children with deletions or intragenic mutations of FOXG1, the recognized clinical features include microcephaly, developmental delay, severe cognitive disabilities, early-onset dyskinesia and hyperkinetic movements, stereotypies, epilepsy, and cerebral malformation. In contrast, children with duplications of FOXG1 are typically normocephalic and have normal brain magnetic resonance imaging. They also have different clinical characteristics in terms of epilepsy, movement disorders, and neurodevelopment compared with children with deletions or intragenic mutations. FOXG1 is a transcriptional factor. It is expressed mainly in the telencephalon and plays a pleiotropic role in the development of the brain. It is a key player in development and territorial specification of the anterior brain. In addition, it maintains the expansion of the neural proliferating pool, and also regulates the pace of neocortical neuronogenic progression. It also facilitates cortical layer and corpus callosum formation. Furthermore, it promotes dendrite elongation and maintains neural plasticity, including dendritic arborization and spine densities in mature neurons. In this review, we summarize the clinical features, molecular genetics, and possible pathogenesis of FOXG1-related syndrome.

Collagen-derived dipeptide prolyl hydroxyproline directly binds to Foxg1 to change its conformation and inhibit the interaction with Runx2

Collagen-derived dipeptide prolyl hydroxyproline (Pro-Hyp) is involved in the proliferation and differentiation of various types of cultured cells. To elucidate the mechanism underlying Pro-Hyp actions during osteoblast differentiation, we hypothesized that proteins binding to Pro-Hyp serve to mediate cellular signaling, affecting Runx2 expression. Recently, we performed the characterization of Foxg1, that it enhances Runx2 expression in the presence of Pro-Hyp. Our findings indicate that Pro-Hyp directly binds to the Foxg1 recombinant protein, which leads to the structural alteration of the Foxg1 protein. In addition, Foxg1 appears to interact with Runx2 in the absence of Pro-Hyp, with Pro-Hyp disrupting the interaction between Foxg1 and Runx2. Collectively, our results indicate that the Pro-Hyp bound Foxg1 alters the structured conformation of Foxg1, resulting in conformational changes that lead to dissociation from Runx2. These novel findings suggest that during osteoblast differentiation, Pro-Hyp mediates Runx2 activity though directly binding to Foxg1 and increases Runx2 expression. Abbreviations: CPT: collagen peptide; GST: Glutathione S-transferase; PAGE: Polyacrylamide gel electrophoresis; PCR: Polymerase chain reaction; prolyl hydroxyproline: Pro-Hyp.

FoxG1 facilitates proliferation and inhibits differentiation by downregulating FoxO/Smad signaling in glioblastoma

BACKGROUND

To investigate the effects and underlying molecular mechanisms of FoxG1 expression on glioblastoma multiforme (GBM) models.

METHODS

Expression levels of FoxG1 and other cancer-related biomarkers were evaluated by qRT-PCR, immunoblotting and immunohistochemistry. Crystal violet staining and MTT assay and were applied in this study to verify cell proliferation ability and viability of GBM cell models with/without drug treatment.

RESULTS

Immunohistochemical and qRT-PCR assays showed that endogenous FoxG1 expression levels were positively correlated to the GBM disease progression. Overexpression of FoxG1 protein resulted in increased cell viability, G2/M cell cycle arrest, as well as the downregulation of p21 and cyclin B1. In addition, western blot assays reported that enforced expression of FoxG1 suppressed GAPF and facilitated the expression of Sox2 and Sox5. Meanwhile the downstream targets of FoxG1, such as FoxO1 and pSmad1/5/8 were activated. Overexpression of FoxG1 under TMZ treatment restored the cell viability as well as the expression levels of Sox2 and Sox5, yet downregulated expression levels of p21 and cyclin B1. The downstream FoxG1-induced FoxO/Smad signaling was re-inhibited under TMZ treatments.

CONCLUSIONS

Our findings suggest that FoxG1 functions as an onco-factor by promoting proliferation, as well as inhibiting differential responses in glioblastoma by downregulating FoxO/Smad signaling.

FOXG1 Expression Is Elevated in Glioma and Inhibits Glioma Cell Apoptosis

FOXG1, a member of forkhead family transcriptional factor, is involved in telencephalon development. Recent studies showed FOXG1 was important for a variety of cellular events in cancer cells. In respect to glioma, FOXG1 has been shown to regulate cell proliferation and cell cycles. However, its impacts on other cellular events were not well studied. Here, we found FOXG1 had high expression in clinical glioma tissues, and its expression positively correlated with glioma malignancy. Moreover, we found FOXG1 played roles in glioma cell apoptosis. The expressions of caspase family members were significantly altered in response to change of FOXG1 expression, indicating a direct regulation of FOXG1 on caspase family members. These data strongly suggest FOXG1 is negative regulator of glioma cell apoptosis.

Members of FOX family could be drug targets of cancers

FOX families play important roles in biological processes, including metabolism, development, differentiation, proliferation, apoptosis, migration, invasion and longevity. Here we are focusing on roles of FOX members in cancers, FOX members and drug resistance, FOX members and stem cells. Finally, FOX members as drug targets of cancer treatment were discussed. Future perspectives of FOXC1 research were described in the end.

FXR-Gankyrin axis is involved in development of pediatric liver cancer

The development of hepatoblastoma (HBL) is associated with failure of hepatic stem cells (HSC) to differentiate into hepatocytes. Despite intensive investigations, mechanisms of the failure of HSC to differentiate are not known. We found that oncogene Gankyrin (Gank) is involved in the inhibition of differentiation of HSC via triggering degradation of tumor suppressor proteins (TSPs) Rb, p53, C/EBPα and HNF4α. Our data show that the activation of a repressor of Gank, farnesoid X receptor, FXR, after initiation of liver cancer by Diethylnitrosamine (DEN) prevents the development of liver cancer by inhibiting Gank and rescuing tumor suppressor proteins. We next analyzed FXR-Gank-Tumor suppressor pathways in a large cohort of HBL patients which include 6 controls and 53 HBL samples. Systemic analysis of these samples and RNA-Seq approach revealed that the FXR-Gank axis is activated; markers of hepatic stem cells are dramatically elevated and hepatocyte markers are reduced in HBL samples. In the course of these studies, we found that RNA binding protein CUGBP1 is a new tumor suppressor protein which is reduced in all HBL samples. Therefore, we generated CUGBP1 KO mice and examined HBL signatures in the liver of these mice. Micro-array studies revealed that the HBL-specific molecular signature is developed in livers of CUGBP1 KO mice at very early ages. Thus, we conclude that FXR-Gank-TSPs-Stem cells pathway is a key determinant of liver cancer in animal models and in pediatric liver cancer. Our data provide a strong basis for development of FXR-Gank-based therapy for treatment of patients with hepatoblastoma.

FOXG1 expression shows correlation with neuronal differentiation in cerebellar development, aggressive phenotype in medulloblastomas, and survival in a xenograft model of medulloblastoma

FOXG1 is a transcription factor that interacts with multiple signaling pathways and modulates neuronal differentiation in the telencephalon. Dysregulation of FOXG1 expression has been previously reported in medulloblastoma. In this study, we demonstrate a regional specific expression of FOXG1 and its colocalization with Nestin expression in the premigratory mitotically active (outer) layer of the external granular layer of the cerebellum. An inverse expression of the granular precursor cell markers, Math1 and Musashi1, in the inner nonmitotic migratory layer of the external granular layer and in the internal granular layer was observed. Furthermore, modulation of FOXG1 in the medulloblastoma cell line, DAOY, was associated with the induction of neuronal differentiation markers and significant changes in multiple signaling pathways regulating cell proliferation, differentiation, survival, and apoptosis. Additionally, we observed enhanced survival in intracerebellar mice xenografts injected with DAOY cells bearing shFOXG1 constructs versus shLuciferase construct. Overall, these findings suggest that down-modulation of FOXG1 is a prerequisite for the onset of neuronal differentiation during cerebellar development and that a decrease of FOXG1 in medulloblastoma cells offers a survival advantage in mice. We propose that the disruption of signaling pathways that promote mature neuronal differentiation by overexpressed FOXG1 is a contributing event in the neoplastic transformation of cerebellar stem cells.

Quantification of glypican 3, β-catenin and claudin-1 protein expression in hepatoblastoma and paediatric hepatocellular carcinoma by colour deconvolution

AIMS

To identify an immunohistochemical panel for paediatric malignant epithelial liver tumours.

METHODS AND RESULTS

Forty-five hepatoblastomas (HBs), 13 paediatric hepatocellular carcinomas (HCCs) and two hepatocellular malignant neoplasms not otherwise specified (NOS) were chosen for immunohistochemical staining of glypican 3 (GPC3), β-catenin, claudin-1, delta-like protein (DLK), and forkhead box protein G1 (FOXG1). Immunostaining was quantitatively analysed with NIH imagej software coupled with colour deconvolution. Different subtypes of HB and HCC showed distinct staining patterns of GPC3, β-catenin, and claudin-1. Moreover, GPC3, β-catenin and claudin-1 all showed higher expression in classic HCC and embryonal HB than in fetal HB; GPC3 showed complete negativity in small-cell undifferentiated (SCU) HB and fibrolamellar HCC (FLC); β-catenin showed the strongest expression in SCU HB but the weakest expression in FLC. A panel of these three immunomarkers was useful for the diagnosis of hepatocellular malignant neoplasms NOS. The expression of DLK and FOXG1 was inconstant among fetal and embryonal HB and classic HCC.

CONCLUSIONS

A panel of GPC3, β-catenin and claudin-1 is helpful for differentiating HB subtypes and distinguishing HB from HCC.

Transcription factors FOXG1 and Groucho/TLE promote glioblastoma growth

Glioblastoma (GBM) is the most common and deadly malignant brain cancer, with a median survival of less than two years. GBM displays a cellular complexity that includes brain tumour-initiating cells (BTICs), which are considered as potential key targets for GBM therapies. Here we show that the transcription factors FOXG1 and Groucho/TLE are expressed in poorly differentiated astroglial cells in human GBM specimens and in primary cultures of GBM-derived BTICs, where they form a complex. FOXG1 knockdown in BTICs causes downregulation of neural stem/progenitor and proliferation markers, increased replicative senescence, upregulation of astroglial differentiation genes, and decreased BTIC-initiated tumour growth upon intracranial transplantation into host mice. These effects are phenocopied by Groucho/TLE knockdown or dominant-inhibition of the FOXG1:Groucho/TLE complex. These results provide evidence that transcriptional programs regulated by FOXG1 and Groucho/TLE are important for BTIC-initiated brain tumour growth, implicating FOXG1 and Groucho/TLE in GBM tumorigenesis.

A 92-gene cancer classifier predicts the site of origin for neuroendocrine tumors

A diagnosis of neuroendocrine carcinoma is often morphologically straight-forward; however, the tumor site of origin may remain elusive in a metastatic presentation. Neuroendocrine tumor subtyping has important implications for staging and patient management. In this study, the novel use and performance of a 92-gene molecular cancer classifier for determination of the site of tumor origin are described in a series of 75 neuroendocrine tumors (44 metastatic, 31 primary; gastrointestinal (n=12), pulmonary (n=22), Merkel cell (n=10), pancreatic (n=10), pheochromocytoma (n=10), and medullary thyroid carcinoma (n=11)). Formalin-fixed, paraffin-embedded samples passing multicenter pathologist adjudication were blinded and tested by a 92-gene molecular assay that predicts tumor type/subtype based upon relative quantitative PCR expression measurements for 87 tumor-related and 5 reference genes. The 92-gene assay demonstrated 99% (74/75; 95% confidence interval (CI) 0.93-0.99) accuracy for classification of neuroendocrine carcinomas and correctly subtyped the tumor site of origin in 95% (71/75; 95% CI 0.87-0.98) of cases. Analysis of gene expression subsignatures within the 92-gene assay panel showed 4 genes with promising discriminatory value for tumor typing and 15 genes for tumor subtyping. The 92-gene classifier demonstrated excellent accuracy for classifying and determining the site of origin in tumors with neuroendocrine differentiation. These results show promise for use of this test to aid in classifying neuroendocrine tumors of indeterminate primary site, particularly in the metastatic setting.

Post-zygotic and inter-individual structural genetic variation in a presumptive enhancer element of the locus between the IL10Rβ and IFNAR1 genes

Although historically considered as junk-DNA, tandemly repeated sequence motifs can affect human phenotype. For example, variable number tandem repeats (VNTR) with embedded enhancers have been shown to regulate gene transcription. The post-zygotic variation is the presence of genetically distinct populations of cells in an individual derived from a single zygote, and this is an understudied aspect of genome biology. We report somatically variable VNTR with sequence properties of an enhancer, located upstream of IFNAR1. Initially, SNP genotyping of 63 monozygotic twin pairs and multiple tissues from 21 breast cancer patients suggested a frequent post-zygotic mosaicism. The VNTR displayed a repeated 32 bp core motif in the center of the repeat, which was flanked by similar variable motifs. A total of 14 alleles were characterized based on combinations of segments, which showed post-zygotic and inter-individual variation, with up to 6 alleles in a single subject. Somatic variation occurred in ∼24% of cases. In this hypervariable region, we found a clustering of transcription factor binding sites with strongest sequence similarity to mouse Foxg1 transcription factor binding motif. This study describes a VNTR with sequence properties of an enhancer that displays post-zygotic and inter-individual genetic variation. This element is within a locus containing four related cytokine receptors: IFNAR2, IL10Rβ, IFNAR1 and IFNGR2, and we hypothesize that it might function in transcriptional regulation of several genes in this cluster. Our findings add another level of complexity to the variation among VNTR-based enhancers. Further work may unveil the normal function of this VNTR in transcriptional control and its possible involvement in diseases connected with these receptors, such as autoimmune conditions and cancer.

Expression screening of cancer/testis genes in prostate cancer identifies NR6A1 as a novel marker of disease progression and aggressiveness

BACKGROUND

Cancer/Testis (CT) genes are expressed in male gonads, repressed in most healthy somatic tissues and de-repressed in various somatic malignancies including prostate cancers (PCa). Because of their specific expression signature and their associations with tumor aggressiveness and poor outcomes, CT genes are considered to be useful biomarkers and they are also targets for the development of new anti-cancer immunotherapies. The aim of this study was to identify novel CT genes associated with hormone-sensitive prostate cancer (HSPC), and castration-resistant prostate cancer (CRPC).

METHODS

To identify novel CT genes we screened genes for which transcripts were detected by RNA profiling specifically in normal testis and in either HSPC or CRPC as compared to normal prostate and 44 other healthy tissues using GeneChips. The expression and clinicopathological significance of a promising candidate--NR6A1--was examined in HSPC, CRPC, and metastatic site samples using tissue microarrays.

RESULTS

We report the identification of 98 genes detected in CRPC, HSPC and testicular samples but not in the normal controls. Among them, cellular levels of NR6A1 were found to be higher in HSPC compared to normal prostate and further increased in metastatic lesions and CRPC. Furthermore, increased NR6A1 immunoreactivity was significantly associated with a high Gleason score, advanced pT stage and cancer cell proliferation.

CONCLUSIONS

Our results show that cellular levels of NR6A1 are correlated with disease progression in PCa. We suggest that this essential orphan nuclear receptor is a potential therapeutic target as well as a biomarker of PCa aggressiveness.

Current issues and controversies in the classification of pediatric hepatocellular tumors

Systematic histopathologic examination of hepatoblastoma specimens from patients enrolled in therapeutic protocols has allowed the identification of clinically relevant histologic subtypes that are being incorporated into risk stratification systems. Genetic and molecular studies have documented recurrent chromosomal abnormalities and aberrant activation of developmental, and oncogenic signaling pathways in hepatoblastoma. Molecular profiling has also identified molecular subclasses and gene signatures that could be used to stratify hepatoblastoma patients. Future international collaboration is needed to develop consensus pathology classifications, and to progressively incorporate genetic and molecular biomarkers into therapeutic pediatric liver tumors protocols.

Cancer genetics and genomics of human FOX family genes

Forkhead-box (FOX) family proteins, involved in cell growth and differentiation as well as embryogenesis and longevity, are DNA-binding proteins regulating transcription and DNA repair. The focus of this review is on the mechanisms of FOX-related human carcinogenesis. FOXA1 is overexpressed as a result of gene amplification in lung cancer, esophageal cancer, ER-positive breast cancer and anaplastic thyroid cancer and is point-mutated in prostate cancer. FOXA1 overexpression in breast cancer and prostate cancer is associated with good or poor prognosis, respectively. Single nucleotide polymorphism (SNP) within the 5'-UTR of the FOXE1 (TTF2) gene is associated with thyroid cancer risk. FOXF1 overexpression in breast cancer is associated with epithelial-to-mesenchymal transition (EMT). FOXM1 is overexpressed owing to gene amplification in basal-type breast cancer and diffuse large B-cell lymphoma (DLBCL), and it is transcriptionally upregulated owing to Hedgehog-GLI, hypoxia-HIF1α or YAP-TEAD signaling activation. FOXM1 overexpression leads to malignant phenotypes by directly upregulating CCNB1, AURKB, MYC and SKP2 and indirectly upregulating ZEB1 and ZEB2 via miR-200b downregulation. Tumor suppressor functions of FOXO transcription factors are lost in cancer cells as a result of chromosomal translocation, deletion, miRNA-mediated repression, AKT-mediated cytoplasmic sequestration or ubiquitination-mediated proteasomal degradation. FOXP1 is upregulated as a result of gene fusion or amplification in DLBCL and MALT lymphoma and also repression of miRNAs, such as miR-1, miR-34a and miR-504. FOXP1 overexpression is associated with poor prognosis in DLBCL, gastric MALT lymphoma and hepatocellular carcinoma but with good prognosis in breast cancer. In neuroblastoma, the entire coding region of the FOXR1 (FOXN5) gene is fused to the MLL or the PAFAH1B gene owing to interstitial deletions. FOXR1 fusion genes function as oncogenes that repress transcription of FOXO target genes. Whole-genome sequencing data from tens of thousands of human cancers will uncover the mutational landscape of FOX family genes themselves as well as FOX-binding sites, which will be ultimately applied for cancer diagnostics, prognostics, and therapeutics.

Forkhead transcription factors: key players in health and disease

Forkhead box (FOX) proteins constitute an evolutionarily conserved family of transcription factors with a central role not only during development, but also in the adult organism. Thus, the misregulation and/or mutation of FOX genes often induce human genetic diseases, promote cancer or deregulate ageing. Indeed, germinal FOX gene mutations cause diseases ranging from infertility to language and/or speech disorders and immunological defects. Moreover, because of their central role in signalling pathways and in the regulation of homeostasis, somatic misregulation and/or mutation of FOX genes are associated with cancer. FOX proteins have undergone diversification in terms of their sequence, regulation and function. In addition to dedicated roles, evidence suggests that Forkhead factors have retained some functional redundancy. Thus, combinations of slightly defective alleles might induce disease phenotypes in humans, acting as quantitative trait loci. Uncovering such variants would be a big step towards understanding the functional interdependencies of different FOX members and their implications in complex pathologies.

Intrinsic sex differences in the early growth hormone responsiveness of sex-specific genes in mouse liver

Sex differences in liver gene expression are dictated by sex differences in circulating GH profiles. Presently, the pituitary hormone dependence of mouse liver gene expression was investigated on a global scale to discover sex-specific early GH response genes that could contribute to sex-specific regulation of downstream GH targets and to ascertain whether intrinsic sex differences characterize hepatic responses to plasma GH stimulation. Global RNA expression analysis identified two distinct classes of sex-specific mouse liver genes: genes subject to positive regulation (class I) and genes subject to negative regulation by pituitary hormones (class II). Genes activated or repressed in hypophysectomized (Hypox) mouse liver within 30-90 min of GH pulse treatment at a physiological dose were identified as putative direct targets of GH action (early response genes). Intrinsic sex differences in the GH responsiveness of a subset of these early response genes were observed. Notably, 45 male-specific genes, including five encoding transcriptional regulators that may mediate downstream sex-specific transcriptional responses, were induced by GH within 30 min in Hypox male but not Hypox female mouse liver. The early GH response genes were enriched in 29 male-specific targets of the transcription factor myocyte enhancer factor 2, whose activation in hepatic stellate cells is associated with liver fibrosis leading to hepatocellular carcinoma, a male-predominant disease. Thus, the rapid activation by GH pulses of certain sex-specific genes is modulated by intrinsic sex-specific factors, which may be associated with prior hormone exposure (epigenetic mechanisms) or genetic factors that are pituitary-independent, and could contribute to sex differences in predisposition to liver cancer or other hepatic patho-physiologies.

Altered response to antidepressant treatment in FoxG1 heterozygous knockout mice

Evidence from a variety of sources suggests that structural alterations in the brain, including neurogenesis, may play a role in both the pathogenesis of mood disorders and the mechanism of action of antidepressants. Previous studies have implicated both the transforming growth factor-beta (TGF-beta), and the phosphatidyl inositol-3 kinase (PI3K)-Akt pathways in the neurogenesis-promoting and behavioral properties of antidepressants. Forkhead box protein G1 (FoxG1) is a major regulator of both of these pathways, and FoxG1 heterozygous null mice (FoxG1+/-) have previously been reported to have deficits in adult hippocampal neurogenesis and behavioral abnormalities including deficits in contextual fear learning. However the role of FoxG1, if any, in the response to antidepressants has not been previously investigated.To investigate the role of the FoxG1 gene in the behavioral and neurogenic properties of antidepressants, we tested FoxG1+/- mice and littermate controls in two different rodent models of antidepressant action: the tail suspension test and the forced swim test. FoxG1+/- mice showed no response to antidepressants in either of these tests. These results suggest that normal levels of FoxG1 may be required for the behavioral response to antidepressants.

Overexpression of FOXG1 contributes to TGF-beta resistance through inhibition of p21WAF1/CIP1 expression in ovarian cancer

Background:

Loss of growth inhibitory response to transforming growth factor-β (TGF-β) is a common feature of epithelial cancers. Recent studies have reported that genetic lesions and overexpression of oncoproteins in TGF-β/Smads signalling cascade contribute to the TGF-β resistance. Here, we showed that the overexpressed FOXG1 was involved in attenuating the anti-proliferative control of TGF-β/Smads signalling in ovarian cancer.

Methods:

FOXG1 and p21^WAF1/CIP1 expressions were evaluated by real-time quantitative reverse-transcription polymerase chain reaction (RT–PCR), western blot and immunohistochemical analyses. The effect of FOXG1 on p21^WAF1/CIP1 transcriptional activity was examined by luciferase reporter assays. Cell lines stably expressing or short hairpin RNA interference-mediated knockdown FOXG1 were established for studying the gain-or-loss functional effects of FOXG1. XTT cell proliferation assay was used to measure cell growth of ovarian cancer cells.

Results:

Quantitative RT–PCR and western blot analyses showed that FOXG1 was upregulated and inversely associated with the expression levels of p21^WAF1/CIP1 in ovarian cancer. The overexpression of FOXG1 was significantly correlated with high-grade ovarian cancer (P=0.025). Immunohistochemical analysis on ovarian cancer tissue array was further evidenced that FOXG1 was highly expressed and significantly correlated with high-grade ovarian cancer (P=0.048). Functionally, enforced expression of FOXG1 selectively blocked the TGF-β-induced p21^WAF1/CIP1 expressions and increased cell proliferation in ovarian cancer cells. Conversely, FOXG1 knockdown resulted in a 20–26% decrease in cell proliferation together with 16–33% increase in p21^WAF1/CIP1 expression. Notably, FOXG1 was able to inhibit the p21^WAF1/CIP1 promoter activity in a p53-independent manner by transient reporter assays.

Conclusion

Our results suggest that FOXG1 acts as an oncoprotein inhibiting TGF-β-mediated anti-proliferative responses in ovarian cancer cells through suppressing p21^WAF1/CIP1 transcription.

Gene expression profiling reveals signatures characterizing histologic subtypes of hepatoblastoma and global deregulation in cell growth and survival pathways

Hepatoblastoma is the most common malignant tumor of the liver of children worldwide. Histologically, hepatoblastomas show marked variation in the type and proportion of epithelial (fetal, embryonal, or small cell) and mesenchymal components with differing prognosis and response to therapy. The pure fetal-type hepatoblastoma, presenting as stage 1 and resectable, has the best prognosis, whereas the small cell histology has been associated with unfavorable outcome. Using gene expression profiling, we demonstrate that in addition to Wnt pathway deregulation, cell growth and survival pathways are also globally deregulated in hepatoblastomas. Furthermore, the different histologic subtypes are characterized by specific gene expression and pathway signatures that give insight into the degree of molecular heterogeneity that is present among these tumors. Although Wnt signaling pathway upregulation is common to all histologic types of hepatoblastoma, this pathway is even more significantly deregulated in aggressive hepatoblastomas. In addition, deregulation of MAPK signaling pathway and antiapoptotic signaling is preferentially upregulated in aggressive epithelial hepatoblastomas with a small cell component. The gene expression signatures reported here provide possible prognostic and diagnostic markers as well as therapeutic targets for this disease.

Genomic deletions correlate with underexpression of novel candidate genes at six loci in pediatric pilocytic astrocytoma

The molecular pathogenesis of pediatric pilocytic astrocytoma (PA) is not well defined. Previous cytogenetic and molecular studies have not identified nonrandom genetic aberrations. To correlate differential gene expression and genomic copy number aberrations (CNAs) in PA, we have used Affymetrix GeneChip HG_U133A to generate gene expression profiles of 19 pediatric patients and the SpectralChip 2600 to investigate CNAs in 11 of these tumors. Hierarchical clustering according to expression profile similarity grouped tumors and controls separately. We identified 1844 genes that showed significant differential expression between tumor and normal controls, with a large number clearly influencing phosphatidylinositol and mitogen-activated protein kinase signaling in PA. Most CNAs identified in this study were single-clone alterations. However, a small region of loss involving up to seven adjacent clones at 7q11.23 was observed in seven tumors and correlated with the underexpression of BCL7B. Loss of four individual clones was also associated with reduced gene expression including SH3GL2 at 9p21.2-p23, BCL7A (which shares 90% sequence homology with BCL7B) at 12q24.33, DRD1IP at 10q26.3, and TUBG2 and CNTNAP1 at 17q21.31. Moreover, the down-regulation of FOXG1B at 14q12 correlated with loss within the gene promoter region in most tumors. This is the first study to correlate differential gene expression with CNAs in PA.

Hepatobiliary pathology

PURPOSE OF REVIEW

Studies are reviewed from the past year concerning the histopathology of liver and biliary diseases and their pathogenesis.

RECENT FINDINGS

Several cases of acute hepatitis E showed portal and periportal hepatitis, with polarization of neutrophils to the interface region and lymphocytes more centrally in the portal tracts. Transfection of hepatitis C virus into cultured fetal hepatocytes resulted in sustained growth of 50-90 nm diameter viral particles. The ductular reaction in nonalcoholic steatohepatitis appears to evolve with fibrosis in response to hepatocyte replicative senescence. Hepatocellular release of hepcidin is critical for iron homeostasis in a manner analogous to pancreatic insulin for glucose homeostasis; this 'endocrine' focus was elaborated in an overview of hemochromatosis. Specific microscopic features of liver-cell adenomas combined with genetic analysis for hepatocyte nuclear factor 1alpha and beta-catenin mutations allows differentiation into four variants. Steroid-sensitive biliary strictures resembling primary sclerosing cholangitis but with increased serum immunoglobulin G4 and infiltrating immunoglobulin G4-positive plasma cells ('immunoglobulin associated cholangitis') are part of a spectrum of disorders including autoimmune pancreatitis and inflammatory pseudotumor.

SUMMARY

Pathologic features of viral hepatitis C and E, immunohistochemistry for the ductular reaction and malignant liver tumors and several systemic disorders are among recent important pathology studies.