Forkhead box O4 transcription factor in human neoplasms: Cannot afford to lose the novel suppressor

Forkhead box O proteins: steering the course of stem cell fate

Stem cells are pivotal players in the intricate dance of embryonic development, tissue maintenance, and regeneration. Their behavior is delicately balanced between maintaining their pluripotency and differentiating as needed. Disruptions in this balance can lead to a spectrum of diseases, underscoring the importance of unraveling the complex molecular mechanisms that govern stem cell fate. Forkhead box O (FOXO) proteins, a family of transcription factors, are at the heart of this intricate regulation, influencing a myriad of cellular processes such as survival, metabolism, and DNA repair. Their multifaceted role in steering the destiny of stem cells is evident, as they wield influence over self-renewal, quiescence, and lineage-specific differentiation in both embryonic and adult stem cells. This review delves into the structural and regulatory intricacies of FOXO transcription factors, shedding light on their pivotal roles in shaping the fate of stem cells. By providing insights into the specific functions of FOXO in determining stem cell fate, this review aims to pave the way for targeted interventions that could modulate stem cell behavior and potentially revolutionize the treatment and prevention of diseases.

FOXO4 May Be a Biomarker of Postmenopausal Osteoporosis

Purpose

Postmenopausal osteoporosis (PMOP) is a common and debilitating chronic disease, but it has just no cure options. The objective of this study was to identify genes associated with osteoporosis and reveal potential therapeutic targets.

Methods

Expression profiles from GSE13850 and GSE56815 datasets were combined for differential expression analysis. Extraction of intersecting genes from the combined datasets and the differentially expressed genes in GSE56814 were performed to construct a multi-scale embedded gene co-expression network analysis (MEGENA) to obtain module genes. Module genes with an area under the receiver operating characteristic curve (AUC) >0.60 were chosen to construct the least absolute shrinkage and selection operator (LASSO) model to obtain feature genes. A regulated network was constructed using differentially expressed micro-RNAs (miRNAs) in GSE74209 and feature genes. Finally, key genetic pathways and pathways of the Kyoto Encyclopedia of Genes and Genomes were identified and explored.

Results

The commonly identified differentially expressed genes involve oxidative phosphorylation and caffeine metabolism. We identified 66 modules with 2354 module genes based on MEGENA. CARD8, FOXO4, IL1R2, MPHOSPH6, MPRIP, MYOM1, PRR5L and YIPF4 were identified as feature genes by the LASSO model. Furthermore, predicted miRNA target genes included 8 genes associated with PMOP. The largest AUC was observed for FOXO4, which was found at the nexus of feature genes and miRNA-regulated genes and which correlated with the upregulation of dendritic cells. Moreover, FOXO4 was found to be involved in ABC transporters, as well as cocaine and nicotine addiction.

Conclusion

FOXO4 may serve as potential biomarker and therapeutic target for PMOP.

EGF Relays Signals to COP1 and Facilitates FOXO4 Degradation to Promote Tumorigenesis

Forkhead-Box Class O 4 (FOXO4) is involved in critical biological functions, but its response to EGF-PKB/Akt signal regulation is not well characterized. Here, it is reported that FOXO4 levels are downregulated in response to EGF treatment, with concurrent elevation of COP9 Signalosome subunit 6 (CSN6) and E3 ubiquitin ligase constitutive photomorphogenic 1 (COP1) levels. Mechanistic studies show that CSN6 binds and regulates FOXO4 stability through enhancing the E3 ligase activity of COP1, and that COP1 directly interacts with FOXO4 through a VP motif on FOXO4 and accelerates the ubiquitin-mediated degradation of FOXO4. Metabolomic studies demonstrate that CSN6 expression leads to serine and glycine production. It is shown that FOXO4 directly binds and suppresses the promoters of serine-glycine-one-carbon (SGOC) pathway genes, thereby diminishing SGOC metabolism. Evidence shows that CSN6 can regulate FOXO4-mediated SGOC gene expression. Thus, these data suggest a link of CSN6-FOXO4 axis and ser/gly metabolism. Further, it is shown that CSN6-COP1-FOXO4 axis is deregulated in cancer and that the protein expression levels of CSN6 and FOXO4 can serve as prognostic markers for cancers. The results illustrate a pathway regulation of FOXO4-mediated serine/glycine metabolism through the function of CSN6-COP1 axis. Insights into this pathway may be strategically designed for therapeutic intervention in cancers.

FOXO4 expression associates with glioblastoma development and FOXO4 expression inhibits cell malignant phenotypes in vitro and in vivo

BACKGROUND AND AIM

Forkhead box protein O4 (FOXO4) is a transcription factor, and aberrant FOXO4 expression is associated with development of various human cancers. This study explored the role of FOXO4 in glioma in vitro and in vivo.

METHODS

FOXO4 expression was first assessed in normal brain tissues, low-grade glioma, glioblastoma multiforme (GBM), normal human astrocytes (HA), and GBM cell lines, while manipulation of FOXO4 expression in glioma cell lines was assessed using qRT-PCR, Western blot, and cell viability CCK-8, Transwell, and a nude mouse subcutaneous xenograft assays.

KEY FINDINGS

The data showed downregulated FOXO4 expression in GBM tissues and cell lines. FOXO4 overexpression induced by transfection with FOXO4 cDNA significantly inhibited GBM cell proliferation, migration, and invasion, but increased tumor cells to undergo apoptosis in vitro, while suppressed growth of GBM cell subcutaneous xenografts in nude mice. In conclusion, FOXO4 possesses an anti-cancer glioma activity, which could be a novel target for future control of GBM.

Current perspective on the regulation of FOXO4 and its role in disease progression

Forkhead box O4 (FOXO4) is a member of the FOXO family that regulates a number of genes involved in metabolism, cell cycle, apoptosis, and cellular homeostasis via transcriptional activity. It also mediates cell responses to oxidative stress and treatment with antitumor agents. The expression of FOXO4 is repressed by microRNAs in multiple cancer cells, while FOXO4 function is regulated by post-translational modifications and interaction with other proteins. The deregulation of FOXO4 is closely linked to the progression of several types of cancer, senescence, and other diseases. In this review, we present recent findings on the regulation of FOXO4 in physiological and pathological conditions and provide an overview of the complex role of FOXO4 in disease development and response to therapy.

The forkhead-box family of transcription factors: key molecular players in colorectal cancer pathogenesis

Colorectal cancer (CRC) is the third most commonly occurring cancer worldwide and the fourth most frequent cause of death having an oncological origin. It has been found that transcription factors (TF) dysregulation, leading to the significant expression modifications of genes, is a widely distributed phenomenon regarding human malignant neoplasias. These changes are key determinants regarding tumour’s behaviour as they contribute to cell differentiation/proliferation, migration and metastasis, as well as resistance to chemotherapeutic agents. The forkhead box (FOX) transcription factor family consists of an evolutionarily conserved group of transcriptional regulators engaged in numerous functions during development and adult life. Their dysfunction has been associated with human diseases. Several FOX gene subgroup transcriptional disturbances, affecting numerous complex molecular cascades, have been linked to a wide range of cancer types highlighting their potential usefulness as molecular biomarkers. At least 14 FOX subgroups have been related to CRC pathogenesis, thereby underlining their role for diagnosis, prognosis and treatment purposes.

This manuscript aims to provide, for the first time, a comprehensive review of FOX genes’ roles during CRC pathogenesis. The molecular and functional characteristics of most relevant FOX molecules (FOXO, FOXM1, FOXP3) have been described within the context of CRC biology, including their usefulness regarding diagnosis and prognosis. Potential CRC therapeutics (including genome-editing approaches) involving FOX regulation have also been included. Taken together, the information provided here should enable a better understanding of FOX genes’ function in CRC pathogenesis for basic science researchers and clinicians.