FOXF2 deficiency promotes hepatocellular carcinoma metastasis by inducing mesenchymal-epithelial transition

Forkhead box F2/ Lysyl oxidase like 1 contribute to epithelial-mesenchymal transition and angiogenesis in thyroid cancer

BACKGROUND

Bioinformatics analysis suggests an association between lysyl oxidase like 1 (LOXL1) and forkhead box F2 (FOXF2), both of which are found to be dysregulated in thyroid cancer. This study aims to elucidate their specific roles in thyroid cancer.

METHODS

The correlation of LOXL1 expression with thyroid cancer staging and the overall survival was analyzed. LOXL1 levels were determined in several thyroid cancer cells, and its effects on poorly differentiated BCPAP cell proliferation, colony formation, malignant phenotypes, epithelial-mesenchymal transition (EMT) progression, and angiogenesis were evaluated. The relationship between LOXL1 and FOXF2 was confirmed using Luciferase reporter and ChIP assays. The impacts of FOXF2 on LOXL1 regulation along with the Wnt/β-catenin signaling were assessed, followed by the verification of transplanted tumor in nude mice.

RESULTS

Elevated LOXL1 expression was associated with advanced clinical staging and poorer overall survival. Reduced LOXL1 suppressed cell proliferation, colony formation, migration, invasion, EMT, and angiogenesis. FOXF2 was found to be down-regulated in thyroid cancer, acting as a transcription factor that recognizes the LOXL1 promoter and modulates its transcriptional expression. Moreover, the regulatory outcome of LOXL1 knockdown was partially reversed upon FOXF2 knockdown, including the modulation of the Wnt/β-catenin signaling and tumor growth in vivo.

CONCLUSION

Our findings indicate that LOXL1 is transcriptionally regulated by FOXF2 and activates the Wnt/β-catenin to promote malignant phenotypes, EMT progression, and angiogenesis in BCPAP cells.

Anti-hepatocellular carcinoma activity of the cyclin-dependent kinase inhibitor AT7519

Hepatocellular carcinoma (HCC) is one of the most common cancerous tumors and one of the leading causes of death among cancer-related disorders. Chemotherapy is ineffective in HCC patients, and the number of drugs that are in use is limited. Thus, new molecules are needed that could increase the effectiveness of anti-HCC regimens. Here, we show that AT7519, a CDK inhibitor, exerts positive effects on HCC cells: it inhibits proliferation, migration and clonogenicity. Detailed analysis of the transcriptomes of cells treated with this compound indicated that AT7519 affects a substantial portion of genes that are associated with HCC development and progression. Moreover, we showed that the concomitant use of AT7519 with gefitinib or cabozantinib sensitized HCC cells to these drugs. Thus, our research indicates that AT7519 is worth considering in monotherapy for hepatocellular carcinoma patients or in combination with other drugs, e.g., gefitinib or cabozantinib.

FOXF2 Regulates PRUNE2 Transcription in the Pathogenesis of Colorectal Cancer

Background: Forkhead box F2, a member of the Forkhead box transcription factor superfamily, plays an important role in several types of cancer. However, the mechanisms of Forkhead box F2 in the progression of colorectal cancer remain unclear. PRUNE2 is closely associated with prostate cancer, neuroblastoma, glioblastoma, and melanoma. The relationship between Forkhead box F2 and PRUNE2 in colorectal cancer remains unknown. Method: We investigated the effects of Forkhead box F2 upregulation on colorectal cancer cell behavior in vitro using Cell Counting Kit-8, colony formation, flow cytometry, Transwell, reverse transcription quantitative polymerase chain reaction and Western blot analyses. Nude mouse xenografts were established to investigate the effect of Forkhead box F2 upregulation on the growth of colorectal cancer cells. Dual-luciferase reporter assays were performed to confirm the Forkhead box F2 regulation of PRUNE2 transcription. A series of in vitro assays was performed in cells with Forkhead box F2 upregulation and PRUNE2 knockdown to elucidate the function and regulatory effects of Forkhead box F2 on PRUNE2 transcription in colorectal cancer. Results: Forkhead box F2 was downregulated in colorectal cancer tissues compared with adjacent tissues. Forkhead box F2 overexpression significantly suppressed the proliferation and invasion of colorectal cancer cells in vitro and in vivo. Moreover, Forkhead box F2 directly targeted PRUNE2 to promote its transcription in colorectal cancer cells. Furthermore, PRUNE2 mediated the Forkhead box F2-regulated proliferation and invasion of colorectal cancer cells. Additionally, we demonstrated a significant positive correlation between Forkhead box F2 and PRUNE2 mRNA levels in colorectal cancer tissues. Conclusion: These results indicated that Forkhead box F2 and PRUNE2 in combination may serve as a prognostic biomarker for colorectal cancer and that Forkhead box F2 upregulation inhibits the proliferation and invasion of colorectal cancer cells by upregulating PRUNE2.

Aberrant DNA Methylation-Mediated FOXF2 Dysregulation Is a Prognostic Risk Factor for Gastric Cancer

Background: The prognosis of gastric cancer (GC) patients is poor. The effect of aberrant DNA methylation on FOXF2 expression and the prognostic role of FOXF2 methylation in GC have not yet been identified.

Methods: The RNA-Seq and gene methylation HM450 profile data were used for analyzing FOXF2 expression in GC and its association with methylation level. Bisulfite sequencing PCR (BSP) was performed to measure the methylation level of the FOXF2 promoter region in GC cell lines and normal GES-1 cells. The cells were treated with the demethylation reagent 5-Aza-dC, and the mRNA and protein expression levels of FOXF2 were then measured by qRT-PCR and western blot assays. The risk score system from SurvivalMeth was calculated by integrating the methylation level of the cg locus and the corresponding Cox regression coefficient.

Results: FOXF2 was significantly downregulated in GC cells and tissues. On the basis of RNA-Seq and Illumina methylation 450 data, FOXF2 expression was significantly negatively correlated with the FOXF2 methylation level (Pearson’s R = −0.42, p < 2.2e⁻¹⁶). The FOXF2 methylation level in the high FOXF2 expression group was lower than that in the low FOXF2 expression group. The BSP assay indicated that the methylation level of the FOXF2 promoter region in GC cell lines was higher than that in GES-1 cells. The qRT-PCR and western blot assay showed that FOXF2 mRNA and protein levels were increased in GC cells following treatment with 5-Aza-Dc. The methylation risk score model indicated that patients in the high risk group had poorer survival probability than those in the low risk group (HR = 1.84 (1.11–3.07) and p = 0.0068). FOXF2 also had a close transcriptional regulation network with four miRNAs and their corresponding target genes. Functional enrichment analysis of the target genes revealed that these genes were significantly related to several important signaling pathways.

Conclusion: FOXF2 was downregulated due to aberrant DNA methylation in GC, and the degree of methylation in the promoter region of FOXF2 was related to the prognosis of patients. The FOXF2/miRNAs/target genes axis may play a vital biological regulation role in GC.

Role of NELF-B in supporting epithelial-mesenchymal transition and cell proliferation during hepatocellular carcinoma progression

Negative elongation factor-B (NELF-B), also known as cofactor of BRCA1 (COBRA1), is one of the four subunits of the NELF complex. It interacts with BRCA1, in addition to other transcription complexes in various tissues. The NELF complex represses the transcription of several genes by stalling RNA polymerase II during the early phase of transcription elongation. The role of NELF-B in liver cancer and hepatocellular carcinoma (HCC), the most prevalent type of liver cancer, remains to be elucidated. It has been previously demonstrated that silencing of NELF-B inhibits the proliferation and migration of HepG2 cells. The present study aimed to investigate the consequences of ectopic expression and silencing of NELF-B in liver cancer HepG2 and SNU449 cell lines. Functional assays were performed to examine the effects on gene and protein expression, viability, migration and invasion of cells. Overexpression of NELF-B did not alter the proliferation and migration of HepG2 cells, or the expression of tested genes, indicating that overexpression alone may not be sufficient for altering these features in HepG2 cells. By contrast, knockdown of NELF-B in SNU449 cells resulted in decreased cell proliferation, together with induction of apoptosis and decreased expression levels of Ki-67 and survivin, which are markers of proliferation and inhibition of apoptosis, respectively. Additionally, silencing of NELF-B resulted in a significant decrease in the hallmarks of epithelial-mesenchymal transition (EMT), including cell migration and invasion, and decreased the expression levels of EMT markers, such as N-cadherin, vimentin and β-catenin. Decreased expression levels of forkhead box F2 transcription factor and increased mRNA levels of trefoil factor 1, a putative tumor suppressor, were also detected following the silencing of NELF-B. The current results demonstrated that NELF-B enhanced the manifestation of most hallmarks of cancer, including cell proliferation, migration, invasion and inhibition of apoptosis, indicating its critical role in the progression of HCC.

Forkhead box F2 as a novel prognostic biomarker and potential therapeutic target in human cancers prone to bone metastasis: a meta-analysis

OBJECTIVE

To undertake a systematic review and meta-analysis to evaluate the prognostic value of Forkhead box F2 (FOXF2) levels in different types of cancers prone to bone metastasis.

METHODS

A systematic search of publications listed in electronic databases (The Web of Science, EMBASE®, PubMed®, PMC, Science Direct and CNKI) from inception to 5 November 2020 was conducted. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were used to assess the relationship between FOXF2 levels and patient prognosis including overall survival (OS) and disease-free survival (DFS).

RESULTS

Sixteen studies enrolling 8461 participants were included in the meta-analysis. High levels of FOXF2 were a predictor of OS (HR: 0.66; 95% CI 0.51, 0.86) and DFS (HR: 0.60; 95% CI 0.48, 0.76). The trim-and-fill analysis, sensitivity analysis and subgroup analyses stratified by the study characteristics confirmed the robustness of the results.

CONCLUSION

These current findings indicate that high FOXF2 levels could be an indicator of a good prognosis in cancer patients with tumours that are prone to bone metastasis. FOXF2 levels might be a clinically important prognostic biomarker.

The regulatory roles and mechanisms of the transcription factor FOXF2 in human diseases

Many studies have focused on the relationship between transcription factors and a variety of common pathological conditions, such as diabetes, stroke, and cancer. It has been found that abnormal transcription factor regulation can lead to aberrant expression of downstream genes, which contributes to the occurrence and development of many diseases. The forkhead box (FOX) transcription factor family is encoded by the FOX gene, which mediates gene transcription and follow-up functions during physiological and pathological processes. FOXF2, a member of the FOX transcription family, is expressed in various organs and tissues while maintaining their normal structural and functional development during the embryonic and adult stages. Multiple regulatory pathways that regulate FOXF2 may also be controlled by FOXF2. Abnormal FOXF2 expression induced by uncontrollable regulatory signals mediate the progression of human diseases by interfering with the cell cycle, proliferation, differentiation, invasion, and metastasis. FOXF2 manipulates downstream pathways and targets as both a pro-oncogenic and anti-oncogenic factor across different types of cancer, suggesting it may be a new potential clinical marker or therapeutic target for cancer. However, FOXF2’s biological functions and specific roles in cancer development remain unclear. In this study, we provide an overview of FOXF2’s structure, function, and regulatory mechanisms in the physiological and pathological conditions of human body. We also discussed the possible reasons why FOXF2 performs the opposite function in the same types of cancer.

FOXO transcription factor family in cancer and metastasis

Forkhead box O (FOXO) transcription factors regulate diverse biological processes, affecting development, metabolism, stem cell maintenance and longevity. They have also been increasingly recognised as tumour suppressors through their ability to regulate genes essential for cell proliferation, cell death, senescence, angiogenesis, cell migration and metastasis. Mechanistically, FOXO proteins serve as key connection points to allow diverse proliferative, nutrient and stress signals to converge and integrate with distinct gene networks to control cell fate, metabolism and cancer development. In consequence, deregulation of FOXO expression and function can promote genetic disorders, metabolic diseases, deregulated ageing and cancer. Metastasis is the process by which cancer cells spread from the primary tumour often via the bloodstream or the lymphatic system and is the major cause of cancer death. The regulation and deregulation of FOXO transcription factors occur predominantly at the post-transcriptional and post-translational levels mediated by regulatory non-coding RNAs, their interactions with other protein partners and co-factors and a combination of post-translational modifications (PTMs), including phosphorylation, acetylation, methylation and ubiquitination. This review discusses the role and regulation of FOXO proteins in tumour initiation and progression, with a particular emphasis on cancer metastasis. An understanding of how signalling networks integrate with the FOXO transcription factors to modulate their developmental, metabolic and tumour-suppressive functions in normal tissues and in cancer will offer a new perspective on tumorigenesis and metastasis, and open up therapeutic opportunities for malignant diseases.

FOXF2 acts as a crucial molecule in tumours and embryonic development

As a key member of the forkhead box transcription factors, forkhead box F2 (FOXF2) serves as a transcriptional regulator and regulates downstream gene expression in embryonic development, metabolism and in some common diseases, such as stroke and gastroparesis. Recent studies have shown that aberrant expression of FOXF2 is associated with a variety of tumorigenic processes, such as proliferation, invasion and metastasis. The role of FOXF2 in the development of many different organs has been confirmed by studies and has been speculated about in case reports. We focus on the mechanisms and signal pathways of tumour development initiated by aberrant expression of FOXF2, and we summarize the diseases and signal pathways caused by aberrant expression of FOXF2 in embryogenesis. This article highlights the differences in the role of FOXF2 in different tumours and demonstrates that multiple factors can regulate FOXF2 levels. In addition, FOXF2 is considered a biomarker for the diagnosis or prognosis of various tumours. Therefore, regulating the level of FOXF2 is an ideal treatment for tumours. FOXF2 could also affect the expression of some organ-specific genes to modulate organogenesis and could serve as a biomarker for specific differentiated cells. Finally, we present prospects for the continued research focus of FOXF2.

FOX transcription factor family in hepatocellular carcinoma

The pathogenesis of hepatocellular carcinoma (HCC) is a multistep process, involving the progressive accumulation of molecular alterations and transcriptomic alterations. The Forkhead-box (FOX) transcription factor family is characterized by its unique DNA binding domain (FKH or winged-helix domain). Human FOX family consists of about 17 subfamilies, at least 43 members. Some of them are liver-enriched transcription factors, suggesting that they may play a crucial role in the development or/and functions of the liver. Dysregulation of FOX transcription factors may contribute to the pathogenesis of HCC because they can activate or suppress the expression of various tumor-related molecules, and pinpoint different molecular and cellular events. Here we summarized, analyzed and discussed the status and the functions of the human FOX family of transcription factors in HCC, aiming to help the further development of them as potential therapeutic targets or/and diagnostic/prognostic markers for HCC.

FOXF2 inhibits proliferation, migration, and invasion of Hela cells by regulating Wnt signaling pathway

This article was aimed to study the FOXF2 effects on cervical cancer. Tumor tissues and adjacent tissues of 41 cervical cancer patients were collected. Human endometrial epithelial cells (hEEC) and Hela cells were cultured. FOXF2 expression vector and its empty vector were transfected into Hela cells, and named as pcDNA 3.1-FOXF2 group and Vector group, respectively. Hela cells without any treatment were set as Blank group. qRT-PCR was used to detect mRNA expression. Nude mouse xenograft assay was performed to test Hela cells proliferation ability in vivo. FOXF2 and β-catenin positive cell numbers were detected by immunohistochemistry. Protein expression was analyzed by Western blot. Cells migration and invasion were conducted by Transwell. Tumor tissues and Hela cells FOXF2 expression were lower than that in adjacent tissues and hEEC (P<0.01). Low FOXF2 expression predicted poor outcomes of cervical cancer patients. Compared with Blank group and Vector group, Hela cells of pcDNA 3.1-FOXF2 group were with higher FOXF2 expression, lower OD₄₉₅ value, migrated and invaded cells, higher E-cadherin expression, lower Vimentin and Snail expression, smaller tumor volume in nude mice, lower c-Myc, CyclinDl, MMP9, Lgr5, and nuclear β-catenin expression (all P<0.01). FOXF2 inhibits Hela cells proliferation, migration, and invasion through regulating Wnt signaling pathway.

IL-17A promotes the invasion-metastasis cascade via the AKT pathway in hepatocellular carcinoma

We previously demonstrated that interleukin‐17A (IL‐17A) is associated with the progression of hepatocellular carcinoma (HCC). However, its role in the invasion–metastasis cascade of HCC and the efficacy of IL‐17A‐targeting therapeutics in HCC remain largely unknown. In this study, we found that IL‐17A promoted intrahepatic and pulmonary metastasesis of HCC cells in an orthotopic implant model. Moreover, our results showed that IL‐17A induced epithelial–mesenchymal transition (EMT) and promoted HCC cell colonization in vitro and in vivo, and the role of IL‐17A in invasion–metastasis was dependent on activation of the AKT pathway. Remarkably, combined therapy using both secukinumab and sorafenib has better inhibition on tumour growth and metastasis compared to sorafenib monotherapy. Additionally, the combination of intratumoral IL‐17A+ cells and E‐cadherin predicted the outcome of patients with HCC at an early stage after hepatectomy based on tissue microarray and immunohistochemistry. In conclusion, our studies reveal that IL‐17A induces early EMT and promotes late colonization of HCC metastasis by activating AKT signalling. Secukinumab is a promising candidate for clinical development in combination with sorafenib for the management of HCC.