Decreased FOXF1 promotes hepatocellular carcinoma tumorigenesis, invasion, and stemness and is associated with poor clinical outcome

Forkhead box F1 functions as a novel prognostic biomarker and induces caspase‑dependent apoptosis in bladder cancer

The downregulated expression of forkhead box F1 (FOXF1) has been found in many malignant tumors but no research was done in bladder cancer (BC). The present study aimed to investigate the prognostic value and antitumor effects of FOXF1 in patients with BC. Herein, a retrospectively recruited BC cohort and public datasets were utilized to identify the predictive ability of FOXF1 and determine its association with the clinical characteristics of BC patients. It was found that the expression level of FOXF1 was notably lower in BC tissues than in para‑cancerous mucosae. Low FOXF1 expression was associated with unfavorable clinicopathological features and poor prognosis. Furthermore, in BC cells, the mRNA and protein expression levels of FOXF1 were examined using reverse transcription‑quantitative PCR and western blot analysis. Cell viability was examined using Cell Counting Kit‑8, EdU and clonogenic capacity assays. Cell apoptosis was detected using flow cytometry. The results revealed that the activation of FOXF1 impaired cell viability and induced apoptosis in BC. The antitumor effects of FOXF1 were also validated using animal models. Subsequently, caspase‑3 was spotted as a downstream gene of FOXF1 by using RNA sequencing and protein‑protein interaction analyses. FOXF1 inhibited proliferation and induced apoptosis of BC cells via caspase signaling pathway. The present study demonstrates the expression patterns, prognostic predictive ability and antitumor effects of FOXF1 in BC. FOXF1 is a favorable biomarker for predicting clinical outcomes in patients with BC and represents a potential therapeutic target.

Transcription Factors: The Fulcrum Between Cell Development and Carcinogenesis

Higher eukaryotic development is a complex and tightly regulated process, whereby transcription factors (TFs) play a key role in controlling the gene regulatory networks. Dysregulation of these regulatory networks has also been associated with carcinogenesis. Transcription factors are key enablers of cancer stemness, which support the maintenance and function of cancer stem cells that are believed to act as seeds for cancer initiation, progression and metastasis, and treatment resistance. One key area of research is to understand how these factors interact and collaborate to define cellular fate during embryogenesis as well as during tumor development. This review focuses on understanding the role of TFs in cell development and cancer. The molecular mechanisms of cell fate decision are of key importance in efforts towards developing better protocols for directed differentiation of cells in research and medicine. We also discuss the dysregulation of TFs and their role in cancer progression and metastasis, exploring TF networks as direct or indirect targets for therapeutic intervention, as well as specific TFs' potential as biomarkers for predicting and monitoring treatment responses.

FOXF1 as an Immunohistochemical Marker of Hilar Cholangiocarcinoma or Metastatic Pancreatic Ductal Adenocarcinoma. Single Institution Experience

Cholangiocarcinoma (CCA) is a liver malignancy associated with a poor prognosis. Its main subtypes are peripheral/intrahepatic and hilar/extrahepatic CCA. Several molecular, morphological and clinical similarities between hilar/extrahepatic CCA and pancreatic ductal adenocarcinoma (PDAC) have been described. FOXF1 is a transcription factor which has been described to have prognostic significance in various tumors and it is involved in the development of bile ducts. The aim of this study is to determine occurrence of nuclear expression of FOXF1 in both subtypes of CCA and metastatic PDAC and assess its potential usefulness as a diagnostic marker. Secondary aims were to investigate the use of C-reactive protein (CRP) immunohistochemistry for diagnosing intrahepatic peripheral CCA and the significance of histological features in CCA subtypes. 32 archive specimens of CCA, combined hepatocellular carcinoma-CCA (HCC-CCA) and liver metastasis of PDAC were stained by FOXF1 and CRP immunohistochemistry and evaluated to determine histological pattern. The CCAs were classified radiologically into peripheral/intrahepatic and hilar subtype. Using Fisher exact test, we identified nuclear FOXF1 as a fairly specific (87%) but insensitive (65%) marker of hilar and extrahepatic CCA and metastatic PDAC (p = 0.005). CRP immunohistochemistry was characterized by a high sensitivity and specificity, of 79% and 88%, respectively (p = 0.001). We did not identify any histomorphological features associated with either types of CCA or metastatic PDAC. As a conclusion of novel finding, FOXF1 immunohistochemistry may be regarded as a specific but insensitive marker of hilar/extrahepatic CCA and metastatic PDAC and it may help distinguish them from peripheral CCA.

Loss of FOXF1 expression promotes human lung-resident mesenchymal stromal cell migration via ATX/LPA/LPA1 signaling axis

Forkhead box F1 (FOXF1) is a lung embryonic mesenchyme-associated transcription factor that demonstrates persistent expression into adulthood in mesenchymal stromal cells. However, its biologic function in human adult lung-resident mesenchymal stromal cells (LR-MSCs) remain to be elucidated. Here, we demonstrate that FOXF1 expression acts as a restraint on the migratory function of LR-MSCs via its role as a novel transcriptional repressor of autocrine motility-stimulating factor Autotaxin (ATX). Fibrotic human LR-MSCs demonstrated lower expression of FOXF1 mRNA and protein, compared to non-fibrotic controls. RNAi-mediated FOXF1 silencing in LR-MSCs was associated with upregulation of key genes regulating proliferation, migration, and inflammatory responses and significantly higher migration were confirmed in FOXF1-silenced LR-MSCs by Boyden chamber. ATX is a secreted lysophospholipase D largely responsible for extracellular lysophosphatidic acid (LPA) production, and was among the top ten upregulated genes upon Affymetrix analysis. FOXF1-silenced LR-MSCs demonstrated increased ATX activity, while mFoxf1 overexpression diminished ATX expression and activity. The FOXF1 silencing-induced increase in LR-MSC migration was abrogated by genetic and pharmacologic targeting of ATX and LPA1 receptor. Chromatin immunoprecipitation analyses identified three putative FOXF1 binding sites in the 1.5 kb ATX promoter which demonstrated transcriptional repression of ATX expression. Together these findings identify FOXF1 as a novel transcriptional repressor of ATX and demonstrate that loss of FOXF1 promotes LR-MSC migration via the ATX/LPA/LPA1 signaling axis.

The Dominant Role of Forkhead Box Proteins in Cancer

Forkhead box (FOX) proteins are multifaceted transcription factors that are significantly implicated in cancer, with various critical roles in biological processes. Herein, we provide an overview of several key members of the FOXA, FOXC, FOXM1, FOXO and FOXP subfamilies. Important pathophysiological processes of FOX transcription factors at multiple levels in a context-dependent manner are discussed. We also specifically summarize some major aspects of FOX transcription factors in association with cancer research such as drug resistance, tumor growth, genomic alterations or drivers of initiation. Finally, we suggest that targeting FOX proteins may be a potential therapeutic strategy to combat cancer.

FOXF1 Induces Epithelial-Mesenchymal Transition in Colorectal Cancer Metastasis by Transcriptionally Activating SNAI1

Forkhead Box F1 (FOXF1) has been recently implicated in cancer progression and metastasis of lung cancer and breast cancer. However, the biological functions and underlying mechanisms of FOXF1 in the regulation of the progression of colorectal cancer (CRC) are largely unknown. We showed that FOXF1 was up-regulated in 93 paraffin-embedded archived human CRC tissue, and both high expression and nuclear location of FOXF1 were significantly associated with the aggressive characteristics and poorer survival of CRC patients. The GSEA analysis showed that the higher level of FOXF1 was positively associated with an enrichment of EMT gene signatures, and exogenous overexpression of FOXF1 induced EMT by transcriptionally activating SNAI1. Exogenous overexpression FOXF1 functionally promoted invasion and metastasis features of CRC cells, and inhibition of SNAI1 attenuates the invasive phenotype and metastatic potential of FOXF1-overexpressing CRC cells. Furthermore, the results of the tissue chip showed that the expression of FOXF1 was positively correlated with SNAI1 in CRC tissues chip. These results suggested that FOXF1 plays a critical role in CRC metastasis by inducing EMT via transcriptional activation of SNAI1, highlighting a potential new therapeutic strategy for CRC.

Antisense lncRNA FOXF1-AS1 Promotes Migration and Invasion of Osteosarcoma Cells Through the FOXF1/MMP-2/-9 Pathway

Osteosarcoma (OS) is the most common primary malignant bone cancer in children and adolescents. Long non-coding RNAs (lncRNAs) have been shown to play significant role in various cancers, including OS. In a previous study, we have reported that a novel antisense lncRNA FOXF1-AS1, also known as FENDRR, could sensitize doxorubicin-resistance of OS cells through down-regulating ABCB1 and ABCC1. Here in, the critical role of FOXF1-AS1 in regulating OS progression was further investigated. Firstly, we found that FOXF1-AS1 and its antisense transcript FOXF1 expression were positively up-regulated in OS tissues and cell lines and correlated with poor prognosis of OS patients. Besides, FOXF1-AS1 as well as FOXF1 silencing significantly inhibited cell proliferation, migration, invasion of OS cells and tumor growth both in vitro and vivo through decreasing the expression of MMP2 and MMP9, whereas enhanced expression of FOXF1-AS1 had the opposite effects. In addition, mechanistically, both of FOXF1-AS1 and FOXF1 could regulate the expression of MMP2 and MMP9 at mRNA and protein levels, whereas FOXF1-AS1 could influence the FOXF1expression but FOXF1 did not have the same effect on FOXF1-AS1. Rescue assay further showed that FOXF1-AS1 overexpression efficiently reversed the knockdown of MMP2 and MMP9 expression induced by si-FOXF1. Thus, we concluded that FOXF1-AS1 may promote migration and invasion of OS cells through the FOXF1/MMP-2/-9 pathway. Taken together, these findings demonstrated the underlying mechanism of FOXF1-AS1 in the regulation of OS progression and provide a novel potential target in the OS therapy.