FOXP3 Is a HCC suppressor gene and Acts through regulating the TGF-β/Smad2/3 signaling pathway

What is the relevance of FoxP3 in the tumor microenvironment and cancer outcomes?

INTRODUCTION

Forkhead box P3 (FoxP3) transcription factor plays critical roles in controlling immune responses and cancer progression in different cancers. FoxP3 expression within the tumor microenvironment (TME) may influence clinical outcomes negatively or positively, and it could play dual roles in cancer, either by promoting or inhibiting tumor development and progression. Some studies reported that high levels of FoxP3 could be associated with tumor progression and worse prognosis, while others reported contradictory results.

AREAS COVERED

In this special report, we present a brief account on the role and function of FoxP3 in the TME, and its contribution to the clinical outcomes of cancer patients. Importantly, we give insights on the potential factors that could contribute to different clinical outcomes in cancer patients.

EXPERT OPINION

Different studies showed that FoxP3 expression can be associated with bad prognoses in cancer patients. However, FoxP3 could have opposing roles by enhancing cancer progression or regression. Location and expression of FoxP3 in T cells or tumor cells can have different impacts on cancer prognoses. Different factors should be considered to establish FoxP3 as a more robust prognostic biomarker and a potential therapeutic target for enhancing anti-tumor immunity and improving clinical outcomes of cancer patients.

Regulatory T cells inhibit FoxP3 to increase the population of tumor initiating cells in hepatocellular carcinoma

PURPOSE

Tumor initiating cells (TICs) or cancer stem cells (CSCs) are considered to be the main culprit of hepatocellular carcinoma (HCC) initiation and progression, nevertheless the mechanism by which tumor microenvironment maintains the HCC 'stemness' is not fully understood. This study aims to investigate the effect of regulatory T cells (Tregs) on the TICs characteristics of HCC.

METHODS

Immunocytochemistry, flow cytometry, real-time PCR, western blot, in vitro sphere-formation, and in vivo tumorigenesis assay were used to detect HCC 'stemness'. Additionally, after forced expression or inhibition of FoxP3, β-catenin expression and HCC 'stemness' were investigated.

RESULTS

Tregs enhanced the 'stemness' of HCC cells by upregulating TIC-related markers CD133, Oct3/4, Sox2, c-Myc, Klf4, Nanog, CD13, EpCAM, and inducting epithelial to mesenchymal transition (EMT), increasing TICs ratio, as well as promoting tumorigenic ability. Moreover, β-catenin and c-Myc were upregulated in HCC cells after co-cultured with Tregs. HCC 'stemness' was inhibited after treatment with Wnt/β-catenin pathway inhibitor. Furthermore, forced expression of FoxP3 resulted in increased GSK3β, decreased β-catenin and TIC ratio in HCC. In contrast, FoxP3 interference reduced GSK3β, enhanced β-catenin and TIC ratio of HCC.

CONCLUSION

This study, for the first time, demonstrated that Tregs increased the population of TICs in HCC by inhibiting FoxP3 as well as promoting β-catenin expression.

Expression landscape of cancer-FOXP3 and its prognostic value in pancreatic adenocarcinoma

FOXP3, a key identifier of Treg, has also been identified in tumor cells, which is referred to as cancer-FOXP3 (c-FOXP3). Human c-FOXP3 undergoes multiple alternative splicing events, generating several isoforms, like c-FOXP3FL and c-FOXP3Δ3. Previous research on c-FOXP3 often ignore its cellular source (immune or tumor cells) and isoform expression patterns, which may obscure our understanding of its clinical significance. Our immunohistochemistry investigations which conducted across 18 tumors using validated c-FOXP3 antibodies revealed distinct expression landscapes for c-FOXP3 and its variants, with the majority of tumors exhibited a predominantly expression of c-FOXP3Δ3. In pancreatic ductal adenocarcinoma (PDAC), we further discovered a potential link between nuclear c-FOXP3Δ3 in tumor cells and poor prognosis. Overexpression of c-FOXP3Δ3 in tumor cells was associated with metastasis. This work elucidates the expression pattern of c-FOXP3 in pan-cancer and indicates its potential as a prognostic biomarker in clinical settings, offering new perspectives for its clinical application.

The effect of FOXP3 genetic polymorphisms on correlations with hepatitis B virus-hepatocellular carcinoma: A case-control study

Background

Previous studies have reported that transcription factor forkhead box protein 3 (FOXP3) polymorphisms are correlated with the progress of some cancers, but the relationships between the FOXP3 polymorphisms and hepatocellular carcinoma (HCC) risk remain unclear.

Method

Genotypes were detected in156 hepatitis B virus (HBV)-HCC patients, 109 HBV-liver cirrhosis (LC) patients, 125 chronic hepatitis B (CHB) patients, and 188 healthy controls. The FOXP3 rs3761547 and rs3761548 polymorphisms were genotyped by polymerase chain reaction (PCR) combined with restriction fragment length polymorphism, and the rs2232365 polymorphism was genotyped using PCR with sequence-specific primers.

Results

We did not obtain any significant results with the FOXP3 rs3761547, rs3761548, and rs2232365 polymorphisms in groups of patients compared to healthy controls (all p > 0.05), no matter the overall group or subgroup.

Conclusions

Our findings suggest that the FOXP3 polymorphisms at rs3761547, rs3761548, and rs2232365 were not related to HBV-HCC risk in the Chinese population.

Human FOXP3 and tumour microenvironment

The tumour microenvironment (TME) is a complex system composed of cancer cells, stromal cells and immune cells. Regulatory T cells (Tregs) in the TME impede immune surveillance of tumours and suppress antitumor immune responses. Transcription factor forkhead box protein 3 (FOXP3) is the main marker of Tregs, which dominates the function of Tregs. FOXP3 was originally thought to be a Tregs-specific expression molecule, and recent studies have found that FOXP3 is expressed in a variety of tumours with inconsistent functional roles. This review summarizes the recent progress of infiltrating Treg-FOXP3 and tumour-FOXP3 in TME, discusses the communication mechanism between FOXP3⁺ cells and effector T cells in TME, the relationship between FOXP3 and clinical prognosis, and the potential of FOXP3-targeted therapy.

FOXP3 and SQSTM1/P62 correlate with prognosis and immune infiltration in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common highly malignant tumours worldwide. FOXP3 and SQSTM1/P62 have been shown to be abnormally expressed in tumour cells, but their function in different tumours remains controversial. The present study was designed to evaluate the expression of FOXP3 and P62 in HCC and their prognostic value as well as their relationship with immune infiltration in HCC patients.

METHODS

The Gene Expression Omnibus (GEO) database and TNMplot.com platform were used to analyse the expression of FOXP3 and P62. The Cancer Genome Atlas (TCGA) database and Kaplan-Meier plotter were used to assess the impacts of FOXP3 and P62 on clinical prognosis. In addition, TCGA database was also used to examine the correlation between the expression of FOXP3 and P62 and tumour immune infiltration using the CIBERSORT algorithm. Finally, immunohistochemistry (IHC) was used to determine expression levels of FOXP3 and P62 in 89 HCC and adjacent normal liver tissues, and their effects on clinicopathological features and prognosis were verified.

RESULTS

FOXP3 expression was downregulated in HCC tissues, while P62 expression was upregulated. FOXP3 underexpression and P62 overexpression were closely related to decreased overall survival (OS) in HCC patients. Additionally, the abnormal expression of FOXP3 and P62 was closely related to the infiltration levels of 12 types of immune cells, including regulatory T cells (Tregs), M2 macrophages, M0 macrophages, and CD8 T cells. Notably, in the validation model, abnormal FOXP3 and P62 expression was significantly associated with adverse clinicopathological factors in HCC patients, including elevated α-fetoprotein (AFP) levels, poor tumour differentiation, and increased Ki67 levels. Furthermore, low FOXP3 and high P62 expression were independent risk factors for predicting OS prognosis in HCC patients.

CONCLUSION

FOXP3 and P62 have been shown to be important prognostic factors in HCC patients and are associated with immune cell infiltration in HCC. These findings suggest that FOXP3 and P62 may be valuable prognostic biomarkers and potential therapeutic targets for HCC treatment.

A Water-Soluble Hydrogen Sulfide Donor Suppresses the Growth of Hepatocellular Carcinoma via Inhibiting the AKT/GSK-3β/β-Catenin and TGF-β/Smad2/3 Signaling Pathways

Hepatocellular carcinoma (HCC) is a disease with high morbidity, high mortality, and low cure rate. Hyaluronic acid (HA) is widely adopted in tissue engineering and drug delivery. 5-(4-Hydroxyphenyl)-3H-1, 2-dithiol-3-thione (ADT-OH) is one of commonly used H₂S donors. In our previous study, HA-ADT was designed and synthesized via coupling of HA and ADT-OH. In this study, compared with sodium hydrosulfide (NaHS, a fast H₂S-releasing donor) and morpholin-4-ium (4-methoxyphenyl)-morpholin-4-ylsulfanylidenesulfido-λ5-phosphane (GYY4137, a slow H₂S-releasing donor), HA-ADT showed stronger inhibitory effect on the proliferation, migration, invasion, and cell cycle of human HCC cells. HA-ADT promoted apoptosis by suppressing the expressions of phospho (p)-protein kinase B (PKB/AKT), p-glycogen synthase kinase-3β (GSK-3β), p-β-catenin, and also inhibited autophagy via the downregulation of the protein levels of p-Smad2, p-Smad3, and transforming growth factor-β (TGF-β) in human HCC cells. Moreover, HA-ADT inhibited HCC xenograft tumor growth more effectively than both NaHS and GYY4137. Therefore, HA-ADT can suppress the growth of HCC cells by blocking the AKT/GSK-3β/β-catenin and TGF-β/Smad2/3 signaling pathways. HA-ADT and its derivatives may be developed as promising antitumor drugs.

The role of FOXP3 in non-small cell lung cancer and its therapeutic potentials

Although in the last few decades we have witnessed the rapid development of treatments for non-small cell lung cancer (NSCLC), it still remains the leading cause of cancer-related death. Increasing efforts have been devoted to exploring potential biomarkers and molecular targets for NSCLC. Foxp3, a transcription factor that was discovered as a master regulator of regulatory T cells (Tregs), has been found to express abnormally in tumoral cells including lung cancer cells. In recent years, increasing evidence have surfaced, revealing the carcinogenic effect of FOXP3 in lung cancer. In this review, we analyzed and summarized the function of FOXP3, its regulation and therapeutic potentials in NSCLC, with a hope to facilitate the development of novel treatments for NSCLC.

The Role of FOXP3 on Tumor Metastasis and Its Interaction with Traditional Chinese Medicine

Forkhead box protein 3 (FOXP3) is an important transcription factor for regulatory T cells (Tregs) and plays an important role in their immunosuppressive function. In recent years, studies have found that FOXP3 is expressed in many kinds of tumors and plays different roles in tumors' biological behaviors, including tumor proliferation, metastasis, drug resistance, and prognosis. However, the effects of FOXP3 on tumor metastasis and its interaction with traditional Chinese medicine (TCM) remain unclear. Therefore, in this review, we focus on the effects of FOXP3 on tumor metastasis and its relationship with TCM, which can provide evidence for further research and therapy in clinical settings.

Tumor Infiltration Levels of CD3, Foxp3 (+) Lymphocytes and CD68 Macrophages at Diagnosis Predict 5-Year Disease-Specific Survival in Patients with Oropharynx Squamous Cell Carcinoma

Simple Summary

Head and neck cancer (HNC) is the sixth most common cancer worldwide, with a general prognosis of 50% disease-specific survival (DSS). The subgroup of oropharyngeal (OP) cancers are of interest because HPV infection is one of several causative agents and carries favorable prognosis. Influxes of inflammatory cells into tumors may vary with prognosis. T lymphocytes are important regarding specific immune defense. Within the immune system T regulatory cells (Foxp3 positive) co-governs this process. We have therefore primarily studied levels of Foxp3 (+) cells in malignant tumors from 170 patients related to prognosis of the patients. Higher levels of T lymphocyte Foxp3 (+) cells predicted better 5-year DSS. This case was unique relative to age, gender, TNM stage, and HPV infection; but more so among tumor HPV (+) than HPV (−) patients. The results encourage further study into the use of immune-based therapy in HNC patients.

Abstract

Head and neck cancer (HNC) is the sixth most common cancer worldwide. Oropharyngeal (OP) cancers are of special interest because of possible underlying HPV infection which is tied to prognosis. Influxes of inflammatory cells into tumors may vary with prognoses. We wanted to study whether the number of tumor-infiltrating lymphocytes (TIL) and tumor-associated macrophages (TAM) in tumors correlated to HPV status and predicted 5-year disease-specific survival (DSS). Formalin-fixed paraffin-embedded (FFPE) biopsies cut sections from 170 patients treated for OP cancer were stained by immunohistochemistry and evaluated for the number of CD68 (+) TAMs, CD3 (+), and Foxp3 (+) (T regulatory) TILs. From FFPE slides HPV by PCR and p16 by immunohistochemistry were established. From FFPE Hematoxylin-Eosin slides, levels of tumor nuclear polymorphism, tumor invasion, desmoplasia, and inflammation were determined as previously published. Levels of TIL CD3 (+) and TIL Foxp3 (+) were increased among the HPV (+) compared to the HPV (−) patients. High levels of TIL Foxp3 (+) and CD68 (+) macrophages predicted better 5-year DSS. TIL Foxp3 (+) levels predicted independent of age, gender, TNM stage, and HPV infection as well as level of stromal desmoplasia, tumor invasion, and nuclear polymorphism, but more pronounced among tumor HPV (+) than HPV (−) patients.

Novel oncogenes and tumor suppressor genes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a very deadly disease. HCC initiation and progression involve multiple genetic events, including the activation of proto-oncogenes and disruption of the function of specific tumor suppressor genes. Activation of oncogenes stimulates cell growth and survival, while loss-of-function mutations of tumor suppressor genes result in unrestrained cell growth. In this review, we summarize the new findings that identified novel proto-oncogenes and tumor suppressors in HCC over the past five years. These findings may inspire the development of novel therapeutic strategies to improve the outcome of HCC patients.

Role of FoxP3-positive regulatory T-cells in regressive and progressive cervical dysplasia

PURPOSE

Forkhead Box Protein 3 (FoxP3) is known as a key mediator in the immunosuppressive function of regulatory T-cells (Tregs). The aim of our study was to investigate whether FoxP3-positive Tregs have the potential to act as an independent predictor in progression as well as in regression of cervical intraepithelial neoplasia, especially in patients with intermediate cervical intraepithelial neoplasia (CIN II).

METHODS

Nuclear FoxP3 expression was immunohistochemically analysed in 169 patient samples (CIN I, CIN II with regressive course, CIN II with progressive course, CIN III). The median numbers were calculated for each slide and correlated with the histological CIN grade. Statistical analysis was performed by SPSS 26 (Mann-Whitney U test, Spearman's rank correlation).

RESULTS

An increased FoxP3 expression in CIN II with progression could be detected in comparison to CIN II with regression (p = 0.003). Total FoxP3 expression (epithelium and dysplasia-connected stroma) was higher in more advanced CIN grades (p < 0.001 for CIN I vs. CIN II; p = 0.227 for CIN II vs. CIN III). A positive correlation could be detected between FoxP3-positive cells in epithelium and total FoxP3 expression (Spearman's Rho: 0,565; p < 0.01).

CONCLUSION

Expression of FoxP3 could be a helpful predictive factor to assess the risks of CIN II progression. As a prognosticator for regression and progression in cervical intraepithelial lesions it might thereby help in the decision process regarding surgical treatment vs. watchful waiting strategy to prevent conisation-associated risks for patients in child-bearing age. In addition, the findings support the potential of Tregs as a target for immune therapy in cervical cancer patients.

Prognostic and predictive significance of the tumor microenvironment in hepatocellular carcinoma

BACKGROUND

Identification of molecular markers that reflect the characteristics of the tumor microenvironment (TME) may be beneficial to predict the prognosis of post-operative hepatocellular carcinoma (HCC) patients.

OBJECTIVE AND METHODS

A total of 100 tissue samples from HCC patients were separately stained by immunohistochemistry to examine the expression levels of CD56, CD8α, CD68, FoxP3, CD31 and pan-Keratin. The prognostic values were analyzed by Cox regression and the Kaplan-Meier method.

RESULTS

Univariate and multivariate logistic analysis showed that FoxP3 was the independent factor associated with microvascular invasion (MVI), tumor size and envelop invasion; CD68 was associated with envelope invasion and AFP. Kaplan-Meier survival curves revealed that CD68 and FoxP3 expression were significantly associated with relapse free survival (RFS) of HCC patients (P< 0.05). The ROC curve indicated that the combination of tumor number, MVI present and CD68 expression yielded a ROC curve area of 82.3% (86.36% specificity, 68.75% sensitivity) to evaluate the prognosis of HCC patients, which was higher than the classifier established by the combination of tumor number and MVI (78.8% probability, 63.64% specificity and 85.42% sensitivity).

CONCLUSIONS

Our study indicated that CD68 and FoxP3 are associated with prognosis of HCC patients, and CD68 can be considered as a potential prognostic and predictive biomarker.

Transcriptional Profiling of Monocytes Deficient in Nuclear Orphan Receptors NR4A2 and NR4A3 Reveals Distinct Signalling Roles Related to Antigen Presentation and Viral Response

The nuclear receptor sub-family 4 group A (NR4A) family are early response genes that encode proteins that are activated in several tissues/cells in response to a variety of stressors. The NR4A family comprises NR4A1, NR4A2 and NR4A3 of which NR4A2 and NR4A3 are under researched and less understood, particularly in the context of immune cells. NR4A expression is associated with multiple diseases e.g. arthritis and atherosclerosis and the development of NR4A-targetting molecules as therapeutics is a current focus in this research field. Here, we use a combination of RNA-sequencing coupled with strategic bioinformatic analysis to investigate the down-stream effects of NR4A2 and NR4A3 in monocytes and dissect their common and distinct signalling roles. Our data reveals that NR4A2 and NR4A3 depletion has a robust and broad-reaching effect on transcription in both the unstimulated state and in the presence of LPS. Interestingly, many of the genes affected were present in both the unstimulated and stimulated states revealing a previously unappreciated role for the NR4As in unstimulated cells. Strategic clustering and bioinformatic analysis identified both distinct and common transcriptional roles for NR4A2 and NR4A3 in monocytes. NR4A2 notably was linked by both bioinformatic clustering analysis and transcription factor interactome analysis to pathways associated with antigen presentation and regulation of MHC genes. NR4A3 in contrast was more closely linked to pathways associated with viral response. Functional studies further support our data analysis pointing towards preferential/selective roles for NR4A2 in the regulation of antigen processing with common roles for NR4A2 and NR4A3 evident with respect to cell migration. Taken together this study provides novel mechanistic insights into the role of the enigmatic nuclear receptors NR4A2 and NR4A3 in monocytes.

Sevoflurane represses the migration and invasion of gastric cancer cells by regulating forkhead box protein 3

Objective

Previous studies suggested that sevoflurane exerts anti-proliferative, anti-migratory, and anti-invasive effects on cancer cells. To determine the role of sevoflurane on gastric cancer (GC) progression, we evaluated its effects on the proliferation, migration, and invasion of SGC7901, AGS, and MGC803 GC cells.

Methods

GC cells were exposed to different concentrations of sevoflurane (1.7, 3.4, or 5.1% v/v). Cell viability, migration, and invasion were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell assays. Immunohistochemical staining and immunoblotting were performed to analyze forkhead box protein 3 (FOXP3) protein expression in tissue specimens and cell lines, respectively.

Results

FOXP3 was downregulated in human GC specimens and cell lines. Functionally, FOXP3 overexpression significantly inhibited the proliferation, migration, and invasion of GC cells and accelerated their apoptosis. Moreover, sevoflurane significantly blocked GC cell migration and invasion compared with the findings in the control group. However, FOXP3 silencing neutralized sevoflurane-induced apoptosis and the inhibition of GC cell migration and invasion. Sevoflurane-induced apoptosis and the suppression of migration and invasion might be associated with FOXP3 overactivation in GC cells.

Conclusions

Sevoflurane activated FOXP3 and prevented GC progression via inhibiting cell migration and invasion in vitro.

Identification of Biomarkers Based on Bioinformatics Analysis: The Expression of Ubiquitin-Conjugating Enzyme E2T (UBE2T) in the Carcinogenesis and Progression of Hepatocellular Carcinoma

BACKGROUND The purpose of this study was to screen and identify key genes in the occurrence and development of hepatocellular carcinoma (HCC) based on bioinformatics analysis. MATERIAL AND METHODS Three Gene Expression Omnibus (GEO) series (GSE) - GSE121248, GSE87630, and GSE84598 - were downloaded from the GEO database. GEO2R was used to screen different genes and a Venn diagram was drawn to screen coexpressed differentially expressed genes (DEGs). Coexpressed DEGs were obtained by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, a protein-protein interaction network diagram was produced by Cytoscape, and module genes were calculated by the Molecular Complex Detection Cytoscape plug-in. Finally, overall survival, progression-free survival, and relapse-free survival analysis of the key genes selected were performed using the online Kaplan-Meier plotter. For the target genes, the online network UCSC Cancer Genome Browser was used to analyze the gene expression profiles of the grade and vascular invasion of HCC. RESULTS A total of 296 coexpressed DEGs were obtained from the 3 GSEs and 12 key genes were obtained from the modular analysis. Survival analysis showed that the upregulated genes UBE2T and FBLN5 were involved in the poor prognosis of HCC. Furthermore, the expression of UBE2T was significantly related to the grade and vascular invasion of HCC. CONCLUSIONS The expression of the UBE2T gene was significantly upregulated in HCC tissue compared to in normal liver tissue. UBE2T may be a new marker for the diagnosis and subsequent therapy of HCC.

Identification of an immune overdrive high-risk subpopulation with aberrant expression of FOXP3 and CTLA4 in colorectal cancer

Colorectal cancer (CRC) is characterized by a heterogeneous tumor microenvironment (TME) that regulates cancer progression and therapeutic response. Overexpression of FOXP3 and CTLA4 is associated with immunosuppressive TME and poor prognosis in many cancer types. However, opposite results were reported in CRC. Thus, we performed comprehensive analyses to evaluate the exact prognostic value of FOXP3 and CTLA4 in CRC. Here, the expression levels of FOXP3 and CTLA4 were used to construct a subtyping system based on >1200 CRC patients from multiple independent public datasets. We revealed that, in CRC patients with relatively high expression of FOXP3, there exist two different subpopulations with opposite survival patterns according to CLTA4 expression. We further established a method for evaluating all cohorts and identified a novel FOXP3^HighCTLA4^High* CRC risk subpopulation that accounts for 5-10% of CRC patients. Moreover, different methods of functional enrichment and immune evaluation were used to analyze the TME characteristics of different FOXP3/CTLA4 subtypes. The FOXP3^HighCTLA4^High* CRC risk subpopulation was characterized by an immune overdrive TME phenotype, including high immune cell infiltration, low tumor purity, high immune checkpoint levels, and TGF-β activation. Finally, the constructed FOXP3/CTLA4 subtyping system was further validated by quantitative RT-PCR, immunochemistry staining, and multicolor immunofluorescence in an independent CRC cohort we collected. This high-risk subpopulation was also observed in kidney cancers and low-grade glioma patients by a Pan-cancer analysis. Together, our study revealed that the established FOXP3/CTLA4 molecular subtyping system could be used to select treatment and management strategies for CRC and other cancers.

Searching for Peptide Inhibitors of T Regulatory Cell Activity by Targeting Specific Domains of FOXP3 Transcription Factor

(1) Background: The ability of cancer cells to evade the immune system is due in part to their capacity to induce and recruit T regulatory cells (Tregs) to the tumor microenvironment. Strategies proposed to improve antitumor immunity by depleting Tregs generally lack specificity and raise the possibility of autoimmunity. Therefore, we propose to control Tregs by their functional inactivation rather than depletion. Tregs are characterized by the expression of the Forkhead box protein 3 (FOXP3) transcription factor, which is considered their “master regulator”. Its interaction with DNA is assisted primarily by its interaction with other proteins in the so-called “Foxp3 interactome”, which elicits much of the characteristic Treg cell transcriptional signature. We speculated that the disruption of such a protein complex by using synthetic peptides able to bind Foxp3 might have an impact on the functionality of Treg cells and thus have a therapeutic potential in cancer treatment. (2) Methods: By using a phage-displayed peptide library, or short synthetic peptides encompassing Foxp3 fragments, or by studying the crystal structure of the Foxp3:NFAT complex, we have identified a series of peptides that are able to bind Foxp3 and inhibit Treg activity. (3) Results: We identified some peptides encompassing fragments of the leuzin zipper or the C terminal domain of Foxp3 with the capacity to inhibit Treg activity in vitro. The acetylation/amidation of linear peptides, head-to-tail cyclization, the incorporation of non-natural aminoacids, or the incorporation of cell-penetrating peptide motifs increased in some cases the Foxp3 binding capacity and Treg inhibitory activity of the identified peptides. Some of them have shown antitumoral activity in vivo. (4) Conclusions: Synthetic peptides constitute an alternative to inhibit Foxp3 protein–protein interactions intracellularly and impair Treg immunosuppressive activity. These peptides might be considered as potential hit compounds on the design of new immunotherapeutic approaches against cancer.

Nuclear FOXP3 inhibits tumor growth and induced apoptosis in hepatocellular carcinoma by targeting c-Myc

The status of FOXP3 and its isoforms in hepatocellular carcinoma (HCC) is unclear. We aimed to investigate the expression and function of FOXP3 and its isoforms in HCC. The study was performed on 84 HCC patients, HCC cell lines and a mouse tumor model. The levels of FOXP3 and its isoforms were determined by nested PCR, quantitative real-time PCR and immunohistochemistry (IHC) staining. The correlation between their levels and clinicopathologic characteristics was analyzed. The full length of FOXP3 (FOXP3) and exon 3-deleted FOXP3 (FOXP3Δ3) were found to be the major isoforms in HCC. The levels of FOXP3Δ3 mRNA and protein in HCC tumor samples were not significantly different from their adjacent normal tissues. The high expression of FOXP3 protein in HCC patients showed a good overall survival. The overexpression of FOXP3 significantly reduced tumor cell proliferation, migration and invasion. The immunofluorescence result indicated that FOXP3 needed to be translocated into the nucleus to exert its inhibitory function. The luciferase assay demonstrated that FOXP3 could be synergistic with Smad2/3/4 to inhibit the oncogene c-Myc. The co-immunoprecipitation results further revealed that FOXP3 could interact with Smad2/3/4. The chromatin immunoprecipitation (ChIP) assay showed that both FOXP3 and Smad2/3/4 bound the promoter of the c-Myc to inhibit it. The in vivo mouse tumor model study confirmed the inhibitory effect of FOXP3. Collectively, the expression of tumor FOXP3 can inhibit the growth of HCC via suppressing c-Myc directly or indirectly via interacting with Smad2/3/4. Therefore, FOXP3 is a tumor suppressor in HCC.

PRELP has prognostic value and regulates cell proliferation and migration in hepatocellular carcinoma

Purpose: Hepatocellular carcinoma (HCC) is an aggressive and prevalent tumor threatening human health. A previous study suggested low PRELP (proline/arginine-rich end leucine-rich repeat protein) expression was associated with poor patient survival in pancreatic ductal adenocarcinoma (PDAC). However, the role of PRELP in HCC has not yet been illuminated. Methods: PRELP expression analyses were carried out using transcriptomic datasets from the Integrative Molecular Database of Hepatocellular Carcinoma (HCCDB). The correlations between PRELP expression and clinicopathological features, and prognostic analyses were performed with a tissue microarray (TMA) and immunohistochemistry (IHC). The endogenous expression and in vitro roles of PRELP were investigated in cultured HCC cell lines. The potential mechanisms were characterized by a Gene Set Enrichment Analysis (GSEA) and gene-gene correlation analyses. Results: We found that PRELP mRNA expression was dramatically decreased in HCCs in comparison with that in adjacent normal tissues (NTs) or hepatic cirrhosis. IHC staining showed that PRELP was down-regulated in HCCs, which mainly located in cytoplasm, and was also found in nuclei. The correlation analyses revealed that PRELP expression was relevant to later p-stages (p= 0.028) and tumor size (p= 0.001). The overall survival (OS) and relapse free survival (RFS) time was shorter in HCC patients with lower PRELP expression levels than that with higher PRELP expression levels. Overexpression of PRELP inhibited, while knockdown of PRELP promoted proliferation and migration of HCC cells. For potential mechanisms, PRELP may inhibit progression of HCCs by interacting with integrin family members and the extracellular microenvironment. Conclusion: Our findings demonstrated that overexpression of PRELP correlates with better patient survival and inhibits both cell proliferation and migration in HCC. Therefore, PRELP can serve as a potential prognostic biomarker and therapeutic target which deserves further investigation.

Prognostic value of immunological profile based on CD8+ and FoxP3+ T lymphocytes in the peritumoral and intratumoral subsites for renal cell carcinoma

PURPOSE

We aimed to assess an "Immunological Profile (IP)" including CD8+ and FoxP3+ T lymphocytes for renal cell carcinoma (RCC) to evaluate its effects on tumor pathological characteristics, disease progression, and survival.

METHODS

Adjacent normal and intratumoral specimens from 42 patients who had undergone radical nephrectomy for RCC were analyzed for counts of CD8+ and FoxP3+ T lymphocytes by immunohistochemistry. Tissue from both sites were evaluated and scored separately according to low (0) or high (1) expression of CD8 and FoxP3. A total score (min: 0, max: 4) was assigned to each patient. Thereafter, patients were divided into two groups for clinicopathologic and survival stratification based on score (IP_Weak 0-2; and IP_Strong 3-4). Survival curves were constructed using the Kaplan-Meier method, and a multivariable Cox regression model was used for overall survival (OS) and progression-free survival (PFS).

RESULTS

The mean follow-up was 54.73 ± 21.34 months. Poor RCC characteristics including pT3-T4, tumor necrosis, lymphovascular invasion, lymph node involvement, and larger tumor size were significantly more common in the IP_Weak patients compared to IP_Strong (p < 0.05). Kaplan-Meier analysis showed that IP_Weak patients had worse OS (62.5 vs. 100%; p = 0.006) and PFS (50 vs. 94.4%; p = 0.002) compared to IP_Strong patients. In multivariable analysis, IP_Weak (HR 8.64; 95% CI 1.09-68.05, p = 0.042) and high tumor node metastasis stage (HR 45.33; 95% CI 4.69-437.68, p < 0.001) were significant independent predictors of poor PFS.

CONCLUSION

Assessment of IP including CD8+ and FoxP3+ T lymphocytes in adjacent normal and intratumoral sites in RCC may serve as a good predictive marker for PFS.

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.

FOXP3 promotes colorectal carcinoma liver metastases by evaluating MMP9 expression via regulating S-adenosylmethionine metabolism

Background

Growing evidence has proved that Forkhead box protein 3 (FOXP3), which is a master regulatory gene in the development and function of regulatory T-cells, is expressed in human cancer cells. This expression indicates the crucial role FOXP3 takes up as the disease progresses. However, its role in colorectal cancer (CRC) liver metastasis is still mostly unknown. This study set out to explore the molecular characteristics of FOXP3 in driving the liver metastasis within CRC.

Methods

We downloaded the RNA-seq data from the GSE50760. Weighted gene co-expression network analysis (WGCNA)WGCNA and RNA-Seq analysis were applied to find the key gene network associated with colorectal cancer liver metastasis. Then we performed pathway enrichment analysis on liver metastasis-associated gene set. Immunohistochemistry, in vitro and in vivo studies were conducted to test expression and function of FOXP3 in CRC tissues and liver metastasis tissues. Non-targeted metabolomics analysis was performed to identify the alteration of FOXP3 expression in metabolites of colorectal cancer liver metastasis. Western blot was performed to confirm changes of matrix metalloproteinase 9MMP9 expression were downstream events of S-adenosyl-methionine (SAM).

Results

We found that FOXP3 and MMP9 exhibited co-expression relationships and affected liver metastasis in CRC. Upregulation of FOXP3 promotes cell migration and invasion in CRC, which suggests a pro-cancer effect. Moreover, metabolomics analysis showed that knockdown of FOXP3 significantly reduced SAM levels, and changes of MMP9 expression were downstream events of SAM, which is concentration-dependent. Besides, The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Western blot analysis confirmed that overexpression of FOXP3 activates the Wnt pathway to promote colon cancer metastasis.

Conclusions

Our results altogether suggested that FOXP3 expression inhibited the SAM cycle to reduce SAMe levels, resulting in altered MMP9 expression and helped CRC liver metastasis.

Further Study of Circulating Antibodies to P16, CD25 and FOXP3 in Hepatocellular Carcinoma

Purpose

It has been reported that circulating levels of IgG antibodies against p16, CD25 and FOXP3 proteins were significantly changed in patients with lung cancer, breast cancer and esophageal cancer. However, different peptide fragments appear to trigger different immune responses. This work aimed to analyze the alteration of plasma IgG for p16-derived peptide antigen called p16a, CD25-derived peptide antigen called CD25a and a FOXP3-derived antigen in hepatocellular carcinoma (HCC).

Patients and methods

An enzyme-linked immunosorbent assay (ELISA) was developed in-house to detect plasma IgG to p16a, CD25a and FOXP3 in 119 patients with HCC and 132 control subjects.

Results

Circulating levels of IgG antibodies for all three peptide antigens were significantly higher in HCC patients than control subjects (P<0.001 for all 3 assays); male patients mainly contributed to increase (P<0.01 for all 3 assays). Further analysis showed that plasma anti-p16a, anti-CD25a and anti-FOXP3 IgG levels were increased mainly in patients with intermediate and late-stage HCC (P<0.01 for both assays). Receiver operating characteristic (ROC) curve analysis showed that with a specificity of >95%, the area under the ROC curve (AUC) was 0.62 with 11.4% sensitivity for anti-p16a assay, 0.68 with 14.3% sensitivity for anti-CD25a IgG assay and 0.64 with 10.1% sensitivity for anti-FOXP3 assay. Of the three groups of HCC patients, group 3 (BCLC stage C+D) showed the best sensitivity for the detection of plasma anti-p16a and anti-FOXP3 IgG levels with an AUC of 0.66 and 0.65.

Conclusion

Circulating IgG antibody to p16a, CD25a and FOXP3 proteins may be a useful biomarker for assessment of HCC prognosis of this malignancy, especially in male patients with HCC.

TAFA5 promotes proliferation and migration in gastric cancer

TAFA chemokine like family member 5 (TAFA5), a TAFA family member that encodes small secreted proteins in the central nervous system, has been demonstrated to have increased expression in human malignancies. However, the expression and function of TAFA5 in gastric cancer (GC) remains unclear. In the present study, public datasets and human GC samples were used to determine the TAFA5 expression levels. The results revealed that TAFA5 was upregulated in GC when compared with adjacent normal tissues. Overexpression of TAFA5 in GC was associated with poor differentiation, and worse tumor, nodal and metastasis stages. In addition, high TAFA5 expression was correlated with unfavorable patient prognoses. In vitro experiments indicated that downregulation of TAFA5 inhibited the proliferation and migration of GC cell lines. Finally, the results from gene set enrichment analysis using data from The Cancer Genome Atlas revealed that TAFA5 expression was significantly correlated with genes associated with epithelial-mesenchymal transition, which was further confirmed by western blot analysis. In conclusion, the results of the present study suggested that TAFA5 had significant effects on GC progression, suggesting that it may serve as a potential therapeutic target for GC therapy.

Downregulation of FOXP3 in neutrophils by IL-8 promotes the progression of oral squamous cell carcinoma

The aim of the present study was to investigate the effects of the transcription factor forkhead box P3 (FOXP3) in neutrophils on the progression of oral squamous cell carcinoma (OSCC). Cancer tissue samples and paracarcinoma tissues were collected from 23 patients with OSCC for the current study. In addition, SCC-9, a human tongue carcinoma cell line, was co-cultured with primary human neutrophils and treated with recombinant interleukin 8 (IL-8). The effect of FOXP3 on the proliferation of SCC-9 cells was analyzed using a Cell Counting Kit 8 assay. FOXP3 expression in neutrophils was analyzed by quantitative PCR following IL-8 treatment. FOXP3 protein expression in neutrophils and the amount of IL-8 protein in the OSCC tumor microenvironment were determined by immunofluorescence analysis. The present study demonstrated that IL-8 downregulated FOXP3 mRNA expression in neutrophils. Neutrophils and peptide P60, a specific inhibitor of FOXP3, increased proliferation of SCC-9 cells. In patients with OSCC, FOXP3 protein expression in neutrophils of the stage IV group was significantly lower compared with that of the stage II and stage III groups, while IL-8 protein expression was higher in cancer tissues compared with that in paracarcinoma tissues. In summary, IL-8 in the tumor microenvironment may recruit neutrophils, and downregulation of FOXP3 in neutrophils by IL-8 may promote the progression of OSCC.

Overexpression of CPXM2 predicts an unfavorable prognosis and promotes the proliferation and migration of gastric cancer

Carboxypeptidase X, M14 family member 2 (CPXM2), has been associated with several human disorders such as developmental diseases. However, whether CPXM2 is involved in oncogenesis or tumor progression remains unclear. In the present study, we used clinical samples from gastric cancer (GC) patients to investigate potential roles of CPXM2 in GC. We also analyzed datasets from the Oncomine database, The Cancer Genome Atlas (TCGA), and the Kaplan‑Meier Plotter to validate these results. We found that CPXM2 was overexpressed in GC and that the overexpression was associated with an unfavorable prognosis, regardless of the Lauren classification and tumor node metastasis staging. In addition, knockdown of CPXM2 in cultured GC cells significantly impeded cell proliferation and migration, as indicated by the cholecystokinin octapeptide, colony formation assay, scratch wound healing assay, and Transwell® migration assay. Furthermore, gene set enrichment analysis using RNA‑seq data from TCGA indicated that high CPXM2 expression in GC patients was positively correlated with the HALLMARK_APICAL_JUNCTION and HALLMARK_EPITHELIAL_MESENCHYMAL_TRANSITION gene sets. Finally, western blotting results revealed that several key molecules involved in the epithelial mesenchymal transition were regulated by CPXM2. Taken together, these results imply an active role for CPXM2 in promoting tumor aggressiveness via epithelial to mesenchymal transition (EMT) modulation in GCs.

Forkhead box P3 gene silencing inhibits the expression of chemokines and chemokine receptors associated with cell growth, migration, and apoptosis in hepatocellular carcinoma cells

The aberrant expression of forkhead box P3 (FOXP3) leads to the formation of malignant tumors. FOXP3 expression levels are also elevated in hepatocellular carcinoma (HCC). The aim of the present study was to investigate the effects of FOXP3 silencing on cell proliferation, migration, apoptosis and chemokine/chemokine receptor expression in the MHCC-97H HCC cell line. Three FOXP3 short hairpin (sh)RNA constructs were designed: Sh-FOXP3-1-pGreenPuro, sh-FOXP3-2-pGreenPuro, and sh-FOXP3-3-pGreenPuro. MHCC-97H cells were transfected with shRNA-FOXP3, and the mRNA and protein expression levels of C-X-C motif chemokine (CXC) ligand 12 (CXCL12), CXCL11, CXC receptor 4 (CXCR4) and CXCR7 were measured. Cell Counting Kit-8, terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling and Transwell assays were used to evaluate cell proliferation, apoptosis and migration, respectively. Of the three FOXP3 lentivirus carriers constructed, sh-FOXP3-1 significantly reduced FOXP3 expression levels and was chosen for further experiments. sh-FOXP3-1 inhibited cell proliferation, promoted apoptosis and inhibited cell migration compared with the negative control. The mRNA and protein expression levels of CXCL12, CXCL11, CXCR4 and CXCR7 were decreased significantly in response to FOXP3 silencing. FOXP3 silencing may therefore inhibit cell growth, induce apoptosis and inhibit migration in HCC cells, possibly by impairing the chemokine/chemokine receptor axes.

Gene profiling of HepG2 cells following nitidine chloride treatment: An investigation with microarray and Connectivity Mapping

Nitidine chloride (NC), an inartificial bioactive alkaloid present in the root of Zanthoxylum nitidum (Roxb.) DC, is known for its versatile anti‑inflammation and anticancer capabilities. The molecular mechanisms underlying its anticancer properties, however, remain obscure. The authors of the present study demonstrated the tumor suppressive effects of NC in a human liver cancer cell line using an MTT assay. The tumor suppressive capacity of NC was also analysed in a tumor xenograft nude mouse model. Changes in tumor cell gene expression profiles following NC treatment were detected by microarray; bioinformatics analysis demonstrated that differentially expressed genes were enriched in several cancer‑associated pathways, including those initiated by transforming growth factor‑β and phosphatidylinositol 4,5‑bisphosphate 3‑kinase/RAC‑α serine/threonine‑protein kinase signaling. A Connectivity Map revealed that parthenolide, which has been identified previously as possessing anti‑inflammatory and anticancer functions, was potentially extremely similar in molecular function to NC. By screening the data from The Cancer Genome Atlas project, eight genes that were upregulated in liver cancer and significantly suppressed by NC treatment were identified. Overexpression of these genes was closely associated with advanced tumor stage and poor differentiation status. This combination of upregulated genes enabled successful identification and prediction of prognosis for liver cancer. The findings of the present study suggest that NC could inhibit the growth of liver cancer cells through several potential molecular targets and signaling pathways.

Upregulation of FoxP4 in HCC promotes migration and invasion through regulation of EMT

Previous studies have indicated that FoxP1, FoxP2 and FoxP3 play important roles in hepatocellular carcinoma (HCC). However, the effect of FoxP4 in HCC requires further elucidation. The aim of the present study was to explore the roles of FoxP4 in HCC and further decipher the detailed mechanism. In present study, it was found that FoxP4, which is overexpressed in HCC tissues and cell lines, facilitated EMT in HCC cell lines through regulation of Slug. First, increased expression of FoxP4 was identified in 110 pairs of human HCC tumor and their adjacent normal tissues. In addition, the association between FoxP4 expression and clinicopathological features of HCC patients indicated that FoxP4 played vital roles in HCC development. Subsequently, gain- and loss-of-function experiments indicated that FoxP4 promoted cellular proliferation, migration as well invasion. In addition, EMT, a key mechanism during cancer metastasis, was regulated by FoxP4. Furthermore, ChIP and qChIP as well as luciferase reporter assays indicated that Slug, an EMT-associated transcription factor, was transcriptionally regulated by FoxP4. In conclusion, FoxP4 functioned as a tumor promoter in HCC cells by transcriptionally regulating Slug, and the present study highlighted the potential effects of FoxP4 on the prognosis and treatment of HCC.

The intricate role of miR-155 in carcinogenesis: potential implications for esophageal cancer research

MiRNAs have immerged as essential modulators of key cellular procuresses involved in post-transcriptional regulation of the human transcriptome. They are essential components of complex regulatory networks that modulate most important physiological functions of cells. MicroRNA-155 (miR-155) is a multifaceted regulator of cell proliferation, cell cycle, development, immunity and inflammation that plays pivotal, and sometimes contradictory, roles in numerous cancers including esophageal cancer. Here, we review the intricate role of miR-155 in cancer by exemplifying carcinogenesis of various tumors, focusing on recent findings that may provide a link between miR-155 and esophageal cancer-related pathways.

The expression of FOXP3 and its role in human cancers

FOXP3 is a transcription factor, which belongs to the family of FOX protein. FOXP3 was initially discovered in regulatory T cells and supposed to play a significant role in the process of regulatory T cell differentiation. Increasing evidence has shown that FOXP3 is also expressed in tumor cells. However, the results of tumor FOXP3 is inconsistent and even the opposite. In some types of human cancers, the expression of FOXP3 is upregulated, and it can promote the development of cancers, leading to a poor prognosis. While in some other types of cancers, it is a different story. The reason for the contradictory data is unknown. The discovery of FOXP3 isoforms, interaction between tumor cells and lymphocytes in the tumor microenvironment, subcellular location, and mutation of FOXP3 may provide some clues. In this review, we first summarize and analyze the recent development. The final section focuses on the regulation of FOXP3 expression.