FOXP1 Expression Research Articles

Expression and prognostic value of FOXP1 in esophageal squamous cell carcinoma

BackgroundForkhead box protein P1 (FOXP1) has been suggested as a prognostic marker in several malignant tumors. However, the significance of FOXP1 in esophageal squamous cell carcinoma (ESCC) is still unclear. The purpose of this study was to investigate the expression pattern of FOXP1 in normal esophageal tissue and ESCC and to analyze the clinicopathological significance and prognostic value of FOXP1 in ESCC. MethodsFOXP1 was detected by immunohistochemistry using tissue microarrays containing tumor tissues and adjacent normal tissues from 270 ESCC patients with oncological follow-up data. ResultsNormal esophageal tissues predominantly showed an exclusive nuclear FOXP1 (n-FOXP1) expression pattern, and no exclusive cytoplasmic FOXP1 (c-FOXP1) staining was found. In ESCC, the expression rates of exclusive n-FOXP1-positive, exclusive c-FOXP1-positive, both nuclear and cytoplasmic positive and complete negative were 14.4%, 28.9%, 10.4% and 46.3%, respectively. High n-FOXP1 expression was significantly correlated with decreased postoperative recurrence and distant metastasis (P < 0.05). Furthermore, elevated c-FOXP1 expression was significantly associated with regional lymph node metastasis and distant metastasis (P < 0.05). High c-FOXP1 expression had an effect on shorter overall survival (OS) time, but the difference was not statistically significant (P > 0.05). Kaplan–Meier analysis showed that ESCC patients with high n-FOXP1 expression survived significantly longer than patients with low n-FOXP1 expression. Multivariate analysis confirmed that patients with high n-FOXP1 staining exhibit good prognosis and n-FOXP1 was an independent factor for ESCC prognosis. ConclusionsOur results suggest that FOXP1 plays an essential role in ESCC progression and prognosis and may be a useful biomarker for predicting survival.

Differential Song Deficits after Lentivirus-Mediated Knockdown of FoxP1, FoxP2, or FoxP4 in Area X of Juvenile Zebra Finches.

Mutations in the transcription factors FOXP1 and FOXP2 are associated with speech impairments. FOXP1 is additionally linked to cognitive deficits, as is FOXP4. These FoxP proteins are highly conserved in vertebrates and expressed in comparable brain regions, including the striatum. In male zebra finches, experimental manipulation of FoxP2 in Area X, a striatal song nucleus essential for vocal production learning, affects song development, adult song production, dendritic spine density, and dopamine-regulated synaptic transmission of striatal neurons. We previously showed that, in the majority of Area X neurons FoxP1, FoxP2, and FoxP4 are coexpressed, can dimerize and multimerize with each other and differentially regulate the expression of target genes. These findings raise the possibility that FoxP1, FoxP2, and FoxP4 (FoxP1/2/4) affect neural function differently and in turn vocal learning. To address this directly, we downregulated FoxP1 or FoxP4 in Area X of juvenile zebra finches and compared the resulting song phenotypes with the previously described inaccurate and incomplete song learning after FoxP2 knockdown. We found that experimental downregulation of FoxP1 and FoxP4 led to impaired song learning with partly similar features as those reported for FoxP2 knockdowns. However, there were also specific differences between the groups, leading us to suggest that specific features of the song are differentially impacted by developmental manipulations of FoxP1/2/4 expression in Area X.SIGNIFICANCE STATEMENT We compared the effects of experimentally reduced expression of the transcription factors FoxP1, FoxP2, and FoxP4 in a striatal song nucleus, Area X, on vocal production learning in juvenile male zebra finches. We show, for the first time, that these temporally and spatially precise manipulations of the three FoxPs affect spectral and temporal song features differentially. This is important because it raises the possibility that the different FoxPs control different aspects of vocal learning through combinatorial gene expression or by acting in different microcircuits within Area X. These results are consistent with the deleterious effects of human FOXP1 and FOXP2 mutations on speech and language and add FOXP4 as a possible candidate gene for vocal disorders.

Down-regulated microRNA-183 mediates the Jak/Stat signaling pathway to attenuate hippocampal neuron injury in epilepsy rats by targeting Foxp1

ABSTRACT Recently, the impacts of microRNAs (miRNAs) have been identified in epilepsy (EP), this study was designed to assess the role of miR-183 in hippocampal neuron injury in EP. Rat EP models were established by injected with lithium-pilocarpine. The pathological observation of rats’ hippocampus sections was conducted. Expression of miR-183, Foxp1, Jak1, Stat1, and Stat3 in rats’ hippocampal tissues was determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. The proliferation ability and the apoptosis of the rats’ neurons were measured. Furthermore, the target relation between miR-183 and Foxp1 was determined by bioinformatics analysis and dual-luciferase gene reporter assay. The levels of miR-183, Jak1, Stat1, and Stat3 were elevated, and the expression of Foxp1 was declined in EP rats’ hippocampal tissues. Inhibited miR-183 could up-regulate Foxp1, inhibited miR-183 together with up-regulated Foxp1 could repress hippocampal neuron injury, promote neuron proliferation, suppress neuron apoptosis, and inactivate the Jak/Stat signaling pathway, resulting in an attenuation of EP progression. Moreover, down-regulated Foxp1 could reverse the attenuation of EP progression which was contributed by inhibited miR-183. Our study implies that inhibited miR-183 could up-regulate Foxp1, resulting in an inactivation of the Jak/Stat signaling pathway and promotion of neuron proliferation, as well as inhibition of apoptosis of hippocampal neurons in EP rats, by which the hippocampal neuron injury and EP progression could be repressed.

MicroRNA-92a regulates the development of cutaneous malignant melanoma by mediating FOXP1.

MicroRNAs are noncoding RNAs which are involved in the occurrence and progression of tumors. This study aims to explore the role of microRNA-92a in cutaneous malignant melanoma (CMM) and its underlying mechanism. The expression level of microRNA-92a in 75 pairs of CMM tissues and paracancerous tissues was determined using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The correlation between microRNA-92a expression with clinical data of CMM patients was analyzed. Besides, microRNA-92a expression in CMM cells and primary epidermal melanocytes (PEM) was determined by qRT-PCR as well. After transfection of si-microRNA-92a in CMM cells, biological performances of CMM were determined using cell counting kit-8 (CCK-8), colony formation and transwell assay, respectively. FOXP1 expression in CMM cells and tissues was determined using Western blot. Kaplan-Meier survival curves were drawn to explore the correlation between the FOXP1 expression and prognosis of CMM patients. MicroRNA-92a was highly expressed in CMM tissues compared with that of paracancerous tissues. Compared with CMM patients with lower expression of microRNA-92a, those with higher expression of microRNA-92a presented higher tumor stage, higher incidences of lymph node metastasis and distant metastasis, as well as lower overall survival. The knockdown of microRNA-92a remarkably decreased proliferative, invasive and metastatic capacities of CMM cells. Western blot results elucidated that microRNA-92a knockdown in CMM cells upregulates FOXP1 expression. Additionally, rescue experiments showed that mi-croRNA-92a regulates biological performances of CMM cells by regulating FOXP1. MicroRNA-92a is highly expressed in CMM, which is remarkably correlated to tumor stage and poor prognosis of CMM patients. We found that microRNA-92a pro-motes malignant progression of CMM by regulating FOXP1.

Endothelial Foxp1 Suppresses Atherosclerosis via Modulation of Nlrp3 Inflammasome Activation

Endothelial dysfunction results in sustained and chronic vascular inflammation, which is central to atherosclerotic diseases. However, transcriptional regulation of vascular endothelial inflammation has not been well clarified. This study aims to explore Foxp (forkhead box P) transcription factor 1 in regulation of endothelial homeostasis, atherogenesis, and its mechanisms. To assess the importance of Foxp1 in atherosclerosis, Foxp1 expression was analyzed in human coronary artery and mouse artery, and we observed significant downregulation of Foxp1 in atherosclerotic and atherosusceptible endothelium. Endothelial-specific Foxp1 knockout mice (Foxp1ECKO) were bred onto ApoeKO mice to generate endothelial Foxp1-deletion hyperlipidemic model Foxp1ECKO;ApoeKO, which displayed significant increases in atherosclerotic lesion formation in aortas and aortic roots with enhanced monocyte adhesion, migration, and infiltration into the vascular wall and formation of inflammatory lipid-laden macrophages. In contrast, endothelial-specific Foxp1 overexpression mice Foxp1ECTg;ApoeKO exhibited reduced atherosclerotic lesion formation with less monocyte infiltration. Foxp1 was further identified as a gatekeeper of vessel inflammation by direct regulation of endothelial inflammasome components, including Nlrp3 (NLR [nucleotide-binding and leucine-rich repeat immune receptors] family pyrin domain containing 3), caspase-1, and IL (interleukin)-1β. Moreover, endothelial Foxp1 was found to be regulated by Klf2 (Kruppel-like factor 2). Oscillatory shear stress downregulated Foxp1 expression via repressing Klf2 expression in endothelium, and, therefore, promoted endothelial inflammasome activation, leading to atherosclerotic lesion formation. Simvastatin upregulated the reduced expression of Klf2 and Foxp1 in atherosusceptible vascular endothelium and alleviated vascular inflammation contributing to its inhibitory effect in atherosclerosis. These data are the first in vivo experimental validation of an atheroprotective role of endothelial Klf2 and Foxp1, which reveals a Klf2-Foxp1 transcriptional network in endothelial cells as a novel regulator of endothelial inflammasome activation for atherogenesis, therefore, provides opportunities for therapeutic intervention of atherosclerotic diseases and uncovers a novel atheroprotective mechanism for simvastatin.

In This Issue

In This Issue

FOXP1 suppresses the endothelial NLRP3 inflammasome.

The transcription factor FOXP1 downregulates activation of the endothelial NLRP3 inflammasome and suppresses vascular inflammation, protecting against atherosclerosis. Upregulation of FOXP1 expression is a novel anti-atherogenic effect of simvastatin.

Endothelial Forkhead Box Transcription Factor P1 Regulates Pathological Cardiac Remodeling Through Transforming Growth Factor-β1-Endothelin-1 Signal Pathway.

Pathological cardiac fibrosis and hypertrophy, the common features of left ventricular remodeling, often progress to heart failure. Forkhead box transcription factor P1 (Foxp1) in endothelial cells (ECs) has been shown to play an important role in heart development. However, the effect of EC-Foxp1 on pathological cardiac remodeling has not been well clarified. This study aims to determine the role of EC-Foxp1 in pathological cardiac remodeling and the underlying mechanisms. Foxp1 EC-specific loss-of-function and gain-of-function mice were generated, and an angiotensin II infusion or a transverse aortic constriction operation mouse model was used to study the cardiac remodeling mechanisms. Foxp1 downstream target gene transforming growth factor-β1 (TGF-β1) was confirmed by chromatin immunoprecipitation and luciferase assays. Finally, the effects of TGF-β1 blockade on EC-Foxp1 deletion-mediated profibrotic and prohypertrophic phenotypic changes were further confirmed by pharmacological inhibition, more specifically by RGD-peptide magnetic nanoparticle target delivery of TGF-β1-siRNA to ECs. Foxp1 expression is significantly downregulated in cardiac ECs during angiotensin II-induced cardiac remodeling. EC-Foxp1 deletion results in severe cardiac remodeling, including more cardiac fibrosis with myofibroblast formation and extracellular matrix protein production, as well as decompensated cardiac hypertrophy and further exacerbation of cardiac dysfunction on angiotensin II infusion or transverse aortic constriction operation. In contrast, EC-Foxp1 gain of function protects against pathological cardiac remodeling and improves cardiac dysfunction. TGF-β1 signals are identified as Foxp1 direct target genes, and EC-Foxp1 deletion upregulates TGF-β1 signals to promote myofibroblast formation through fibroblast proliferation and transformation, resulting in severe cardiac fibrosis. Moreover, EC-Foxp1 deletion enhances TGF-β1-promoted endothelin-1 expression, which significantly increases cardiomyocyte size and reactivates cardiac fetal genes, leading to pathological cardiac hypertrophy. Correspondingly, these EC-Foxp1 deletion-mediated profibrotic and prohypertrophic phenotypic changes and cardiac dysfunction are normalized by the blockade of TGF-β1 signals through pharmacological inhibition and RGD-peptide magnetic nanoparticle target delivery of TGF-β1-siRNA to ECs. EC-Foxp1 regulates the TGF-β1-endothelin-1 pathway to control pathological cardiac fibrosis and hypertrophy, resulting in cardiac dysfunction. Therefore, targeting the EC-Foxp1-TGF-β1-endothelin-1 pathway might provide a future novel therapy for heart failure.

PF368 DYSREGULATION OF BACH2 AND FOXP1 GENES IN T AND B CELLS IS MORE PRONOUNCED IN CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS COMPARED TO AGED‐MATCHED HEALTHY DONORS WITH AN IMPACT ON SURVIVAL

Background:We previously investigated BACH2/RPDM1 gene expression in B/T cells from chronic lymphocytic leukemia (CLL) patients and aged‐matched healthy donors (HD) to understand the immunosenescence with aging, which showed that BACH2/PRDM1 are strongly correlated with aging. Recent data show that candidate immune suppressor gene FOXP1 is an important regulator of CLL pathogenesisAims:We further investigated the significance of BACH2, PRDM1, FOXP1 and inhibitory molecule expression in T/B cells from CLL patients.Methods:Peripheral blood mononuclear cells were isolated from untreated CLL patients and age‐matched HD using Lymphoprep density gradient centrifugation. T/B cells were purified by magnetic isolation or FACS sorting. BACH2, PRDM1, FOXP1, PD1, PD‐L1 and TIM3 transcripts were quantified using RT‐qPCR. Nuclear labeling of BACH2/PRDM1 and FOXP1 was accomplished using fixed and permeabilized cells, pre‐labeled for membrane markers and acquired by flow cytometry. Prognostic value of BACH2/PRDM1 and FOXP1 expression in purified CD19+ B cells was analyzed retrospectively in a cohort of CLL patients (n = 270), and correlated with clinical parameters.Results:BACH2 gene expression in HDs is significantly downregulated while PRDM1 gene expression increased in T and B cells according to age groups. BACH2 expression is further reduced in T/B cells from CLL patients compared to age‐matched HDs. Also, PRDM1 is significantly upregulated in T cells from CLL patients but not in leukemic‐B cells. We didn’t observe any age‐related changes in FOXP1 expression. However, among BACH2, FOXP1 and PRDM1 protein expression in lymphocytes from CLL patients, we observe a significant increase of BACH2 and FOXP1 protein expression in CD19+ B cells compared to T cell subsets (n = 21). We analyzed PD1, TIM3 transcript/protein expression in T cells and PD‐L1 expression in B cells to evaluate the exhaustion phenotype associated with CLL and aging. This analysis showed us that PD1 expression is significantly upregulated in CD4+/CD8+ T cells in the older vs younger HDs (n = 60) and also in T cells from CLL patients (n = 41) when compared with age‐matched HDs both at transcript and protein level. High PD‐L1 mRNA and protein expression were also strongly correlated with increased age in HD B cells with a further increase detected in leukemic B cells. In addition, we found a strong inverse correlation between BACH2 and PD1 in CD4+/CD8+ T cells; and between BACH2 and PDL1 in CD19+ B cells. TIM3 transcript/protein expression in T cells was very low in CLL patients and not detected in HD T cells. Prognostic value of BACH2/PRDM1 and FOXP1 expression in purified CD19+ B cells was analysed by RT‐qPCR retrospectively in a cohort of CLL patients, and correlated with clinical stage and IGHV mutation status. In this retrospectively analysed CLL cohort, increased BACH2 expression was correlated with improved treatment‐free survival (p = 0.0352). On the contrary, increased FOXP1 expression was correlated with worsened overall survival of CLL patients in the same cohort (p = 0.0165). However, there was no correlation between BACH2/FOXP1 and Binet stage or IGHV mutation status. We didn’t observe any significant correlations with PRDM1 in terms of survival of CLL patients.Summary/Conclusion:The decrease of BACH2 and increase of FOXP1 in leukemic‐B cells impact on CLL patients’ survival. PD1 and PD‐L1 expression in T/B cells from CLL patients and aged‐matched HDs are significantly correlated with aging‐associated exhaustion of immune cells. The role of BACH2 and FOXP1 in tumor microenvironment is thus further investigated.

Prognostic values and clinical implications of programmed cell death-ligand 1 (PD-L1), fork head transcription factor P-1 (FOXP-1) and signal transducer and activator of transcription-3 (STAT-3) expression in diffuse large B-cell lymphoma (DLBCL); an immunohistochemical study

ContextPD-L1 is an inhibitory ligand that functions as an essential immune checkpoint. FOXP-1 is a member of the FOXP family. STAT-3 plays a critical role in regulation of cell proliferation and survival. The detailed expression of the three markers together in DLBCL tissues and their prognostic value in patients with DLBCL were not fully investigated.Aim was to assess the expression of PD-L1, FOXP-1 and STAT-3 in diffuse large B-cell lymphoma (DLBCL) and to correlate their expression with the pathological findings, prognostic parameters and clinical implications of patients.MethodsPD-L1, FOXP-1 and STAT-3 were assessed in DLBCL tissues derived from 50 patients using immunohistochemistry. Patients were followed up for 3 years for response to therapy progression, recurrence and survival.ResultsHigh PD-L1 expression was associated with bone marrow involvement (p = 0.004), extra-nodal involvement (p = 0.006) and advanced stage (p = 0.003). High FOXP-1 expression was associated with presence of bone marrow involvement and high risk group (p < 0.001). High STAT-3 expression was associated with older age of the patient (p < 0.001), presence of bone marrow involvement (p = 0.002), extra-nodal involvement (p = 0.009), and high risk group (p = 0.005). High expression of PD-L1, FOXP-1 and STAT-3 was related to poor response to therapy, poor OS rate and RFS rates (p < 0.001).ConclusionHigh expression of PD-L1, FOXP-1 and STAT-3 was related poor prognosis in DLBCL patients.

The transcription factor Foxp1 regulates the differentiation and function of dendritic cells

Dendritic cells (DCs) are the sentinels of the immune system and play a critical role in initiating adaptive immune responses against pathogens. As the most powerful antigen presenting cells, DCs are also important in maintaining immune homeostasis and participating in the development of autoimmune diseases. How the maturation and function of DCs is regulated in these conditions and what is the function of various transcription factors is still unclear. In this study, we found that the expression of the transcription factor Foxp1 gradually increased during the maturation of DCs. Then, we constructed a recombinant adenovirus carrying Foxp1-interfering RNA (Ad-simFoxp1) and transfected murine bone marrow-derived DCs in vitro. DCs transfected with Ad-simFoxp1 exhibited markedly lower costimulatory molecules, and decreased cytokines. And Ad-simFoxp1 greatly inhibited mature DC-induced T cell responses. Moreover, in vivo infusion with Ad-simFoxp1-modified DCs significantly delayed the onset of experimental autoimmune encephalomyelitis (EAE). Therefore, adoptive transfection of Ad-simFoxp1 in DCs may be a potential treatment strategy against autoimmune diseases.

Evaluation of S1PR1, pSTAT3, S1PR2, and FOXP1 expression in aggressive, mature B cell lymphomas

Aggressive, mature B-cell lymphomas include Burkitt Lymphoma (BL), High Grade B Cell Lymphomas (HGBL) (eg, Double-Hit B cell lymphomas (HGBL-DH: HGBL with MYC and BCL2 and/or BCL6 translocations)), HGBL, Not Otherwise Specified (HGBL, NOS) and Diffuse Large B Cell Lymphoma (DLBCL). Overlapping morphologic and immunohistochemical features of these lymphomas pose diagnostic challenges in some cases, and better understanding of potential diagnostic biomarkers and possible therapeutic targets is needed. Sphingosine 1 Phosphate Receptors (S1PR1-5) are G-protein coupled receptors that bind S1P and influence migration and survival in multiple cell types, including lymphocytes. S1PRs are emerging as biomarkers in B cell biology and interaction between S1PR pathways and STAT3 or FOXP1 has been reported in DLBCL. Our aim was to extend the understanding of S1PR1, STAT3 and S1PR2, FOXP1 expression beyond DLBCL, into additional aggressive, mature B cell lymphomas using immunohistochemical expression analysis of human tissue samples. S1PR1 and S1PR2 showed different expression patterns in mantle zones and follicle centers in reactive lymphoid tissue. BL showed a unique expression pattern compared to HGBL and DLBCL. Additionally, S1PR1 and S1PR2 expression were typically mutually exclusive and were expressed in a low proportion of cases (frequently HGBL involving extranodal sites). FOXP1 was expressed in a high proportion of various case types and pSTAT3 was detected in a significant proportion of HGBL and DLBCL. These findings provide further evidence that S1PR1, pSTAT3, S1PR2 and FOXP1 play a role in a subset of aggressive, mature B cell lymphomas.

Expression of FOXP1 and FOXO3a in extrahepatic cholangiocarcinoma and the implications in clinicopathological significance and prognosis.

Aims: Extrahepatic cholangiocarcinoma (EHCC) is a highly malignant tumor with poor prognosis and intrinsic resistance to cytotoxic agents. The molecular mechanisms associated with high malignancy and resistance to chemotherapy and radiotherapy have not been fully elucidated. This study investigated the clinicopathological significances of FOXP1 and FOXO3a expression in EHCC.Methods: We assayed FOXP1 and FOXO3a expressions in 100 EHCC, 30 peritumoral tissues, 10 adenoma and 15 normal biliary tract tissues using EnVision immunohistochemistry.Results: The positive rates of FOXP1 and FOXO3a proteins were significantly lower in EHCC tumors than in peritumoral tissues, adenoma, and normal bile tract tissues (P<0.05 or P<0.01). Adenoma and pericancerous tissues with negative FOXP1 and/or FOXO3a protein expressions exhibited atypical hyperplasia. The positive correlation was established between the expression of FOXP1 and FOXO3a in EHCC (P<0.01). The positive rates of FOXP1 and FOXO3a expression were significantly higher in cases with well differentiation, no metastasis in lymph node, no invasion to surrounding tissues and organs, TNM I + II stage and radical resection (p<0.05 or p<0.01). Kaplan-Meier survival analysis showed that EHCC patients with positive FOXP1 and FOXO3a expression survived significantly higher than patients with negative FOXP1 and FOXO3a expression, respectively (P<0.001). Cox multivariate analysis revealed that negative FOXP1 or FOXO3a expressions were independent poor prognostic factors in EHCC patients. The AUCs for FOXP1 and FOXO3a were 0.676 (95% CI: 0.589–0.763, P＜0.001) and 0.652 (95% CI: 0.563–741, P=0.002), respectively.Conclusion: The present study indicates that negative FOXP1 and FOXO3a expressions are closely associated with the pathogenesis, clinical, pathological and biological behaviors, and poor prognosis in EHCC.

Leukocyte integrin signaling regulates FOXP1 gene expression via FOXP1-IT1 long non-coding RNA-mediated IRAK1 pathway

Leukocyte integrin-dependent downregulation of the transcription factor FOXP1 is required for monocyte differentiation and macrophage functions, but the precise gene regulatory mechanism is unknown. Here, we identify multi-promoter structure (P1, P2, and P3) of the human FOXP1 gene. Clustering of the β2-leukocyte integrin Mac-1 downregulated transcription from these promoters. We extend our prior observation that IL-1 receptor-associated kinase 1 (IRAK1) is physically associated with Mac-1 and provide evidence that IRAK1 is a potent suppressor of human FOXP1 promoter. IRAK1 reduced phosphorylation of histone deacetylase 4 (HDAC4) via inhibiting phosphorylation of calcium/calmodulin dependent protein kinase II delta (CaMKIIδ), thereby promoting recruitment of HDAC4 to P1 chromatin. A novel human FOXP1 intronic transcript 1 (FOXP1-IT1) long non-coding RNA (lncRNA), whose gene is embedded within that of FOXP1, has been cloned and found to bind directly to HDAC4 and regulate FOXP1 in cis manner. Overexpression of FOXP1-IT1 counteracted Mac-1 clustering-dependent downregulation of FOXP1, reduced IRAK1 downregulation of HDAC4 phosphorylation, and attenuated differentiation of THP-1 monocytic cells. In contrast, Mac-1 clustering inhibited FOXP1-IT1 expression with reduced binding to HDAC4 as well as phosphorylation of CaMKIIδ to activate the IRAK1 signaling pathway. Importantly, both IRAK1 and HDAC4 inhibitors significantly reduced integrin clustering-triggered downregulation of FOXP1 expression in purified human blood monocytes. Identification of this Mac-1/IRAK-1/FOXP1-IT1/HDAC4 signaling network featuring crosstalk between lncRNA and epigenetic factor for the regulation of FOXP1 expression provides new targets for anti-inflammatory therapeutics.

IL-13 secreted by ILC2s promotes the self-renewal of intestinal stem cells through circular RNA circPan3.

Intestinal stem cells (ISCs) are maintained by stemness signaling for precise modulation of self-renewal and differentiation under homeostasis. However, the way in which intestinal immune cells regulate the self-renewal of ISCs remains elusive. Here we found that mouse and human Lgr5+ ISCs showed high expression of the immune cell-associated circular RNA circPan3 (originating from the Pan3 gene transcript). Deletion of circPan3 in Lgr5+ ISCs impaired their self-renewal capacity and the regeneration of gut epithelium in a manner dependent on immune cells. circPan3 bound mRNA encoding the cytokine IL-13 receptor subunit IL-13Rα1 (Il13ra1) in ISCs to increase its stability, which led to the expression of IL-13Rα1 in ISCs. IL-13 produced by group 2 innate lymphoid cells in the crypt niche engaged IL-13Rα1 on crypt ISCs and activated signaling mediated by IL-13‒IL-13R, which in turn initiated expression of the transcription factor Foxp1. Foxp1 is associated with β-catenin in rendering its nuclear translocation, which caused activation of the β-catenin pathway and the maintenance of Lgr5+ ISCs.

Positive expression of FOXP1 protein as a good prognostic factor in childhood acute lymphoblastic leukemia: a retrospective study

Background Deficiency of FOXP1 in early B-lymphoid precursors results in a block at the transition of pro-B to pre-B-cell stage and severely reduces the peripheral mature B-cell compartment. Objective The objective of the current study was to detect the prognostic value of positive FOXP1 protein expression on acute lymphoblastic leukemia (ALL) in children and adults evaluated by disease-free survival (DFS) and overall survival and its relation with BCR-ABL fusion gene in those patient. Materials and methods A retrospective study was carried out on 50 bone marrow samples from fixed bone marrow aspirates taken from patients previously diagnosed with ALL at South Egypt Cancer Institute. They were classified into 25 BCR-ABL-positive samples and 25 BCR-ABL-negative samples. Results Positive expression of FOXP1 protein in B lymphocytes in patients with ALL was associated with better overall survival and DFS, especially in children. Coexistence of both FOXP1 and BCR-ABL proteins in the patients with ALL was associated with good prognosis than BCR-ABL-positive patients with negative expression of FOXP1. Conclusion The positive expression of FOXP1 protein in B lymphocytes in pediatric patients with ALL and its association with better overall survival and DFS indicate that FOXP1 protein expression in pediatric ALL is a good prognostic marker. Coexistence of both FOXP1 and BCR-ABL proteins in the patients with ALL appeared as a good prognostic factor.

FOXP1 negatively regulates tumor infiltrating lymphocyte migration in human breast cancer.

BackgroundFOXP1, a transcriptional regulator of lymphocyte development, is abnormally expressed in some human tumors. This study investigated FOXP1-mediated regulation of tumor infiltrating lymphocytes (TIL) in untreated primary breast cancer (BC).MethodsFOXP1 expression was analyzed in tissues from primary untreated breast tumors, BC cell lines and the METABRIC gene expression BC dataset. Cytokine and chemokine expression and lymphocyte migration in response to primary tumor supernatants (SN) was compared between FOXP1hi and FOXP1lo primary BC.FindingFOXP1 expression was higher in estrogen receptor positive compared to negative BC. FOXP1hi tumors were significantly associated with lower TIL and fewer tertiary lymphoid structures (TLS) compared to FOXP1lo BC. Silencing FOXP1 in BC cell lines positively impacted cytokine and chemokine expression with the inverse effect associated with overexpression. CXCL9, CXCL10, CXCL11, CXCL13, CX3CL, CCL20, IL2, IL21, GZMB and IFNG expression decreased while IL10 and TGFβ increased in FOXP1hi compared to FOXP1lo primary BC. Lymphocyte migration using primary BC supernatants detected decreased mobility toward FOXP1hi supernatants. FOXP1lo BC expresses higher levels of chemokines driving TIL migration. The METABRIC gene expression dataset analysis show FOXP1 expression is associated with unfavorable BC outcomes.InterpretationThese data identify FOXP1 as an important negative regulator of immune responses in BC via its regulation of cytokine and chemokine expression.FundBelgian Fund for Scientific Research (FNRS 3.4513.12F) and Opération Télévie (7.4636.13F and 7.4609.15F), Fonds J.C. Heuson and Fonds Lambeau-Marteaux.

Upregulation of mtSSB by interleukin-6 promotes cell growth through mitochondrial biogenesis-mediated telomerase activation in colorectal cancer.

It is now widely accepted that mitochondrial biogenesis is inhibited in most cancer cells. Interestingly, one of the possible exceptions is colorectal cancer (CRC), in which the content of mitochondria has been found to be higher than in normal colon mucosa. However, to date, the causes and effects of this phenomenon are still unclear. In the present study, we systematically investigated the functional role of mitochondrial single-strand DNA binding protein (mtSSB), a key molecule in the regulation of mitochondrial DNA (mtDNA) replication, in the mitochondrial biogenesis and CRC cell growth. Our results demonstrated that mtSSB was frequently upregulated in CRC tissues and that upregulated mtSSB was associated with poor prognosis in CRC patients. Furthermore, overexpression of mtSSB promoted CRC cell growth in vitro by regulating cell proliferation. The in vivo assay confirmed these results, indicating that the forced expression of mtSSB significantly increases the growth capacity of xenograft tumors. Mechanistically, the survival advantage conferred by mtSSB was primarily caused by increased mitochondrial biogenesis and subsequent ROS production, which induced telomerase reverse transcriptase (TERT) expression and telomere elongation via Akt/mTOR pathway in CRC cells. In addition, FOXP1, a member of the forkhead box family, was identified as a new transcription factor for mtSSB. Moreover, our results also demonstrate that proinflammatory IL-6/STAT3 signaling facilitates mtSSB expression and CRC cell proliferation via inducing FOXP1 expression. Collectively, our findings demonstrate that mtSSB induced by inflammation plays a critical role in the regulation of mitochondrial biogenesis, telomerase activation, and subsequent CRC proliferation, providing a strong evidence for mtSSB as drug target in CRC treatment.

Prognostic Biomarkers Converge on a Germinal Centre Dark Zone Phenotype As a Determinant of Adverse Outcome in Follicular Lymphoma Patients Treated with Rituximab and Chemotherapy

Introduction: Follicular lymphoma (FL) is a clinically and genetically heterogeneous disease with highly variable patient outcomes. Recently, Huet et al. proposed a 23-gene expression-based risk score for predicting progression-free survival (PFS) in FL patients treated with rituximab and chemotherapy (Huet et al. Lancet Oncology 2018). The m7-FLIPI risk score has also been described as a clinico-genetic model predicting patient outcomes (Pastore et al. Lancet Oncology 2015). Moreover, EZH2 wild-type status and high expression of the FOXP1 transcription factor are associated with increased risk of lymphoma progression (Mottok et al. Blood 2018). This multitude of prognostic tools in FL raises the question whether they identify common biology. The aims of this study were to assess whether the 23-gene predictor score identifies a poor risk group of patients in our own gene expression dataset, and whether commonality exists between the 23-gene score, the m7-FLIPI, EZH2 mutation status and FOXP1 expression.Methods: In our previous work, we generated Illumina DASL microarray expression profiles for 137 FL patients who were treated with rituximab and CVP chemotherapy (cyclophosphamide, vincristine and prednisone). Using genes from the 23-gene linear risk predictor, we determined each patient's risk score by setting coefficients at -1 and +1 for genes associated with favorable and unfavorable PFS, respectively. We dichotomized the distribution of scores using the maximally selected log-rank statistic. We also performed unsupervised, hierarchical clustering to identify underlying subgroups in an unbiased fashion. Survival analyses were performed using the log-rank test and Cox regression analyses. We used gene set enrichment analysis to identify concordant differences of relevant gene signatures between specimens with either low or high expression of FOXP1.Results: Twenty genes from the 23-gene predictor (87%) were identified in the DASL gene expression dataset. The coefficients from univariate Cox regression analysis from our data were correlated with coefficients from Huet et al. (Pearson r = .7, P < .001; Spearman r = .44, P = .051). All poor-risk genes from the 23-gene predictor were associated with poor PFS in our data, and vice versa. Concordantly, calculated risk scores were significantly associated with PFS in the univariate Cox regression analysis (P = .007). Dichotomizing the distribution of risk scores identified 68% of cases with high risk score who had inferior PFS and OS compared to 32% of cases with low risk score (5-year PFS 54% vs. 77%, P = .004; 5-year OS 73% vs. 86%, P = .04). Hence, the risk score stratified patients into groups with diverging outcomes. This association was found to be independent of the Follicular Lymphoma Prognostic Index (FLIPI). In addition, the mean risk score was significantly higher in cases with high expression of FOXP1 (P < .001) and in cases with high m7-FLIPI risk score (P = .023). Unsupervised hierarchical clustering identified two main clusters (“cluster 1” and “cluster 2”) that were characterized by low and high expression of genes associated with poor outcome, respectively. Patients from “cluster 2” experienced worse PFS compared to patients in “cluster 1” (P = .046; 5-year PFS 54% vs. 68%). The 5-year OS was 72% for patients in “cluster 2”, vs. 81% in “cluster 1” (P = .13).We have previously reported that a germinal centre dark zone signature is enriched in cases with high FOXP1 expression, and the ICA13 signature reported by Huet et al. has been described as being highly expressed in centroblasts. Using gene set enrichment analysis, we found that genes with positive weight and coefficients in the ICA13 and the 23-gene predictor score, respectively, were enriched in the FOXP1-high phenotype (adjusted P = .009 and .005, respectively). GeneMANIA illustrated co-expression interconnectivity among ORAI2, TCF4, AFF3, FOXO1, CXCR4 and FOXP1, suggesting that genes with prognostic significance operate in tightly regulated networks.Conclusions: Our results exemplify the robustness of the predictor model by Huet et al. Further, we demonstrate biomarker convergence on a common phenotype: FOXP1 expression, EZH2 wild-type status and expression of dark zone-related genes, which characterize a subset of FL cases with adverse outcome following rituximab and chemotherapy. DisclosuresSarkozy:Roche/Genentech: Consultancy. Sehn:Roche/Genentech: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria. Weigert:Novartis: Research Funding; Roche: Research Funding. Steidl:Juno Therapeutics: Consultancy; Tioma: Research Funding; Bristol-Myers Squibb: Research Funding; Roche: Consultancy; Seattle Genetics: Consultancy; Nanostring: Patents & Royalties: patent holding.

Molecular Features of Primary Central Nervous System Lymphoma in a Large Tissue Microarray

Molecular Features of Primary Central Nervous System Lymphoma in a Large Tissue Microarray