Expression of FOXP1 in epithelial ovarian cancer (EOC) and its correlation with chemotherapy resistance and prognosis

Identification of FOXP1 as a favorable prognostic biomarker and tumor suppressor in intrahepatic cholangiocarcinoma

BACKGROUND

Forkhead-box protein P1 (FOXP1) has been proposed to have both oncogenic and tumor-suppressive properties, depending on tumor heterogeneity. However, the role of FOXP1 in intrahepatic cholangiocarcinoma (ICC) has not been previously reported.

METHODS

Immunohistochemistry was performed to detect FOXP1 expression in ICC and normal liver tissues. The relationship between FOXP1 levels and the clinicopathological characteristics of patients with ICC was evaluated. Finally, in vitro and in vivo experiments were conducted to examine the regulatory role of FOXP1 in ICC cells.

RESULTS

FOXP1 was significantly downregulated in the ICC compared to their peritumoral tissues (p < 0.01). The positive rates of FOXP1 were significantly lower in patients with poor differentiation, lymph node metastasis, invasion into surrounding organs, and advanced stages (p < 0.05). Notably, patients with FOXP1 positivity had better outcomes (overall survival) than those with FOXP1 negativity (p < 0.05), as revealed by Kaplan-Meier survival analysis. Moreover, Cox multivariate analysis showed that negative FOXP1 expression, advanced TNM stages, invasion, and lymph node metastasis were independent prognostic risk factors in patients with ICC. Lastly, overexpression of FOXP1 inhibited the proliferation, migration, and invasion of ICC cells and promoted apoptosis, whereas knockdown of FOXP1 had the opposite role.

CONCLUSION

Our findings suggest that FOXP1 may serve as a novel outcome predictor for ICC as well as a tumor suppressor that may contribute to cancer treatment.

miR-34a-FOXP1 Loop in Ovarian Cancer

Ovarian cancer (OC) is the main cause of gynecological cancer mortality in most developed countries. microRNA (miR) expression dysregulation has been highlighted in human cancers, and miR-34a is found to be downregulated and associated with inhibition of tumor growth and invasion in several malignancies, including OC. The winged helix transcription factor forkhead box P1 (FOXP1) is reported as either an oncogene or tumor suppressor in various cancers. This study aimed to elucidate potential clinical and biological associations of miR-34a and transcription factor FOXP1 in OC. We investigated nine OC patients' blood samples and two OC cell lines (SKOV-3 and OVCAR-3) using quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) to determine both miR-34a and FOXP1 expressions. We have found that miR-34a and FOXP1 are reversely correlated in both in vitro and in vivo. Inhibition of miR-34a transiently led to upregulation of FOXP1 mRNA expression and increased cellular invasion in vitro. Our data indicate that miR-34a could be a potential biomarker for improving the diagnostic efficiency of OC, and miR-34a overexpression may reduce OC pathogenesis by targeting FOXP1.

Identification of transcriptional programs using dense vector representations defined by mutual information with GeneVector

Deciphering individual cell phenotypes from cell-specific transcriptional processes requires high dimensional single cell RNA sequencing. However, current dimensionality reduction methods aggregate sparse gene information across cells, without directly measuring the relationships that exist between genes. By performing dimensionality reduction with respect to gene co-expression, low-dimensional features can model these gene-specific relationships and leverage shared signal to overcome sparsity. We describe GeneVector, a scalable framework for dimensionality reduction implemented as a vector space model using mutual information between gene expression. Unlike other methods, including principal component analysis and variational autoencoders, GeneVector uses latent space arithmetic in a lower dimensional gene embedding to identify transcriptional programs and classify cell types. In this work, we show in four single cell RNA-seq datasets that GeneVector was able to capture phenotype-specific pathways, perform batch effect correction, interactively annotate cell types, and identify pathway variation with treatment over time.

Immunohistochemistry technique for effect of gold nanoparticles, laser, and photodynamic therapy on FoxP1 level in infected mice with mammary adenocarcinoma

The current study was performed to investigate the treatment of tumors with gold nanoparticles, laser, and photodynamic therapy (PDT) by using an immunohistochemistry method and to investigate the expression of FOXP1 in infected mice with mammary adenocarcinoma whether it can be used as an indicator to estimate the recovery of tissues from cancer disease. Twenty-five albino female mice were used in this research; they were divided into five groups, four groups were infected with mammary adenocarcinoma, and then three of them were treated with gold nanoparticles, laser, and PDT, respectively, while the fourth group was left without any treatment and represents the positive control, and the fifth group (normal mice) represents the negative control. Tissue sections were taken from different groups of mice in order to estimate FOXP1 expression in infected mice by using an immunohistochemistry assay. FOXP1 expression was higher in the tumor and kidney tissues of the mice treated with PDT than that in mice treated with either gold nanoparticles or laser alone. Also, in the group of mice treated with laser, FOXP1 expression was higher than the expression in mice which were treated with gold nanoparticles but lower than that in mice which were treated with PDT. FOXP1 can be used as a biomarker for the prognosis outcome of breast and other solid tumors, as well as it considers a key tumor suppressor. PDT is the best choice to treat cancer in comparison to using either gold nanoparticles or the laser separately.

FOXP1 and FOXO3a Are Prognostic Markers in Gallbladder Squamous Cell/Adenosquamous Carcinomas and Adenocarcinomas

The pathologic characteristics of squamous cell/adenosquamous carcinomas (SC/ASC) have not been well clarified. As a rare subtype of gallbladder cancer (GBC), no biological markers for diagnosis and prognosis are available. This research evaluated the expression of FOXP1 and FOXO3a in 69 SC/ASC, and 146 adenocarcinoma (AC) samples were analyzed via immunohistochemistry. SC/ASCs were associated with higher rates of lymph node metastasis, invasion, and patients older than 45 years comparing to ACs. FOXP1 and FOXO3a positivity rates were significantly lower in SC/ASC and AC samples from patients with large tumor size, a high TNM stage, lymph node metastasis, invasion, and no history of tumor resection (biopsy only). Positive FOXP1 expression levels were significantly decreased in cases of poorly differentiated AC. The univariate Kaplan-Meier analysis revealed that negative FOXP1 and FOXO3a expression, poor differentiation, large tumor size, high TNM stage, lymph node metastasis, invasion, and an inability to undergo curative resection were all closely associated with decreased overall survival in SC/ASC and AC patients. The multivariate cox regression analysis showed that negative FOXP1 and FOXO3a expression levels were independent predictors of poor prognosis in SC/ASC and AC patients. Our results indicate that negative FOXP1 and FOXO3a expression are closely associated with the pathogenesis, clinicopathologic properties, and prognosis of GBC patients. FOXP1 and FOXO3a may thus be biomarkers of GBC carcinogenesis, progression, and prognosis.

Long noncoding RNA VPS9D1-AS1 augments the malignant phenotype of non-small cell lung cancer by sponging microRNA-532-3p and thereby enhancing HMGA2 expression

We investigated the influence of the long noncoding RNA VPS9D1 antisense RNA 1 (VPS9D1-AS1) on the malignant phenotype of non-small cell lung cancer (NSCLC) cells in vitro and in vivo. We also explored the mechanisms by which VPS9D1-AS1 exerts its oncogenic action during NSCLC progression. VPS9D1-AS1 expression was upregulated in NSCLC; the extent of its upregulation significantly correlated with patients’ adverse clinicopathological characteristics and shorter overall survival. When VPS9D1-AS1 was knocked down in NSCLC cells, their proliferation, colony-forming capacity, migration, and invasiveness were lower, whereas their apoptosis rate was higher, compared to the control. VPS9D1-AS1 knockdown attenuated tumor growth of NSCLC cells in vivo. Mechanistically, VPS9D1-AS1 directly interacted with microRNA-532-3p (miR-532-3p) in NSCLC cells; the impact of VPS9D1-AS1 knockdown on NSCLC cells was attenuated by miR-532-3p inhibition. Furthermore, VPS9D1-AS1 knockdown decreased the expression of high mobility group AT-hook 2 (HMGA2) in NSCLC cells via miR-532-3p sponging. Recovery of HMGA2 expression partially reversed the inhibitory effects of VPS9D1-AS1 knockdown on NSCLC cells. Thus, VPS9D1-AS1 functions as a competing endogenous RNA that positively regulates HMGA2 expression by sponging miR-532-3p in NSCLC cells, suggesting that the VPS9D1-AS1–miR-532-3p–HMGA2 pathway can be a potential diagnostic and/or therapeutic target in NSCLC.

miR-29c-3p inhibits autophagy and cisplatin resistance in ovarian cancer by regulating FOXP1/ATG14 pathway

Autophagy, characterized by the elevator of autophagy-related gene 14 (ATG14) and the dysregulation of autophagy-related proteins, contributes to the cisplatin (DDP) resistance in ovarian cancer. Forkhead box protein P1 (FOXP1), which is a well-defined transcription factor, is reported to have the oncogenic effect on ovarian cancer. This study aims to identify the effect of miR-29c-3p/FOXP1/ATG14 pathway in regulating autophagy and DDP resistance in ovarian cancer. The expressions of miR-29c-3p, FOXP1, ATG14 and autophagy-related proteins were detected in DDP-sensitive ovarian cancer cell lines (SKOV3 and A2780) and DDP-resistant cell lines (SKOV3/DDP and A2780/DDP). Cell viability was detected using the MTT assay. The therapeutic effect of miR-29c-3p overexpression was observed in the xenograft model of nude mice.Compared with DDP-sensitive cells, miR-29c-3p was decreased in DDP-resistant cells, and an enhancement of FOXP1, ATG14, autophagy, and drug resistance was shown in DDP-resistant cells. The anti-resistant effect of miR-29c-3p was observed as overexpressing miR-29c-3p inhibited cell viability of DDP-resistant cells. Moreover, FOXP1 was a target of miR-29c-3p, which was confirmed by the luciferase reporter assay, and ATG14 was transactivated by FOXP1, which was confirmed by the ChIP assay. Overexpression of miR-29c-3p increased DDP sensitivity by downregulating FOXP1/ATG14 in vitro. The tumor volume was reduced after the injection of miR-29c-3p-overexpressing SKOV3/DDP cells in vivo. Overexpression of miR-29c-3p inhibited autophagy and DDP resistance partly via downregulating FOXP1/ATG14 pathway, suggesting miR-29c-3p as a novel target in overcoming DDP resistance in ovarian cancer.

microRNA-605 inhibits the oncogenicity of non-small-cell lung cancer by directly targeting Forkhead Box P1

Background and aims: microRNA-605 (miR-605) is dysregulated in multiple cancers and plays crucial roles in regulating cancer progression. However, little is known about the expression pattern and detailed roles of miR-605 in non-small-cell lung cancer (NSCLC). Thus, in this study, we evaluated miR-605 expression in NSCLC along with its clinical significance. More importantly, the detailed roles and the underlying molecular mechanisms of miR-605 in NSCLC were explored.

Material and methods: Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was employed to detect miR-605 expression in NSCLC tissues and cell lines. A series of experiments were performed to determine the effects of miR-605 upregulation on NSCLC cell proliferation, apoptosis, migration and invasion in vitro and tumor growth in vivo. In addition, the downstream regulatory mechanisms of miR‐605 action in NSCLC cells were explored.

Results: Decreased expression of miR-605 was frequently detected in NSCLC tissues and cell lines. Low expression of miR-605 was significantly correlated with the tumor size, TNM stage, and distane metastasis in NSCLC patients. Exogenous miR-605 expression inhibited proliferation, increased apoptosis, and inhibited metastasis of NSCLC cells in vitro. Additionally, miR-605 overexpression hindered the growth of NSCLC cells in vivo. Furthermore, Forkhead Box P1 (FOXP1) was identified as a direct target gene of miR-605 in NSCLC cells. Moreover, FOXP1 was highly expressed in NSCLC cells and showed an inverse correlation with miR-605 expression levels. Besides, silencing of FOXP1 simulated roles similar to miR-605 upregulation in NSCLC cells. FOXP1 reintroduction partially abolished the anticancer effects of miR-605 in NSCLC cells.

Conclusion: Our results revealed that miR-605 inhibited the oncogenicity of NSCLC cells in vitro and in vivo by directly targeting FOXP1, suggesting the importance of the miR-605/FOXP1 pathway in the malignant development of NSCLC.

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.

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.

Cytoplasmic FOXP1 expression is correlated with ER and calpain II expression and predicts a poor outcome in breast cancer

BACKGROUND

Nuclear forkhead box protein P1 (N-FOXP1) expression in invasive breast cancer has been documented in the literature. However, the FOXP1 expression patterns at different stages of breast cancer progression are largely unknown, and the significance of cytoplasmic FOXP1 (C-FOXP1) expression in breast cancer has not been well illustrated. The aims of this study were to investigate FOXP1 expression patterns in invasive ductal carcinoma (IDC), ductal carcinoma in situ (DCIS), atypical ductal hyperplasia (ADH) and usual ductal hyperplasia (UDH), and to analyze the clinicopathological relevance of C-FOXP1 and its prognostic value in IDC.

METHODS

N-FOXP1 and C-FOXP1 expression in cases of IDC, DCIS, ADH and UDH was determined using immunohistochemistry. The correlation between C-FOXP1 expression and clinicopathological parameters as well as the overall survival (OS) and disease-free survival (DFS) rates of patients with IDC were analyzed.

RESULTS

Exclusive N-FOXP1 expression was found in 85.0% (17/20), 40.0% (8/20), 12.2% (5/41) and 10.8% (9/83) of UDH, ADH, DCIS, and IDC cases, respectively, and exclusive C-FOXP1 expression was observed in 0% (0/20), 0% (0/20), 4.9% (2/41), and 31.3% (26/83) of the cases, respectively. Both N- and C-FOXP1 staining were observed in 15.0% (3/20), 60.0% (12/20), 82.9% (34/41) and 48.2% (40/83) of the above cases, respectively, while complete loss of FOXP1 expression was observed in only 9.6% (8/83) of IDC cases. Estrogen receptor (ER) expression in C-FOXP1-positive IDC cases (31/66, 47.0%) was significantly lower than that in C-FOXP1-negative cases (13/17, 76.5%) (p = 0.030). Calpain II expression was observed in 83.3% (55/66) of C-FOXP1-positive IDC cases, which was significantly higher than that in C-FOXP1-negative cases (9/17, 52.9%) (p = 0.007). Calpain II was significantly associated with pAKT (p = 0.029), pmTOR (p = 0.011), p4E-BP1 (p < 0.001) and p-p70S6K (p = 0.003) expression levels. The 10-year OS and DFS rates of the C-FOXP1-positive patients were 60.5% and 48.7%, respectively, both of which were lower than those of the C-FOXP1-negative patients (93.3, 75.3%). The OS curve showed a dramatic impact of C-FOXP1 status on OS (p = 0.045).

CONCLUSIONS

Cytoplasmic relocalization of FOXP1 protein was a frequent event in breast IDC. Calpain II might play an important role in nucleocytoplasmic trafficking of FOXP1 and the AKT pathway might be involved in this process. C-FOXP1 expression was inversely associated with ER expression and might be a predictor of poor OS in patients with IDC.

Upregulation of FOXP1 is a new independent unfavorable prognosticator and a specific predictor of lymphatic dissemination in cutaneous melanoma patients

Background

FOXP1 is a pleiotropic protein that plays important roles in immune responses (B-cell development regulation and differentiation of monocyte), organ development (cardiac valves, lung, and esophagus), and neuronal development. Besides being the primary regulator of normal human tissue development, FOXP1 also plays a role in tumorigenesis. However, the potential value of FOXP1 expression in tumor prognosis remains controversial. FOXP1 expression was assessed in tumor cells (TCs) and stromal cells (SCs) of cutaneous melanomas with the aim of analyzing the associations between FOXP1 expression and clinicopathological characteristics. We believe this article to be the first report analyzing the correlations between FOXP1 expression and clinicopathological, as well as histological, characteristics in melanoma.

Materials and methods

In total, 96 formalin-fixed, paraffin-embedded primary cutaneous melanoma tissue specimens were subjected to immunohistochemical analysis for FOXP1, and the results were correlated with classical clinicopathological features and patient survival.

Results

FOXP1 overexpression in TCs was strongly associated with the presence of metastases in sentinel lymph nodes (p=0.0003, OR=11.66) and positive status of regional lymph nodes (p=0.0006, OR=22.15). In 96% (52 of 54) of patients presenting with low FOXP1 expression, no clinical or histopathological features of lymphatic dissemination were observed. However, thinner and nonulcerated tumors were reported to have increased numbers of FOXP1-positive SCs. In addition, a strong association was observed between FOXP1 upregulation in SCs and the absence of regional lymph node metastases. There was a significant correlation between FOXP1 upregulation in TCs and shorter cancer-specific overall survival (log-rank test, p=0.0040) and disease-free survival (log-rank test, p=0.0021). FOXP1 expression was confirmed in multivariate analysis as a factor that significantly unfavorably impacts prognosis in melanoma patients (HR=3.14, p=0.0299, adjusted for age, Breslow thickness, and sex).

Conclusion

The findings from this study indicate that FOXP1 has a major role in melanoma progression, which makes it a candidate for molecular target-based cancer therapy.

Patient-derived ovarian cancer xenografts re-growing after a cisplatinum treatment are less responsive to a second drug re-challenge: a new experimental setting to study response to therapy

Even if ovarian cancer patients are very responsive to a cisplatinum-based therapy, most will relapse with a resistant disease. New experimental animal models are needed to explore the mechanisms of resistance, to better tailor treatment and improve patient prognosis. To address these aims, seven patient-derived high-grade serous/endometrioid ovarian cancer xenografts were characterized for the antitumor response after one and two cycles of cisplatinum and classified as Very Responsive, Responsive, and Low Responsive to drug treatment. Xenografts re-growing after the first drug cycle were much less responsive to the second one. The expression of epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs) genes was investigated in cisplatinum-treated and not-treated tumors. We found that different EMT (TCF3, CAMK2N1, EGFR, and IGFBP4) and CSCs (SMO, DLL1, STAT3, and ITGA6) genes were expressed at higher levels in Low Responsive than in Responsive and Very Responsive xenografts. The expression of STAT3 was found to be associated with lower survival (HR = 13.7; p = 0.013) in the TCGA patient data set. MMP9, CD44, DLL4, FOXP1, MERTK, and PTPRC genes were found more expressed in tumors re-growing after cisplatinum treatment than in untreated tumors. We here describe a new in vivo ovarian carcinoma experimental setting that will be instrumental for specific trials of combination therapy to counteract cisplatinum resistance in order to improve the prognosis of ovarian patients.

Epstein-Barr virus encoded miR-BART11 promotes inflammation-induced carcinogenesis by targeting FOXP1

Epstein-Barr virus (EBV) infection and chronic inflammation are closely associated with the development and progression of nasopharyngeal carcinoma (NPC) and gastric cancer (GC), and the infiltration of inflammatory cells, including tumor-associated macrophages (TAMs), is often observed in these cancers. EBV encodes 44 mature micro RNAs (miRNAs), but the roles of only a few EBV-encoded miRNA targets are known in cancer development, and here, our aim was to elucidate the effects of EBV-miR-BART11 on FOXP1 expression, and potential involvement in inflammation-induced carcinogenesis. We constructed an EBV miRNA-dependent gene regulatory network and predicted that EBV-miR-BART11 is able to target forkhead box P1 (FOXP1), a key molecule involved in monocyte to macrophage differentiation. Here, using luciferase reporter assay, we confirmed that EBV-miR-BART11 directly targets the 3′-untranslated region of FOXP1 gene, inhibits FOXP1 induction of TAM differentiation, and the secretion of inflammatory cytokines into the tumor microenvironment, inducing the proliferation of NPC and GC cells. FOXP1 overexpression hindered monocyte differentiation and inhibited NPC and GC cells growth. Our results demonstrated that EBV-miR-BART11 plays a crucial role in the promotion of inflammation-induced NPC and GC carcinogenesis by inhibiting FOXP1 tumor-suppressive effects. We showed a novel EBV-dependent mechanism that may induce the carcinogenesis of NPC and GC, which may help define new potential biomarkers and targets for NPC and GC diagnosis and treatment.

MicroRNA-152 inhibits ovarian cancer cell proliferation and migration and may infer improved outcomes in ovarian cancer through targeting FOXP1

microRNA (miR) are a class of endogenous small non-coding RNA that are aberrantly expressed and are critical in tumorigenesis. Amongst them, miR-152 was reported to be dysregulated in epithelial ovarian cancer (EOC). However, the function and mechanism of miR-152 is not well understood. In the present study, total RNA was extracted from 58 ovarian epithelial carcinoma tissue samples and adjacent non-tumor tissues and measured by reverse transcription-quantitative polymerase chain reaction. The observations of the present study revealed that the expression of miR-152 was significantly downregulated in EOC specimens, as well as three ovarian cancer (OC) cell lines. The higher expression of miR-152 indicated a better overall survival rate in patients with EOC. Following miR-152 mimic transfection into SKOV3 or OVCAR3 cells, MTT assay revealed that cell proliferation was significantly inhibited (P<0.05). Although miR-152 had no effect on SKOV3 cell migration, miR-152 inhibited OVCAR3 cell migration. Bioinformatics analyses and luciferase reporter assays demonstrated that miR-152 targeted the 3'-untranslated region (3'-UTR) of the forkhead box protein 1 (FOXP1). Furthermore, introducing FOXP1 without the 3'-UTR abrogated the effect of miR-152-induced proliferation and migration alteration, respectively. In addition, the expression level of FOXP1 was higher in the EOC tumor tissues and cell lines. Additionally, the level of miR-152 and FOXP1 was inversely correlated in grade 3 and 4 ovarian tumor tissues. Altogether, these observations indicated that miR-152 may be involved in the inhibition of OC through repression of FOXP1. In the future, miR-152 and FOXP1 may act as novel biomarkers for early detection of EOC or therapeutic targets.

Members of FOX family could be drug targets of cancers

FOX families play important roles in biological processes, including metabolism, development, differentiation, proliferation, apoptosis, migration, invasion and longevity. Here we are focusing on roles of FOX members in cancers, FOX members and drug resistance, FOX members and stem cells. Finally, FOX members as drug targets of cancer treatment were discussed. Future perspectives of FOXC1 research were described in the end.

The clinicopathological significance of forkhead box P1 and forkhead box O3a in pancreatic ductal adenocarcinomas

Pancreatic ductal adenocarcinoma is a highly malignant tumor with poor prognosis, and the biomarkers for the early diagnosis, targeting therapy, and prognosis are still not clinically available. This study investigated the expression of forkhead box P1 and forkhead box O3a proteins in human pancreatic ductal adenocarcinoma tumor tissues and pancreatic tissues with and without benign lesions using immunohistochemical staining. Results showed that the positive rates of forkhead box P1 and forkhead box O3a protein expression were significantly lower in pancreatic ductal adenocarcinoma tumors compared to peritumoral tissues, benign pancreatic tissues, and normal pancreatic tissues (p < 0.01). Pancreatic tissues with negative forkhead box P1 and forkhead box O3a protein expression exhibited dysplasia or intraepithelial neoplasia. The positive rates of forkhead box P1 and forkhead box O3a expression were significantly lower in cases with tumor mass >5 cm, lymph node metastasis, invasion to surrounding tissues and organs, and tumor-node-metastasis III + IV stage disease compared to cases with tumor mass ⩽5 cm (p < 0.05), no lymph node metastasis (p < 0.001 and p = 0.001, respectively), no invasion (p = 0.003 and p = 0.004, respectively), and tumor-node-metastasis I or II stage disease (p < 0.05). Kaplan-Meier survival analysis showed that pancreatic ductal adenocarcinoma patients with negative forkhead box P1 and forkhead box O3a expression survived significantly shorter than patients with positive forkhead box P1 and forkhead box O3a expression (p = 0.000). Cox multivariate analysis revealed that negative forkhead box P1 and forkhead box O3a expression was an independent poor prognosis factor in pancreatic ductal adenocarcinoma patients. The area under the curve of a receiver operating characteristic curve was 0.642 for forkhead box P1 (95% confidence interval: 0.553-0.730) and 0.655 for forkhead box O3a (95% confidence interval: 0.6568-0.742). Loss of forkhead box P1 and forkhead box O3a protein expression is associated with carcinogenesis, progression, and poor prognosis in patients with pancreatic ductal adenocarcinomas.

FOXP1 functions as an oncogene in promoting cancer stem cell-like characteristics in ovarian cancer cells

Ovarian cancer has the highest mortality rate of all gynecological cancers with a high recurrence rate. It is important to understand the nature of recurring cancer cells to terminally eliminate ovarian cancer. The winged helix transcription factor Forkhead box P1 (FOXP1) has been reported to function as either oncogene or tumor-suppressor in various cancers. In the current study, we show that FOXP1 promotes cancer stem cell-like characteristics in ovarian cancer cells. Knockdown of FOXP1 expression in A2780 or SKOV3 ovarian cancer cells decreased spheroid formation, expression of stemness-related genes and epithelial to mesenchymal transition-related genes, cell migration, and resistance to Paclitaxel or Cisplatin treatment, whereas overexpression of FOXP1 in A2780 or SKOV3 ovarian cancer cells increased spheroid formation, expression of stemness-related genes and epithelial to mesenchymal transition-related genes, cell migration, and resistance to Paclitaxel or Cisplatin treatment. In addition, overexpression of FOXP1 increased promoter activity of ABCG2, OCT4, NANOG, and SOX2, among which the increases in ABCG2, OCT4, and SOX2 promoter activity were dependent on the presence of FOXP1-binding site. In xenotransplantation of A2780 ovarian cancer cells into nude mice, knockdown of FOXP1 expression significantly decreased tumor size. These results strongly suggest FOXP1 functions as an oncogene by promoting cancer stem cell-like characteristics in ovarian cancer cells. Targeting FOXP1 may provide a novel therapeutic opportunity for developing a relapse-free treatment for ovarian cancer patients.

Prognostic value of decreased FOXP1 protein expression in various tumors: a systematic review and meta-analysis

The prognostic value of forkhead box protein P1 (FOXP1) protein expression in tumors remains controversial. Therefore, we conducted a systematic review and meta-analysis, searching the PubMed, Embase and Web of Science databases to identify eligible studies. In total, we analyzed 22 articles that examined 9 tumor types and included 2468 patients. Overall, decreased expression of FOXP1 protein was associated with favorable overall survival (OS) in lymphoma patients (HR = 0.38, 95%CI: 0.30–0.48, p < 0.001). In patients with solid tumors, decreased FOXP1 expression correlated with unfavorable OS (HR = 1.82, 95%CI: 1.18–2.83, p = 0.007). However, when FOXP1 protein expression was nuclear, decreased expression was also associated with favorable OS (HR = 0.53, 95%CI: 0.32–0.86, p = 0.011). Furthermore, decreased FOXP1 expression resulted in the best OS in patients with mucosa-associated lymphoid tissue (MALT) lymphomas (HR = 0.26, 95%CI: 0.11–0.59, p = 0.001), but the worst OS was observed in non-small cell lung cancer (NSCLC) patients (HR = 3.11, 95%CI: 1.87–5.17, p < 0.001). In addition, decreased FOXP1 expression was significantly correlated with an unfavorable relapse-free survival (RFS) in breast cancer patients (HR = 1.93, 95%CI: 1.33–2.80, p = 0.001).