FOXM1 in Cancer: Interactions and Vulnerabilities

FAM188B Expression Is Critical for Cell Growth via FOXM1 Regulation in Lung Cancer

Although family with sequence similarity 188 member B (FAM188B) is known to be a member of a novel putative deubiquitinase family, its biological role has not been fully elucidated. Here, we demonstrate the oncogenic function of FAM188B via regulation of forkhead box M1 (FOXM1), another oncogenic transcription factor, in lung cancer cells. FAM188B knockdown induced the inhibition of cell growth along with the downregulation of mRNA and protein levels of FOXM1. FAM188B knockdown also resulted in downregulation of Survivin and cell cycle-related proteins, which are direct targets of FOXM1. Interestingly, FOXM1 co-immunoprecipitated with FAM188B, and the levels of FOXM1 ubiquitination increased with FAM188B knockdown but decreased with FAM188B overexpression. In addition, in vivo xenograft of FAM188B siRNA (siFAM188B) RNA-treated cells resulted in the retardation of tumor growth compared with that in the control. Furthermore, protein levels of FAM188B and FOXM1 were elevated in the human lung cancer tissues, and FAM188B expression was negatively correlated with the overall survival of lung cancer patients. These results indicate that FAM188B exerts its oncogenic effects by regulating FOXM1 deubiquitination and thus its stability. Therefore, FAM188B might be a potential therapeutic target to control lung cancer progression.

Thiostrepton and miR-216b synergistically promote osteosarcoma cell cytotoxicity and apoptosis by targeting FoxM1

Osteosarcoma is a common primary bone cancer that there are currently no effective treatment strategies for. Forkhead box M1 (FoxM1) is key in the development of osteosarcoma, and microRNA (miR)-216b serves an antitumor role by targeting FoxM1. Moreover, thiostrepton (TST), a natural thiazole antibiotic, induces antitumor effects and specifically targets FoxM1. Therefore, the present study investigated whether thiostrepton and miR-216b synergistically inhibited osteosarcoma cells by targeting FoxM1. The MTT assay, reverse transcription-quantitative PCR, a dual-luciferase reporter assay and flow cytometry were performed. Compared with the human osteoblast cell line hFOB1.19, miR-216b expression was significantly downregulated in the osteosarcoma cell lines U2OS, MG63 and Saos-2. By contrast, FoxM1 expression was significantly upregulated in osteosarcoma cell lines compared with the hFOB1.19 cell line. The results indicated that miR-216b targeted the 3′-untranslated region of FoxM1. Moreover, the results suggested that miR-216b cooperated with TST to decrease cell cytotoxicity and increase cell apoptosis. In addition, miR-216b cooperated with TST to increase Bax expression and decrease Bcl-2 expression. In conclusion, the combination of TST and miR-216b synergistically promoted osteosarcoma cell cytotoxicity and apoptosis by targeting FoxM1. Therefore, the present study suggested that the combination of TST and miR-216b may serve as a promising therapeutic strategy for osteosarcoma.

Rosmarinic Acid Methyl Ester Regulates Ovarian Cancer Cell Migration and Reverses Cisplatin Resistance by Inhibiting the Expression of Forkhead Box M1

Rosmarinic acid methyl ester (RAME), a derivative of rosmarinic acid (RA), is reported to have several therapeutic effects, including anti-tumor effects against cervical cancer. However, its anti-tumor effects in ovarian cancer is unclear. In this study, we studied the molecular pathways associated with the anti-tumor effects of RAME in ovarian cancer. To identify the effects of RAME in ovarian cancer, RNA sequencing was performed in RAME-treated ovarian cancer cells; we found that RAME treatment downregulated the genes closely involved with the target genes of the transcription factor Forkhead box M1 (FOXM1). It was reported that FOXM1 is overexpressed in a variety of cancer cells and is associated with cell proliferation and tumorigenesis. Therefore, we hypothesized that FOXM1 is a key target of RAME; this could result in its anti-tumor effects. Treatment of ovarian cancer cells with RAME-inhibited cell migration and invasion, as shown by wound healing and transwell migration assays. To examine whether RAME represses the action of FOXM1, we performed quantitative RT-PCR and ChIP-qPCR. Treatment of ovarian cancer cells with RAME decreased the mRNA expression of FOXM1 target genes and the binding of FOXM1 to its target genes. Moreover, FOXM1 expression was increased in cisplatin-resistant ovarian cancer cells, and combination treatment with RAME and cisplatin sensitized the cisplatin-resistant ovarian cancer cells, which was likely due to FOXM1 inhibition. Our research suggests that RAME is a promising option in treating ovarian cancer patients, as it revealed a novel molecular pathway underlying its anti-tumor effects.

Suppression of Tumor Growth, Metastasis, and Signaling Pathways by Reducing FOXM1 Activity in Triple Negative Breast Cancer

Simple Summary

Triple negative breast cancer is an aggressive subtype of breast cancer that frequently metastasizes. Because the transcription factor FOXM1 is highly upregulated in triple negative breast cancer and controls many cell activities that lead to cancer progression and metastasis, we sought to determine if FOXM1 inhibitory compounds could effectively suppress the invasiveness and progression of triple negative breast cancer cells and tumors. Our findings show that these compounds inhibit cell motility, invasiveness, and the expression of important proteins associated with epithelial to mesenchymal transition. These compounds also suppressed the proliferation and metastatic outgrowth of triple negative breast tumors. Thus, these findings highlight the crucial role of FOXM1 in promoting the progression and metastasis of these cancers, and suggest that FOXM1 inhibitory compounds may have therapeutic potential and prove beneficial in intervention against triple negative breast cancer.

Abstract

Metastasis-related complications account for the overwhelming majority of breast cancer mortalities. Triple negative breast cancer (TNBC), the most aggressive breast cancer subtype, has a high propensity to metastasize to distant organs, leading to poor patient survival. The forkhead transcription factor, FOXM1, is especially upregulated and overexpressed in TNBC and is known to regulate multiple signaling pathways that control many key cancer properties, including proliferation, invasiveness, stem cell renewal, and therapy resistance, making FOXM1 a critical therapeutic target for TNBC. In this study, we test the effectiveness of a novel class of 1,1-diarylethylene FOXM1 inhibitory compounds in suppressing TNBC cell migration, invasion, and metastasis using in vitro cell culture and in vivo tumor models. We show that these compounds inhibit the motility and invasiveness of TNBC MDA-MB-231 and DT28 cells, along with reducing the expression of important epithelial to mesenchymal transition (EMT) associated genes. Further, orthotopic tumor studies in NOD-SCID-gamma (NSG) mice demonstrate that these compounds reduce FOXM1 expression and suppress TNBC tumor growth as well as distant metastasis. Gene expression and protein analyses confirm the decreased levels of EMT factors and FOXM1-regulated target genes in tumors and metastatic lesions in the inhibitor-treated animals. The findings suggest that these FOXM1 suppressive compounds may have therapeutic potential in treating triple negative breast cancer, with the aim of reducing tumor progression and metastatic outgrowth.

Co-expression Network Analysis Identifies Fourteen Hub Genes Associated with Prognosis in Clear Cell Renal Cell Carcinoma

Renal cancer is a common genitourinary malignance, of which clear cell renal cell carcinoma (ccRCC) has high aggressiveness and leads to most cancer-related deaths. Identification of sensitive and reliable biomarkers for predicting tumorigenesis and progression has great significance in guiding the diagnosis and treatment of ccRCC. Here, we identified 2397 common differentially expressed genes (DEGs) using paired normal and tumor ccRCC tissues from GSE53757 and The Cancer Genome Atlas (TCGA). Then, we performed weighted gene co-expression network analysis and protein-protein interaction network analysis, 17 candidate hub genes were identified. These candidate hub genes were further validated in GSE36895 and Oncomine database and 14 real hub genes were identified. All the hub genes were up-regulated and significantly positively correlated with pathological stage and histologic grade of ccRCC. Survival analysis showed that the higher expression level of each hub gene tended to predict a worse clinical outcome. ROC analysis showed that all the hub genes can accurately distinguish between tumor and normal samples, and between early stage and advanced stage ccRCC. Moreover, all the hub genes were positively associated with distant metastasis, lymph node infiltration, tumor recurrence and the expression of MKi67, suggesting these genes might promote tumor proliferation, invasion and metastasis. Furthermore, the functional annotation demonstrated that most genes were enriched in cell-cycle related biological function. In summary, our study identified 14 potential biomarkers for predicting tumorigenesis and progression, which might contribute to early diagnosis, prognosis prediction and therapeutic intervention.

Identification of Chemoresistance-Associated Key Genes and Pathways in High-Grade Serous Ovarian Cancer by Bioinformatics Analyses

Purpose

High-grade serous ovarian cancer (HGSOC) is the leading cause of death among gynecological malignancies. This is mainly attributed to its high rates of chemoresistance. To date, few studies have investigated the molecular mechanisms underlying this resistance to treatment in ovarian cancer patients. In this study, we aimed to explore these molecular mechanisms using bioinformatics analysis.

Methods

We analyzed microarray data set GSE51373, which included 16 platinum-sensitive HGSOC samples and 12 platinum-resistant control samples. Differentially expressed genes (DEGs) were identified using RStudio. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using DAVID, and a DEG-associated protein–protein interaction (PPI) network was constructed using STRING. Hub genes in the PPI network were identified, and the prognostic value of the top ten hub genes was evaluated. MGP, one of the hub genes, was verified by immunohistochemistry.

Results

All samples were confirmed to be of high quality. A total of 109 DEGs were identified, and the top ten enriched GO terms and four KEGG pathways were obtained. Specifically, the PI3K-AKT signaling pathway and the Rap1 signaling pathway were identified as having significant roles in chemoresistance in HGSOC. Furthermore, based on the PPI network, KIT, FOXM1, FGF2, HIST1H4D, ZFPM2, IFIT2, CCNO, MGP, RHOBTB3, and CDC7 were identified as hub genes. Five of these hub genes could predict the prognosis of HGSOC patients. Positive immunostaining signals for MGP were observed in the chemoresistant samples.

Conclusion

Taken together, the findings of this study may provide novel insights into HGSOC chemoresistance and identify important therapeutic targets.

Comprehensive expression analysis of mRNA and microRNA for the investigation of compensatory mechanisms in the rat kidney after unilateral nephrectomy

Compensation is a physiological response that occurs during chemical exposure to maintain homeostasis. Because compensatory responses are not usually considered adverse effects, it is important to understand compensatory mechanisms for chemical risk assessment. Although the kidney is a major target organ for toxicity, there is controversy over whether hyperplasia or hypertrophy contributes to the compensatory mechanism, and there is limited information to apply for chemical risk assessment. In the present study, compensatory mechanisms of the kidney were investigated in a unilateral nephrectomy (UNx) model using adult male and female F344 rats. In residual kidneys of male and female rats after UNx, 5-bromo-2'-deoxyuridine-labeling indices and mRNA expression of cell cycle-related genes were increased, although there were no fluctuations in mRNA expression of transforming growth factor-β1, which contributes to hypertrophy in renal tubules. Pathway analysis using mRNA expression data from a complementary DNA (cDNA) microarray revealed that canonical pathways related to cell proliferation were mainly activated and that forkhead box M1 (FOXM1) was an upstream regulator of compensatory cell proliferation in residual kidneys of male and female rats. cDNA microarray for microRNAs (miRNAs) demonstrated that nine miRNAs were downregulated in residual kidneys, and mRNA/miRNA integrated analysis indicated that miRNAs were associated with the expression of factors downstream of FOXM1. Overall, these results suggested that FOXM1-mediated hyperplasia rather than hypertrophy contributed to compensatory mechanisms in the kidney and that miRNAs regulated downstream FOXM1 signaling. These results will be beneficial for evaluating nephrotoxicity in chemical risk assessment and for developing new biomarkers to predict nephrotoxicity.

Glioblastoma Multiforme Stem Cell Cycle Arrest by Alkylaminophenol Through the Modulation of EGFR and CSC Signaling Pathways

Cancer stem cells (CSCs), a small subpopulation of cells existing in the tumor microenvironment promoting cell proliferation and growth. Targeting the stemness of the CSC population would offer a vital therapeutic opportunity. 3,4-Dihydroquinolin-1(2H)-yl)(p-tolyl)methyl)phenol (THTMP), a small synthetic phenol compound, is proposed to play a significant role in controlling the CSC proliferation and survival. We assessed the potential therapeutic effects of THTMP on glioblastoma multiforme (GBM) and its underlying mechanism in various signaling pathways. To fully comprehend the effect of THTMP on the CSCs, CD133⁺ GBM stem cell (GSC) and CD133^- GBM Non-stem cancer cells (NSCC) population from LN229 and SNB19 cell lines was used. Cell cycle arrest, apoptosis assay and transcriptome analysis were performed for individual cell population. THTMP strongly inhibited NSCC and in a subtle way for GSC in a time-dependent manner and inhibit the resistance variants better than that of temozolomide (TMZ). THTMP arrest the CSC cell population at both G1/S and G2/M phase and induce ROS-mediated apoptosis. Gene expression profiling characterize THTMP as an inhibitor of the p53 signaling pathway causing DNA damage and cell cycle arrest in CSC population. We show that the THTMP majorly affects the EGFR and CSC signaling pathways. Specifically, modulation of key genes involved in Wnt, Notch and Hedgehog, revealed the significant role of THTMP in disrupting the CSCs’ stemness and functions. Moreover, THTMP inhibited cell growth, proliferation and metastasis of multiple mesenchymal patient-tissue derived GBM-cell lines. THTMP arrests GBM stem cell cycle through the modulation of EGFR and CSC signaling pathways.

FOXM1: a potential therapeutic target in human solid cancers

Introduction: FOXM1 is one of the most frequently overexpressed proteins in human solid cancers. Here, we discuss novel direct targets of FOXM1 as well as new pathways involving FOXM1, through which this protein exerts its oncogenic activity.Areas covered: We give a detailed review of FOXM1 transcriptional targets involved in 16 different types of human cancer as published in the literature in the last 5 years. We also discuss a novel positive feedback loop between FOXM1 and AKT - both well-established master regulators of cancer.Expert opinion: Despite the discovery of several FOXM1 inhibitors over the years (by our team and others), their therapeutic use is limited by their adverse off-target effects.Newly-discovered proteins regulated by FOXM1 present a promising alternative approach to target its pro-cancer activity. In addition, targeting regulating proteins that take part in the positive feedback loop between FOXM1/AKT has the double advantage of suppressing both, and can lead to developing novel anti-cancer drugs.

MicroRNA-215-3p Suppresses the Growth, Migration, and Invasion of Colorectal Cancer by Targeting FOXM1

Previous investigations have indicated that microRNA-215-3p is dysregulated in many kinds of cancers and functions as oncogene or tumor suppressor. However, the potential role of microRNA-215-3p in the progression of colorectal cancer remains not well known. Herein, we demonstrated that microRNA-215-3p was downregulated in human colorectal cancer tissues and was reversely correlated to the lymph node metastasis of colorectal cancer. Overexpression of microRNA-215-3p inhibited the clonogenic abilities and metastasis-relevant traits of colorectal cancer cell in vitro. Consistently, upregulation of microRNA-215-3p inhibited the growth and metastasis of colorectal cancer cell in vivo. Forkhead box protein M1 was identified as a direct target of microRNA-215-3p and reexpression of forkhead box protein M1 reversed the suppressive impacts of microRNA-215-3p on the growth, mobility, and invasion abilities of colorectal cancer cell. Altogether, these results revealed the vital role of microRNA-215-3p in the tumorigenesis and metastasis of colorectal cancer.

High expression of FOXM1 critical for sustaining cell proliferation in mitochondrial DNA-less liver cancer cells

The copy number of mitochondrial DNA (mtDNA) is decreased in most cancer types, including hepatocellular carcinoma (HCC), compared to normal counterparts. However, a decrease in mtDNA usually leads to defects in cell proliferation, which contradicts the robustness of cancer cell proliferation. In this study, we found that four out of seven HCC cell lines were of the mtDNA-less type. Interestingly, FOXM1, a member of the FOX transcription factor family, was highly expressed in a subset of them with proliferative potential maintained. B-MYB, a partner of FOXM1, was also expressed in the same cell lines. RNAi-mediated experiments demonstrated that when FOXM1/B-MYB was silenced in the cell lines, cell cycle-related genes were downregulated, while p21^Cip1 was induced with senescence-associated β-galactosidase, resulting in G₁/S cell cycle arrest. These results suggest that high expression of FOXM1/B-MYB is critical for sustaining cell proliferation in mtDNA-less cells. In addition, we found that high expression of FOXM1 was mediated by the deubiquitinating enzyme, OTUB1, in one cell line. Thus, interference with FOXM1/B-MYB expression, such as through OTUB1 inhibition, may induce a dormant state of senescence-like proliferation arrest in mtDNA-less cancer cells. This finding may be utilized for the development of precision medicine for relevant cancers.

FOXM1 contributes to docetaxel resistance in castration-resistant prostate cancer by inducing AMPK/mTOR-mediated autophagy

Docetaxel-mediated chemotherapy is the first line therapy for metastatic castration-resistant prostate cancer (CRPC) patients, but its therapeutic benefit is limited by the development of resistance. Although Forkhead box protein M1 (FOXM1) has been implicated in prostate tumorigenesis and metastasis, its role in docetaxel resistance has not been studied. Here, we showed that FOXM1 expression was upregulated in the docetaxel resistant CRPC cell lines (PC3-DR and VCaP-DR) and knockdown of FOXM1 sensitized the cells to docetaxel both in vitro and in vivo. In addition, autophagy was found to be significantly enhanced in resistant cells. Moreover, FOXM1 overexpression cells showed increased autophagic flux and higher numbers of autophagosomes. Knockdown of ATG7, beclin-1 or cotreatment with chloroquine, partly restored sensitivity to docetaxel in the FOXM1-overexpressing cells. Mechanistically, FOXM1 targeted AMPK/mTOR to activate the autophagy pathway and altered docetaxel response in CRPC. These findings identify the role of FOXM1 as well as the mechanism underlying FOXM1 action in docetaxel sensitivity and may, therefore, aid in design of CRPC therapies.

Maternal Embryonic Leucine Zipper Kinase Promotes Tumor Growth and Metastasis via Stimulating FOXM1 Signaling in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a common gastrointestinal malignancy and is one of the most important cause of cancer related mortalities in the world. However, there is no clinically effective targeted therapeutic drugs for ESCC due to lack of valuable molecular therapeutic targets. In the present study, we investigated the biological function and molecular mechanisms of maternal embryonic leucine zipper kinase (MELK) in ESCC. The expression of MELK mRNA and protein was determined in cell lines and clinical samples of ESCC. MTT, focus formation and soft agar assays were carried out to measure cell proliferation and colony formation. Wound healing and transwell assays were used to assess the capacity of tumor cell migration and invasion. Nude mice models of subcutaneous tumor growth and lung metastasis were performed to examine the function of MELK in tumorigenecity and metastasis of ESCC cells. High expression of MELK was observed in ESCC cell line and human samples, especially in the metastatic tumor tissues. Moreover, overexpression of MELK promoted cell proliferation, colony formation, migration and invasion, and increased the expression and enzyme activity of MMP-2 and MMP-9 in ESCC cells. More importantly, enhanced expression of MELK greatly accelerated tumor growth and lung metastasis of ESCC cells in vivo. In contrast, knockdown of MELK by lentiviral shRNA resulted in an opposite effect both in vitro and in animal models. Mechanistically, MELK facilitated the phosphorylation of FOXM1, leading to activation of its downstream targets (PLK1, Cyclin B1, and Aurora B), and thereby promoted tumorigenesis and metastasis of ESCC cells. In conclusion, MELK enhances tumorigenesis, migration, invasion and metastasis of ESCC cells via activation of FOXM1 signaling pathway, suggesting MELK is a potential therapeutic target for ESCC patients, even those in an advanced stage.

TPGS-1000 exhibits potent anticancer activity for hepatocellular carcinoma in vitro and in vivo

D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS1000) is the most active water-soluble derivative of vitamin E and has been widely used as a carrier of solvents, plasticizers, emulsifiers, absorbent agents and refractory drug delivery systems. However, its anti-hepatocellular carcinoma (HCC) properties have not been explored. HCC cells were treated with different concentrations of TPGS1000. Cell survival was tested by CCK8 assay, and cell migration was tested by wound healing and Transwell assay. EdU staining verified cell proliferation, and signalling pathway was assayed by Western blot analysis. The BALB/c-nu mouse xenograft model was established to test HCC cell growth in vivo. In vitro TPGS1000 significantly inhibited the viability and mobility of HCC cells (HepG2, Hep3B and Huh7) in a dose-dependent manner. Cell cycle analysis indicated that TPGS1000 treatment arrested the HCC cell cycle in the G0/G1 phase, and induction of cell apoptosis was confirmed by TUNEL and Annexin V-7-AAD staining. Further pharmacological analysis indicated that collapse of the transmembrane potential of mitochondria, increased ROS generation, PARP-induced cell apoptosis and FoxM1-p21-mediated cell cycle arresting, were involved in the anti-HCC activity of TPGS1000. Moreover, treatment in vivo with TPGS1000 effectively impaired the growth of HCC xenografts in nude mice.

Suppression of Hepatocellular Carcinoma Progression through FOXM1 and EMT Inhibition via Hydroxygenkwanin-Induced miR-320a Expression

Daphne genkwa, a Chinese medicinal herb, is used frequently in Southeast Asian countries to treat diseases; the flavonoid hydroxygenkwanin (HGK) is extracted from its flower buds. The bioactivity of HGK, particularly as an anti-liver cancer agent, has not been explored. In this study, human hepatocellular carcinoma (HCC) cell lines and an animal xenograft model were employed to investigate both the activity of HGK against liver cancer and its cellular signaling mechanisms. HCC cells treated with HGK were subjected to cell function assays. Whole transcriptome sequencing was used to identify genes whose expression was influenced by HGK, and the flavonoid’s cancer suppression mechanisms were further investigated through gain- and loss-of-function assays. Finally, in vitro findings were tested in a mouse xenograft model. The data showed that HGK induced the expression of the microRNA miR-320a, which in turn inhibited the expression of the transcription factor ‘forkhead box protein M1’ (FOXM1) and downstream FOXM1-regulated proteins related to epithelial–mesenchymal transition, thereby leading to the suppression of liver cancer cell growth and invasion. Significant inhibition of tumor growth was also observed in HGK-treated mice. Hence, the present study demonstrated the activity of HGK against liver cancer and validated its potential use as a therapeutic agent.

The role of myoglobin in epithelial cancers: Insights from transcriptomics

The muscle-associated respiratory protein myoglobin (MB) is expressed in multiple types of cancer, including breast and prostate tumors. In Kaplan-Meier analyses of the two tumor types, MB positivity is associated with favorable prognoses. Despite its well-characterized function in myocytes, the role of MB in cancer remains unclear. To study the impact of endogenous MB expression, small interfering RNA MB-knockdown cells were engineered using breast, prostate and colon cancer cell lines (MDA-MB468, LNCaP, DLD-1), and their transcriptomes were investigated using RNA-Seq at different oxygen levels. In MB-positive cells, increased expression of glycolytic genes was observed, which was possibly mediated by a higher activity of hypoxia-inducible factor 1α. In addition, the results of the gene set enrichment analysis suggested that MB contributed to fatty acid transport and turnover. MB-positive, wild-type-p53 LNCaP cells also exhibited increased expression of p53 target genes involved in cell cycle checkpoint control and prevention of cell migration. MB-positive cells expressing mutant p53 exhibited upregulation of genes associated with prolonged cancer cell viability and motility. Therefore, it was hypothesized that these transcriptomic differences may result from MB-mediated generation of nitric oxide or reactive oxygen species, thus employing established enzymatic activities of the globin. In summary, the transcriptome comparisons identified potential molecular functions of MB in carcinogenesis by highlighting the interaction of MB with key metabolic and regulatory processes.

The transcription factor FOXM1 regulates the balance between proliferation and aberrant differentiation in head and neck squamous cell carcinoma

Sustained expression of FOXM1 is a hallmark of nearly all human cancers including squamous cell carcinomas of the head and neck (HNSCC). HNSCCs partially preserve the epithelial differentiation program, which recapitulates fetal and adult traits of the tissue of tumor origin but is deregulated by genetic alterations and tumor-supporting pathways. Using shRNA-mediated knockdown, we demonstrate a minimal impact of FOXM1 on proliferation and migration of HNSCC cell lines under standard cell culture conditions. However, FOXM1 knockdown in three-dimensional (3D) culture and xenograft tumor models resulted in reduced proliferation, decreased invasion, and a more differentiated-like phenotype, indicating a context-dependent modulation of FOXM1 activity in HNSCC cells. By ectopic overexpression of FOXM1 in HNSCC cell lines, we demonstrate a reduced expression of cutaneous-type keratin K1 and involucrin as a marker of squamous differentiation, supporting the role of FOXM1 in modulation of aberrant differentiation in HNSCC. Thus, our data provide a strong rationale for targeting FOXM1 in HNSCC. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

HHLA2 is a novel prognostic predictor and potential therapeutic target in malignant glioma

Glioma is the most common and aggressive tumor type of the central nervous system and is associated with poor prognosis. To date, novel emerging immunotherapies have significantly improved outcomes for patients with various cancer types. Human endogenous retrovirus‑H long terminal repeat‑associating protein 2 (HHLA2), a newly discovered immune checkpoint molecule, has demonstrated its potential as a novel therapeutic target. Therefore, the present study aimed to investigate the clinical prognostic value of HHLA2 in gliomas and its mechanistic role. A systematic review of datasets from The Cancer Genome Atlas was performed. The RNA‑seq data of a total of 669 cases were analyzed and the biological function of HHLA2 was predicted by Gene Ontology (GO) and pathway enrichment analysis. Immunohistochemistry labelling images for HHLA2 was obtained from the Human Protein Atlas. xCell was used to comprehensively analyze the model of tumor‑infiltrating immune cell in glioma. The Cox proportional hazards regression model was used to predict outcomes for glioma patients. The results revealed that the expression levels of HHLA2 were significantly lower in high‑grade glioma, as well as glioma with wild‑type isocitrate dehydrogenase, no deletion of 1p/19q and telomerase reverse transcriptase promoter mutation. Receiver operating characteristic analysis revealed that HHLA2 was a predictor of the neural subtype. The tumor‑infiltrating immune cell model indicated that HHLA2 was negatively associated with tumor‑associated macrophages. GO analysis and pathway enrichment analysis revealed that HHLA2‑associated genes were functionally involved in inhibition of neoplasia‑associated processes. HHLA2 was significantly negatively correlated with certain genes, including interleukin‑10, transforming growth factor‑β, vascular endothelial growth factor and δ‑like canonical Notch ligand 4, and other immune checkpoint molecules, including programmed cell death 1, lymphocyte activating 3 and CD276. Survival analysis indicated that high expression of HHLA2 predicted a favorable prognosis. In conclusion, the present study revealed that upregulation of HHLA2 is significantly associated with a favorable outcome for patients with glioma. Targeting HHLA2 as an immune stimulator may become a valuable approach for the treatment of glioma in clinical practice.

Suppression of FOXM1 activities and breast cancer growth in vitro and in vivo by a new class of compounds

The transcription factor FOXM1 is upregulated and overexpressed in aggressive, therapy-resistant forms of hormone receptor-positive and triple negative breast cancers, and is associated with less good patient survival. FOXM1 signaling is also a key driver in many other cancers. Here, we identify a new class of compounds effective in suppressing FOXM1 activity in breast cancers, and displaying good potency for antitumor efficacy. The compounds bind directly to FOXM1 and alter its proteolytic sensitivity, reduce the cellular level of FOXM1 protein by a proteasome- dependent process, and suppress breast cancer cell proliferation and cell cycle progression and increase apoptosis. RNA-seq and gene set enrichment analyses indicate that the compounds decrease expression of FOXM1-regulated genes and suppress gene ontologies under FOXM1 regulation. Several compounds have favorable pharmacokinetic properties and show good tumor suppression in preclinical breast tumor models. These compounds may be suitable for further clinical evaluation in targeting aggressive breast cancers driven by FOXM1.

Expression of FSCN1 and FOXM1 are associated with poor prognosis of adrenocortical carcinoma patients

Background

Adrenocortical carcinoma (ACC) is a rare malignant endocrine tumour. Due to a high tumour recurrence rate, the post-operative overall survival (OS) and disease-free survival (DFS) of ACCs is limited. Our research aims to identify the role of the epithelial-mesenchymal transition (EMT) related genes FSCN1 and FOXM1 in the tumour microenvironment and assess their prognostic value in ACCs.

Methods

Clinical and specimen data from 130 adrenocortical carcinoma (ACC) patients was acquired from the Cancer Genome Atlas (TCGA) database (n = 79) and a West China Hospital (WCH) cohort (n = 51). In the WCH cohort, archived formalin-fixed paraffin embedded (FFPE) samples were collected for immunohistochemical analysis. The correlation between the EMT genes and the tumour microenvironment status was estimated based on the Tumour Immune Estimation Resource (TIMER) algorithm. Kaplan-Meier analysis, followed by univariate and multivariate regression analyses, were performed to identify the prognostic association of FSCN1 and FOXM1.

Results

FSCN1 and FOXM1 were over-expressed in ACC tissue when compared with adrenocortical adenoma and normal adrenal tissue. Over-expression of FSCN1 or FOXM1 was associated with the tumour microenvironment and immune signatures in ACCs. Patients with higher expression of FSCN1 or FOXM1 were more likely to have worse prognoses. The prognostic effects were further verified in both early (stage I/II) and advanced (stage III/IV) ACCs. Furthermore, FSCN1 and FOXM1 appeared as independent prognostic factors in ACC.

Conclusions

These results show that FSCN1 and FOXM1 are independent prognostic factors in ACCs and over-expression of FSCN1 or FOXM1 indicates a worse prognosis.

A novel FoxM1-PSMB4 axis contributes to proliferation and progression of cervical cancer

The abnormally high activity of the proteasome system is closely related to the occurrence and development of various tumors. PSMB4 is a non-catalytic subunit for the proteasome assembly. Although the reports from genetic screening have demonstrated it's a driver gene for cell growth in several types of solid tumor, its expression pattern and regulatory mechanisms in malignant diseases are still elusive. Here, we found that PSMB4 is overexpressed in cervical cancer tissues. And knockdown of PSMB4 significantly inhibited cervical cancer cell proliferation. The mechanistic study revealed that FoxM1, a master regulator of cell division, binds directly to the promoter region of PSMB4 and regulates the PSMB4 expression in the mRNA level. In addition, the data analysis from TCGA showed a positive correlation between FxoM1 and PSMB4 in cervical cancer. Furthermore, the loss of functional and rescue experiments confirmed that PSMB4 is required for FoxM1-driven cervical cancer cell proliferation. Collectively, our study explains the phenomenon of dysregulated expression of PSMB4 in cervical cancer tissues and verifies its driver effect on cancer cell proliferation. More importantly, it highlights a FoxM1-PSMB4 axis could be a potential target for the treatment of cervical cancer.

Transcription Factors That Govern Development and Disease: An Achilles Heel in Cancer

Development requires the careful orchestration of several biological events in order to create any structure and, eventually, to build an entire organism. On the other hand, the fate transformation of terminally differentiated cells is a consequence of erroneous development, and ultimately leads to cancer. In this review, we elaborate how development and cancer share several biological processes, including molecular controls. Transcription factors (TF) are at the helm of both these processes, among many others, and are evolutionarily conserved, ranging from yeast to humans. Here, we discuss four families of TFs that play a pivotal role and have been studied extensively in both embryonic development and cancer—high mobility group box (HMG), GATA, paired box (PAX) and basic helix-loop-helix (bHLH) in the context of their role in development, cancer, and their conservation across several species. Finally, we review TFs as possible therapeutic targets for cancer and reflect on the importance of natural resistance against cancer in certain organisms, yielding knowledge regarding TF function and cancer biology.

Integrated transcriptomics reveals master regulators of lung adenocarcinoma and novel repositioning of drug candidates

BACKGROUND

Lung adenocarcinoma is the major cause of cancer-related deaths in the world. Given this, the importance of research on its pathophysiology and therapy remains a key health issue. To assist in this endeavor, recent oncology studies are adopting Systems Biology approaches and bioinformatics to analyze and understand omics data, bringing new insights about this disease and its treatment.

METHODS

We used reverse engineering of transcriptomic data to reconstruct nontumorous lung reference networks, focusing on transcription factors (TFs) and their inferred target genes, referred as regulatory units or regulons. Afterwards, we used 13 case-control studies to identify TFs acting as master regulators of the disease and their regulatory units. Furthermore, the inferred activation patterns of regulons were used to evaluate patient survival and search drug candidates for repositioning.

RESULTS

The regulatory units under the influence of ATOH8, DACH1, EPAS1, ETV5, FOXA2, FOXM1, HOXA4, SMAD6, and UHRF1 transcription factors were consistently associated with the pathological phenotype, suggesting that they may be master regulators of lung adenocarcinoma. We also observed that the inferred activity of FOXA2, FOXM1, and UHRF1 was significantly associated with risk of death in patients. Finally, we obtained deptropine, promazine, valproic acid, azacyclonol, methotrexate, and ChemBridge ID compound 5109870 as potential candidates to revert the molecular profile leading to decreased survival.

CONCLUSION

Using an integrated transcriptomics approach, we identified master regulator candidates involved with the development and prognostic of lung adenocarcinoma, as well as potential drugs for repurposing.

UCHL3 promotes pancreatic cancer progression and chemo-resistance through FOXM1 stabilization

The dysregulation of deubiquitinating enzymes has been reported to be important in the development of many human cancers, including pancreatic cancer. However, the precise role and potential mechanism of action of the deubiquitinating enzyme UCHL3 in pancreatic cancer progression and chemo-resistance, are poorly elucidated. In the current study, the consequences of UCHL3 knockdown in pancreatic cancer cells were evaluated via cell viability and colony formation assays. In vivo experiments were also conducted to confirm the effect of UCHL3 and FOXM1 depletion on tumor growth in nude mouse xenograft models. Cell migration and invasion were assessed by wound-healing and transwell assays, respectively. Co-immunoprecipitation (co-IP) and in vitro deubiquitination assays were performed to investigate the interactions between UCHL3 and FOXM1. Immunohistochemical (IHC) staining was utilized to examine the expression of UCHL3 and FOXM1 in pancreatic cancer tissues. Our results demonstrate that UCHL3 deubiquitinated and stabilized FOXM1, thereby potentiating proliferation, migration, and invasion of pancreatic cancer cells. Furthermore, knockdown of UCHL3 increased FOXM1 ubiquitination, which enhanced FOXM1 turnover and promoted pancreatic cancer cells' sensitivity to gemcitabine. High UCHL3 expression was positively associated with FOXM1 expression level in pancreatic cancer patient samples. Collectively, our study established the UCHL3-FOXM1 axis as a pivotal driver of pancreatic cancer progression and gemcitabine resistance and provided evidence for the potential therapeutic benefit of targeting the UCHL3-FOXM1 axis for pancreatic cancer treatment.

Aurora kinase A stabilizes FOXM1 to enhance paclitaxel resistance in triple-negative breast cancer

Triple-negative breast cancer (TNBC) has a relatively poor outcome. Acquired chemoresistance is a major clinical challenge for TNBC patients. Previously, we reported that kinase-dead Aurora kinase A (Aurora-A) could effectively transactivate the FOXM1 promoter. Here, we demonstrate an additional pathway through which Aurora-A stabilizes FOXM1 by attenuating its ubiquitin in TNBC. Specifically, Aurora-A stabilizes FOXM1 in late M phase and early G1 phase of the cell cycle, which promotes proliferation of TNBC cells. Knock-down of Aurora-A significantly suppresses cell proliferation in TNBC cell lines and can be rescued by FOXM1 overexpression. We observe that paclitaxel-resistant TNBC cells exhibit high expression of Aurora-A and FOXM1. Overexpression of Aurora-A offers TNBC cells an additional growth advantage and protection against paclitaxel. Moreover, Aurora-A and FOXM1 could be simultaneously targeted by thiostrepton. Combination of thiostrepton and paclitaxel treatment reverses paclitaxel resistance and significantly inhibits cell proliferation. In conclusion, our study reveals additional mechanism through which Aurora-A regulates FOXM1 and provides a new therapeutic strategy to treat paclitaxel-resistant triple-negative breast cancer.

HMGA1 promotes breast cancer angiogenesis supporting the stability, nuclear localization and transcriptional activity of FOXM1

Background

Breast cancer is the most common malignancy in women worldwide. Among the breast cancer subtypes, triple-negative breast cancer (TNBC) is the most aggressive and the most difficult to treat. One of the master regulators in TNBC progression is the architectural transcription factor HMGA1. This study aimed to further explore the HMGA1 molecular network to identify molecular mechanisms involved in TNBC progression.

Methods

RNA from the MDA-MB-231 cell line, silenced for HMGA1 expression, was sequenced and, with a bioinformatic analysis, molecular partners HMGA1 could cooperate with in regulating common downstream gene networks were identified. Among the putative partners, the FOXM1 transcription factor was selected. The relationship occurring between HMGA1 and FOXM1 was explored by qRT-PCR, co-immunoprecipitation and protein stability assays. Subsequently, the transcriptional activity of HMGA1 and FOXM1 was analysed by luciferase assay on the VEGFA promoter. The impact on angiogenesis was assessed in vitro, evaluating the tube formation ability of endothelial cells exposed to the conditioned medium of MDA-MB-231 cells silenced for HMGA1 and FOXM1 and in vivo injecting MDA-MB-231 cells, silenced for the two factors, in zebrafish larvae.

Results

Here, we discover FOXM1 as a novel molecular partner of HMGA1 in regulating a gene network implicated in several breast cancer hallmarks. HMGA1 forms a complex with FOXM1 and stabilizes it in the nucleus, increasing its transcriptional activity on common target genes, among them, VEGFA, the main inducer of angiogenesis. Furthermore, we demonstrate that HMGA1 and FOXM1 synergistically drive breast cancer cells to promote tumor angiogenesis both in vitro in endothelial cells and in vivo in a zebrafish xenograft model. Moreover, using a dataset of breast cancer patients we show that the co-expression of HMGA1, FOXM1 and VEGFA is a negative prognostic factor of distant metastasis-free survival and relapse-free survival.

Conclusions

This study reveals FOXM1 as a crucial interactor of HMGA1 and proves that their cooperative action supports breast cancer aggressiveness, by promoting tumor angiogenesis. Therefore, the possibility to target HMGA1/FOXM1 in combination should represent an attractive therapeutic option to counteract breast cancer angiogenesis.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1307-8) contains supplementary material, which is available to authorized users.

Prenylated xanthones from Metaxya rostrata suppress FoxM1 and induce active cell death by distinct mechanisms

BACKGROUND

Metaxya rostrata C.Presl (Metaxyaceae) is a tree fern widespread in Central and South America and the dried rhizome is used in ethnic medicine against intestinal ulcers or tumors. An activity-guided isolation resulted in two structurally related xanthones: 2-deprenyl-rheediaxanthone B (XB) and 2-deprenyl-7-hydroxy-rheediaxanthone B (OH-XB).

HYPOTHESIS/PURPOSE

This study analyzed the cytotoxic activity and underlying cellular mechanisms of OH-XB for the first time in comparison to XB.

METHODS

We exposed the colorectal cancer cell line SW480 and F331 fibroblasts to XB and OH-XB and determined cell viability by neutral red uptake and nuclear morphology by staining with Hoechst dye. Cell cycle distribution and the mechanism of cell death were analyzed by FACS and western blot. Knockdown of FoxM1 expression was performed with siRNA.

RESULTS

OH-XB was at least as cytotoxic as XB in the induction of cell cycle arrest and active cell death. While both compounds strongly inhibited the transcription factor FoxM1, the cellular mechanisms of growth arrest and cell death induction differed widely: OH-XB induced S-phase cell cycle arrest in contrast to a G2-M-phase arrest by XB. It caused morphological modifications typical for classical apoptosis with increased caspase 7 activity and enhanced cleavage of PARP, while XB caused caspase 2 activation and mitotic catastrophe. After knockdown of FoxM1 expression no induction of caspase activity could be observed.

CONCLUSION

In summary, our data clearly showed that XB and OH-XB are promising new lead compounds for cancer therapy with distinct cellular mechanisms. Both compounds are candidates for further pre-clinical and clinical investigations.

E2A attenuates tumor-initiating capacity of colorectal cancer cells via the Wnt/beta-catenin pathway

BACKGROUND

The E2A gene, which encodes two basic helix-loop-helix transcription factors, E12 and E47, regulates colorectal cancer progression and epithelial-mesenchymal transition. However, whether E2A regulates the tumor-initiating capacity of colorectal cancer is unclear. Thus, we have studied E2A expression in the initiation of colorectal cancer in vivo and in vitro.

METHODS

Immunohistochemistry and immunoblot were performed to determine protein levels of E2A in colorectal cancer specimens and cells. RNAi was employed to downregulate E2A expression, and the subsequent change in protein level was evaluated by immunoblot. Sphere-forming assay and enumeration of liver metastasis in mouse models were used to identify the tumor formation ability of colorectal cancer cells.

RESULTS

E2A expression in colorectal cancer clinical specimens was inversely associated with patients' progression-free survival. Functional studies demonstrated that E2A significantly decreased tumor formation in vitro and in vivo. Furthermore, nuclear translocation of beta-catenin and activation of the Wnt/beta-catenin pathway occurred after suppression of E2A in colorectal cancer cells. FoxM1 was identified as a down-stream target by mRNA microarray, implying that FoxM1 plays a main role in determining how E2A regulates the tumor-initiating capacity of colorectal cancer.

CONCLUSION

E2A suppresses tumor-initiating capacity by targeting the FoxM1-Wnt/β-catenin pathway.

Large-scale gene expression analysis reveals robust gene signatures for prognosis prediction in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the leading cause of cancer-related death worldwide. High mortality in LUAD motivates us to stratify the patients into high- and low-risk groups, which is beneficial for the clinicians to design a personalized therapeutic regimen. To robustly predict the risk, we identified a set of robust prognostic gene signatures and critical pathways based on ten gene expression datasets by the meta-analysis-based Cox regression model, 25 of which were selected as predictors of multivariable Cox regression model by MMPC algorithm. Gene set enrichment analysis (GSEA) identified the Aurora-A pathway, the Aurora-B pathway, and the FOXM1 transcription factor network as prognostic pathways in LUAD. Moreover, the three prognostic pathways were also the biological processes of G2-M transition, suggesting that hyperactive G2-M transition in cell cycle was an indicator of poor prognosis in LUAD. The validation in the independent datasets suggested that overall survival differences were observed not only in all LUAD patients, but also in those with a specific TNM stage, gender, and age group. The comprehensive analysis demonstrated that prognostic signatures and the prognostic model by the large-scale gene expression analysis were more robust than models built by single data based gene signatures in LUAD overall survival prediction.

circANKS1B regulates FOXM1 expression and promotes cell migration and invasion by functioning as a sponge of the miR-149 in colorectal cancer

Background: Circular RNAs (circRNAs) and microRNAs (miRNAs) play key roles in the development of human cancers. CircANKS1B has been reported to be increased in breast cancer. Methods: Real-time polymerase chain reaction (real-time PCR) assay was used to measure expressions of circANKS1B, ANKS1B, and FOXM1. Western blot assay was employed to examine the protein level of FOXM1 and Slug. The abilities of cell migration and invasion were measured by wound-healing and transwell assays. The interaction between circANKS1B and miR-149 was confirmed by site-directed mutagenesis and luciferase assays. Results: The expression of circANKS1B was up-regulated in colorectal cancer tissues and cells. Additionally, circANKS1B increased the expression of FOXM1. Furthermore, the enhancement of CRC cell migration and invasion by circANKS1B was dependent on FOXM1. However, previous studies have shown that miR-149 can directly target FOXM1 and act as tumor suppressor in CRC. Consequently, our results showed that miR-149 could directly bind to circANKS1B and FOXM1. The inhibition of circANKS1B could reduce FOXM1 and Slug protein levels, thus suppressing CRC cell migration and invasion. Conclusion: Taken together, circANKS1B promotes colorectal cancer cell migration and invasion by acting as a molecular sponge of miR-149 to modulate FOXM1 and Slug protein levels.

Correlated low IGF2BP1 and FOXM1 expression predicts a good prognosis in lung adenocarcinoma

IGF2BP1 and FOXM1 are shown to be critical in the regulation of caner progression. However, the prognostic value of IGF2BP1 in lung adenocarcinoma and its relationship with FOXM1 still remains unclear. In this study, the expression and biological significance of both IGF2BP1 and FOXM1 were evaluated in 188 lung adenocarcinoma, at mRNA and protein levels. We showed that mRNA and protein levels of IGF2BP1 and FOXM1 were upregulated in lung adenocarcinoma compared to adjacent non-cancerous tissues. High IGF2BP1 expression was correlated with a poor prognosis for lung adenocarcinoma patients. Moreover, IGF2BP1 expression was positively associated with FOXM1 expression. Meanwhile, the findings indicated that low IGF2BP1 combined with low FOXM1 expression, was negatively correlated with pathological stage and lymph node metastasis, predicted good outcomes for lung adenocarcinoma patients. Additionally, low IGF2BP1 and FOXM1 expression status, is an independent prognostic factor for lung adenocarcinoma after surgical resection. We demonstrate that low IGF2BP1 and FOXM1 expression can serve as a potential factor for the clinical diagnosis and prognosis of lung adenocarcinoma, and targeted inhibition of IGF2BP1 and FOXM1 might be an alternative strategy for the management of lung adenocarcinoma.

PRRX1 isoforms cooperate with FOXM1 to regulate the DNA damage response in pancreatic cancer cells

PRRX1 is a homeodomain transcriptional factor, which has two isoforms, PRXX1A and PRRX1B. The PRRX1 isoforms have been demonstrated to be important in pancreatic cancer, especially in the regulation of epithelial-to-mesenchymal transition (EMT) in Pancreatic Ductal Adenocarcinoma (PDAC) and of mesenchymal-to-epithelial transition (MET) in liver metastasis. In order to determine the functional underpinnings of PRRX1 and its isoforms, we have unraveled a new interplay between PRRX1 and the FOXM1 transcriptional factors. Our detailed biochemical analysis reveals the direct physical interaction between PRRX1 and FOXM1 proteins that requires the PRRX1A/B 200-222/217 amino acid (aa) region and the FOXM1 Forkhead domain. Additionally, we demonstrate the cooperation between PRRX1 and FOXM1 in the regulation of FOXM1-dependent transcriptional activity. Moreover, we establish FOXM1 as a critical downstream target of PRRX1 in pancreatic cancer cells. We demonstrate a novel role for PRRX1 in the regulation of genes involved in DNA repair pathways. Indeed, we show that expression of PRRX1 isoforms may limit the induction of DNA damage in pancreatic cancer cells. Finally, we demonstrate that targeting FOXM1 with the small molecule inhibitor FDI6 suppress pancreatic cancer cell proliferation and induces their apoptotic cell death. FDI6 sensitizes pancreatic cancer cells to Etoposide and Gemcitabine induced apoptosis. Our data provide new insights into PRRX1's involvement in regulating DNA damage and provide evidence of a possible PRRX1-FOXM1 axis that is critical for PDAC cells.

The multifaceted roles of FOXM1 in pulmonary disease

Forkhead box M1 (FOXM1), a transcriptional regulator of G1/S and G2/M transition and M phase progression in the cell cycle, plays a principal role in many physiological and pathological processes. A growing number of studies have focused on the relationship between abnormal FOXM1 expression and pulmonary diseases, such as lung cancer, chronic obstructive pulmonary disease (COPD), asthma, acute lung injury (ALI), pulmonary fibrosis, and pulmonary arterial hypertension (PAH). These studies indicate that the FOXM1 regulatory network is a major predictor of poor outcomes, especially in lung cancer, and provide novel insight into various pulmonary diseases. For the first time, this review summarizes the mechanistic relationship between FOXM1 dysregulation and pulmonary diseases, the benefits of targeting abnormal FOXM1 expression, and the questions that remain to be addressed in the future.

FOXM1 plays a role in autophagy by transcriptionally regulating Beclin-1 and LC3 genes in human triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) is associated with poor prognosis owing to its aggressive and heterogeneous nature, and the lack of therapeutic targets. Although Forkhead Box M1 (FOXM1) is one of the most important oncogenes contributing to tumorigenesis, progression, and drug resistance in TNBC, the underlying molecular mechanisms are not well understood. Emerging evidence indicates that autophagy plays a critical role in cell survival and protective mechanism in TNBC. However, signaling pathways that are involved in the regulation of autophagy remain to be elucidated. In the present study, we examined the role of FOXM1 in regulating autophagy in TNBC cells and found that FOXM1 is upregulated during induction of autophagy. We found that inhibition of FOXM1 suppressed starvation and rapamycin-induced autophagy and expression of the major autophagy regulators, LC3 and Beclin-1. Further studies demonstrated that FOXM1 directly binds to the promotors of LC3 and Beclin-1 genes and transcriptionally regulates their expression by chromatin immunoprecipitation (ChIP) and luciferase gene reporter assays. In conclusion, our study provides the first evidence about the role of FOXM1 in regulating expression of LC3 and Beclin-1 and autophagy in TNBC cells. Our findings provide novel insight into the role of FOXM1 regulation of the autophagic survival pathway and potential molecular target for treating TNBC. KEY MESSAGES: • FOXM1 promotes tumorigenesis and progression of TNBC. However, the underlying molecular mechanism by which FOXM1 promotes TNBC tumorigenesis is unclear. The goal of our study was to determine the role of FOXM1 in the regulation of autophagy that plays a role in TNBC progression. Our findings show that FOXM1 binds to promoters of the genes encoding the major autophagy proteins, Beclin and LC3, and provide new insights into the regulation of autophagy, which is being targeted in many clinical trials.

Alternatively activated NUSAP1 promotes tumor growth and indicates poor prognosis in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies with high mortality. The key genes involved in initiation and development of HCC is not entirely clear.

METHODS

We performed a meta-analysis of available transcriptome data from 6 independent HCC datasets [5 datasets from the Gene Expression Omnibus (GEO) and 1 dataset from The Cancer Genome Atlas (TCGA)]. The associations of the nucleolar and spindle-associated protein 1 (NUSAP1) expression level with clinicopathological factors and survival times were analyzed. Two representative HCC cell models were built to observe the proliferation capacity of HCC cells when NUSAP1 expression was inhibited by shNUSAP1.

RESULTS

Based on the transcriptome and survival data in the GEO and TCGA databases, NUSAP1 gene was markedly upregulated in HCC. High expression of NUSAP1 in HCC is related to the iCluster1 molecular subgroup, poor survival, poor tumor differentiation and TNM stage. Additionally, pathway analysis based on RNAseq data suggested that NUSAP1 could activate the expression of genes involves in cell proliferation. Furthermore, downregulation of NUSAP1 expression could significantly inhibit the proliferation of SMMC-7721 and Huh7 cells in vitro.

CONCLUSIONS

Our study provides evidence that NUSAP1 may serve as a candidate prognostic marker and a target for future therapeutic intervention in HCC.

Overexpression of FoxM1 predicts poor prognosis of intrahepatic cholangiocarcinoma

FoxM1 is an oncoprotein that is significantly overexpressed in many malignancies including hepatocellular carcinoma, but its role in intrahepatic cholangiocarcinoma (ICC) remains unclear. This study explores the expression of FoxM1 in human ICC, its relationships with clinical outcomes, and its role in the proliferation, migration, and invasion of ICC in vitro and in vivo. The results show that FoxM1 was markedly elevated in tumor tissues versus the paired peritumoral tissues. Overexpression of FoxM1 was correlated with multiple tumor nodules, tumor size > 5 cm, positive lymph node metastasis and advanced TNM stage. Cox analysis revealed that overexpression of FoxM1 is an independent prognostic indicator for both the overall survival and disease-free survival of ICC patients after hepatectomy. Furthermore, up/downregulation of FoxM1 markedly promoted/inhibited ICC cell proliferation, migration, and invasion in vitro and in vivo. Bioinformatic analysis indicated that overexpression of FoxM1 resulted in the dysregulation of multiple signaling pathways in ICC, and selected components of some key signaling pathways such as c-Myc signaling were confirmed in vitro. In addition, overexpression of FoxM1 enhanced MMP-9 and MMP-2 protein expression in ICC cells. In conclusion, FoxM1 promotes ICC progression and is a reliable predictor of poor prognosis in ICC.

Centromere protein U expression promotes non-small-cell lung cancer cell proliferation through FOXM1 and predicts poor survival

Purpose

Centromere protein U (CENPU) abnormally exhibits high expression in various types of human tumor tissues and participates in tumor progression; however, its expression pattern and biological function in lung cancer have not yet been elucidated. In the present study, we explored the clinical significance and biological function of CENPU in lung cancer.

Materials and methods

The Cancer Genome Atlas (TCGA) data analyses, quantitative real-time PCR (RT-PCR), and Western blotting were performed to quantify CENPU and FOXM1 expression in non-small-cell lung cancer (NSCLC) samples. Survival data were obtained from Kaplan–Meier plotter or PROGgene V2 prognostic database. The function of CENPU in lung cancer cell proliferation was determined using 5-ethynyl-2′-deoxyuridine (EdU), Cell Counting Kit-8 (CCK-8), and cell cycle assays, and the underlying mechanism was determined through bioinformatic analyses and validated by in vitro siRNA or plasmid transfection experiments.

Results

CENPU was abnormally overexpressed in NSCLC samples compared with matched paired normal tissues. Higher expression of CENPU predicted worse overall survival (OS) and relapse-free survival (RFS) in NSCLC patients. Knockdown of CENPU expression by siRNA significantly inhibited proliferation and delayed cell cycle progression of lung cancer cells. To figure out the mechanism, bioinformatic analyses were performed and the results showed that the transcription factor, FOXM1, positively correlated with CENPU. Further in vitro experiments indicated that FOXM1 was the possible downstream transcription factor of CENPU as the knockdown of CENPU led to lower expression of FOXM1 and the overexpression of FOXM1 significantly reversed the inhibition of proliferation caused by CENPU knockdown. Furthermore, FOXM1 was highly expressed in NSCLC. The knockdown of FOXM1 also attenuated proliferation and induced G1 arrest in lung cancer cells.

Conclusion

CENPU was highly expressed in NSCLC tissues, wherein it promoted lung cancer cell proliferation via the transcription factor, FOXM1, which could be a potential target for therapeutic strategies.

Identification of core genes and outcomes in hepatocellular carcinoma by bioinformatics analysis

Hepatocellular carcinoma (HCC) is the most common malignant liver disease in the world. However, the mechanistic relationships among various genes and signaling pathways are still largely unclear. In this study, we aimed to elucidate potential core candidate genes and pathways in HCC. The expression profiles GSE14520, GSE25097, GSE29721, and GSE62232, which cover 606 tumor and 550 nontumour samples, were downloaded from the Gene Expression Omnibus (GEO) database. Furthermore, HCC RNA-seq datasets were also downloaded from the Cancer Genome Atlas (TCGA) database. The differentially expressed genes (DEGs) were filtered using R software, and we performed gene ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analysis using the online databases DAVID 6.8 and KOBAS 3.0. Furthermore, the protein-protein interaction (PPI) network complex of these DEGs was constructed by Cytoscape software, the molecular complex detection (MCODE) plug-in and the online database STRING. First, a total of 173 DEGs (41 upregulated and 132 downregulated) were identified that were aberrantly expressed in both the GEO and TCGA datasets. Second, GO analysis revealed that most of the DEGs were significantly enriched in extracellular exosomes, cytosol, extracellular region, and extracellular space. Signaling pathway analysis indicated that the DEGs had common pathways in metabolism-related pathways, cell cycle, and biological oxidations. Third, 146 nodes were identified from the DEG PPI network complex, and two important modules with a high degree were detected using the MCODE plug-in. In addition, 10 core genes were identified, TOP2A, NDC80, FOXM1, HMMR, KNTC1, PTTG1, FEN1, RFC4, SMC4, and PRC1. Finally, Kaplan-Meier analysis of overall survival and correlation analysis were applied to these genes. The abovementioned findings indicate that the identified core genes and pathways in this bioinformatics analysis could significantly enrich our understanding of the development and recurrence of HCC; furthermore, these candidate genes and pathways could be therapeutic targets for HCC treatment.

FOXM1c promotes oesophageal cancer metastasis by transcriptionally regulating IRF1 expression

Objectives

We aimed to elucidate the role and molecular mechanisms of FOXM1 in regulating metastasis in oesophageal squamous cell carcinoma (ESCC) as well as its clinical implications.

Materials and methods

The expression levels of four isoforms of FOXM1 were analysed by real‐time PCR. Next, genetically modification using overexpression and RNAi systems and transwell were employed to examine FOXM1c function in invasion and migration. Dual luciferase and ChIP assays were performed to decipher the underlying mechanism for transcriptional regulation. The expression levels of FOXM1 and IRF1 were determined by immunohistochemistry staining in ESCC specimens.

Results

The FOXM1c was predominantly overexpressed in ESCC cell lines compared to the other FOXM1 isoforms. Ectopic expression of FOXM1c promoted invasion and migration of ESCC cells lines, whereas downregulation of FOXM1c inhibited these processes. Moreover, FOXM1c expression was positively correlated with IRF1 expression in ESCC cell lines and tumour specimens. IRF1 is, at least in part, responsible for FOXM1c‐mediated invasion and migration. Mechanistically, we identified IRF1 as a transcriptional target of FOXM1c and found a FOXM1c‐binding site in the IRF1 promoter region. Furthermore, high expression levels of both FOXM1c and IRF1 were positively associated with low survival rate and predicted a poor prognosis of oesophageal cancer patients.

Conclusion

FOXM1c promotes the metastasis by transcriptionally targeting IRF1 and may serve as a potential prognostic predictor for oesophageal cancer.

p53 modeling as a route to mesothelioma patients stratification and novel therapeutic identification

Background

Malignant pleural mesothelioma (MPM) is an orphan disease that is difficult to treat using traditional chemotherapy, an approach which has been effective in other types of cancer. Most chemotherapeutics cause DNA damage leading to cell death. Recent discoveries have highlighted a potential role for the p53 tumor suppressor in this disease. Given the pivotal role of p53 in the DNA damage response, here we investigated the predictive power of the p53 interactome model for MPM patients’ stratification.

Methods

We used bioinformatics approaches including omics type analysis of data from MPM cells and from MPM patients in order to predict which pathways are crucial for patients’ survival. Analysis of the PKT206 model of the p53 network was validated by microarrays from the Mero-14 MPM cell line and RNA-seq data from 71 MPM patients, whilst statistical analysis was used to identify the deregulated pathways and predict therapeutic schemes by linking the affected pathway with the patients’ clinical state.

Results

In silico simulations demonstrated successful predictions ranging from 52 to 85% depending on the drug, algorithm or sample used for validation. Clinical outcomes of individual patients stratified in three groups and simulation comparisons identified 30 genes that correlated with survival. In patients carrying wild-type p53 either treated or not treated with chemotherapy, FEN1 and MMP2 exhibited the highest inverse correlation, whereas in untreated patients bearing mutated p53, SIAH1 negatively correlated with survival. Numerous repositioned and experimental drugs targeting FEN1 and MMP2 were identified and selected drugs tested. Epinephrine and myricetin, which target FEN1, have shown cytotoxic effect on Mero-14 cells whereas marimastat and batimastat, which target MMP2 demonstrated a modest but significant inhibitory effect on MPM cell migration. Finally, 8 genes displayed correlation with disease stage, which may have diagnostic implications.

Conclusions

Clinical decisions related to MPM personalized therapy based on individual patients’ genetic profile and previous chemotherapeutic treatment could be reached using computational tools and the predictions reported in this study upon further testing in animal models.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1650-0) contains supplementary material, which is available to authorized users.

MiR-216b inhibits osteosarcoma cell proliferation, migration, and invasion by targeting Forkhead Box M1

Osteosarcoma (OS) is considered the most common type of primary malignant bone tumor, which has a high rate of mortality in children and adolescents. However, the current treatment methods for OS are ineffective. Therefore, there is an urgent requirement to identify the critical targets. This study aimed to identify the roles and significance of microRNA-216b (miR-216b) in OS. To explore the cellular and molecular functions of miR-216b and Forkhead Box M1 (FoxM1) in OS, the expression of miR-216b and FoxM1 at the transcriptional level was measured using quantitative real-time PCR (qRT-PCR). Wound healing assay, 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide assay (MTT) assay, flow cytometry, and transwell invasion assay were conducted to study the function of miR-216b and FoxM1 in OS cells. Dual luciferase reporter assay was performed to identify the relationships between miR-216b and FoxM1. qRT-PCR results revealed that miR-216b expression was significantly downregulated, and FoxM1 was observed to be significantly upregulated in human OS cell lines (MG-63) and tissues. MTT data showed that upregulation of miR-216b expression led to cell growth inhibition in MG-63 cells. The results of the invasion assay and wound healing assay illustrated that miR-216b upregulation or FoxM1 downregulation could inhibit the invasion and migration in MG-63 cells. In vivo, the tumor volume was significantly decreased by miR-194 mimic treatment compared with the control group. Furthermore, the results of the luciferase assay indicated that FoxM1 is a direct target of miR-216b. These findings may provide novel insights into the molecular mechanism of miR-216b and FoxM1 in the progression of OS, and suggested that miR-216b may serve as a potential tumor inhibitor of OS by targeting FoxM1.

Forkhead box M1 inhibits endothelial cell apoptosis and cell-cycle arrest through ROS generation

BACKGROUND

Hyperglycemia, a characteristic feature of diabetes, induces vascular complications by accelerating endothelial cell (EC) apoptosis and limiting their proliferation. The potential role of Forkhead box M1 (FoxM1) in high glucose (HG)-induced EC injury remains largely unknown. We aimed to investigate the role and underlying mechanism of FoxM1 in regulating EC injury.

MATERIAL AND METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with various concentrations of glucose (5.5, 15, 30 and 50 mM). The expression of FoxM1 was determined via qPCR and western blotting. Overexpression of FoxM1 was achieved by transfection with FoxM1 overexpression plasmid. Reactive oxygen species (ROS) production, cell apoptotic rates, and cell cycle analysis were detected by flow cytometry, and cell proliferation was measured by CCK8 assay.

RESULTS

The expression level of FoxM1 was downregulated in HUVECs under HG condition when compared to cells with normal glucose. HG treatment induced overproduction of ROS and subsequent apoptosis. However, FoxM1 overexpression of FoxM1 reduced the levels of ROS and inhibited apoptosis. In addition, HG induced impairment of cell proliferation and caused cell cycle arrest in the G0/G1 phrase. Contrarily, FoxM1 overexpression promoted cell proliferation and alleviated G0/G1 cell cycle arrest caused by HG stimulation. Moreover, treatment with HG reduced phosphorylation of the Akt and ERK signaling pathways, and this was remarkably reversed by FoxM1 overexpression.

CONCLUSION

FoxM1 protects ECs from HG-induced growth arrest and cell apoptosis by suppressing ROS caused by the regulation of Akt and ERK pathways, which can aid in developing new therapeutic strategies for the treatment of EC dysfunction.

Regulation of the master regulator FOXM1 in cancer

FOXM1 (forkhead box protein M1) is a critical proliferation-associated transcription factor that is widely spatiotemporally expressed during the cell cycle. It is closely involved with the processes of cell proliferation, self-renewal, and tumorigenesis. In most human cancers, FOXM1 is overexpressed, and this indicates a poor prognosis for cancer patients. FOXM1 maintains cancer hallmarks by regulating the expression of target genes at the transcriptional level. Due to its potential role as molecular target in cancer therapy, FOXM1 was named the Molecule of the Year in 2010. However, the mechanism of FOXM1 dysregulation remains indistinct. A comprehensive understanding of FOXM1 regulation will provide novel insight for cancer and other diseases in which FOXM1 plays a major role. Here, we summarize the transcriptional regulation, post-transcriptional regulation and post-translational modifications of FOXM1, which will provide extremely important implications for novel strategies targeting FOXM1.

SPDEF is overexpressed in gastric cancer and triggers cell proliferation by forming a positive regulation loop with FoxM1

The SAM-pointed domain-containing ETS transcription factor (SPDEF) is an epithelial-specific transcription factor of the E26 transformation-specific (ETS) family, which binds the target gene through the high-affinity sequence of GGAT. It is suggested that SPDEF targets the promoter activity of Forkhead Box M1 (FoxM1), which has been proven to be highly expressed in gastric cancer. We found that SPDEF was overexpressed both at the messenger RNA (mRNA) and at the protein level in human gastric cancer species. The gastric cancer cells transfected with the SPDEF expression plasmid or SPDEF small interfering RNA (siRNA) led to observations on the clone genetics assay that indicated the promotion or the inhibition of gastric cancer cell proliferation, respectively. Both mRNA and protein levels of FoxM1 were regulated by SPDEF in gastric cancer cells and FoxM1 was also overexpressed in the corresponding human gastric cancer species. The overexpression and inhibition of FoxM1 could upregulate and downregulate the mRNA and protein levels of SPDEF expression, respectively. The recovery experiments verified that the overexpression of FoxM1 could at least partially revert both the expression of SPDEF and the proliferation of the cell lines even with the siRNA inhibition of SPDEF. The result of the dual luciferase activity assay showed that SPDEF bound to the promoter of FoxM1 and activated it. FoxM1 might also bind to the promoter of SPDEF to affect its expression. The results were checked in vivo. In conclusion, SPDEF is overexpressed in gastric cancer, which can form a positive regulation loop with FoxM1 to promote gastric carcinogenesis.

Clinicopathological and prognostic significance of FoxM1 in hepatocellular carcinoma patients: a meta-analysis

Background and aims

Recently, the abnormal expression of FoxM1 has been found in many malignant tumors. However, the clinicopathological and prognostic value of FoxM1 expression in hepatocellular carcinoma (HCC) patients remains controversial. We conducted a meta-analysis to establish the relationship between FoxM1 expression and the clinicopathological features and prognostic value in patients with HCC.

Methods

An electronic search for relevant articles was conducted according to a set of criteria in the PubMed, Cochrane Library, Web of Science, EMBASE, Chinese CNKI and Chinese WanFang databases. The correlation data between FoxM1 expression and clinicopathological features and survival outcomes were analyzed. Pooled odds ratios (ORs) and hazard ratios (HRs) with 95% CIs were calculated using STATA14.2.

Results

A total of 14 studies comprising of 2,036 patients were enrolled in this meta-analysis. The results showed that FoxM1 expression was related to the incidence, tumor size (>5 cm), vascular invasion, differentiation and TNM stage. Moreover, overexpression of FoxM1 indicated a poor 3- and 5-year overall survival rate (OS) and recurrence-free survival rate (disease-free survival rate).

Conclusion

Our meta-analysis indicated that FoxM1 expression was associated with incidence, tumor size (>5 cm), vascular invasion, differentiation and TNM stage. Accordingly, FoxM1 may be a reliable prognostic biomarker for patients with HCC. However, additional high-quality studies are still needed to further support these findings.

Expression and functional characterization of FOXM1 in non-small cell lung cancer

Objectives

FOXM1 is a key member of the FOX transcription factor family, which plays a vital role in a series of physiological processes. In the present study, non-small cell lung cancer (NSCLC) patients and cell lines were studied to explore the correlation between FOXM1 expression and this malignancy.

Materials and methods

The expression status of FOXM1 was detected in 128 cases of NSCLC tissues and NSCLC cell lines. The relationship of FOXM1 expression and clinicopathological features of NSCLC patients was evaluated by us. In addition, we also explored the biological functions of FOXM1 in NSCLC cell lines.

Results

The FOXM1 is highly expressed in NSCLC tissues and cell lines. FOXM1 expression was closely correlated with lymph node status and TNM stage. Cox regression analysis were performed to demonstrate the prognosis role of FOXM1.

Conclusion

FOXM1 conferred a proliferation and invasion advantage to NSCLC cell. The FOXM1 can be regarded as an important molecular marker in NSCLC prognosis.

Targeting forkhead box M1 transcription factor in breast cancer

Breast cancer continues to be the most commonly diagnosed malignancy and second most common cause of cancer-related deaths among women in the United States. Improved understanding of the molecular heterogeneity of breast tumors and the approval of multiple targeted therapies have revolutionized the treatment landscape and long-term survival rates for patients with breast cancer. Despite the development of highly effective targeted agents, drug resistance and disease progression remain major clinical concerns. Improved understanding of the molecular mechanisms mediating drug resistance will allow new treatments to be developed. The forkhead box M1 (FoxM1) transcription factor is overexpressed in breast cancer and strongly associated with resistance to targeted therapies and chemotherapy. FoxM1 regulates all hallmarks of cancer, including proliferation, mitosis, EMT, invasion, and metastasis. Inhibition of FoxM1 transcription factor function is a potential strategy for overcoming breast cancer progression. In this research update, we review the role of FoxM1 in breast cancer and pharmacological approaches for blocking FoxM1 transcription factor function. Future preclinical studies should evaluate combination drug strategies to inhibit FoxM1 function and upstream kinase signaling pathways as potential strategies to treat resistant and metastatic breast cancers.