The roles of FOXM1 in pancreatic stem cells and carcinogenesis

Down-regulation of microRNA-23a promotes pancreatic ductal adenocarcinoma initiation and progression by up-regulation of FOXM1 expression

Transcriptional factor Forkhead box M1 (FOXM1) plays an important role in pancreatic ductal adenocarcinoma (PDAC) development and progression. The molecular mechanisms underlying its dysregulation remain unclear. We identified and functionally validated the microRNAs (miRNAs) that critically regulate FOXM1 expression in PDAC. The expression levels of miRNA-23a (miR-23a-3p and -5p) were altered in PDAC cell lines and their effects on FOXM1 signaling and cell proliferation and migration and tumorigenesis were examined in vitro and in vivo using mouse PDAC models. Compared with non-tumor pancreatic tissues, PDAC tissues and cell lines exhibited significantly reduced levels of miR-23a expression. Reduced miR-23a expression and concomitant increase in FOXM1 expression were also observed in acinar-to-ductal metaplasia and pancreatic intraepithelial neoplasia, the major premalignant lesions of PDAC. Transgenic expression of miR-23a reduced the expression of FOXM1 and suppressed cell proliferation and migration in PDAC cells, whereas the inhibitors of miR-23a did the opposite. Loss or reduced levels of miR-23a increased the levels of FOXM1 expression, while increased expression of FOXM1 down-regulated miR-23a expression, suggesting that miR-23a and FOXM1 were mutual negative regulators of their expression in PDAC cells. Therefore, the miR-23a/FOXM1 signaling axis is important in PDAC initiation and progression and could serve as an interventional or therapeutic target for patients with early or late stages of PDAC.

Cancer Stem Cells in Carcinogenesis and Potential Role in Pancreatic Cancer

A poor prognosis is associated with pancreatic cancer because of resistance during treatment and early distant metastases. The discovery of cancer stem cells has opened up novel avenues for research into the biology and treatment of cancer. Many investigations have pointed out the role of these types of stem cells in the oncogenesis and progression of hematologic and solid malignancies, specifically. Due to the existence of cancer stem cells in the proliferation and preservation of pancreatic tumors, such malignancies could be difficult to eradicate using conventional treatment techniques like chemotherapy and radiotherapy. It is hypothesized that pancreatic malignancies originate from a limited population of aberrant cancer stem cells to promote carcinogenesis, tumour metastasis, and therapeutic resistance. This review examines the role of pancreatic cancer stem cells in this disease and their significance in carcinogenesis, as well as the signals which modulate them, and also examines the ongoing clinical studies that are now being conducted with pancreatic stem cells.

From imaging to clinical outcome: dual-region CT radiomics predicting FOXM1 expression and prognosis in hepatocellular carcinoma

Background

Liver cancer, especially hepatocellular carcinoma (HCC), remains a significant global health challenge. Traditional prognostic indicators for HCC often fall short in providing comprehensive insights for individualized treatment. The integration of genomics and radiomics offers a promising avenue for enhancing the precision of HCC diagnosis and prognosis.

Methods

From the Cancer Genome Atlas (TCGA) database, we categorized mRNA of HCC patients by Forkhead Box M1 (FOXM1) expression and performed univariate and multivariate studies to pinpoint autonomous HCC risk factors. We deployed subgroup, correlation, and interaction analyses to probe FOXM1's link with clinicopathological elements. The connection between FOXM1 and immune cells was evaluated using the CIBERSORTx database. The functions of FOXM1 were investigated through analyses of Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). After filtering through TCGA and the Cancer Imaging Archive (TCIA) database, we employed dual-region computed tomography (CT) radiomics technology to noninvasively predict the mRNA expression of FOXM1 in HCC tissues. Radiomic features were extracted from both tumoral and peritumoral regions, and a radiomics score (RS) was derived. The performance and robustness of the constructed models were evaluated using 10-fold cross-validation. A radiomics nomogram was developed by incorporating RS and clinical variables from the TCGA database. The models' discriminative abilities were assessed using metrics such as the area under the curve (AUC) of the receiver operating characteristic curves (ROC) and precision-recall (PR) curves.

Results

Our findings emphasized the overexpression of FOXM1 as a determinant of poor prognosis in HCC and illustrated its impact on immune cell infiltration. After selecting arterial phase CT, we chose 7 whole-tumor features and 3 features covering both the tumor and its surroundings to create WT and WP models for FOXM1 prediction. The WT model showed strong predictive capabilities for FOXM1 expression by PR curve. Conversely, the WP model did not demonstrate the good predictive ability. In our study, the radiomics score (RS) was derived from whole-tumor regions on CT images. The RS was significantly associated with FOXM1 expression, with an AUC of 0.918 in the training cohort and 0.837 in the validation cohort. Furthermore, the RS was correlated with oxidative stress genes and was integrated with clinical variables to develop a nomogram, which demonstrated good calibration and discrimination in predicting 12-, 36-, and 60-month survival probabilities. Additionally, bioinformatics analysis revealed FOXM1's potential role in shaping the immune microenvironment, with its expression linked to immune cell infiltration.

Conclusion

This study highlights the potential of integrating FOXM1 expression and radiomics in understanding HCC's complexity. Our approach offers a new perspective in utilizing radiomics for non-invasive tumor characterization and suggests its potential in providing insights into molecular profiles. Further research is needed to validate these findings and explore their clinical implications in HCC management.

FABP5 inhibitor SBFI-26 regulates FOXM1 expression and Wnt signaling pathway in ovarian granulosa cell of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most prevalent endocrinopathy among females of reproductive age. Due to its unclear etiopathogenesis, it is of vital significance to take a deeper understanding of molecular mechanisms underlying PCOS. Quantitative real-time PCR (RT-qPCR) and western blot were applied for detection of gene expression and protein expression individually. Cell Counting Kit-8 (CCK-8) and colony formation assays were used for the evaluation of cell proliferation while Caspase-3/9 activity was measured for the assessment of cell apoptosis. We found that FOXM1 was overexpressed in ovarian granulosa cell (OGC) of patients with PCOS. Functionally, upregulation of FOXM1 promotes the proliferative ability of PCOS-OGC cells. As for mechanism, FOXM1 exerts its functions in PCOS-OGC cell through activation of the Wnt signaling pathway. More importantly, a novel FABP5 inhibitor, SBFI-26, was verified to downregulate the expression of FOXM1 to impede the proliferation of PCOS-OGC cells. In addition, SBFI-26 inactivates Wnt signaling pathway in PCOS-OGC cells. FABP5 inhibitor SBFI-26 regulates FOXM1 expression and Wnt signaling pathway in OGC of patients with PCOS, which might provide a new perspective into PCOS treatment.

Serine Metabolic Reprogramming in Tumorigenesis, Tumor Immunity, and Clinical Treatment

Serine has been recently identified as an essential metabolite for oncogenesis, progression, and adaptive immunity. Influenced by many physiologic or tumor environmental factors, the metabolic pathways of serine synthesis, uptake, and usage are heterogeneously reprogrammed and frequently amplified in tumor or tumor-associated cells. The hyperactivation of serine metabolism promotes abnormal cellular nucleotide/protein/lipid synthesis, mitochondrial function, and epigenetic modifications, which drive malignant transformation, unlimited proliferation, metastasis, immunosuppression, and drug resistance of tumor cells. Dietary restriction of serine or phosphoglycerate dehydrogenase depletion mitigates tumor growth and extends the survival of tumor patients. Correspondingly, these findings triggered a boom in the development of novel therapeutic agents targeting serine metabolism. In this study, recent discoveries in the underlying mechanism and cellular function of serine metabolic reprogramming are summarized. The vital role of serine metabolism in oncogenesis, tumor stemness, tumor immunity, and therapeutic resistance is outlined. Finally, some potential tumor therapeutic concepts, strategies, and limitations of targeting the serine metabolic pathway are described in detail. Taken together, this review underscores the importance of serine metabolic reprogramming in tumorigenesis and progression and highlights new opportunities for dietary restriction or selective pharmacologic intervention.

FOXM1: A small fox that makes more tracks for cancer progression and metastasis

Transcription factors (TFs) are indispensable for the modulation of various signaling pathways associated with normal cell homeostasis and disease conditions. Among cancer-related TFs, FOXM1 is a critical molecule that regulates multiple aspects of cancer cells, including growth, metastasis, recurrence, and stem cell features. FOXM1 also impact the outcomes of targeted therapies, chemotherapies, and immune checkpoint inhibitors (ICIs) in various cancer types. Recent advances in cancer research strengthen the cancer-specific role of FOXM1, providing a rationale to target FOXM1 for developing targeted therapies. This review compiles the recent studies describing the pivotal role of FOXM1 in promoting metastasis of various cancer types. It also implicates the contribution of FOXM1 in the modulation of chemotherapeutic resistance, antitumor immune response/immunotherapies, and the potential of small molecule inhibitors of FOXM1.

Research progress of sophoridine's pharmacological activities and its molecular mechanism: an updated review

Background: Sophoridine, the major active constituent of Sophora alopecuroides and its roots, is a bioactive alkaloid with a wide range of pharmacological effects, including antitumor, anti-inflammatory, antiviral, antibacterial, analgesic, cardioprotective, and immunoprotective activities. Sophora flavescens Aiton is a traditional Chinese medicine that is bitter and cold. Additionally, it also exhibits the effects of clearing heat, eliminating dampness, and expelling insects. Aims of the study: To summarize the pharmacological research and associated mechanisms of sophoridine, we compiled this review by combining a huge body of relevant literature. Materials and methods: The information related to this article was systematically collected from the scientific literature databases including PubMed, Google Scholar, Web of Science, Science Direct, Springer, China National Knowledge Infrastructure, published books, PhD and MS dissertations. Results: Its antitumor activity is particularly remarkable, as it can inhibit cancer cell proliferation, invasion, and metastasis while inducing cell cycle arrest and apoptosis. Additionally, sophoridine also holds therapeutic potential for myocardial ischemia, osteoporosis, arrhythmias, and neurological disorders, primarily through the suppression of related inflammatory factors and cell apoptosis. However, sophoridine has also exhibited adverse effects such as hepatotoxicity and neurotoxicity. The antidisease effect and mechanism of sophoridine are diverse, so it has high research value. Conclusion: As an important traditional Chinese medicine alkaloid, modern pharmacological studies have demonstrated that sophoridine has prominent bioactivities, especially on anti-tumor anti-inflammation activities, and cardiovascular system protection. These activities provide prospects for novel drug development for cancer and some chronic diseases. Nevertheless, the understanding of the multitarget network pharmacology, long-term in vivo toxicity, and clinical efficacy of sophoridine require further detailed research.

Glucotropaeolin Promotes Apoptosis by Calcium Dysregulation and Attenuates Cell Migration with FOXM1 Suppression in Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC) has naturally aggressive characteristics including postoperative recurrence, resistance to conventional treatment, and metastasis. Surgical resection with chemotherapeutic agents has been conducted as the major treatment for PDAC. However, surgical treatment is ineffective in the case of advanced cancer, and conventional adjuvant chemotherapy, including gemcitabine and 5-fluorouracil, show low effectiveness due to the high drug resistance of PDAC to this type of treatment. Therefore, the development of innovative therapeutic drugs is crucial to solving the present limitation of conventional drugs. Glucotropaeolin (GT) is a glucosinolate that can be isolated from the Brassicaceae family. GT has exhibited a growth-inhibitory effect against liver and colon cancer cells; however, there is no study regarding the anticancer effect of GT on PDAC. In our study, we determined the antiproliferative effect of GT in PANC-1 and MIA PaCa-2, representative of PDAC. We revealed the intracellular mechanisms underlying the anticancer effect of GT with respect to cell viability, reactive oxygen species (ROS) accumulation, alteration of mitochondrial membrane potential (MMP), calcium dysregulation, cell migration, and the induction of apoptosis. Moreover, GT regulated the signaling pathways related to anticancer in PDAC cells. Finally, the silencing of the forkhead box protein M, a key factor regulating PDAC progression, contributes to the anticancer property of GT in terms of the induction of apoptosis and cell migration. Therefore, GT may be a potential therapeutic drug against PDAC.

Sequential Treatment with Activin and Hepatocyte Growth Factor Induces FOXM1 to Promote Colorectal Cancer Liver Metastasis

BACKGROUND

Cancer stem cells (CSCs) are involved in liver metastasis in colorectal cancer (CRC). Activin and hepatocyte growth factor (HGF) are important regulators of stem cell properties. This study was performed to explore the effect of activin and HGF on CRC invasion and metastasis. The key genes involved in the action of activin and HGF in CRC were identified.

METHODS

HCT116 CRC cells were sequentially treated with activin and HGF and examined for migration and invasion in vitro and liver metastasis in vivo. RNA sequencing was performed to identify differentially expressed genes in response to activin and HGF.

RESULTS

Sequential treatment with activin and HGF-enhanced CRC cell migration, invasion, and metastasis. CXCR4 and AFP expressions were increased by activin and HGF treatment. Knockdown of FOXM1 blocked liver metastasis from HCT116 cells pretreated with activin and HGF and suppressed CXCR4 and AFP expression. Activin alone increased the mRNA and protein expression of FOXM1. In contrast, HGF alone enhanced the phosphorylation of FOXM1, without altering the total protein level of FOXM1. SMAD2 was required for activin-mediated FOXM1 induction. FOXM1 transactivated CXCR4 by directly binding to the promoter of CXCR4. Additionally, CXCR4 regulated AFP expression through the NF-κB pathway.

CONCLUSIONS

Sequential treatment with activin and HGF accelerates CRC invasion and liver metastasis, which involves the upregulation and activation of FOXM1 and induction of CXCR4 and AFP.

Inside the stemness engine: Mechanistic links between deregulated transcription factors and stemness in cancer

Cell identity is largely determined by its transcriptional profile. In tumour, deregulation of transcription factor expression and/or activity enables cancer cell to acquire a stem-like state characterised by capacity to self-renew, differentiate and form tumours in vivo. These stem-like cancer cells are highly metastatic and therapy resistant, thus warranting a more complete understanding of the molecular mechanisms downstream of the transcription factors that mediate the establishment of stemness state. Here, we review recent research findings that provide a mechanistic link between the commonly deregulated transcription factors and stemness in cancer. In particular, we describe the role of master transcription factors (SOX, OCT4, NANOG, KLF, BRACHYURY, SALL, HOX, FOX and RUNX), signalling-regulated transcription factors (SMAD, β-catenin, YAP, TAZ, AP-1, NOTCH, STAT, GLI, ETS and NF-κB) and unclassified transcription factors (c-MYC, HIF, EMT transcription factors and P53) across diverse tumour types, thereby yielding a comprehensive overview identifying shared downstream targets, highlighting unique mechanisms and discussing complexities.

Structure-based virtual screening identified novel FOXM1 inhibitors as the lead compounds for ovarian cancer

Ovarian cancer (OC) is a gynecological tumor with possibly the worst prognosis, its 5-year survival rate being only 47.4%. The first line of therapy prescribed is chemotherapy consisting of platinum and paclitaxel. The primary reason for treatment failure is drug resistance. FOXM1 protein has been found to be closely associated with drug resistance, and inhibition of FOXM1 expression sensitizes cisplatin-resistant ovarian cancer cells. Combining existing first-line chemotherapy drugs with FOXM1 prolongs the overall survival of patients, therefore, FOXM1 is considered a potential therapeutic target in ovarian cancer. Previous research conducted by our team revealed a highly credible conformation of FOXM1 which enables binding by small molecules. Based on this conformation, the current study conducted virtual screening to determine a new structural skeleton for FOXM1 inhibitors which would enhance their medicinal properties. DZY-4 showed the highest affinity towards FOXM1, and its inhibitory effect on proliferation and migration of ovarian cancer at the cellular level was better than or equal to that of cisplatin, while its efficacy was equivalent to that of cisplatin in a nude mouse model. In this study, the anti-tumor effect of DZY-4 is reported for the first time. DZY-4 shows potential as a drug that can be used for ovarian cancer treatment, as well as a drug lead for future research.

Dysregulated FOXM1 signaling in the regulation of cancer stem cells

Since the introduction of the cancer stem cell (CSC) paradigm, significant advances have been made in understanding the functional and biological plasticity of these elusive components in malignancies. Endowed with self-renewing abilities and multilineage differentiation potential, CSCs have emerged as cellular drivers of virtually all facets of tumor biology, including metastasis, tumor recurrence/relapse, and drug resistance. The functional and biological characteristics of CSCs, such as self-renewal, cell fate decisions, survival, proliferation, and differentiation are regulated by an array of extracellular factors, signaling pathways, and pluripotent transcriptional factors. Besides the well-characterized regulatory role of transcription factors OCT4, SOX2, NANOG, KLF4, and MYC in CSCs, evidence for the central role of Forkhead box transcription factor FOXM1 in the establishment, maintenance, and functions of CSCs is accumulating. Conventionally identified as a master regulator of the cell cycle, a comprehensive understanding of this molecule has revealed its multifarious oncogenic potential and uncovered its role in angiogenesis, invasion, migration, self-renewal, and drug resistance. This review compiles the large body of literature that has accumulated in recent years that provides evidence for the mechanisms by which FOXM1 expression promotes stemness in glioblastoma, breast, colon, ovarian, lung, hepatic, and pancreatic carcinomas. We have also compiled the data showing the association of stem cell mediators with FOXM1 using TCGA mRNA expression data. Further, the prognostic importance of FOXM1 and other stem cell markers is presented. The delineation of FOXM1-mediated regulation of CSCs can aid in the development of molecularly targeted pharmacological approaches directed at the selective eradication of CSCs in several human malignancies.

FAT10 promotes chemotherapeutic resistance in pancreatic cancer by inducing epithelial-mesenchymal transition via stabilization of FOXM1 expression

Pancreatic cancer (PC) is one of the deadliest malignant tumors, and its resistance to gemcitabine chemotherapy is the primary reason for poor prognosis in patients. Ubiquitin-like protein FAT10 has recently been reported to promote tumor chemotherapy resistance. In this study, the expression of FAT10 in PC was significantly higher than that in adjacent noncancerous tissues. Increased expression of FAT10 in PC was related to a late TNM stage and decreased overall survival. Functional experiments revealed that downregulating the expression of FAT10 inhibits the proliferation and epithelial-mesenchymal transition (EMT) of PC cells, promotes the apoptosis of PC cells, and enhances sensitivity to gemcitabine chemotherapy. In addition, upregulation of FAT10 increased the expression of FOXM1 protein. The effect of downregulating FAT10 was reversed by FOXM1 overexpression, and FOXM1 knockdown inhibited EMT driven by FAT10 overexpression. Mechanistically, FAT10 stabilized the expression of FOXM1 by competing with ubiquitin to bind FOXM1 and inhibiting the ubiquitination-mediated degradation of FOXM1. In conclusion, the FAT10-FOXM1 axis is a pivotal driver of PC proliferation and gemcitabine resistance, and the results provide novel insights into chemotherapy resistance in PC.

Romidepsin and tamoxifen cooperatively induce senescence of pancreatic cancer cells through downregulation of FOXM1 expression and induction of reactive oxygen species/lipid peroxidation

BACKGROUND

Although improvement has been made in therapeutic strategies against pancreatic carcinoma, overall survival has not significantly enhanced over the past decade. Thus, the establishment of better therapeutic regimens remains a high priority.

METHODS

Pancreatic cancer cell lines were incubated with romidepsin, an inhibitor of histone deacetylase, and tamoxifen, and their effects on cell growth, signaling and gene expression were analyzed. Xenografts of human pancreatic cancer CFPAC1 cells were medicated with romidepsin and tamoxifen to evaluate their effects on tumor growth.

RESULTS

The inhibition of the growth of pancreatic cancer cells induced by romidepsin and tamoxifen was effectively reduced by N-acetyl cysteine and α-tocopherol, respectively. The combined treatment greatly induced reactive oxygen species production and mitochondrial lipid peroxidation, and these effects were prevented by N-acetyl cysteine and α-tocopherol. Tamoxifen enhanced romidepsin-induced cell senescence. FOXM1 expression was markedly downregulated in pancreatic cancer cells treated with romidepsin, and tamoxifen further reduced FOXM1 expression in cells treated with romidepsin. Siomycin A, an inhibitor of FOXM1, induced senescence in pancreatic cancer cells. Similar results were obtained in knockdown of FOXM1 expression by siRNA.

CONCLUSION

Since FOXM1 is used as a prognostic marker and therapeutic target for pancreatic cancer, a combination of the clinically available drugs romidepsin and tamoxifen might be considered for the treatment of patients with pancreatic cancer.

Knockdown of UCHL3 inhibits esophageal squamous cell carcinoma progression by reducing CRY2 methylation

UCHL3 (Ubiquitin carboxyl-terminal hydrolase L3), a member of deubiquitinating enzymes, has been implicated in various cancers. However, the role of UCHL3 in esophageal squamous cell carcinoma (ESCC) remains unknown. In the current study, we aimed to investigate the role of UCHL3 in ESCC growth and migration, and whether UCHL3 could modulate CRY2 methylation through FOXM1. The expression of UCHL3 and CRY2 in ESCC tissues was assessed using qRT-PCR, western blotting and immunohistochemistry (IHC). Cell viability was determined by CCK-8 and colony formation assays. Hoechst 33342 and flow cytometry were used to detect cell apoptosis. Transwell assay was performed to investigate cell migration and invasion. In vivo animal model was used to assess cell tumorigenesis. Methylation-Specific PCR (MSP) was applied to detect CRY2 methylation in the promoter region. The results showed that UCHL3 expression was elevated in ESCC tissues and cells, while CRY2 expression was decreased. UCHL3 silencing inhibited cell viability, invasion, migration and induced cell apoptosis in vitro, repressed tumor growth in vivo, and increased CRY2 expression and decreased FOXM1 expression. In addition, UCHL3 knockdown decreased CRY2 methylation through downregulating FOXM1, leading to an increase in the expression of CRY2. Moreover, CRY2 silencing abolished UCHL3 deficiency-mediated inhibition in cell growth and migration. In summary, this study reveals that knockdown of UCHL3 inhibits ESCC growth and migration by reducing CRY2 methylation through downregulation of FOXM1 expression.

A multi-mode Wnt- and stemness-regulatory module dictated by FOXM1 and ASPM isoform I in gastric cancer

BACKGROUND

Gastric cancer (GC) is the third leading cause of cancer mortality globally and a molecularly heterogeneous disease. Identifying the driver pathways in GC progression is crucial to improving the clinical outcome. Recent studies identified ASPM (abnormal spindle-like microcephaly-associated) and FOXM1 (Forkhead box protein M1) as novel Wnt and cancer stem cell (CSC) regulators; their pathogenetic roles and potential crosstalks in GC remain unclarified.

METHODS

The expression patterns of ASPM isoforms and FOXM1 were profiled in normal gastric epithelial and GC tissues. The functional roles of ASPM and FOXM1 in Wnt activity, cancer stemness and GC progression, and the underlying signaling processes were investigated.

RESULTS

Approximately one third of GC cells upregulate the expression of ASPM isoform I (ASPMiI) in their cytoplasm; the tumors with a high ASPMiI positive score (≥ 10%) are associated with a poor prognosis of the patients. Mechanistically, the molecular interplay among FOXM1, ASPMiI and DVL3 was found to converge on β-catenin to control the Wnt activity and the stemness property of GC cells. This multi-mode Wnt-regulatory module serves to reinforce Wnt signals in CSCs by transcriptional regulation (FOXM1-ASPM), protein-protein interactions (ASPMiI-DVL3-β-catenin), and nuclear translocation (FOXM1-β-catenin).

CONCLUSIONS

This study illuminates a novel Wnt- and stemness-regulatory mechanism in GC cells and identifies a novel subset of FOXM1^highASPMiI^high GC with potential to guide Wnt- and stemness-related diagnostics and therapies.

The Glycolytic Pathway as a Target for Novel Onco-Immunology Therapies in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal forms of human cancer, characterized by unrestrained progression, invasiveness and treatment resistance. To date, there are limited curative options, with surgical resection as the only effective strategy, hence the urgent need to discover novel therapies. A platform of onco-immunology targets is represented by molecules that play a role in the reprogrammed cellular metabolism as one hallmark of cancer. Due to the hypoxic tumor microenvironment (TME), PDA cells display an altered glucose metabolism-resulting in its increased uptake-and a higher glycolytic rate, which leads to lactate accumulation and them acting as fuel for cancer cells. The consequent acidification of the TME results in immunosuppression, which impairs the antitumor immunity. This review analyzes the genetic background and the emerging glycolytic enzymes that are involved in tumor progression, development and metastasis, and how this represents feasible therapeutic targets to counteract PDA. In particular, as the overexpressed or mutated glycolytic enzymes stimulate both humoral and cellular immune responses, we will discuss their possible exploitation as immunological targets in anti-PDA therapeutic strategies.

The FOXM1/ATX signaling contributes to pancreatic cancer development

Both autotaxin (ATX) and Forkhead Box M1 (FOXM1) have been commonly recognized as oncogenes in multiple types of human malignancies. However, the expression and biological functions of ATX in pancreatic ductal adenocarcinoma (PDAC), and its correlation with FOXM1 are poorly understood. The present study aimed to investigate their correlation and biological consequences in PDAC development. By dual luciferase reporter and chromatin immunoprecipitation assays, we found that ATX was a downstream transcriptional target gene of FOXM1. Further cellular functional experiments indicated that ATX was required for FOXM1-mediated PDAC cell proliferation and migration. Data from molecular biological experiments showed that ATX could enhance FOXM1 expression in turn by inhibiting the Hippo signaling pathway, suggesting that ATX and FOXM1 formed a positive feedback loop to facilitate PDAC progression. Using immunohistochemistry (IHC) method, both ATX and FOXM1 expression were found to be frequently up-regulated in PDAC tumor tissues when compared with adjacent normal tissues, and elevated ATX and FOXM1 expression were positively correlated with each other. In conclusion, the present work identified a positive feedback loop between ATX and FOXM1 which promotes PDAC cell proliferation and migration.

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.

FOXM1 functions collaboratively with PLAU to promote gastric cancer progression

Background: Gastric cancer (GC) is one of the main mortality cause worldwide. Previously, we found Forkhead box protein (FOXM1) or Urokinase-type plasminogen activator (PLAU) are independent prognostic markers of GC. This study aims to explore the combining prognostic efficacy and the potential insights underlying additive effect of FOXM1 to PLAU in GC progression through in-silico analyses. Method: The expression of FOXM1 and PLAU were profiled in 33 cancer types using public data. A merged GC expression dataset containing 598 samples was used for evaluating prognostic significance of FOXM1/PLAU. Gene Set Enrichment Analysis (GSEA) was performed to elucidate the mechanisms underlying FOXM1/PLAU promoted GC progression. The Cancer Genome Atlas (TCGA) was used for analyzing the association between FOXM1/PLAU and tumor immune infiltration. Genomic and proteomic differences between FOXM1+PLAU+ and FOXM1-PLAU- groups were also computed using TCGA GC data. Drugs targeting FOXM1/PLAU associated gene expression pattern was analyzed using LINCs database. Results: FOXM1 and PLAU are overexpressed in 17/33 cancer types including GC. Kaplan-Meier analyses indicate that the FOXM1+PLAU+ subgroup have the worst prognosis, while FOXM1-PLAU- subgroup have the best survival. Bioinformatics analysis indicated that FOXM1+PLAU+ associated genes are enriched in TGF-beta, DNA repair and drug resistance signaling pathways; FOXM1 and PLAU expression are negatively correlated with tumor immune infiltration. Genomic and proteomic differences between FOXM1+PLAU+ and FOXM1-PLAU- groups were presented. Data mining from LINCs suggested several chemicals or drugs that could target the gene expression pattern of FOXM1+PLAU+ patients. Conclusion: FOXM1+PLAU+ can serve as effective prognostic biomarkers and potential therapeutic targets for GC. Due to the additive effect of these two genes, screening for drugs or chemicals that targeting the expression patterns PLAU+FOXM1+ subgroup may exert important clinical impact on GC management.

Silencing transcription factor FOXM1 represses proliferation, migration, and invasion while inducing apoptosis of liver cancer stem cells by regulating the expression of ALDH2

OBJECTIVE

This study is performed to explore the role of transcription factor FOXM1 in promoting the self-renewal and proliferation of liver cancer stem cells (LCSCs) by regulating the expression of acetaldehyde dehydrogenase-2 (ALDH2).

METHODS

CD133⁺ CD24⁺ LCSCs were sorted and identified. A series of experiments were carried out to determine the proliferation, colony formation rate, migration, invasion, and apoptosis of LCSCs after interfering with FOXM1. Proliferation-, epithelial-mesenchymal transition (EMT)-, apoptosis-, and stemness-related factors were then detected by western blot analysis. Tumor xenograft in nude mice was used to figure out the role of FOXM1 in tumorigenesis in vivo by regulating ALDH2 expression. Luciferase activity assay was conducted to determine whether FOXM1 could target ALDH2 promoter region and thereby affecting ALDH2 expression.

RESULTS

The sorted CD133⁺ CD24⁺ Huh-7 cells had the characteristic of stem cells. FOXM1 was highly expressed in CD133⁺ CD24⁺ Huh-7 cells. Silencing FOXM1 inhibited the proliferation and colony formation of LCSCs and decreased the expression of proliferating cell nuclear antigen and Ki-67 protein; inhibited the migration, invasion, and EMT of LCSCs while promoting the apoptosis of LCSCs, as well as promoted the expression of Bax and cleaved-caspase-3, and inhibited the expression of Bcl-2. Silencing FOXM1 inhibited the expression of Nanog, Oct4, and Sox2 in LCSCs by decreasing the expression of ALDH2. in vivo experiment, silencing FOXM1 suppressed tumorigenesis of LCSCs by decreasing the expression of ALDH2.

CONCLUSION

Our study provides evidence that silencing FOXM1 inhibits stemness of LCSCs by decreasing the expression of ALDH2, and represses the proliferation, migration, invasion, and tumorigenesis while inducing the apoptosis of LCSCs.

Downregulation of FOXO3a by DNMT1 promotes breast cancer stem cell properties and tumorigenesis

Breast cancer stem cells (BCSCs) are tumor initiating cells that can self-renew and are highly tumorigenic and chemoresistant. Therefore, the identification of factors critical for BCSC function is vital for the development of therapies. Here, we report that DNMT1-mediated FOXO3a promoter hypermethylation leads to downregulation of FOXO3a expression in breast cancer. FOXO3a is functionally related to the inhibition of FOXM1/SOX2 signaling and to the consequent suppression of BCSCs properties and tumorigenicity. Moreover, we found that SOX2 directly transactivates DNMT1 expression and thereby alters the methylation landscape, which in turn feedback inhibits FOXO3a expression. Inhibition of DNMT activity suppressed tumor growth via regulation of FOXO3a/FOXM1/SOX2 signaling in breast cancer. Clinically, we observed a significant inverse correlation between FOXO3a and FOXM1/SOX2/DNMT1 expression levels, and loss of FOXO3a expression or increased expression of FOXM1, SOX2, and DNMT1 predicted poor prognosis in breast cancer. Collectively, our findings suggest an important role of the DNMT1/FOXO3a/FOXM1/SOX2 pathway in regulating BCSCs properties, suggesting potential therapeutic targets for breast cancer.

Subgroup-specific prognostic signaling and metabolic pathways in pediatric medulloblastoma

Background

Using a pathway-focused approach, we aimed to provide a subgroup-specific basis for finding novel therapeutic strategies and further refinement of the risk stratification in pediatric medulloblastoma.

Method

Based on genome-wide Cox regression and Gene Set Enrichment Analysis, we investigated prognosis-related signaling pathways and core genes in pediatric medulloblastoma subgroups using 530 patient data from Medulloblastoma Advanced Genomic International Consortium (MAGIC) project. We further examined the relationship between expression of the prognostic core genes and frequent chromosome aberrations using broad range copy number change data.

Results

In SHH subgroup, relatively high expression of the core genes involved in p53, PLK1, FOXM1, and Aurora B signaling pathways are associated with poor prognosis, and their average expression synergistically increases with co-occurrence of losses of 17p, 14q, or 10q, or gain of 17q. In Group 3, in addition to high MYC expression, relatively elevated expression of PDGFRA, IGF1R, and FGF2 and their downstream genes in PI3K/AKT and MAPK/ERK pathways are related to poor survival outcome, and their average expression is increased with the presence of isochromosome 17q [i(17q)] and synergistically down-regulated with simultaneous losses of 16p, 8q, or 4q. In Group 4, up-regulation of the genes encoding various immune receptors and those involved in NOTCH, NF-κB, PI3K/AKT, or RHOA signaling pathways are associated with worse prognosis. Additionally, the expressions of Notch genes correlate with those of the prognostic immune receptors. Besides the Group 4 patients with previously known prognostic aberration, loss of chromosome 11, those with loss of 8q but without i(17q) show excellent survival outcomes and low average expression of the prognostic core genes whereas those harboring 10q loss, 1q gain, or 12q gain accompanied by i(17q) show bad outcomes. Finally, several metabolic pathways known to be reprogrammed in cancer cells are detected as prognostic pathways including glutamate metabolism in SHH subgroup, pentose phosphate pathway and TCA cycle in Group 3, and folate-mediated one carbon-metabolism in Group 4.

Conclusions

The results underscore several subgroup-specific pathways for potential therapeutic interventions: SHH-GLI-FOXM1 pathway in SHH subgroup, receptor tyrosine kinases and their downstream pathways in Group 3, and immune and inflammatory pathways in Group 4.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5742-x) contains supplementary material, which is available to authorized users.

Super-enhancers: novel target for pancreatic ductal adenocarcinoma

Super-enhancers (SEs) are unique areas of the genome which drive high-level of transcription and play a pivotal role in the cell physiology. Previous studies have established several important genes in cancer as SE-driven oncogenes. It is likely that oncogenes may hack the resident tissue regenerative program and interfere with SE-driven repair networks, leading to the specific pancreatic ductal adenocarcinoma (PDAC) phenotype. Here, we used ChIP-Seq to identify the presence of SE in PDAC cell lines. Differential H3K27AC marks were identified at enhancer regions of genes including c-MYC, MED1, OCT-4, NANOG, and SOX2 that can act as SE in non-cancerous, cancerous and metastatic PDAC cell lines. GZ17-6.02 affects acetylation of the genes, reduces transcription of major transcription factors, sonic hedgehog pathway proteins, and stem cell markers. In accordance with the decrease in Oct-4 expression, ChIP-Seq revealed a significant decrease in the occupancy of OCT-4 in the entire genome after GZ17-6.02 treatment suggesting the possible inhibitory effect of GZ17-6.02 on PDAC. Hence, SE genes are associated with PDAC and targeting their regulation with GZ17-6.02 offers a novel approach for treatment.

Hypoxia-driven paracrine osteopontin/integrin αvβ3 signaling promotes pancreatic cancer cell epithelial-mesenchymal transition and cancer stem cell-like properties by modulating forkhead box protein M1

Pancreatic stellate cells (PSCs), a key component of the tumor microenvironment, contribute to tumor invasion, metastasis, and chemoresistance. Osteopontin (OPN), a phosphorylated glycoprotein, is overexpressed in pancreatic cancer. However, OPN expression in PSCs and its potential roles in tumor–stroma interactions remain unclear. The present study first showed that OPN is highly expressed and secreted in activated PSCs driven by hypoxia, and this process is in a ROS‐dependent manner; in addition, OPN was shown to be involved in the PSC‐induced epithelial–mesenchymal transition (EMT) and cancer stem cell (CSC)‐like properties of pancreatic cancer cells (PCCs). Mechanistically, OPN from activated PSCs interacts with the transmembrane receptor integrin αvβ3 on PCCs to upregulate forkhead box protein M1 (FOXM1) expression and induce malignant phenotypes of PCCs. Moreover, the Akt and Erk pathways participate in OPN/integrin αvβ3 axis‐induced FOXM1 expression of PCCs. Our further analysis showed that OPN and FOXM1 are significantly upregulated in pancreatic cancer tissues and are associated with poor clinical outcome, indicating that OPN and FOXM1 might be considered as diagnostic and prognostic biomarkers for patients with pancreatic cancer. In conclusion, we show here for the first time that OPN promotes the EMT and CSC‐like properties of PCCs by activating the integrin αvβ3‐Akt/Erk‐FOXM1 cascade in a paracrine manner, suggesting that targeting the tumor microenvironment represents a promising therapeutic strategy in pancreatic cancer.

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.

Lentiviral RNA interference-mediated downregulation of Forkhead box M1 expression suppresses growth of oral squamous cell carcinoma in vitro

Oral squamous cell carcinoma (OSCC) is one of the most fatal types of oral cancer worldwide. Forkhead box M1 (FOXM1) is associated with the occurrence and development of a number of types of human cancer, but its function in OSCC remains unclear. The present study aimed to explore the effect of FOXM1 downregulation using lentivirus-mediated short hairpin (sh)RNA against FOXM1 (LV-shFOXM1) in the cell line Tca8113 in vitro. Infection of Tca8113 cells with LV-shFOXM1 inhibited the mRNA and protein expression level of FOXM1. The downregulation of FOXM1 resulted in cell cycle arrest of Tca8113 cells, and the inhibition of proliferation, migration and invasion. The protein expression level of cyclins B1 and D1 were downregulated, whereas those of p27 and p21 were upregulated following infection with LV-shFOXM1, compared with the blank control and LV-shCON groups. In addition, FOXM1 downregulation decreased the expression of matrix metalloproteinase-2 and LV-shFOXM1 significantly suppressed OSCC cell viability. Therefore, FOXM1 may be a target for the treatment of OSCC.

Lx2-32c inhibits the formation of mammosphere from MDA-MB-231 cells and induces apoptosis involving in down-regulating FoxM1

Cancer stem cells (CSCs) are a subset of cancer cells which have self-renewal ability and exist in various tumors. Inhibition of CSCs self-renewal is considered as a new method for tumor therapy. A novel semi-synthetic taxane analogue, Lx2-32c, could overcome drug resistance in various cancer cell lines. In this study, it was found that Lx2-32c inhibited the proliferation and mammosphere formation of MDA-MB-231-derived cancer stem cell-like cells (MCSCLCs) and induced apoptosis, as well as down-regulated the expression of FoxM1 and CD44 in MCSCLCs. Simultaneously, it was proved that Lx2-32c combined with thiostreption, a FoxM1 inhibitor inhibited proliferation and mammosphere formation of MCSCLCs and induced apoptosis to a more extent than Lx2-32c alone; thiostreption could also enhance the effect of Lx2-32c of reduction of the expression of FoxM1 and CD44. All of these results indicated that Lx2-32c is a novel semi-synthetic taxane analogue which inhibits the self-renewal of MCSCLCs cells and induces apoptosis involving in down-regulating FoxM1.

Downregulation of FoxM1 inhibits cell growth and migration and invasion in bladder cancer cells

The FoxM1 (Forkhead Box M1) transcription factor plays a key role in regulation of cell growth, cell cycle, and transformation. Higher expression of FoxM1 has been observed in various types of human cancers including bladder cancer. However, the exact function of FoxM1 in bladder cancer has not been elucidated. To investigate the cellular and molecular function of FoxM1 in bladder cancer, we measured the consequences of downregulation and upregulation of FoxM1 in bladder cancer cells using MTT assay, wound healing assay, and invasion assay. We found that downregulation of FoxM1 inhibited cell growth, but induced apoptosis in bladder cancer cells. Moreover, we found that inhibition of FoxM1 retarded cell migration and invasion. In line with this, upregulation of FoxM1 led to cell growth promotion and inhibited cell apoptosis in bladder cancer cells. Consistently, upregulation of FoxM1 led to increased cell migration and invasion. Our Western blotting results identified that downregulation of FoxM1 increased p27 level and inhibited VEGF, while overexpression of FoxM1 reduced p27 level and increased VEGF. Our findings suggest that FoxM1 could be a useful target for the treatment of bladder cancer.

Paeoniflorin inhibits cell growth and induces cell cycle arrest through inhibition of FoxM1 in colorectal cancer cells

Paeoniflorin (PF) exhibits tumor suppressive functions in a variety of human cancers. However, the function of PF and molecular mechanism in colorectal cancer are elusive. In the present study, we investigated whether PF could exert its antiproliferative activity, anti-migration, and anti-invasive function in colorectal cancer cells. We found that PF inhibited cell growth and induced apoptosis and blocked cell cycle progression in the G0/G1 phase in colorectal cancer cells. Moreover, we found that PF suppressed cell migration and invasion in colorectal cancer cells. FoxM1 has been reported to play an important oncogenic role in human cancers. We also determine whether PF inhibited the expression of FoxM1, leading to its anti-cancer activity. We found that PF treatment in colorectal cancer cells resulted in down-regulation of FoxM1. The rescue experiments showed that overexpression of FoxM1 abrogated the tumor suppressive function induced by PF treatment. Notably, depletion of FoxM1 promoted the anti-tumor activity of PF in colorectal cancer cells. Therefore, inhibition of FoxM1 could participate in the anti-tumor activity of PF in colorectal cancer cells.

FoxM1 Promotes Cell Proliferation, Invasion, and Stem Cell Properties in Nasopharyngeal Carcinoma

Background: The self-renewal and tumourigenicity of FoxM1 in nasopharyngeal carcinoma (NPC) remain largely unknown. In this study, we attempt to investigate the self-renewal and tumourigenicity of FoxM1 and its clinical significance in nasopharyngeal carcinoma (NPC). Methods: Several assays including cell counting Kit-8 (CCK-8) assays, colony formation, flow cytometry, immunofluorescence, tumor spheres, and mice model were used to detect the biological function of FoxM1 in NPC. The association between FoxM1 and clinical pathological features, and stem cell markers was analyzed using immunohistochemistry. Results: High expression of FoxM1 was prominently present in the T4 stages, cancer cells migrating into the stroma and vasculature. Overexpression of FoxM1 enhanced tumor proliferation, cell cycle progression, migration and stress fibers formation in vitro. In NPC tissues, FoxM1 correlated significantly with stem cells-related clinical pathological features including late clinical stage, tumor recurrence and distant metastasis. Meanwhile, FoxM1 linked closely with the expression levels of stem cell markers including Nanog, Sox2, and OCT4 in tumor samples, and also promoted the expression of these stemness-related genes in vitro. Moreover, FoxM1 conferred the self-renewal properties of cancer cells by increasing side populations (SP) cells and formed larger and more tumor spheres. Importantly, FoxM1 enhanced the ability of tumourigenicity of NPC cell lines in mice xenograft. Conclusions: We demonstrate that FoxM1 greatly induces cancer progression and cancer stem cell (CSC) features in NPC.

The FOXO3-FOXM1 axis: A key cancer drug target and a modulator of cancer drug resistance

The FOXO3 and FOXM1 forkhead box transcription factors, functioning downstream of the essential PI3K-Akt, Ras-ERK and JNK/p38MAPK signalling cascades, are crucial for cell proliferation, differentiation, cell survival, senescence, DNA damage repair and cell cycle control. The development of resistance to both conventional and newly emerged molecularly targeted therapies is a major challenge confronting current cancer treatment in the clinic. Intriguingly, the mechanisms of resistance to ‘classical’ cytotoxic chemotherapeutics and to molecularly targeted therapies are invariably linked to deregulated signalling through the FOXO3 and FOXM1 transcription factors. This is owing to the involvement of FOXO3 and FOXM1 in the regulation of genes linked to crucial drug action-related cellular processes, including stem cell renewal, DNA repair, cell survival, drug efflux, and deregulated mitosis. A better understanding of the mechanisms regulating the FOXO3-FOXM1 axis, as well as their downstream transcriptional targets and functions, may render these proteins reliable and early diagnostic/prognostic factors as well as crucial therapeutic targets for cancer treatment and importantly, for overcoming chemotherapeutic drug resistance.

Sophoridine suppresses cell growth in human medulloblastoma through FoxM1, NF-κB and AP-1

Sophoridine is an alkaloid extracted from Sophora alopecuroides that has extensive pharmacological actions. In the present study, the effect of sophoridine on cell growth of human medulloblastoma and its mechanism were investigated. Human medulloblastoma D283-Med cells were incubated with 0, 0.5, 1 or 2 mg/ml sophoridine for 24, 48 or 72 h. Cell proliferation and cytotoxicity were analyzed using MTT and lactate dehydrogenase assays, respectively. Next, analyses of cell apoptosis and caspase-3/8 activity were performed using flow cytometry or spectrophotometry, respectively. Lastly, the change in FoxM1, TrkB, BDNF, NF-κB and AP-1 expression was investigated using western blot analysis. In the present study, treatment with sophoridine significantly suppressed cell growth and induced apoptosis in human medulloblastoma cells. In addition, sophoridine significantly increased cytotoxicity and caspase-3/8 activity in human medulloblastoma. Finally, it was found that sophoridine suppresses the protein expression of FoxM1, TrkB, BDNF NF-κB and AP-1 in human medulloblastoma cells. The present study suggests that sophoridine suppresses cell growth of human medulloblastoma through the inhibition of the FoxM1, NF-κB and AP-1 signaling pathway.

Statin and Bisphosphonate Induce Starvation in Fast-Growing Cancer Cell Lines

Statins and bisphosphonates are increasingly recognized as anti-cancer drugs, especially because of their cholesterol-lowering properties. However, these drugs act differently on various types of cancers. Thus, the aim of this study was to compare the effects of statins and bisphosphonates on the metabolism (NADP⁺/NADPH-relation) of highly proliferative tumor cell lines from different origins (PC-3 prostate carcinoma, MDA-MB-231 breast cancer, U-2 OS osteosarcoma) versus cells with a slower proliferation rate like MG-63 osteosarcoma cells. Global gene expression analysis revealed that after 6 days of treatment with pharmacologic doses of the statin simvastatin and of the bisphosphonate ibandronate, simvastatin regulated more than twice as many genes as ibandronate, including many genes associated with cell cycle progression. Upregulation of starvation-markers and a reduction of metabolism and associated NADPH production, an increase in autophagy, and a concomitant downregulation of H3K27 methylation was most significant in the fast-growing cancer cell lines. This study provides possible explanations for clinical observations indicating a higher sensitivity of rapidly proliferating tumors to statins and bisphosphonates.

Comprehensive Dissection of Transcriptome Data and Regulatory Factors in Pancreatic Cancer Cells

Features of pancreatic cancers include high mortality rates caused by rapid tumor progression and a lack of effective therapy. Underpinning the molecular mechanisms involved in the alteration of the gene expression program in the pancreatic cancer remains to be understood. In the current study, we performed a comprehensive analysis using 282 pancreatic tumor and normal samples from seven independent expression data sets to provide a better view on the interactions between different transcription factors (TFs) and the most affected biological pathways in pancreatic cancer. We highlighted common differentially expressed genes (DEGs) and common affected processes within pancreatic cancer samples. We revealed 16 main DE-TFs that regulated gene expression alterations as well as the most significant processes in pancreatic cancer compared to normal cells. For example, we found the upregulated FOXM1 to be a top regulator of pancreatic cellular transformation based on results from different analyses, including from its regulation of gene regulatory networks, its presence in protein complex, its significant regulation of genes related to cancer pathways, and its regulation of most of the identified DE-TFs. Furthermore, we provided a model and assessed the role of different DE-TFs in the regulation of the most affected pancreatic- and cancer-specific processes. In conclusion, our bioinformatics meta-analysis of high throughput expression data sets, besides clarifying common affected genes and pathways, also showed the mechanisms involved in regulating these common profiles. Our results, especially for DE-TFs, could potentially be useful for screening for pancreatic cancer, and for confirming or determining novel pharmacological targets. J. Cell. Biochem. 118: 3976-3985, 2017. © 2017 Wiley Periodicals, Inc.

Diarylheptanoids suppress proliferation of pancreatic cancer PANC-1 cells through modulating shh-Gli-FoxM1 pathway

Pancreatic cancer is one of the leading causes of cancer, and it has the lowest 5-year survival rates. It is necessary to develop more potent anti-pancreatic cancer drugs to overcome the fast metastasis and resistance to surgery, radiotherapy, chemotherapy, and combinations of these. We have identified several diarylheptanoids as anti-pancreatic cancer agents from Alpinia officinarum (lesser galangal) and Alnus japonica. These diarylheptanoids suppressed cell proliferation and induced the cell cycle arrest of pancreatic cancer cells (PANC-1). Among them, the most potent compounds 1 and 7 inhibited the shh-Gli-FoxM1 pathway and their target gene expression in PANC-1 cells. Furthermore, they suppressed the expression of the cell cycle associated genes that were rescued by the overexpression of exogenous FoxM1. Taken together, (E)-7-(4-hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3-one (1) from Alpinia officinarum (lesser galangal) and platyphyllenone (7) from Alnus japonica inhibit PANC-1 cell proliferation by suppressing the shh-Gli-FoxM1 pathway, and they can be potential candidates for anti-pancreatic cancer drug development.

Crocetinic acid inhibits hedgehog signaling to inhibit pancreatic cancer stem cells

Pancreatic cancer is the fourth leading cause of cancer deaths in the US and no significant treatment is currently available. Here, we describe the effect of crocetinic acid, which we purified from commercial saffron compound crocetin using high performance liquid chromatography. Crocetinic acid inhibits proliferation of pancreatic cancer cell lines in a dose- and time-dependent manner. In addition, it induced apoptosis. Moreover, the compound significantly inhibited epidermal growth factor receptor and Akt phosphorylation. Furthermore, crocetinic acid decreased the number and size of the pancospheres in a dose-dependent manner, and suppressed the expression of the marker protein DCLK-1 (Doublecortin Calcium/Calmodulin-Dependent Kinase-1) suggesting that crocetinic acid targets cancer stem cells (CSC). To understand the mechanism of CSC inhibition, the signaling pathways affected by purified crocetinic acid were dissected. Sonic hedgehog (Shh) upon binding to its cognate receptor patched, allows smoothened to accumulate and activate Gli transcription factor. Crocetinic acid inhibited the expression of both Shh and smoothened. Finally, these data were confirmed in vivo where the compound at a dose of 0.5 mg/Kg bw suppressed growth of tumor xenografts. Collectively, these data suggest that purified crocetinic acid inhibits pancreatic CSC, thereby inhibiting pancreatic tumorigenesis.

Hepatocellular carcinoma stem cell-like cells are enriched following low-dose 5-fluorouracil chemotherapy

It has been proposed that cancer stem cells (CSCs) are involved in tumor resistance to chemotherapy and tumor relapse. The goal of the present study was to determine the effect of low-dose 5-fluorouracil (5-Fu) on enriched hepatocellular CSC-like cells. Increased cell motility and epithelial-mesenchymal transition were observed by migration assay in human hepatoblastoma PLC/RAF/5 cells following 5-Fu treatment, as well as a significant enhancement in their sphere-forming abilities. CSC-like cells were identified by side population cell analysis. The percentage of CSC-like cells in the surviving cells was greatly increased in response to 5-Fu. These findings indicate that low-dose 5-Fu treatment may efficiently enrich the CSC-like cell population in PLC/RAF/5 cells.

Secretome protein signature of human pancreatic cancer stem-like cells

Emerging research has demonstrated that pancreatic ductal adenocarcinoma (PDAC) contains a sub-population of cancer stem cells (CSCs) characterized by self-renewal, anchorage-independent-growth, long-term proliferation and chemoresistance. The secretome analysis of pancreatic CSCs has not yet been performed, although it may provide insight into tumour/microenvironment interactions and intracellular processes, as well as to identify potential biomarkers. To characterize the secreted proteins of pancreatic CSCs, we performed an iTRAQ-based proteomic analysis to compare the secretomes of Panc1 cancer stem-like cells (Panc1 CSCs) and parental cell line. A total of 72 proteins were found up-/down-regulated in the conditioned medium of Panc1 CSCs. The pathway analysis revealed modulation of vital physiological pathways including glycolysis, gluconeogenesis and pentose phosphate. Through ELISA immunoassays we analysed the presence of the three proteins most highly secreted by Panc1 CSCs (ceruloplasmin, galectin-3, and MARCKS) in sera of PDAC patient. ROC curve analysis suggests ceruloplasmin as promising marker for patients negative for CA19-9. Overall, our study provides a systemic secretome analysis of pancreatic CSCs revealing a number of secreted proteins which participate in pathological conditions including cancer differentiation, invasion and metastasis. They may serve as a valuable pool of proteins from which biomarkers and therapeutic targets can be identified.

BIOLOGICAL SIGNIFICANCE

The secretome of CSCs is a rich reservoir of biomarkers of cancer progression and molecular therapeutic targets, and thus is a topic of great interest for cancer research. The secretome analysis of pancreatic CSCs has not yet been performed. Recently, our group has demonstrated that Panc-1 CSCs isolated from parental cell line by using the CSC selective medium, represent a model of great importance to deepen the understanding of the biology of pancreatic adenocarcinoma. To our knowledge, this is the first proteomic study of pancreatic CSC secretome. We performed an iTRAQ-based analysis to compare the secretomes of Panc1 CSCs and Panc1 parental cell line and identified a total of 43 proteins secreted at higher level by pancreatic cancer stem cells. We found modulation of different vital physiological pathways (such as glycolysis and gluconeogenesis, pentose phosphate pathway) and the involvement of CSC secreted proteins (for example 72kDa type IV collagenase, galectin-3, alpha-actinin-4, and MARCKS) in pathological conditions including cancer differentiation, invasion and metastasis. By ELISA verification we found that MARCKS and ceruloplasmin discriminate between controls and PDAC patients; in addition ROC curve analyses indicate that MARCKS does not have diagnostic accuracy, while ceruloplasmin could be a promising marker only for patients negative for CA19-9. We think that the findings reported in our manuscript advance the understanding of the pathways implicated in tumourigenesis, metastasis and chemoresistance of pancreatic cancer, and also identify a pool of proteins from which novel candidate diagnostic and therapeutic biomarkers could be discovered.

Molecular Biomarkers of Pancreatic Intraepithelial Neoplasia and Their Implications in Early Diagnosis and Therapeutic Intervention of Pancreatic Cancer

Lack of early detection and effective interventions is a major reason for the poor prognosis and dismal survival rates for pancreatic cancer. Pancreatic intraepithelial neoplasia (PanIN) is the most common precursor of invasive pancreatic ductal adenocarcinoma (PDAC). Each stage in the progression from PanIN to PDAC is well characterized by multiple significant genetic alterations affecting signaling pathways. Understanding the biological behavior and molecular alterations in the progression from PanIN to PDAC is crucial to the identification of noninvasive biomarkers for early detection and diagnosis and the development of preventive and therapeutic strategies for control of pancreatic cancer progression. This review focuses on molecular biomarkers of PanIN and their important roles in early detection and treatment of pancreatic cancer.

Silibinin-induced glioma cell apoptosis by PI3K-mediated but Akt-independent downregulation of FoxM1 expression

The oncogenic transcription factor Forkhead box M1 (FoxM1) is overexpressed in many human tumors, including glioma. As a critical regulator of the cell cycle and apoptosis-related genes, FoxM1 is a potential therapeutic target against human malignant glioma. Silibinin, a flavonoid isolated from Silybum marianum, dose-dependently reduced glioma cell proliferation, promoted apoptosis, and downregulated FoxM1 expression. Knockdown of FoxM1 by small hairpin RNA (shRNA) transfection also promoted glioma cell apoptosis and augmented the antiproliferative and pro-apoptotic properties of silibinin. Moreover, silibinin increased caspase-3 activation, upregulated pro-apoptotic Bax, and suppressed anti-apoptotic Bcl-2 expression, effects enhanced by FoxM1 knockdown. Silibinin treatment suppressed U87 cell PI3K phospho-activation, and simultaneous silibinin exposure, FoxM1 knockdown, and PI3K inhibition additively increased U87 cell apoptosis. Furthermore, PI3K inhibition reduced FoxM1 expression. Akt activity was also suppressed by FoxM1 downregulation but Akt inhibition did not alter FoxM1 expression. Thus, silibinin likely inhibited glioma cell proliferation and induced apoptosis through inactivation of PI3K and FoxM1, leading to activation of the mitochondrial apoptotic pathway. FoxM1 may be a novel target for chemotherapy against human glioma.

CD24 tracks divergent pluripotent states in mouse and human cells

Reprogramming is a dynamic process that can result in multiple pluripotent cell types emerging from divergent paths. Cell surface protein expression is a particularly desirable tool to categorize reprogramming and pluripotency as it enables robust quantification and enrichment of live cells. Here we use cell surface proteomics to interrogate mouse cell reprogramming dynamics and discover CD24 as a marker that tracks the emergence of reprogramming-responsive cells, while enabling the analysis and enrichment of transgene-dependent (F-class) and -independent (traditional) induced pluripotent stem cells (iPSCs) at later stages. Furthermore, CD24 can be used to delineate epiblast stem cells (EpiSCs) from embryonic stem cells (ESCs) in mouse pluripotent culture. Importantly, regulated CD24 expression is conserved in human pluripotent stem cells (PSCs), tracking the conversion of human ESCs to more naive-like PSC states. Thus, CD24 is a conserved marker for tracking divergent states in both reprogramming and standard pluripotent culture.

Characterizing the cellular stages that lead to induced reprogramming is of much interest and cell surface markers could offer unique advantages for this. Here the authors use surface proteomics and discover CD24 as a marker that tracks reprogramming-responsive cells and enables the analysis and enrichment of transgene-dependent and -independent induced pluriopotent stem cells.

Pancreatic cancer stromal biology and therapy

Pancreatic cancer is one of the most lethal malignancies. Significant progresses have been made in understanding of pancreatic cancer pathogenesis, including appreciation of precursor lesions or premalignant pancreatic intraepithelial neoplasia (PanINs), description of sequential transformation from normal pancreatic tissue to invasive pancreatic cancer and identification of major genetic and epigenetic events and the biological impact of those events on malignant behavior. However, the currently used therapeutic strategies targeting tumor epithelial cells, which are potent in cell culture and animal models, have not been successful in the clinic. Presumably, therapeutic resistance of pancreatic cancer is at least in part due to its drastic desmoplasis, which is a defining hallmark for and circumstantially contributes to pancreatic cancer development and progression. Improved understanding of the dynamic interaction between cancer cells and the stroma is important to better understanding pancreatic cancer biology and to designing effective intervention strategies. This review focuses on the origination, evolution and disruption of stromal molecular and cellular components in pancreatic cancer, and their biological effects on pancreatic cancer pathogenesis.

Pancreatic cancer stem cells: new insight into a stubborn disease

Resistance to conventional therapy and early distant metastasis contribute to the unsatisfactory prognosis of patients with pancreatic cancer. The concept of cancer stem cells (CSCs) brings new insights into cancer biology and therapy. Many studies have confirmed the important role of these stem cells in carcinogenesis and the development of hematopoietic and solid cancers. Recent studies have shown that CSCs regulate aggressive behavior, recurrence, and drug resistance in pancreatic cancer. Here, we review recent advances in pancreatic cancer stem cells (PCSCs) research. Particular attention is paid to the regulation mechanisms of pancreatic cancer stem cell functions, such as stemness-related signaling pathways, microRNAs, the epithelial-mesenchymal transition (EMT), and the tumor microenvironment, and the development of novel PCSCs targeted therapy. We seek to further understand PCSCs and explore potential therapeutic targets for pancreatic cancer.

miR-320 enhances the sensitivity of human colon cancer cells to chemoradiotherapy in vitro by targeting FOXM1

miR-320 expression level is found to be down-regulated in human colon cancer. To date, however, its underlying mechanisms in the chemo-resistance remain largely unknown. In this study, we demonstrated that ectopic expression of miR-320 led to inhibit HCT-116 cell proliferation, invasion and hypersensitivity to 5-Fu and Oxaliplatin. Also, knockdown of miR-320 reversed these effects in HT-29 cells. Furthermore, we identified an oncogene, FOXM1, as a direct target of miR-320. In addition, miR-320 could inactive the activity of Wnt/β-catenin pathway. Finally, we found that miR-320 and FOXM1 protein had a negative correlation in colon cancer tissues and adjacent normal tissues. These findings implied that miR-320-FOXM1 axis may overcome chemo-resistance of colon cancer cells and provide a new therapeutic target for the treatment of colon cancer.

FOXM1: A key oncofoetal transcription factor in health and disease

Forkhead Box M1 (FOXM1) is a bona fide oncofoetal transcription factor, which orchestrates complex temporal and spatial gene expression throughout embryonic and foetal development as well as during adult tissue homeostasis and repair. Controlled FOXM1 expression and activity provides a balanced transcriptional programme to ensure proper growth and maturation during embryogenesis and foetal development as well as to manage appropriate homeostasis and repair of adult tissues. Conversely, deregulated FOXM1 upregulation likely affects cell migration, invasion, angiogenesis, stem cell renewal, DNA damage repair and cellular senescence, which impact tumour initiation, progression, metastasis, angiogenesis and drug resistance. A thorough understanding of the regulation and role of FOXM1 in health and in cancer should contribute to the development of better diagnostics and treatments for cancer as well as congenital disorders and other developmental diseases.