Lian-Mei-Yin formula alleviates diet-induced hepatic steatosis by suppressing Yap1/FOXM1 pathway-dependent lipid synthesis.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, with a global prevalence of 25%. Patients with NAFLD are more likely to suffer from advanced liver disease, cardiovascular disease, or type II diabetes. However, unfortunately, there is still a shortage of FDA-approved therapeutic agents for NAFLD. Lian-Mei-Yin (LMY) is a traditional Chinese medicine formula used for decades to treat liver disorders. It has recently been applied to type II diabetes which is closely related to insulin resistance. Given that NAFLD is another disease involved in insulin resistance, we hypothesize that LMY might be a promising formula for NAFLD therapy. Herein, we verify that the LMY formula effectively reduces hepatic steatosis in diet-induced zebrafish and NAFLD model mice in a time- and dose-dependent manner. Mechanistically, LMY suppresses Yap1-mediated Foxm1 activation, which is crucial for the occurrence and development of NAFLD. Consequently, lipogenesis is ameliorated by LMY administration. In summary, the LMY formula alleviates diet-induced NAFLD in zebrafish and mice by inhibiting Yap1/Foxm1 signaling-mediated NAFLD pathology.

Repurposing Two Old Friends to Fight Cancer: Caffeine and Statins.

Statins are a class of cholesterol-lowering drugs that inhibit 3-hydroxy-3-methylglutaryl-CoA reductase, the rate-limiting enzyme of the mevalonate pathway. Evidence suggests that certain cancers depend on the mevalonate pathway for growth and survival, and thus blocking the mevalonate pathway with statins may offer a viable therapeutic approach for treating cancer, or at least enhance the efficacy of existing cancer drugs. In this issue of Cancer Research, Tran and colleagues showed that caffeine works jointly with FOXM1 inhibition to enhance the antitumor activity of statins in neuroblastoma cells. They found that caffeine synergizes with statins by suppressing statin-induced feedback activation of the mevalonate pathway. Here, we reflect on the potential of combining caffeine and statin drugs as a strategy for potentiating anticancer activity. See related article by Tran et al., p. 2248.

Apoptotic and anti-Warburg effect of Morusin via ROS mediated inhibition of FOXM1/c-Myc signaling in prostate cancer cells.

Though Morusin is known to induce apoptotic, antiprolifertaive, and autophagic effects through several signaling pathways, the underlying molecular mechanisms of Morusin still remain unclear until now. To elucidate antitumor mechanism of Morusin, cytotoxicity assay, cell cycle analysis, Western blotting, TUNEL assay, RNA interference, immunofluorescense, immunoprecipitation, reactive oxygen species (ROS) measurement, and inhibitor study were applied in this study. Morusin enhanced cytotoxicity, increased the number of TUNEL positive cells, sub-G1 population and induced the cleavages of PARP and caspase3, attenuated the expression of HK2, PKM2, LDH, c-Myc, and Forkhead Box M1 (FOXM1) along with the reduction of glucose, lactate, and ATP in DU145 and PC3 cells. Furthermore, Morusin disrupted the binding of c-Myc and FOXM1 in PC-3 cells, which was supported by String and cBioportal database. Notably, Morusin induced c-Myc degradation mediated by FBW7 and suppressed c-Myc stability in PC3 cells exposed to MG132 and cycloheximide. Also, Morusin generated ROS, while NAC disrupted the capacity of Morusin to reduce the expression of FOXM1, c-Myc, pro-PARP, and pro-caspase3 in PC-3 cells. Taken together, these findings provide scientific evidence that ROS mediated inhibition of FOXM1/c-Myc signaling axis plays a critical role in Morusin induced apoptotic and anti-Warburg effect in prostate cancer cells. Our findings support scientific evidence that ROS mediated inhibition of FOXM1/c-Myc signaling axis is critically involved in apoptotic and anti-Warburg effect of Morusin in prostate cancer cells.

Caffeine Supplementation and FOXM1 Inhibition Enhance the Antitumor Effect of Statins in Neuroblastoma.

High-risk neuroblastoma exhibits transcriptional activation of the mevalonate pathway that produces cholesterol and nonsterol isoprenoids. A better understanding of how this metabolic reprogramming contributes to neuroblastoma development could help identify potential prevention and treatment strategies. Here, we report that both the cholesterol and nonsterol geranylgeranyl-pyrophosphate branches of the mevalonate pathway are critical to sustain neuroblastoma cell growth. Blocking the mevalonate pathway by simvastatin, a cholesterol-lowering drug, impeded neuroblastoma growth in neuroblastoma cell line xenograft, patient-derived xenograft (PDX), and TH-MYCN transgenic mouse models. Transcriptional profiling revealed that the mevalonate pathway was required to maintain the FOXM1-mediated transcriptional program that drives mitosis. High FOXM1 expression contributed to statin resistance and led to a therapeutic vulnerability to the combination of simvastatin and FOXM1 inhibition. Furthermore, caffeine synergized with simvastatin to inhibit the growth of neuroblastoma cells and PDX tumors by blocking statin-induced feedback activation of the mevalonate pathway. This function of caffeine depended on its activity as an adenosine receptor antagonist, and the A2A adenosine receptor antagonist istradefylline, an add-on drug for Parkinson's disease, could recapitulate the synergistic effect of caffeine with simvastatin. This study reveals that the FOXM1-mediated mitotic program is a molecular statin target in cancer and identifies classes of agents for maximizing the therapeutic efficacy of statins, with implications for treatment of high-risk neuroblastoma. SIGNIFICANCE: Caffeine treatment and FOXM1 inhibition can both enhance the antitumor effect of statins by blocking the molecular and metabolic processes that confer statin resistance, indicating potential combination therapeutic strategies for neuroblastoma. See related commentary by Stouth et al., p. 2091.

A database of integrated molecular and phytochemical interactions of the foxm1 pathway for lung cancer.

The FoxM1 pathway is an oncogenic signaling pathway involved in essential mechanisms including control cell-cycle progression, apoptosis and cell growth which are the common hallmarks of various cancers. Although its biological functions in the tumor development and progression are known, the mechanism by which it participates in those processes is not understood. The present work reveals images of the oncogenic FoxM1 pathway controlling the cell cycle process with alternative treatment options via phytochemical substances in the lung cancer study. The downstream significant protein modules of the FoxM1 pathway were extracted by the Molecular Complex Detection (MCODE) and the maximal clique (Mclique) algorithms. Furthermore, the effects of post-transcriptional modification by microRNA, transcription factor binding and the phytochemical compounds are observed through their interactions with the lung cancer protein modules. We provided two case studies to demonstrate the usefulness of our database. Our results suggested that the combination of various phytochemicals is effective in the treatment of lung cancer. The ultimate goal of the present work is to partly support the discovery of plant-derived compounds in combination treatment of classical chemotherapeutic agents to increase the efficacy of lung cancer method probably with minor side effects. Furthermore, a web-based system displaying results of the present work is set up for investigators posing queries at http://sit.mfu.ac.th/lcgdb/index_FoxM1.php.Communicated by Ramaswamy H. Sarma.

Aromatic monophenols from cinnamon bark act as proteasome inhibitors by upregulating ER stress, suppressing FoxM1 expression, and inducing apoptosis in prostate cancer cells.

Cinnamon contains bioactive substances with diverse medicinal properties. We investigated the anticancer potential of abundant monophenols from cinnamon, namely, cinnamaldehyde, cinnamic acid, and eugenol, by hypothesizing that they possess proteasome inhibitory activities capable of suppressing cancer cell proliferation and inducing apoptosis. This hypothesis was tested by evaluating proteasome inhibitory activities of the compounds, and assessing downstream molecular and cellular events that are known to be impacted by proteasome inhibitors. The cinnamon compounds inhibited the catalytic activities of the proteasome in prostate cancer cells, but not in normal cells. Treatment with cinnamon compounds or the synthetic proteasome inhibitor MG132 upregulated p27 and IkBα proteins, and downregulated FoxM1 and angiogenic markers. These molecular events were associated with the decreased proliferation of prostate cancer cells. Treatment with cinnamon compounds or MG132 upregulated the expression of genes associated with endoplasmic reticulum (ER) stress/unfolded protein response (BIP, PERK, CHOP, and XBP1(S)). Furthermore, cinnamon compounds or MG132 upregulated the expression of genes required for the assembly of the caspase-8 activation platform in autophagosomes (LC3B, ATG5, p62, and Beclin1). The autophagy inhibitor, 3-methyladenine, blocked the compounds-mediated activation of caspase-8 and its downstream target caspase-3. In conclusion, proteasome inhibition by aromatic monophenols from cinnamon inhibits proliferation and leads to the death of prostate cancer cells by autophagy-dependent apoptosis.

Mistletoe Extract Targets the STAT3-FOXM1 Pathway to Induce Apoptosis and Inhibits Metastasis in Breast Cancer Cells.

Mistletoe extracts (Viscum album L.) have been widely used as complementary and alternative medicines for the treatment of cancer, and their cytotoxic effects have been reported on various types of cancer. However, the molecular targets of mistletoe extracts have not been well studied. Herein, we investigated molecules associated with the in vitro and in vivo anticancer effects of mistletoe extract using 4T1 murine breast cancer cells. Mistletoe extract induced apoptosis and inhibited the signal transducer and activator of transcription3 (STAT3) phosphorylation. This inhibition was accompanied by the downregulations of forkhead box M1 (FOXM1) and the DNA repair proteins, RAD51 and survivin. Mistletoe extract simultaneously increased the expression of the DNA damage marker proteins, phosphorylated H2A histone family member X (H2A.X), and phosphorylated p38. Furthermore, mistletoe extract effectively suppressed tumor growth in 4T1 tumor-bearing BALB/c mice. In addition to tumor growth inhibition, mistletoe extract inhibited lung metastasis in the tumor-bearing mice and cell invasiveness by downregulating the expressions of matrix metalloproteinases (MMPs), urokinase-type plasminogen activator (uPA), uPA receptor, and markers of epithelial-mesenchymal transition (snail and fibronectin). Taken together, our results suggest that mistletoe extract targets the STAT3-FOXM1 pathway for its cytotoxic effects, and that mistletoe extracts might be useful for the treatment of patients with cancers highly expressing the STAT3-FOXM1 pathway.

Broussoflavonol B from Broussonetia kazinoki Siebold Exerts Anti-Pancreatic Cancer Activity through Downregulating FoxM1.

Pancreatic cancer has a high mortality rate due to poor rates of early diagnosis. One tumor suppressor gene in particular, p53, is frequently mutated in pancreatic cancer, and mutations in p53 can inactivate normal wild type p53 activity and increase expression of transcription factor forkhead box M1 (FoxM1). Overexpression of FoxM1 accelerates cellular proliferation and cancer progression. Therefore, inhibition of FoxM1 represents a therapeutic strategy for treating pancreatic cancer. Broussoflavonol B (BF-B), isolated from the stem bark of Broussonetia kazinoki Siebold has previously been shown to inhibit the growth of breast cancer cells. This study aimed to investigate whether BF-B exhibits anti-pancreatic cancer activity and if so, identify the underlying mechanism. BF-B reduced cell proliferation, induced cell cycle arrest, and inhibited cell migration and invasion of human pancreatic cancer PANC-1 cells (p53 mutated). Interestingly, BF-B down-regulated FoxM1 expression at both the mRNA and protein level. It also suppressed the expression of FoxM1 downstream target genes, such as cyclin D1, cyclin B1, and survivin. Cell cycle analysis showed that BF-B induced the arrest of G0/G1 phase. BF-B reduced the phosphorylation of extracellular signal-regulated kinase ½ (ERK½) and expression of ERK½ downstream effector c-Myc, which regulates cell proliferation. Furthermore, BF-B inhibited cell migration and invasion, which are downstream functional properties of FoxM1. These results suggested that BF-B could repress pancreatic cancer cell proliferation by inactivation of the ERK/c-Myc/FoxM1 signaling pathway. Broussoflavonol B from Broussonetia kazinoki Siebold may represent a novel chemo-therapeutic agent for pancreatic cancer.

Liver Fibrosis and Inflammation under the Control of ERK2.

Chronic liver injury could lead the formation of liver fibrosis, eventually some would develop to hepatocellular carcinoma (HCC), one of the leading malignancies worldwide. The aim of the study is to dissect the role of extracellular signal-regulated kinase 2 (ERK2) signaling in liver fibrosis and inflammation. The choline-deficient, ethionine-supplemented (CDE) diet could lead to fatty livers and generate oval cells, activate hepatocyte stellate cell (HSC) and recruit immune cells as the liver fibrosis model mice. WT and ERK2 deficient (ERK2-/-) mice were compared in terms of liver weight/body weight, liver function, liver fibrosis markers and the differential gene expression in hepatotoxicity. ERK2-/- mice display the less degree of liver fibrosis when compared to WT mice. The protein level of alpha smooth muscle (α-SMA) was reduced and several hepatocellular carcinoma-related genes such as MMP9, FoxM1 were down-regulated. In addition, the cell proliferation and the percentages of activated T cells were reduced in ERK2-/- mice upon liver injury. Therefore, ERK2 plays an important role in regulating liver cirrhosis and inflammation.

Tetramethylpyrazine reduces prostate cancer malignancy through inactivation of the DPP10­AS1/CBP/FOXM1 signaling pathway.

Tetramethylpyrazine (TMP), a Chinese herbal medicine, has been reported to possess anticancer effects. Emerging evidence suggests that various long noncoding RNAs (lncRNAs) serve important roles in cancer initiation and progression. In the present study, the tumor­suppressive effects of TMP in human PCa cells was examined and the underlying mechanisms of its actions were determined. The data showed that TMP treatment reduced cell viability and increased apoptosis in a dose­dependent manner. Reverse transcription­quantitative PCR showed TMP treatment increased the expression of lncRNA DPP10­AS1 in PCa cells. Furthermore, DPP10­AS1 was also upregulated in TMP­resistant PCa cells. Knockdown of DPP10­AS1 reversed TMP resistance, whereas increased expression of DPP10­AS1 abrogated the TMP­mediated cytotoxicity in PCa cells. In addition, forkhead box M1 (FOXM1) was verified as the functional target of DPP10­AS1, and knockdown of FOXM1 reversed the TMP/DPP10­AS1­induced cell cytotoxicity. Mechanistically, DPP10­AS1 was associated with CREB binding protein, thereby induced H3K27ac enrichment at the promoter region of the FOXM1 gene. In conclusion, the present study showed that TMP may be a promising treatment agent for PCa and lncRNA DPP10­AS1 may be a promising therapeutic target for TMP treatment.

Destabilization of FoxM1 and Inhibition of Topoisomerase I Contribute to Cytotoxicity of Prenylated Xanthones Isolated from Metaxya rostrata.

We recently isolated the prenylated xanthones 2-deprenyl-rheediaxanthone B (XB) and 2-deprenyl-7-hydroxy-rheediaxanthone B (OH-XB) from the South American tree fern Metaxya rostrata. This study explores the mechanisms underlying the FoxM1 downregulation induced by both xanthones. Analysis of cell viability and cell-death induction in SW480, HCT116, Caco-2, DLD1 and HT29 exposed to xanthones found cell-loss and activation of caspase in all cell lines except HT29 that do not have high FoxM1 protein levels. To determine the cellular mechanism of xanthone-induced FoxM1 loss, protein stability was analyzed by cycloheximide-chase experiments and showed reduction of FoxM1 stability by XB but not OH-XB. Destabilization was prevented by inhibiting proteasome activity using MG-132 and moderately by the lysosomal inhibitor bafilomycin A1 (baf A1). OH-XB had a stronger impact than XB on FoxM1 mRNA expression by qRT-PCR, and MG-132 positively affected FoxM1 protein level in OH-XB exposed cells even though no decrease in protein abundance had been induced by the xanthone. Additionally, the compound inhibited topoisomerase I causing DNA DSB and early cell cycle arrest. This may reduce FoxM1 gene expression, which may in turn compromise DNA repair and enhance xanthone-induced cell death. With regard to xanthone-induced cell death, MG-132 protected cultures from cell loss induced by both compounds, and baf A1 was active against these XB-induced effects. In summary, both destabilization of FoxM1 protein and topoisomerase I inhibition contribute to both XB and OH-XB cytotoxic activity albeit at different ratios.

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.

Suppression of colorectal cancer cell growth by combined treatment of 6-gingerol and γ-tocotrienol via alteration of multiple signalling pathways.

Our previous study reported that combined treatment of γ-tocotrienol with 6-gingerol showed promising anticancer effects by synergistically inhibiting proliferation of human colorectal cancer cell lines. This study aimed to identify and elucidate molecular mechanisms involved in the suppression of SW837 colorectal cancer cells modulated by combined treatment of γ-tocotrienol and 6-gingerol. Total RNA from both untreated and treated cells was prepared for transcriptome analysis using RNA sequencing techniques. We performed high-throughput sequencing at approximately 30-60 million coverage on both untreated and 6G + γT3-treated cells. The results showed that cancer-specific differential gene expression occurred and functional enrichment pathway analysis suggested that more than one pathway was modulated in 6G + γT3-treated cells. Combined treatment with 6G + γT3 augmented its chemotherapeutic effect by interfering with the cell cycle process, downregulating the Wnt signalling pathway and inducing apoptosis mainly through caspase-independent programmed cell death through mitochondrial dysfunction, activation of ER-UPR, disruption of DNA repair mechanisms and inactivation of the cell cycle process through the downregulation of main genes in proliferation such as FOXM1 and its downstream genes. The combined treatment exerted its cytotoxic effect through upregulation of genes in stress response activation and cytostatic effects demonstrated by downregulation of main regulator genes in the cell cycle. Selected genes involved in particular pathways including ATF6, DDIT3, GADD34, FOXM1, CDK1 and p21 displayed concordant patterns of gene expression between RNA sequencing and RT-qPCR. This study provides new insights into combined treatment with bioactive compounds not only in terms of its pleiotropic effects that enhance multiple pathways but also specific target genes that could be exploited for therapeutic purposes, especially in suppressing cancer cell growth.

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.

Inhibition of Wnt3a/FOXM1/ß-Catenin Axis and Activation of GSK3ß and Caspases are Critically Involved in Apoptotic Effect of Moracin D in Breast Cancers.

Although Moracin D derived from Morus alba was known to have anti-inflammatory and antioxidant activities, the underlying antitumor mechanism of Moracin D has not been unveiled thus far. Thus, in the recent study, the apoptotic mechanism of Moracin D was elucidated in breast cancer cells. Herein, Moracin D exerted significant cytotoxicity in MDA-MB-231 and MCF-7 cells. Furthermore, Moracin D increased sub G1 population; cleaved poly (Adenosine diphosphate (ADP-ribose)) polymerase (PARP); activated cysteine aspartyl-specific protease 3 (caspase 3); and attenuated the expression of c-Myc, cyclin D1, B-cell lymphoma 2 (Bcl-2), and X-linked inhibitor of apoptosis protein (XIAP) in MDA-MB231 cells. Of note, Moracin D reduced expression of Forkhead box M1 (FOXM1), ß-catenin, Wnt3a, and upregulated glycogen synthase kinase 3 beta (GSK3ß) on Tyr216 along with disturbed binding of FOXM1 with ß-catenin in MDA-MB-231 cells. Conversely, GSK3ß inhibitor SB216763 reversed the apoptotic ability of Moracin D to reduce expression of FOXM1, ß-catenin, pro-caspase3, and pro-PARP in MDA-MB-231 cells. Overall, these findings provide novel insight that Moracin D inhibits proliferation and induces apoptosis via suppression of Wnt3a/FOXM1/ß-catenin signaling and activation of caspases and GSK3ß.

Upregulation of FoxM1 by MnSOD Overexpression Contributes to Cancer Stem-Like Cell Characteristics in the Lung Cancer H460 Cell Line.

Manganese superoxide dismutase promotes migration and invasion in lung cancer cells via upregulation of the transcription factor forkhead box M1. Here, we assessed whether upregulation of forkhead box M1 by manganese superoxide dismutase overexpression mediates the acquisition of cancer stem-like cell characteristics in non-small cell lung cancer H460 cells. The second-generation spheroids from H460 cells were used as lung cancer stem-like cells. The levels of manganese superoxide dismutase, forkhead box M1, stemness markers (CD133, CD44, and ALDH1), and transcription factors (Bmi1, Nanog, and Sox2) were analyzed by Western blot. Sphere formation in vitro and carcinogenicity of lung cancer stem-like cells were evaluated by spheroid formation assay and limited dilution xenograft assays. Knockdown or overexpression of manganese superoxide dismutase or/and forkhead box M1 by transduction with short hairpin RNA(shRNA) or complementary DNA were performed for mechanistic studies. We showed that manganese superoxide dismutase and forkhead box M1 amounts as well as the expression levels of stemness markers and transcription factors sphere formation in vitro, and carcinogenicity of lung cancer stem-like cells were higher than in monolayer cells. Lung cancer stem-like cells transduced with manganese superoxide dismutase shRNA or FoxM1 shRNA exhibited decreased sphere formation and lower amounts of stemness markers and transcription factors. Overexpression of manganese superoxide dismutase or FoxM1 in H460 cells resulted in elevated sphere formation rates and protein levels of stemness markers and transcription factors. Meanwhile, manganese superoxide dismutase knockdown or overexpression accordingly altered forkhead box M1 levels. However, forkhead box M1 knockdown or overexpression had no effect on manganese superoxide dismutase levels but inhibited or promoted lung cancer stem-like cell functions. Interestingly, forkhead box M1 overexpression alleviated the inhibitory effects of manganese superoxide dismutase knockdown in lung cancer stem-like cells. In a panel of non-small cell lung cancer cells, including H441, H1299, and H358 cells, compared to the respective monolayer counterparts, the expression levels of manganese superoxide dismutase and forkhead box M1 were elevated in the corresponding spheroids. These findings revealed the role of forkhead box M1 upregulation by manganese superoxide dismutase overexpression in maintaining lung cancer stem-like cell properties. Therefore, inhibition of forkhead box M1 upregulation by manganese superoxide dismutase overexpression may represent an effective therapeutic strategy for non-small cell lung cancer.

Apoptotic effect of lambertianic acid through AMPK/FOXM1 signaling in MDA-MB231 breast cancer cells.

Though lambertianic acid (LA) was known to exert antitumor effect in liver and prostate cancers, its underlying anticancer mechanism is never reported in breast cancers so far. Thus, in this study, apoptotic mechanism of LA was elucidated in MDA-MB-231 breast cancer cells. Here, LA increased cytotoxicity in MCF-7 and MDA-MB-231 cells; enhanced sub-G1 population, G2/M arrest, and cleaved poly(ADP-ribose) polymerase; activated phosphorylation of AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase pathway; and also suppressed phosphorylation of AKT and the expression of forkhead box M1 (FOXM1), X-linked inhibitor of apoptosis protein, B-cell lymphoma 2, and CyclinB1 in MDA-MB-231 cells. Furthermore, AMPK inhibitor compound C reversed the effect of LA on FOXM1, Cyclin B1, and cleaved poly(ADP-ribose) polymerase in MDA-MB-231 cells. Notably, immunoprecipitation revealed that LA disturbed the direct binding of AKT and FOXM1 in MDA-MB-231 cells. Overall, these findings suggest that LA-induced apoptosis is mediated via activation of AMPK and inhibition of AKT/FOXM1 signaling pathway.

Treatment with docetaxel in combination with Aneustat leads to potent inhibition of metastasis in a patient-derived xenograft model of advanced prostate cancer.

BACKGROUND: Docetaxel used for first-line treatment of advanced prostate cancer (PCa) is only marginally effective. We previously showed, using the LTL-313H subrenal capsule patient-derived metastatic PCa xenograft model, that docetaxel combined with Aneustat (OMN54), a multivalent plant-derived therapeutic, led to marked synergistic tumour growth inhibition. Here, we investigated the effect of docetaxel+Aneustat on metastasis. METHODS: C4-2 cells were incubated with docetaxel, Aneustat and docetaxel+Aneustat to assess effects on cell migration. The LTL-313H model, similarly treated, was analysed for effects on lung micro-metastasis and kidney invasion. The LTL-313H gene expression profile was compared with profiles of PCa patients (obtained from Oncomine) and subjected to IPA to determine involvement of cancer driver genes. RESULTS: Docetaxel+Aneustat markedly inhibited C4-2 cell migration and LTL-313H lung micro-metastasis/kidney invasion. Oncomine analysis indicated that treatment with docetaxel+Aneustat was associated with improved patient outcome. The drug combination markedly downregulated expression of cancer driver genes such as FOXM1 (and FOXM1-target genes). FOXM1 overexpression reduced the anti-metastatic activity of docetaxel+Aneustat. CONCLUSIONS: Docetaxel+Aneustat can inhibit PCa tissue invasion and metastasis. This activity appears to be based on reduced expression of cancer driver genes such as FOXM1. Use of docetaxel+Aneustat may provide a new, more effective regimen for therapy of metastatic PCa.

Activation of an AKT/FOXM1/STMN1 pathway drives resistance to tyrosine kinase inhibitors in lung cancer.

BACKGROUND: Tyrosine kinase inhibitors (TKIs) have demonstrated clinical benefits in the treatment of several tumour types. However, the emergence of TKI resistance restricts the therapeutic effect. This study uses non-small cell lung cancer (NSCLC) to explore the mechanisms contributing to TKI resistance in tumours. METHODS: Biological phenotypes and RNA microarray expression data were analysed in NSCLC cells with and without TKI pretreatment. Specific inhibitors and siRNAs were used to validate the direct involvement of an AKT/FOXM1/STMN1 pathway in TKI resistance. Patients' tissues were analysed to explore the clinical importance of FOXM1 and STMN1. RESULTS: In vitro and in vivo studies showed that TKIs induced the enrichment of cancer stem cells (CSC), promoted epithelial to mesenchymal transition (EMT), and conferred multidrug resistance on NSCLC cells in a cell type- and TKI class-dependent manner. Mechanistically, TKIs activated an AKT/FOXM1/STMN1 pathway. The crucial role of this pathway in TKI-induced enrichment of CSC and drug resistance was verified by silencing FOXM1 and STMN1 or blocking the AKT pathway. Additionally, overexpression of STMN1 was associated with upregulation of FOXM1 in advanced NSCLC patients, and STMN1/FOXM1 upregulation predicted a poor outcome. CONCLUSIONS: Our findings elucidate an additional common mechanism for TKI resistance and provide a promising therapeutic target for reversing TKI resistance in NSCLC.

Siomycin A Induces Apoptosis in Human Lung Adenocarcinoma A549 Cells by Suppressing the Expression of FoxM1.

Forkhead box M1 (FoxM1), a transcription factor of the Forkhead family, is demonstrated to be critical for proliferation, apoptosis, migration and invasion of lung cancer. In this study, we extensively investigated the anticancer effect of siomycin A, which was identified as an inhibitor of FoxM1 transcriptional activity, on human lung adenocarcinoma A549 cells. Our study indicated that treatment with siomycin A resulted in the suppression of FoxM1 expression, which consequently contributed to its effect of cell growth inhibition and cell apoptosis induction in A549 cells. Then the molecular mechanism of siomycin A's apoptotic action on A549 cells was further investigated. The results revealed that siomycin A induced apoptosis by influencing the downstream events of FoxM1, including inhibiting the expression of Bcl-2 and Mcl-1, as well as leading to caspase-3 cleavage. Taken together, our findings may be useful for understanding the mechanism of action of siomycin A on lung cancer cells and provide new insights into the possible application of such a compound in lung cancer therapy in the future.