Deguelin inhibits growth of breast cancer cells by modulating the expression of key members of the Wnt signaling pathway

Deguelin inhibits the glioblastoma progression through suppressing CCL2/NFκB signaling pathway

Glioblastoma multiforme (GBM) is the most common primary intracranial tumor with characteristics of high aggressiveness and poor prognosis. Deguelin, a component from the bark of Leguminosae Mundulea sericea (African plant), displays antiproliferative effects in some tumors, however, the inhibitory effect and mechanism of deguelin on GBM were still poorly understood. At first, we found that deguelin reduced the viability of GBM cells by causing cell cycle arrest in G2/M phase and inducing their apoptosis. Secondly, deguelin inhibited the migration of GBM cells. Next, RNA-seq analysis identified that CCL2 (encoding chemokine CCL2) was downregulated significantly in deguelin-treated GBM cells. As reported, CCL2 promoted the cell growth, and CCL2 was associated with regulating NFκB signaling pathway, as well as involved in modulating tumor microenvironment (TME). Furthermore, we found that deguelin inactivated CCL2/NFκB signaling pathway, and exougous CCL2 could rescue the anti-inhibitory effect of deguelin on GBM cells via upregulating NFκB. Finally, we established a syngeneic intracranial orthotopic GBM model and found that deguelin regressed the tumor growth, contributed to an anti-tumorigenic TME and inhibited angiogenesis of GBM by suppressing CCL2/NFκB in vivo. Taken together, these results suggest the anti-GBM effect of deguelin via inhibiting CCL2/NFκB pathway, which may provide a new strategy for the treatment of GBM.

Deguelin Restores Paclitaxel Sensitivity in Paclitaxel-Resistant Ovarian Cancer Cells via Inhibition of the EGFR Signaling Pathway

Background

Ovarian cancer is one of women's malignancies with the highest mortality among gynecological cancers. Paclitaxel is used in first-line ovarian cancer chemotherapy. Research on paclitaxel-resistant ovarian cancer holds significant clinical importance.

Methods

Cell viability and flow cytometric assays were conducted at different time and concentration points of deguelin and paclitaxel treatment. Immunoblotting was performed to assess the activation status of key signaling molecules important for cell survival and proliferation following treatment with deguelin and paclitaxel. The fluo-3 acetoxymethyl assay for P-glycoprotein transport activity assay and cell viability assay in the presence of N-acetyl-L-cysteine were also conducted.

Results

Cell viability and flow cytometric assays demonstrated that deguelin resensitized paclitaxel in a dose- and time-dependent manner. Cotreatment with deguelin and paclitaxel inhibited EGFR and its downstream signaling molecules, including AKT, ERK, STAT3, and p38 MAPK, in SKOV3-TR cells. Interestingly, cotreatment with deguelin and paclitaxel suppressed the expression level of EGFR via the lysosomal degradation pathway. Cotreatment did not affect the expression and function of P-glycoprotein. N-acetyl-L-cysteine failed to restore cell cytotoxicity when used in combination with deguelin and paclitaxel in SKOV3-TR cells. The expression of BCL-2, MCL-1, and the phosphorylation of the S155 residue of BAD were downregulated. Moreover, inhibition of paclitaxel resistance by deguelin was also observed in HeyA8-MDR cells.

Conclusion

Our research showed that deguelin effectively suppresses paclitaxel resistance in SKOV3-TR ovarian cancer cells by downregulating the EGFR and its downstream signaling pathway and modulating the BCL-2 family proteins. Furthermore, deguelin exhibits inhibitory effects on paclitaxel resistance in HeyA8-MDR ovarian cancer cells, suggesting a potential mechanism for paclitaxel resensitization that may not be cell-specific. These findings suggest that deguelin holds promise as an anticancer therapeutic agent for overcoming chemoresistance in ovarian cancer.

The therapeutic effect of traditional Chinese medicine on breast cancer through modulation of the Wnt/β-catenin signaling pathway

Breast cancer, the most prevalent malignant tumor among women globally, is significantly influenced by the Wnt/β-catenin signaling pathway, which plays a crucial role in its initiation and progression. While conventional chemotherapy, the standard clinical treatment, suffers from significant drawbacks like severe side effects, high toxicity, and limited prognostic efficacy, Traditional Chinese Medicine (TCM) provides a promising alternative. TCM employs a multi-targeted therapeutic approach, which results in fewer side effects and offers a high potential for effective treatment. This paper presents a detailed analysis of the therapeutic impacts of TCM on various subtypes of breast cancer, focusing on its interaction with the Wnt/β-catenin signaling pathway. Additionally, it explores the effectiveness of both monomeric and compound forms of TCM in the management of breast cancer. We also discuss the potential of establishing biomarkers for breast cancer treatment based on key proteins within the Wnt/β-catenin signaling pathway. Our aim is to offer new insights into the prevention and treatment of breast cancer and to contribute to the standardization of TCM.

Deguelin inhibits the proliferation of human multiple myeloma cells by inducing apoptosis and G2/M cell cycle arrest: Involvement of Akt and p38 MAPK signalling pathway

Deguelin exhibits antiproliferative activity against various cancer cell types. Previous studies have reported that deguelin exhibits pro-apoptotic activity against human cancer cells. The current study aimed at further elaborating the anticancer effects of deguelin against multiple myeloma cells. Cell growth estimations were made through MTT assay. Phase contrast microscopy was used for the analysis of the viability of multiple myeloma cells. Colony formation from multiple myeloma cells was studied using a clonogenic assay. Antioxidative assays for determining levels of glutathione (GSH) and superoxide dismutase (SOD) were carried out after treating multiple myeloma cells with deguelin. The apoptosis of multiple myeloma cells was studied using AO/EB and Annexin V-FITC/PI staining methods. Multiple myeloma cell cycle analysis was performed through flow cytometry. mRNA expression levels were depicted using qRT-PCR. Migration and invasion of multiple myeloma cells were determined with the wound-healing and transwell assays, respectively. Deguelin specifically inhibited the multiple myeloma cell growth while the normal plasma cells were minimally affected. Multiple myeloma cells when treated with deguelin exhibited remarkably lower viability and colony-forming ability. Multiple myeloma cells treated with deguelin produced more SOD and had higher GSH levels. The multiple myeloma cell growth, migration, and invasion were significantly declined by in vitro administration of deguelin. In conclusion, deguelin treatment, when applied in vitro, induced apoptotic cell death and resulted in mitotic cessation at the G2/M phase through modulation of cell cycle regulatory mRNAs in multiple myeloma cells.

Wnt Signaling Pathway Collapse upon β-Catenin Destruction by a Novel Antimicrobial Peptide SKACP003: Unveiling the Molecular Mechanism and Genetic Activities Using Breast Cancer Cell Lines

Despite progress in breast cancer treatment, the survival rate for patients with metastatic breast cancer remains low due to chemotherapeutic agent resistance and the lack of specificity of the current generation of cancer drugs. Our previous findings indicated that the antimicrobial peptide SKACP003 exhibited anticancer properties, particularly against the MCF-7, MDA-MB-231, and MDA-MB-453 breast cancer cell lines. However, the mechanism of SKACP003-induced cancer cell death is unknown. Here, we investigated the molecular mechanism by which SKACP003 inhibits the cell cycle, cell proliferation, and angiogenesis in breast cancer cell lines. The results revealed that all the breast cancer cell lines treated at their IC₅₀ values significantly inhibited the replicative phase of the cell cycle. The SKACP003-induced growth inhibition induced apoptosis, as evidenced by a decrease in BCL-2 and an increase in BAX and caspase gene (Cas-3, Cas-8, and Cas-9) expression. Reduced expression of the β-Catenin signaling pathway was associated with the SKACP003-induced apoptosis. SKACP003-treated breast cancer cells showed decreased expression of Wnt/β-Catenin targeting genes such as C-Myc, P⁶⁸, and COX-2 and significant downregulation of CDK-4 and CDK-6 genes. Furthermore, cytoplasmic β-catenin protein levels in SKACP003-treated cell lines were significantly lower than in control cell lines. The results of the current study suggest that the newly identified antimicrobial peptide SKACP003 has great potential as a candidate for specifically targeting the β-catenin and thus significantly reducing the progression and prognosis of breast cancer cell lines.

Countering Triple Negative Breast Cancer via Impeding Wnt/β-Catenin Signaling, a Phytotherapeutic Approach

Triple negative breast cancer (TNBC) is characterized as a heterogeneous disease with severe malignancy and high mortality. Aberrant Wnt/β-catenin signaling is responsible for self-renewal and mammosphere generation, metastasis and resistance to apoptosis and chemotherapy in TNBC. Nonetheless, in the absence of a targeted therapy, chemotherapy is regarded as the exclusive treatment strategy for the treatment of TNBC. This review aims to provide an unprecedented overview of the plants and herbal derivatives which repress the progression of TNBC through prohibiting the Wnt/β-catenin pathway. Herbal medicine extracts and bioactive compounds (alkaloids, retinoids. flavonoids, terpenes, carotenoids and lignans) alone, in combination with each other and/or with chemotherapy agents could interrupt the various steps of Wnt/β-catenin signaling, i.e., WNT, FZD, LRP, GSK3β, Dsh, APC, β-catenin and TCF/LEF. These phytotherapy agents diminish proliferation, metastasis, breast cancer stem cell self-renewal and induce apoptosis in cell and animal models of TNBC through the down-expression of the downstream target genes of Wnt signaling. Some of the herbal derivatives simultaneously impede Wnt/β-catenin signaling and other overactive pathways in triple negative breast cancer, including: mTORC1; ER stress and SATB1 signaling. The herbal remedies and their bioactive ingredients perform essential roles in the treatment of the very fatal TNBC via repression of Wnt/β-catenin signaling.

The Potential for Natural Products to Overcome Cancer Drug Resistance by Modulation of Epithelial-Mesenchymal Transition

The acquisition of resistance and ultimately disease relapse after initial response to chemotherapy put obstacles in the way of cancer therapy. Epithelial-mesenchymal transition (EMT) is a biologic process that epithelial cells alter to mesenchymal cells and acquire fibroblast-like properties. EMT plays a significant role in cancer metastasis, motility, and survival. Recently, emerging evidence suggested that EMT pathways are very important in making drug-resistant involved in cancer. Natural products are gradually emerging as a valuable source of safe and effective anticancer compounds. Natural products could interfere with the different processes implicated in cancer drug resistance by reversing the EMT process. In this review, we illustrate the molecular mechanisms of EMT in the emergence of cancer metastasis. We then present the role of natural compounds in the suppression of EMT pathways in different cancers to overcome cancer cell drug resistance and improve tumor chemotherapy. HighlightsDrug-resistance is one of the obstacles to cancer treatment.EMT signaling pathways have been correlated to tumor invasion, metastasis, and drug-resistance.Various studies on the relationship between EMT and resistance to chemotherapy agents were reviewed.Different anticancer natural products with EMT inhibitory properties and drug resistance reversal effects were compared.

Pharmacological basis and new insights of deguelin concerning its anticancer effects

Deguelin is a rotenoid of the flavonoid family, which can be extracted from Lonchocarpus, Derris, or Tephrosia. It possesses the inhibition of cancer cell proliferation by inducing apoptosis through regulating the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway, the NF-κB signaling pathway, the Wnt signaling pathway, the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway and epidermal growth factor receptor (EGFR) signaling, activating the p38 mitogen-activated protein kinase (MAPK) pathway, repression of Bmi1, targeting cyclooxygenase-2 (COX-2), targeting galectin-1, promotion of glycogen synthase kinase-3β (GSK3β)/FBW7-mediated Mcl-1 destabilization and targeting mitochondria via down-regulating Hexokinases II-mediated glycolysis, PUMA-mediation, which are some crucial molecules which modulate closely cancer cell growth and metastasis. Deguelin inhibits tumor cell propagation and malignant transformation through targeting angiogenesis, targeting lymphangiogenesis, targeting focal adhesion kinase (FAK), inhibiting the CtsZ/FAK signaling pathway, targeting epithelial-mesenchymal transition (EMT), the NF-κB signaling pathway, regulating NIMA-related kinase 2 (NEK2). In addition, deguelin possesses other biological activities, such as targeting cell cycle arrest, modulation of autophagy, inhibition of hedgehog pathway, inducing differentiation of mutated NPM1 acute myeloid leukemia etc. Therefore, deguelin is a promising chemopreventive agent for cancer therapy.

Perspectives on natural compounds in chemoprevention and treatment of cancer: an update with new promising compounds

Cancer is the second deadliest disease worldwide. Although recent advances applying precision treatments with targeted (molecular and immune) agents are promising, the histological and molecular heterogeneity of cancer cells and huge mutational burdens (intrinsic or acquired after therapy) leading to drug resistance and treatment failure are posing continuous challenges. These recent advances do not negate the need for alternative approaches such as chemoprevention, the pharmacological approach to reverse, suppress or prevent the initial phases of carcinogenesis or the progression of premalignant cells to invasive disease by using non-toxic agents. Although data are limited, the success of several clinical trials in preventing cancer in high-risk populations suggests that chemoprevention is a rational, appealing and viable strategy to prevent carcinogenesis. Particularly among higher-risk groups, the use of safe, non-toxic agents is the utmost consideration because these individuals have not yet developed invasive disease. Natural dietary compounds present in fruits, vegetables and spices are especially attractive for chemoprevention and treatment because of their easy availability, high margin of safety, relatively low cost and widespread human consumption. Hundreds of such compounds have been widely investigated for chemoprevention and treatment in the last few decades. Previously, we reviewed the most widely studied natural compounds and their molecular mechanisms, which were highly exploited by the cancer research community. In the time since our initial review, many promising new compounds have been identified. In this review, we critically review these promising new natural compounds, their molecular targets and mechanisms of anticancer activity that may create novel opportunities for further design and conduct of preclinical and clinical studies.

Deguelin targets multiple oncogenic signaling pathways to combat human malignancies

Cancer is an anomalous growth and differentiation of cells known to be governed by oncogenic factors. Plant-based natural metabolites have been well recognized to possess chemopreventive properties. Deguelin, a natural rotenoid, is among the class of bioactive phytoconstituents from a diverse range of plants with potential antineoplastic effects in different cancer subtypes. However, the precise mechanisms of how deguelin inhibits tumor progression remains elusive. Deguelin has shown promising results in targeting the hallmarks of tumor progression via inducing tumor apoptosis, cell cycle arrest, and inhibition of angiogenesis and metastasis. Based on initial scientific excerpts, deguelin has been reported to inhibit tumor growth via different signaling pathways, including mitogen-activated protein kinase, phosphoinositide 3-kinase, serine/threonine protein kinase B (also known as Akt), mammalian target of rapamycin, nuclear factor-κB, matrix metalloproteinase (MMP)-2, MMP-9 and caspase-3, caspase-8, and caspase-9. This review summarizes the mechanistic insights of antineoplastic action of deguelin to gain a clear understanding of its therapeutic effects in cancer. The anticancer potential of deguelin with respect to its efficacy in targeting tumorigenesis via nanotechnological approaches is also investigated. The initial scientific findings have presented deguelin as a promising antitumorigenic agent which can be used for monotherapy as well as synergistically to augment efficacy of chemotherapeutic treatment regimes.

Estrogen receptor alpha regulates the Wnt/β-catenin signaling pathway in colon cancer by targeting the NOD-like receptors

It has been reported that estrogen receptors (ERs) participate in carcinogenesis by directly regulating NOD-like receptors (NLRs). However, the expression profiles of ERs and NLRs in tumor and the ER-NLR regulated signaling pathway are not clear. In this study, we summarized gene expression profiles of ERs and NLRs across normal and tumor tissue by comprehensive data mining. Then we explored the ER-NLR regulated signaling pathway by RNA sequencing (RNA-seq). The results showed that the NLRs and ERs were differentially expressed in different neoplasm tissues. Such expression discrepancies might influence inflammatory regulation and tumorigenesis. Importantly, we identified that ER-NLR regulate Wnt/β-catenin pathway in colon cancer. Taking colon adenocarcinoma (COAD) as example, we found that Wnt2b/LRP8/Dvl1/Axin2/GSK3a/APC/β-catenin genes were differentially expressed in ER^-/- mouse colon tissue and colon cancer cells. The selective ERα antagonist could significantly decrease Wnt2b/LRP8/Dvl1 expression, increase destruction complex (Axin2/GSK3a/APC) expression, and promote degradation of β-catenin in colon carcinoma cell by inhibited NLRP3 expression. In short, the research demonstrates that NLRs are potential biomarkers for cancer, and ERs can regulate the Wnt/β-catenin signaling pathway in cancer by targeting the NLRs. Our results provide a possible signaling pathway in which ER-NLR is correlated with Wnt/β-catenin.

Biopharmacological considerations for accelerating drug development of deguelin, a rotenoid with potent chemotherapeutic and chemopreventive potential

Deguelin is a rotenoid compound that exists in abundant quantities in the bark, roots, and leaves of the Leguminosae family of plants. An analysis of evidence from both in vitro and in vivo studies suggests that deguelin displays potent anticancer activity against multiple cancer types and exhibits chemopreventive potential in Akt-inducible transgenic mouse models. Deguelin appears to impede carcinogenesis by enhancing cell apoptosis and hindering malignant transformation and tumor cell propagation. Crucial oncogenic pathways likely targeted by deguelin include the epithelial-to-mesenchymal transition; angiogenesis-related pathways; and the phosphoinositide 3-kinase/Akt, Wnt, epidermal growth factor receptor, c-Met, and hedgehog signal transduction cascades. This review article provides a comprehensive summary of current preclinical research featuring deguelin as a leading chemotherapeutic and chemopreventive compound, and it highlights the importance of identifying companion molecular biomarkers and performing systemic pharmacokinetic studies for accelerating the process of developing deguelin as a clinical anticancer agent.

Deguelin induces apoptosis in colorectal cancer cells by activating the p38 MAPK pathway

Objectives

Deguelin, a rotenoid extracted from Mundulea sericea (Leguminosae), exhibits antitumor effects on several types of human cancers. Due to the limited studies of deguelin on colorectal cancer (CRC), the present study was designed to investigate the antitumor effect of deguelin and to explore the underlying mechanism in CRC.

Materials and methods

Cell viability was assessed by the cell counting kit-8 (CCK-8) assay, and cell apoptosis was determined by the annexin v-propidium iodide staining using flow cytometry and Western blot in CRC cell lines after incubation with deguelin. The antitumor effect of deguelin was further evaluated in tumor xenograft models. Moreover, SB203580, a specific inhibitor of p38 MAPK, was used to confirm the involvement of p38 MAPK pathway in deguelin-induced apoptosis.

Results

Deguelin significantly inhibited cell proliferation and induced apoptosis in CRC cell lines (SW620 and RKO) in a time-dependent and dose-dependent manner. Western blot analysis also showed that the expression of proapoptotic proteins (cleaved caspase 3 and cleaved PARP) was upregulated, while that of antiapoptotic proteins (Bcl-2 and survivin) was downregulated after deguelin treatment in CRC cell lines. Moreover, oral administration of deguelin significantly suppressed tumor growth and induced apoptosis in subcutaneous xenograft mouse models without obvious toxicity. Additionally, Western blot revealed that deguelin-induced apoptosis might be regulated by the p38 MAPK pathway and inhibition of p38 MAPK could attenuate deguelin-induced proliferative inhibition and apoptosis in CRC cells.

Conclusion

Collectively, these results demonstrated that deguelin inhibited CRC cell growth by inducing apoptosis via activation of p38 MAPK pathway.

The Natural Flavonoid Compound Deguelin Inhibits HCMV Lytic Replication within Fibroblasts

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus for which there is no vaccine or cure. This viral infection, once acquired, is life-long, residing latently in hematopoietic cells. However, latently infected individuals with weakened immune systems often undergo HCMV reactivation, which can cause serious complications in immunosuppressed and immunocompromised patients. Current anti-viral therapies target late stages of viral replication, and are often met with therapeutic resistance, necessitating the development of novel therapeutics. In this current study, we identified a naturally-occurring flavonoid compound, deguelin, which inhibits HCMV lytic replication. Our findings reveal that nanomolar concentrations of deguelin significantly suppress the production of the infectious virus. Further, we show that deguelin inhibits the lytic cycle during the phase of the replication cycle consistent with early (E) gene and protein expression. Importantly, our data reveal that deguelin inhibits replication of a ganciclovir-resistant strain of HCMV. Together, our findings identify a novel, naturally occurring compound that may prove useful in the treatment of HCMV replication.

Repression of Noxa by Bmi1 contributes to deguelin-induced apoptosis in non-small cell lung cancer cells

Deguelin, a natural rotenoid isolated from several plants, has been reported to exert anti‐tumour effects in various cancers. However, the molecular mechanism of this regulation remains to be fully elucidated. Here, we found that deguelin inhibited the growth of non‐small cell lung cancer (NSCLC) cells both in vitro and in vivo by downregulation of Bmi1 expression. Our data showed that Bmi1 is highly expressed in human NSCLC tissues and cell lines. Knockdown of Bmi1 significantly suppressed NSCLC cell proliferation and colony formation. Deguelin treatment attenuated the binding activity of Bmi1 to the Noxa promoter, thus resulting in Noxa transcription and apoptosis activation. Knockdown of Bmi1 promoted Noxa expression and enhanced deguelin‐induced apoptosis, whereas overexpression of Bmi1 down‐regulated Noxa protein level and deguelin‐induced apoptosis. Overall, our study demonstrated a novel apoptotic mechanism for deguelin to exert its anti‐tumour activity in NSCLC cells.

The "Yin and Yang" of Natural Compounds in Anticancer Therapy of Triple-Negative Breast Cancers

Among the different types of breast cancers, triple-negative breast cancers (TNBCs) are highly aggressive, do not respond to conventional hormonal/human epidermal growth factor receptor 2 (HER2)-targeted interventions due to the lack of the respective receptor targets, have chances of early recurrence, metastasize, tend to be more invasive in nature, and develop drug resistance. The global burden of TNBCs is increasing regardless of the number of cytotoxic drugs being introduced into the market each year as they have only moderate efficacy and/or unforeseen side effects. Therefore, the demand for more efficient therapeutic interventions, with reduced side effects, for the treatment of TNBCs is rising. While some plant metabolites/derivatives actually induce the risk of cancers, many plant-derived active principles have gained attention as efficient anticancer agents against TNBCs, with fewer adverse side effects. Here we discuss the possible oncogenic molecular pathways in TNBCs and how the purified plant-derived natural compounds specifically target and modulate the genes and/or proteins involved in these aberrant pathways to exhibit their anticancer potential. We have linked the anticancer potential of plant-derived natural compounds (luteolin, chalcones, piperine, deguelin, quercetin, rutin, fisetin, curcumin, resveratrol, and others) to their ability to target multiple dysregulated signaling pathways (such as the Wnt/β-catenin, Notch, NF-κB, PI3K/Akt/mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK) and Hedgehog) leading to suppression of cell growth, proliferation, migration, inflammation, angiogenesis, epithelial-mesenchymal transition (EMT) and metastasis, and activation of apoptosis in TNBCs. Plant-derived compounds in combination with classical chemotherapeutic agents were more efficient in the treatment of TNBCs, possibly with lesser side effects.

Dietary phytochemicals in breast cancer research: anticancer effects and potential utility for effective chemoprevention

Cancerous tissue transformation developing usually over years or even decades of life is a highly complex process involving strong stressors damaging DNA, chronic inflammation, comprehensive interaction between relevant molecular pathways, and cellular cross-talk within the neighboring tissues. Only the minor part of all cancer cases are caused by inborn predisposition; the absolute majority carry a sporadic character based on modifiable risk factors which play a central role in cancer prevention. Amongst most promising candidates for dietary supplements are bioactive phytochemicals demonstrating strong anticancer effects. Abundant evidence has been collected for beneficial effects of flavonoids, carotenoids, phenolic acids, and organosulfur compounds affecting a number of cancer-related pathways. Phytochemicals may positively affect processes of cell signaling, cell cycle regulation, oxidative stress response, and inflammation. They can modulate non-coding RNAs, upregulate tumor suppressive miRNAs, and downregulate oncogenic miRNAs that synergically inhibits cancer cell growth and cancer stem cell self-renewal. Potential clinical utility of the phytochemicals is discussed providing examples for chemoprevention against and therapy for human breast cancer. Expert recommendations are provided in the context of preventive medicine.

Deguelin Impairs Cell Adhesion, Migration and Invasion of Human Lung Cancer Cells through the NF-[Formula: see text]B Signaling Pathways

Deguelin, a rotenoid, is isolated from a natural plant species, and has biological activities including antitumor function. In the present study, we investigated the effect of deguelin on the cell adhesion, migration and invasion of NCI-H292 human lung cancer cells in vitro. Cell viability was analyzed by using flow cytometer. Cell adhesion was determined by using the cell-matrix adhesion assay. Wound healing assay was used to examine cell migration. Cell migration and invasion were investigated using a Boyden chamber assay. The protein expression was measured by Western blotting and confocal laser microscopy. The electrophoretic mobility shift assay was used to measure NF-[Formula: see text]B p65 binding to DNA.We selected the concentrations of deguelin at 0, 0.5, 1.0, 1.5, 2.0 and 2.5[Formula: see text][Formula: see text]M and we found that those concentrations of deguelin did not induce significant cytotoxic effects on NCI-H292 cells. Thus, we selected those concentrations of deguelin for metastasis assay. We found that deguelin inhibited cell adhesion, migration and invasion in dose-dependent manners that was assayed by wound healing and transwell methods, respectively. Deguelin decreased the expression of MMP-2/-9, SOS 1, Rho A, p-AKT (Thr308), p-ERK1/2, p-p38, p-JNK, NF-[Formula: see text]B (p65) and uPA in NCI-H292 cells. Deguelin suppressed the expression of PI3K, SOS 1, NF-[Formula: see text]B (p65), but did not significantly affect PKC and Ras in the nuclei of NCI-H292 cells that were confirmed by confocal laser microscopy. We suggest that deguelin may be used as a novel anticancer metastasis of lung cancer in the future.

Deguelin exerts anticancer activity of human gastric cancer MGC-803 and MKN-45 cells in vitro

During the pathogenesis of gastric cancer, Akt signaling is considered as a pivotal inducer of gastric cancer development. Here we report the identification of anticancer activities of deguelin, a natural agent that inhibits Akt signaling. When applied to MGC-803 and MKN-45 cells, deguelin suppressed the proliferation and arrested cell cycle by p21-mediated inhibition of cyclin E. We further present in vitro evidence that deguelin promoted apoptosis of cancer cells by decreasing the phospho-Akt signaling and affecting expression of the apoptosis-associated genes Bax and Bcl-2. Additionally, deguelin was found to suppress the migration and invasion of gastric cancer cells. Taken together, these results indicated that deguelin exerted anticancer activity of human gastric cancer MGC-803 and MKN-45 cells in vitro.

Dalbinol, a rotenoid from Amorpha fruticosa L., exerts anti-proliferative activity by facilitating β-catenin degradation in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a highly malignant tumor, and the main cause of treatment failure is malignant proliferation. Aberrations in Wnt/β-catenin signaling are associated with HCC development. Despite the improvements in overall survival made over the past decade from the advent of molecularly targeted therapies, these treatments do not have efficacy in all patients with different pathogeneses. Therefore, there is a demand for novel chemotherapeutic agents for HCC. To this end, we built a natural compound library and screened out a rotenoid named dalbinol from the seeds of Amorpha fruticosa L. Our data demonstrated that dalbinol inhibited the growth of HepG2, HepG2/ADM and Huh7 cells in a concentration-dependent manner. Pharmacological experiments also showed that dalbinol suppressed growth and induced apoptosis in these HCC cell lines in vitro. Furthermore, we found that dalbinol promoted β-catenin degradation, which was mediated by the ubiquitin-proteasome pathway. To summarize, our results illustrate that dalbinol inhibited HCC cell growth by facilitating β-catenin degradation through the ubiquitin-proteasome pathway. Hence, we propose that dalbinol will be a promising agent for the treatment of HCC subtypes with aberrant Wnt/β-catenin pathway activation.

Deguelin inhibits epithelial-to-mesenchymal transition and metastasis of human non-small cell lung cancer cells by regulating NIMA-related kinase 2

Background

Non‐small cell lung cancer is a lethal malignancy with a high mortality rate. Deguelin displays an anti‐tumor effect and inhibits metastasis in various cancers. The aberrant expression of NIMA‐related kinase 2 (NEK2) indicates poor prognosis and induces epithelial‐to‐mesenchymal transition (EMT) and metastasis processes. However, the underlying mechanism between deguelin and NEK2 has remained elusive.

Methods

NSCLC cell lines were treated with deguelin. Wound‐healing and invasion assays were applied to study the inhibitory effect of deguelin on NSCLC cells. EMT markers, E‐cadherin and Vimentin, were also detected by Western blot. NEK2 protein and messenger RNA expression levels were evaluated when NSCLC cells were treated with different concentrations of deguelin. The effect of NEK2 on NSCLC cell metastasis was evaluated through NEK2 knockdown. To investigate whether deguelin induced EMT by regulating NEK2, we overexpressed NEK2 in both NCI‐H520 and SK‐MES‐1 cell lines, and then used real time‐PCR to study the E‐cadherin and Vimentin messenger RNA expression in both NSCLC cells.

Results

Deguelin inhibited migration and invasion processes in NSCLC cell lines and decreased NEK2 expression in a concentration‐dependent manner. Furthermore, NEK2 knockdown inhibited NSCLC cell migration and invasion. Finally, overexpressing NEK2 in NCI‐H520 and SK‐MES‐1 cells could restore the inhibition of metastasis induced by deguelin.

Conclusions

Deguelin could inhibit EMT and metastasis, while overexpression of NEK2 promotes these processes. Deguelin could decrease NEK2 expression, while NEK2 overexpression could restore deguelin‐induced inhibition of metastasis.

EGFR expression is associated with cytoplasmic staining of CXCR4 and predicts poor prognosis in triple-negative breast carcinomas

The purpose of the present study was to investigate the significance of C-X-C motif chemokine receptor type 4 (CXCR4) and epidermal growth factor receptors (EGFRs) in triple-negative breast cancer (TNBC). CXCR4 and EGFR expression levels were immunohistochemically determined in 207 primary breast cancer specimens. The associations between receptor expression and clinicopathological characteristics were analyzed, and receptor expression was also assessed as a prognostic factor. In the human MDA-MB-231 TNBC cell line, CXCR4 or EGFR was stably knocked down by short hairpin RNA, and the biological behavior of the cells, including migration, invasion and tumorigenesis, was investigated. The results revealed that TNBC was associated with younger age, higher histological grade and an aggressive phenotype. CXCR4 and EGFR were highly expressed in patients with TNBC, and those with high CXCR4 or EGFR expression exhibited an unfavorable prognosis in terms of disease-free survival and overall survival. In MDA-MB-231 cells, the expression of CXCR4 protein was decreased following EGFR silencing, while CXCR4 knockdown also caused a decrease in EGFR protein levels. The migratory and invasive capabilities of MDA-MB-231 cells were decreased following the knockdown of CXCR4 or EGFR expression. A strong correlation between CXCR4 and EGFR expression was identified in patients with TNBC. The results suggest that elevated expression levels of these two receptors may serve as predictive factors for poor prognosis in patients with TNBC. In addition, tumor proliferation, migration, invasion and tumorigenesis are weakened in MDA-MB-231 cells following suppression of CXCR4 or EGFR expression. Therefore, EGFR and CXCR4 may be potential therapeutic targets for TNBC.

Overexpression of Forkhead Box L1 (FOXL1) Inhibits the Proliferation and Invasion of Breast Cancer Cells

Forkhead box L1 (FOXL1) is a member of the Forkhead box (FOX) superfamily and was reported to be dysregulated in various types of cancers. However, its expression pattern and underlying cellular function in breast cancer remain largely unexplored. Thus, the aim of this study was to detect FOXL1 expression in breast cancer and to analyze its role in the progression of breast cancer. Our results demonstrated that FOXL1 expression at both the mRNA and protein levels was downregulated in breast cancer tissues and cell lines. Ectopic FOXL1 suppressed breast cancer cell proliferation, migration, and invasion in vitro. Furthermore, overexpression of FOXL1 significantly attenuated tumor growth in breast xenograft models in vivo. Finally, overexpression of FOXL1 significantly downregulated the protein expression levels of β-catenin, c-Myc, and cyclin D1 in MDA-MB-231 cells. Taken together, the present study demonstrated that FOXL1 inhibited the proliferation, invasion, and migration of breast cancer in vitro and breast tumor growth in vivo through deactivating the Wnt/β-catenin signaling pathway. Thus, these findings suggest that FOXL1 may be a potential novel target for breast cancer therapy.

Modulation of signal transduction pathways by natural compounds in cancer

Cancer is generally regarded as the result of abnormal growth of cells. According to World Health Organization, cancer is the leading cause of mortality worldwide. Mother nature provides a large source of bioactive compounds with excellent therapeutic efficacy. Numerous phytochemicals from nature have been investigated for anticancer properties. In this review article, we discuss several natural compounds, which have shown anti-cancer activity. Natural compounds induce cell cycle arrest, activate intrinsic and extrinsic apoptosis pathways, generate Reactive Oxygen Species (ROS), and down-regulate activated signaling pathways, resulting in inhibition of cell proliferation, progression and metastasis of cancer. Several preclinical studies have suggested that natural compounds can also increase the sensitivity of resistant cancers to available chemotherapy agents. Furthermore, combining FDA approved anti-cancer drugs with natural compounds results in improved efficacy. On the basis of these exciting outcomes of natural compounds against several cancer types, several agents have already advanced to clinical trials. In conclusion, preclinical results and clinical outcomes against cancer suggest promising anticancer efficacy of agents from natural sources.

A novel thiophene-3-carboxamide analog of annonaceous acetogenin exhibits antitumor activity via inhibition of mitochondrial complex I

Previously we synthesized JCI‐20679, a novel thiophene‐3‐carboxamide analog of annonaceous acetogenins which have shown potent antitumor activity, with no serious side effects, in mouse xenograft models. In this study, we investigated the antitumor mechanism of JCI‐20679. The growth inhibition profile (termed “fingerprint”) of this agent across a panel of 39 human cancer cell lines (termed “JFCR39”) was measured; this fingerprint was analyzed by the COMPARE algorithm utilizing the entire drug sensitivity database for the JFCR39 panel. The JCI‐20679‐specific fingerprint exhibited a high similarity to those of two antidiabetic biguanides and a natural rotenoid deguelin which were already known to be mitochondrial complex I inhibitors. In addition, the fingerprint exhibited by JCI‐20679 was not similar to that displayed by any typical anticancer drugs within the database, suggesting that it has a unique mode of action. In vitro experiments using bovine heart‐derived mitochondria showed direct inhibition of mitochondrial complex I by JCI‐20679 and associated derivatives. This inhibition of enzymatic activity positively correlated with tumor cell growth inhibition. Furthermore, a fluorescently labeled derivative of JCI‐20679 localized to the mitochondria of live cancer cells in vitro. These results suggest that JCI‐20679 can inhibit cancer cell growth by inhibiting mitochondrial complex I. Our results show that JCI‐20679 is a novel anticancer drug lead with a unique mode of action.

γ-Tocotrienol reversal of epithelial-to-mesenchymal transition in human breast cancer cells is associated with inhibition of canonical Wnt signalling

OBJECTIVES

Frizzled-7 (FZD7) receptor-dependent activation of the canonical Wnt/β-catenin pathway plays a crucial role in epithelial-to-mesenchymal transition (EMT) and breast cancer metastasis. FZD7 and its co-receptor, low-density lipoprotein receptor-related protein 6 (LRP6), are highly expressed in MDA-MB-231 and T-47D breast cancer cells, and endogenous ligands for FZD7 include Wnt3a and Wnt5a/b. γ-Tocotrienol, a natural isoform of vitamin E, inhibits human breast cancer cell proliferation and EMT. Here, studies have been conducted to investigate the role of the canonical Wnt pathway in mediating inhibitory effects of γ-tocotrienol on EMT in human breast cancer cells.

MATERIALS AND METHODS

MDA-MB-231, T-47D and MCF-10A cells were maintained in serum-free defined media containing selected doses of γ-tocotrienol. Cell viability was determined using the MTT colorimetric assay, Western blot analysis was used to measure protein expression and the wound-healing assay was employed to study cell mobility and migration. Immunohistochemical fluorescence staining visualized expression and localization of EMT cell markers.

RESULTS

γ-Tocotrienol was found to induce dose-responsive inhibition of MDA-MB-231 and T-47D cell growth at doses that had no effect on immortalized normal MCF-10A mammary epithelial cells. These growth inhibitory effects were associated with suppression in canonical Wnt signalling, reversal of EMT and significant reduction in breast cancer cell motility.

CONCLUSIONS

γ-Tocotrienol suppression of metastatic breast cancer cell proliferation and EMT was associated with suppression of the canonical Wnt/β-catenin signalling pathway.

Novel Phenotypic Outcomes Identified for a Public Collection of Approved Drugs from a Publicly Accessible Panel of Assays

Phenotypic assays have a proven track record for generating leads that become first-in-class therapies. Whole cell assays that inform on a phenotype or mechanism also possess great potential in drug repositioning studies by illuminating new activities for the existing pharmacopeia. The National Center for Advancing Translational Sciences (NCATS) pharmaceutical collection (NPC) is the largest reported collection of approved small molecule therapeutics that is available for screening in a high-throughput setting. Via a wide-ranging collaborative effort, this library was analyzed in the Open Innovation Drug Discovery (OIDD) phenotypic assay modules publicly offered by Lilly. The results of these tests are publically available online at www.ncats.nih.gov/expertise/preclinical/pd2 and via the PubChem Database (https://pubchem.ncbi.nlm.nih.gov/) (AID 1117321). Phenotypic outcomes for numerous drugs were confirmed, including sulfonylureas as insulin secretagogues and the anti-angiogenesis actions of multikinase inhibitors sorafenib, axitinib and pazopanib. Several novel outcomes were also noted including the Wnt potentiating activities of rotenone and the antifolate class of drugs, and the anti-angiogenic activity of cetaben.

Suppressive function of low-dose deguelin on the invasion of oral cancer cells by downregulating tumor necrosis factor alpha-induced nuclear factor-kappa B signaling

BACKGROUND

Deguelin has both antiproliferation and antimetastasis activities. However, high-dose deguelin elicits many undesired side effects. The purpose of this study was to investigate whether the low-dose deguelin can prevent the metastasis of oral cancer.

METHODS

The dose effects of deguelin on metastasis of oral cancer cells were analyzed by in vitro invasion assay and an orthotropic xenograft mouse model. The involvement of tumor necrosis factor alpha (TNF-α)-induced nuclear factor-kappa B (NF-κB) signaling was examined by Western blot and reporter assay.

RESULTS

Low-dose deguelin, which has minimal cytotoxicity, significantly inhibited the invasion and migration of oral cancer cells. These inhibitory effects of low-dose deguelin were mediated by suppressing TNF-α-induced activation of IκB kinase leading to the inhibition of IκB phosphorylation, NF-κB transcriptional activity, and matrix metalloproteinase-2 (MMP2) expression. The low-dose deguelin treatment significantly inhibited tumor growth and invasion without systemic toxicity.

CONCLUSION

The low-dose deguelin suppressed the invasion and migration of oral cancer by downregulating TNF-α-induced NF-κB signaling. © 2015 Wiley Periodicals, Inc. Head Neck 38: E524-E534, 2016.

Synthesis and Evaluation of a Novel Deguelin Derivative, L80, which Disrupts ATP Binding to the C-terminal Domain of Heat Shock Protein 90

The clinical benefit of current anticancer regimens for lung cancer therapy is still limited due to moderate efficacy, drug resistance, and recurrence. Therefore, the development of effective anticancer drugs for first-line therapy and for optimal second-line treatment is necessary. Because the 90-kDa molecular chaperone heat shock protein (Hsp90) contributes to the maturation of numerous mutated or overexpressed oncogenic proteins, targeting Hsp90 may offer an effective anticancer therapy. Here, we investigated antitumor activities and toxicity of a novel deguelin-derived C-terminal Hsp90 inhibitor, designated L80. L80 displayed significant inhibitory effects on the viability, colony formation, angiogenesis-stimulating activity, migration, and invasion of a panel of non-small cell lung cancer cell lines and their sublines with acquired resistance to paclitaxel with minimal toxicity to normal lung epithelial cells, hippocampal cells, vascular endothelial cells, and ocular cells. Biochemical analyses and molecular docking simulation revealed that L80 disrupted Hsp90 function by binding to the C-terminal ATP-binding pocket of Hsp90, leading to the disruption of the interaction between hypoxia-inducible factor (HIF)-1α and Hsp90, downregulation of HIF-1α and its target genes, including vascular endothelial growth factor (VEGF) and insulin-like growth factor 2 (IGF2), and decreased the expression of various Hsp90 client proteins. Consistent with these in vitro findings, L80 exhibited significant antitumor and antiangiogenic activities in H1299 xenograft tumors. These results suggest that L80 represents a novel C-terminal Hsp90 inhibitor with effective anticancer activities with minimal toxicities.

Evasion of anti-growth signaling: A key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds

The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting.

Preventative therapies for healthy women at high risk of breast cancer

Tamoxifen has been shown to reduce the risk of developing estrogen receptor (ER)-positive breast cancer by at least 50%, in both pre- and postmenopausal women. The current challenge is to find new agents with fewer side effects and to find agents that are specifically suitable for premenopausal women with ER-negative breast cancer. Other selective estrogen receptor modulators (SERMs), such as raloxifene, arzoxifene, and lasofoxifene, have been shown to reduce the incidence of breast cancer by 50%-80%. SERMs are interesting agents for the prevention of breast cancer, but longer follow-up is needed for some of them for a complete risk-benefit profile of these drugs. Aromatase inhibitors have emerged as new drugs in the prevention setting for postmenopausal women. In the Mammary Prevention 3 (MAP3) trial, a 65% reduction in invasive breast cancer with exemestane was observed, and the Breast Cancer Intervention Study-II trial, which compared anastrozole with placebo, reported a 60% reduction in those cancers. Although SERMs and aromatase inhibitors have been proven to be excellent agents in the preventive setting specifically for postmenopausal women and ER-positive breast cancer, newer agents have to be found specifically for ER-negative breast cancers, which mostly occur in premenopausal women.

Simultaneous disruption of estrogen receptor and Wnt/β-catenin signaling is involved in methyl amooranin-mediated chemoprevention of mammary gland carcinogenesis in rats

Methyl-amoorain (methyl-25-hydroxy-3-oxoo-lean-12-en-28-oate, AMR-Me), a novel synthetic oleanane triterpenoid, exerts a striking chemopreventive effect against 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumorigenesis through antiproliferative and proapoptotic actions. Nevertheless, the underlying mechanisms of action remain to be established. As estrogen receptor (ER) and canonical Wnt/b-catenin signaling are involved in the development and progression of breast cancer, the current study was designed to investigate the effects of AMR-Me treatment on the expressions of ER-a, ER-b, b-catenin and cyclin D1 in rat mammary tumors induced by DMBA. Mammary tumor samples were harvested from an 18-week chemopreventive study in which AMR-Me (0.8–1.6 mg/kg) was shown to inhibit mammary carcinogenesis in a dose–response manner. The expressions of ER-a, ER-b, b-catenin, and cyclin D1 were determined by immunohistochemistry and reverse transcription-polymerase chain reaction. AMR-Me downregulated the expression of intratumor ER-a and ER-b and lowered the ratio of ER-a to ER-b. AMR-Me also reduced the expression, cytoplasmic accumulation, and nuclear translocation of b-catenin, the essential transcriptional cofactor for Wnt signaling. Furthermore, AMR-Me modulated the expression of cell growth regulatory gene cyclin D1, which is a downstream target for both ER and Wnt signaling. AMR-Me at 1.6 mg/kg for 18 weeks did not exhibit any hepatotoxicity or renotoxicity. The results of the present study coupled with our previous findings indicate that simultaneous disruption of ER and Wnt/b-catenin signaling possibly contributes to antiproliferative and apoptosis-inducing effects implicated in AMR-Me-mediated chemoprevention of DMBA-induced breast tumorigenesis in rats. Our results also suggest a possible crosstalk between two key regulatory pathways, namely ER and Wnt/b-catenin signaling, involved in mammary carcinogenesis and the value of simultaneously targeting these pathways to achieve breast cancer chemoprevention.

Inhibition of survivin restores the sensitivity of breast cancer cells to docetaxel and vinblastine

Combination therapy is considered a viable strategy to overcome the resistance to chemotherapeutics. Survivin as a member of the inhibitor of apoptosis protein (IAP) family, which is involved in resistance to various drugs. We investigated the role of combination therapy in downregulating survivin and increasing drug's efficacy in MDA-MB-231 cells. MTT assay and DAPI staining were applied to study the anti-proliferative activity and apoptosis response of the agents. Real-time RT-PCR and Western blot analysis were applied to study survivin mRNA and protein. Our findings showed that combined treatment of cells with docetaxel and vinblastine reduces survivin expression and consequently decreases the IC50 value of docetaxel from 70 to 5 nM (p < 0.05). Furthermore, combination therapy with deguelin, a survivin inhibitor, exerted a considerable enhancement in synergistic efficacy of docetaxel and vinblastine (p < 0.05). Survivin downregulation may thus be considered a potential strategy in increasing the efficacy of chemotherapeutics in cancer patients.

Chemoprevention in gastrointestinal physiology and disease. Natural products and microbiome

The human intestinal tract harbors a complex ecosystem of commensal bacteria that play a fundamental role in the well-being of their host. There is a general consensus that diet rich in plant-based foods has many advantages in relation to the health and well-being of an individual. In adults, diets that have a high proportion of fruit and vegetables and a low consumption of meat are associated with a highly diverse microbiota and are defined by a greater abundance of Prevotella compared with Bacteroides, whereas the reverse is associated with a diet that contains a low proportion of plant-based foods. In a philosophical term, our consumption of processed foods, widespread use of antibiotics and disinfectants, and our modern lifestyle may have forever altered our ancient gut microbiome. We may never be able to identify or restore our microbiomes to their ancestral state, but dietary modulation to manipulate specific gut microbial species or groups of species may offer new therapeutic approaches to conditions that are prevalent in modern society, such as functional gastrointestinal disorders, obesity, and age-related nutritional deficiency. We believe that this will become an increasingly important area of health research.

Targeting beta-catenin signaling to induce apoptosis in human breast cancer cells by z-guggulsterone and Gugulipid extract of Ayurvedic medicine plant Commiphora mukul

Background

z-Guggulsterone (z-Gug) and Gugulipid (GL) have been used to treat a variety of ailments. We now report their anti-cancer effect and mechanism against human breast cancer.

Methods

Using the human estrogen receptor-positive (MCF-7) and triple-negative (MDA-MB-231) breast cancer cells as well as the normal human mammary epithelial cell line (HMEC), we evaluated the anti-breast-cancer efficacy and apoptosis inducing activity of GL. We determined the cellular and molecular mechanism of GL-inhibited breast cancer cell growth.

Results

GL significantly inhibited growth of MCF-7 and MDA-MB-231 cells with an IC₅₀~2 μM at pharmacologically relevant concentrations standardized to its major active constituent z-Gug. The GL-induced growth inhibition correlated with apoptosis induction as evidenced by an increase in cytoplasmic histone-associated DNA fragmentation and caspase 3 activity. The GL-induced apoptosis was associated with down-regulation of the β-Catenin signaling pathway. The decreased expression of Wnt/β-Catenin targeting genes, such as cyclin D1, C-myc and survivin, and the inhibition of the activity of the transcription factor (T-cell factor 4, TCF-4) were observed in GL-treated breast cancer cells. The GL treatment resulted in a significant reduction of β-Catenin /TCF-4 complex in both of the cancer cells. The GL-induced apoptotic cell death was significantly enhanced by RNA Interference of β-Catenin and TCF-4. On the other hand, the normal human mammary epithelial cell HMEC, compared with the human breast cancer cells, is significantly more resistant to growth inhibition and apoptosis induction by GL.

Conclusion

The present study indicates that the β-Catenin signaling pathway is the target for GL-induced growth inhibition and apoptosis in human breast cancer.

Deguelin action involves c-Met and EGFR signaling pathways in triple negative breast cancer cells

Background

Treatment of breast cancer patients with antiestrogens and aromatase inhibitor(s) or Herceptin have shown significant success in steroid receptor positive or Her-2+ breast cancers respectively. However, choice of treatments for breast cancer patients with negative status for estrogen, progesterone receptors and HER2/neu is limited. As a result, search for appropriate therapy regimen for these triple negative breast cancers (TNBC) has become a major focus of investigations for many laboratories. Recently, Deguelin, a natural product isolated from African plant Mundulea sericea (Leguminossae) has shown both antiproliferative actions in various cancers including breast as well as chemoprenventive activity against carcinogen induced experimental cancers. In this report we evaluated efficacy and mechanism of action of Deguelin in triple negative breast cancer cell lines.

Methods/Findings

In vitro, Deguelin in a dose and time dependent manner inhibited the growth of MDA-MB-231, MDA-MB-468, BT-549 and BT-20 cells. Deguelin (2 or 4 mg/kg body weight), when injected intraperitoneally, reduced the in vivo tumor growth of MDA-MB-231 cells transplanted subcutaneously in athymic mice. Moreover it was nontoxic as evident from daily observations on mobility, food and water consumption and comparison of bodyweight and other visceral organ weights with those in control animals at the termination of the study. The western blot analyses and immunostaining studies indicated that the deguelin effects may be mediated through EGFR-PAKT/c-Met p-ERK and NF-κB by down regulating their downstream targets such as p-STAT3, c-Myc, Survivin.

Conclusion/Significance

These results suggest that Deguelin may have a significant therapeutic value for the treatment of TNBC patients.

Efficacy and mechanism of action of Deguelin in suppressing metastasis of 4T1 cells

Cancer related deaths in breast cancer patients are due to metastasis of the disease. Murine 4T1 cells (Murine mammary cancer cell line developed from 6-thioguanine resistant tumor) provide an excellent research tool for metastasis related studies because these cells are highly aggressive and readily metastasize to the lungs. In this study we determined the effect of Deguelin on in vivo/vitro growth and metastasis of 4T1 cells. Deguelin inhibited the in vitro growth of 4T1 cells in a time and dose dependent manner accompanied with reduced nuclear PCNA immunostaining. In cells treated with Deguelin, reduced expression of nuclear c-Met, and its downstream targets such p-ERK and p-AKT was observed. Deguelin reduced the cell migration in 4T1 cells as determined by scratch wound assay. Combined treatment with Deguelin + ERK or PI3K/AKT inhibitor had no additional effect on cell migration. These results indicated that the action of Deguelin on cell migration may be mediated by AKT and ERK mediated signaling pathways. In vivo, Deguelin treatment significantly inhibited growth of 4T1 cells. Deguelin also reduced the occurrence of metastatic lung lesions by 33 % when cells were injected intravenously into Balb/c female mice. There was no difference in the body weight, nor was there a difference in liver and spleen weights between vehicle treated-control and Deguelin-treated animals, which indicated that Deguelin was nontoxic at the dose used in the present study. These results provide rationale for developing Deguelin as a chemotherapeutic agent for triple negative breast cancer patients.

A novel antitumor activity of deguelin targeting the insulin-like growth factor (IGF) receptor pathway via up-regulation of IGF-binding protein-3 expression in breast cancer

In this study, we investigated the antitumor effects of deguelin in several human breast cancer cells in vitro and in vivo. Deguelin inhibited cell viability and the anchorage-dependent and anchorage-independent colony formation of triple-negative (MDA-MB-231 and MDA-MB-468) and triple-positive (MCF-7) breast cancer cells, and it significantly reduced the growth of MCF-7 cell xenograft tumors. The induction of apoptosis, inhibition of insulin-like growth factor-1 receptor (IGF-1R) signaling activation, and up-regulation of IGF-binding protein-3 (IGFBP-3) expression may be associated with deguelin-mediated antitumor effects. Our findings suggest a potential therapeutic use for deguelin in patients with triple-negative breast cancer and for those with breast cancers who are sensitive to endocrine- and HER2-targeted therapies.

Modulation of CYP19 expression by cabbage juices and their active components: indole-3-carbinol and 3,3'-diindolylmethene in human breast epithelial cell lines

Purpose

The aim of this study was to evaluate the effect of white cabbage and sauerkraut juices of different origin and indole-3-carbinol (I3C) and diindolylmethane (DIM) on expression of CYP19 gene encoding aromatase, the key enzyme of estrogen synthesis.

Methods

Human breast cell lines (MCF7, MDA-MB-231 and MCF10A) were examined to compare the action of cabbage juices versus their active components (I3C, DIM). Real-time PCR and Western blot were used in order to analyse CYP19 mRNA and protein, respectively.

Results

Remarkable differences in the effect on CYP19 transcript and protein level were found between the cabbage juices (in 2.5–25 mL/L concentrations) and indoles (in 2.5–50 μM doses) in the three cell lines. While cabbage juices at the lower doses diminished the aromatase expression in nontumorigenic/immortalized MCF10A breast cells (0.25–0.86-fold change, P < 0.05), I3C and DIM were more efficient in decreasing the aromatase expression in estrogen-dependant MCF7 breast cancer cells (0.24–0.82-fold change, P < 0.05). Inhibition of aromatase by juice obtained from cabbage grown on industrial farm was correlated with the induction of apoptosis (1.7–1.8-fold change, P < 0.01) in MCF10A cells. In estrogen-independent MDA-MB-231 cells, up-regulation of CYP19 expression by I3C and DIM (1.5–2.0-fold change, P < 0.05) was observed. Similarly, in MCF7 cells juices increased aromatase expression (1.1–2.2-fold change, P < 0.05).

Conclusion

These results, particularly that obtained in nontumorigenic/immortalized MCF10A cells, suggest that chemopreventive activity of cabbage against breast cancer observed in epidemiological studies may be partly explained by inhibition of the aromatase expression.

Deguelin, a novel anti-tumorigenic agent targeting apoptosis, cell cycle arrest and anti-angiogenesis for cancer chemoprevention

Deguelin is a natural compound of the flavonoid family products isolated from Derris trifoliata Lour. or Mundulea sericea (Leguminosae). It exhibited significant anti-tumorigenesis and anti-proliferative activity in various types of cancer both in vitro and in vivo. Deguelin induced cell apoptosis by blocking anti-apoptotic pathways, such as PI3K-Akt, IKK-IκBα-NF-κB and AMPK-mTOR-survivin, while inhibiting tumor cell propagation and malignant transformation through p27-cyclinE-pRb-E2F1 cell cycle control and HIF-1α-VEGF anti-angiogenic pathways. In pre-clinical trials, deguelin markedly decreased the tumor incidence. These biological findings identified deguelin as a novel anti-tumorigenic agent targeting apoptosis, cell cycle arrest and anti-angiogenesis for cancer chemoprevention and chemotherapy.

Deguelin suppresses pancreatic tumor growth and metastasis by inhibiting epithelial-to-mesenchymal transition in an orthotopic model

Deguelin is known to suppress the growth of cancer cells; however, its anti-metastatic effects have not been studied so far in any cancer model. In the present study, we aimed to evaluate the anti-metastatic potential of deguelin in vivo and in tumor growth factor-β1 (TGFβ1)-stimulated cells. Our results demonstrate that tumor growth, peritoneal dissemination and liver/lung metastasis of orthotopically implanted PanC-1-luc cells were significantly reduced in deguelin-treated mice along with the induction of apoptosis. Furthermore, deguelin-treated tumors showed increased epithelial signature such as increased expression of E-Cadherin and cytokeratin-18 and decreased expression of Snail. Similar observations were made when PanC-1, COLO-357 and L3.6pl cells were treated in vitro with deguelin. Moreover, E-cadherin was transcriptionally upregulated and accumulated in the membrane fraction of deguelin-treated cells, as indicated by increased interaction of E-Cadherin with β-catenin. TGFβ1-induced downregulation of E-Cadherin and upregulation of Snail were abrogated by deguelin treatment. In addition, deguelin inhibited TGFβ1-induced Smad3 phosphorylation and Smad4 nuclear translocation in PanC-1 cells. Furthermore, when TGFβ1-induced nuclear factor kappa B (NFκB) activation was inhibited, TGFβ1-induced Snail upregulation or E-Cadherin downregulation was blocked. Deguelin also significantly downregulated the constitutive phosphorylation and DNA binding of NFκB in a dose-dependent manner. Interestingly, overexpression of either NFκB or Snail completely abrogated deguelin-mediated epithelial-to-mesenchymal transition (EMT) inhibition, whereas overexpression of NFκB but not Snail rescued cells from deguelin-induced apoptosis. Hence, deguelin targets NFκB to induce reversal of EMT and apoptosis but downstream effectors might be different for both processes. Taken together, our results suggest that deguelin suppresses both pancreatic tumor growth and metastasis by inducing apoptosis and inhibiting EMT.

Modulation of Wnt/β-catenin signaling pathway by bioactive food components

The Wnt/β-catenin signaling pathway, one of the most conserved intercellular signaling cascade, is a known regulator of cellular functions related to tumor initiation and progression, cell proliferation, differentiation, survival and adhesion. Because aberrant Wnt/β-catenin signaling has been observed in a variety of human cancers including a majority of colorectal cancers, about half of prostate cancers and a third of melanomas, inhibitors of its complex signaling pathways are being investigated for therapy as well as chemoprevention of these cancers. During the last decade, several naturally occurring dietary agents have been shown to target intermediates in the Wnt/β-catenin signaling pathway. In this review, we highlight the current understanding of the Wnt/β-catenin signaling pathway and present an analysis of the key findings from laboratory studies on the effects of a panel of dietary agents against a variety of cancers. Promise of these agents for treating and preventing human cancer is then discussed.

Ginsenoside Rp1 from Panax ginseng exhibits anti-cancer activity by down-regulation of the IGF-1R/Akt pathway in breast cancer cells

Cancer prevention is effective and reduces health care costs because cancer is often a preventable disease that can be affected by lifestyle factors. Therefore, researchers are interested in discovering natural compounds that have anticancer activities, such as delaying the development of cancer and preventing its progression. One such natural agent is ginseng (Panax ginseng), which is traditionally used in some parts of the world as a popular remedy for various diseases including cancer. We hypothesized that the ginsenoside Rp1, a component of ginseng, reduces cancer cell proliferation through inhibition of the insulin-like growth factor 1 receptor (IGF-1R)/Akt pathway. We first tested the efficacy of Rp1 against human breast cancer cell lines. Treatment with Rp1 inhibited breast cancer cell proliferation and inhibited both anchorage-dependent and -independent breast cancer cell colony formation. In addition, treatment with 20 μM Rp1 induced cycle arrest and apoptosis-mediated cell growth suppression. Our findings further indicated that Rp1 decreased the stability of the IGF-1R protein in breast cancer cells. Therefore, we suggest that Rp1 has potential as an anticancer drug and that IGF-1R is an important target for treatment and prevention of breast cancer.