Inhibitory effects of wogonin on the invasion of human breast carcinoma cells by downregulating the expression and activity of matrix metalloproteinase-9

5-Methoxytryptophan enhances the sensitivity of sorafenib on the inhibition of proliferation and metastasis for lung cancer cells

BACKGROUND

Lung cancer is a leading cause of cancer-related mortality worldwide, and effective therapies are limited. Lung cancer is a leading cause of cancer-related mortality worldwide with limited effective therapy. Sorafenib is a multi-tyrosine kinase inhibitor frequently used to treat numerous types of malignant tumors. However, it has been demonstrated that sorafenib showed moderate antitumor activity and is associated with several side effects in lung cancer, which restricted its clinical application. This study aimed to examine the antitumor effect of the combination treatment of sorafenib and 5-methoxytryptophan (5-MTP) on cell growth and metastasis of Lewis lung carcinoma (LLC) cells.

METHOD

The anticancer effect of the combination treatment of sorafenib and 5-MTP was determined through cytotoxicity assay and colony forming assays. The mechanism was elucidated using flow cytometry and western blotting. Wound healing and Transwell assays were conducted to evaluate the impact of the combination treatment on migration and invasion abilities. An in vivo model was employed to analyze the effect of the combination treatment on the tumorigenic ability of LLC cells.

RESULT

Our results demonstrated that the sorafenib and 5-MTP combination synergistically reduced viability and proliferation compared to sorafenib or 5-MTP treatment alone. Reduction of cyclin D1 expression was observed in the sorafenib alone or combination treatments, leading to cell cycle arrest. Furthermore, the sorafenib-5-MTP combination significantly increased the inhibitory effect on migration and invasion of LLC cells compared to the single treatments. The combination also significantly downregulated vimentin and MMP9 levels, contributing to the inhibition of metastasis. The reduction of phosphorylated Akt and STAT3 expression may further contribute to the inhibitory effect on proliferation and metastasis. In vivo, the sorafenib-5-MTP combination further reduced tumor growth and metastasis compared to the treatment of sorafenib alone.

CONCLUSIONS

In conclusion, our data indicate that 5-MTP sensitizes the antitumor activity of sorafenib in LLC cells in vitro and in vivo, suggesting that sorafenib-5-MTP has the potential to serve as a therapeutic option for patients with lung cancer.

Targeting extracellular matrix through phytochemicals: a promising approach of multi-step actions on the treatment and prevention of cancer

Extracellular matrix (ECM) plays a pivotal and dynamic role in the construction of tumor microenvironment (TME), becoming the focus in cancer research and treatment. Multiple cell signaling in ECM remodeling contribute to uncontrolled proliferation, metastasis, immune evasion and drug resistance of cancer. Targeting trilogy of ECM remodeling could be a new strategy during the early-, middle-, advanced-stages of cancer and overcoming drug resistance. Currently nearly 60% of the alternative anticancer drugs are derived from natural products or active ingredients or structural analogs isolated from plants. According to the characteristics of ECM, this manuscript proposes three phases of whole-process management of cancer, including prevention of cancer development in the early stage of cancer (Phase I); prevent the metastasis of tumor in the middle stage of cancer (Phase II); provide a novel method in the use of immunotherapy for advanced cancer (Phase III), and present novel insights on the contribution of natural products use as innovative strategies to exert anticancer effects by targeting components in ECM. Herein, we focus on trilogy of ECM remodeling and the interaction among ECM, cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), and sort out the intervention effects of natural products on the ECM and related targets in the tumor progression, provide a reference for the development of new drugs against tumor metastasis and recurrence.

The Use of San-Huang-Xie-Xin-Tang Reduces the Mortality Rate among Breast Cancer Patients

Globally, breast cancer is the most common cause of cancer deaths. In Taiwan, it is the most prevalent cancer among females. Since San-Huang-Xie-Xin-Tang (SHXXT) exerts not only an anti-inflammatory but an immunomodulatory effect, it may act as a potent anti-tumor agent. Herein, the study aimed to explore the influence of SHXXT and its constituents on the mortality rate among breast cancer patients in Taiwan regarding the component effect and the dose-relationship effect. By using the Taiwan National Health Insurance (NHI) Research Database (NHIRD), the study analyzed 5387 breast cancer patients taking Chinese herbal medicine (CHM) and 5387 breast cancer patients not using CHM. CHM means SHXXT and its constituents in the study. The Kaplan-Meier method was utilized to determine the mortality probabilities among patients. Whether the CHM influences the mortality rate among patients was estimated by Cox proportional hazard regression analysis. The use of CHM could lower the cancer mortality rate by 59% in breast cancer patients. The protective effect was parallel to the cumulative days of CHM use and the annual average CHM dose. In addition, the mortality rate was lower in patients who used SHXXT compared to those who only used one of its constituents. SHXXT and its constituents were all promising therapeutic weapons against breast cancer.

Acacetin and Pinostrobin Inhibit Malignant Breast Epithelial Cell Adhesion and Focal Adhesion Formation to Attenuate Cell Migration

Naturally occurring flavonoids, such as acacetin and pinostrobin, disrupt a wide range of processes during tumor progression, such as cell proliferation, apoptosis, and angiogenesis. Although the antiproliferative and antiapoptotic effects of acacetin and pinostrobin have been studied using various cell lines, relatively little is known about the effects of acacetin and pinostrobin on cancer cell migration and metastasis. For instance, it is unclear whether acacetin or pinostrobin have any effect on breast cancer cell migration or adhesion. In this study, we assessed the effects of acacetin and pinostrobin on malignant MDA-MB-231 and T47D breast epithelial cells and non-tumorigenic MCF10A breast epithelial cells. Our results demonstrate that both acacetin and pinostrobin selectively inhibit the migration of both MDA-MB-231 and T47D cells in a dose-dependent manner while exhibiting blunted effects on MCF10A cells. Interestingly, neither compound had an effect on cell proliferation in any of the 3 cell lines. Furthermore, both acacetin and pinostrobin inhibit MDA-MB-231 and T47D cell adhesion, cell spreading, and focal adhesion formation, but have no significant effect on MCF10A cells. Collectively, these results suggest that both acacetin and pinostrobin selectively inhibit malignant breast epithelial cell migration through attenuation of cell adhesion and focal adhesion formation. These findings indicate that both acacetin and pinostrobin may serve as potential therapeutic options to target breast tumor cell migration during late-stage tumor progression.

Fascinating Chemopreventive Story of Wogonin: A Chance to Hit on the Head in Cancer Treatment

Cancer, global havoc, is a group of debilitating diseases that strikes family as well as society. Cancer cases are drastically increasing these days. Despite many therapies and surgical procedures available, cancer is still difficult to control due to limited effective therapies or targeted therapies. Natural products can produce lesser side effects to the normal cells, which are the major demerit of chemotherapies and radiation. Wogonin, a natural product extracted from the plant, Scutellaria baicalensis has been widely studied and found with a high caliber to tackle most of the cancers via several mechanisms that include intrinsic as well as extrinsic apoptosis signaling pathways, carcinogenesis diminution, telomerase activity inhibition, metastasis inhibition in the inflammatory microenvironment, anti-angiogenesis, cell growth inhibition and arrest of the cell cycle, increased generation of H₂O₂ and accumulation of Ca²⁺ and also as an adjuvant along with anticancer drugs. This article discusses the role of wogonin in various cancers, its synergism with various drugs, and the mechanism by which wogonin controls tumor growth.

Targeting the tumor immune microenvironment with "nutraceuticals": From bench to clinical trials

The occurrence of immune effector cells in the tissue microenvironment during neoplastic progression is critical in determining tumor growth outcomes. On the other hand, tumors may also avoid immune system-mediated elimination by recruiting immunosuppressive leukocytes and soluble factors, which coordinate a tumor microenvironment that counteracts the efficiency of the antitumor immune response. Checkpoint inhibitor therapy results have indicated a way forward via activation of the immune system against cancer. Widespread evidence has shown that different compounds in foods, when administered as purified substances, can act as immunomodulators in humans and animals. Although there is no universally accepted definition of nutraceuticals, the term identifies a wide category of natural compounds that may impact health and disease statuses and includes purified substances from natural sources, plant extracts, dietary supplements, vitamins, phytonutrients, and various products with combinations of functional ingredients. In this review, we summarize the current knowledge on the immunomodulatory effects of nutraceuticals with a special focus on the cancer microenvironment, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of nutraceuticals for envisioning future therapies employing nutraceuticals as chemoadjuvants.

Wogonoside Attenuates Cutaneous Squamous Cell Carcinoma by Reducing Epithelial-Mesenchymal Transition/Invasion and Cancer Stem-Like Cell Property

Purpose

Cutaneous squamous cell carcinoma (cSCC) is the most common second basal cell carcinoma in our population. Wogonoside, the main in vivo metabolite of wogonin, possesses anti-inflammatory, anti-angiogenesis and anti-cancer activities. Nevertheless, the effectiveness of wogonoside therapy on cSCC has not been clarified.

Methods

In this study, we investigated the effects of wogonoside on cell proliferation, invasion, epithelial–mesenchymal transition (EMT) and cancer stem-like cell (CSC) properties of SCL-1 and SCC12 cell lines, and the effects on tumor formation in vivo. In vitro, cells were treated with 0, 25, 50 and 100 μM wogonoside for 48 h. In vivo, SCL-1 cells were subcutaneously injected into the right thigh of mice to form xenograft tumors. Animals were randomly divided into two groups (n=10): the control group and the 80 mg/kg wogonoside group.

Results

The results showed that wogonoside attenuated proliferation, invasion and EMT of SCL-1 and SCC12 cell lines, and enhanced the rate of apoptosis. Meanwhile, wogonoside efficiently abolished the CSC traits of cSCC; the expression of CSC markers (ALDH1, SOX-2, Oct4 and CD44) and the percentage of CD133⁺ cells were remarkably downregulated. In addition, we found that wogonoside repressed the activation of both PI3K/AKT and Wnt/β-catenin pathways. In vivo, wogonoside significantly inhibited tumor formation.

Conclusion

The results indicated that wogonoside could attenuate cSCC by reducing EMT, invasion and CSC properties. The efficacy of intervention may be related to inhibition of the PI3K/Akt and Wnt/β-catenin pathways. These novel findings could furnish new ideas on the potential therapeutic application of wogonoside in cSCC cancellation and cancer intervention.

Pivarubicin Is More Effective Than Doxorubicin Against Triple-Negative Breast Cancer In Vivo

Triple-negative breast cancer (TNBC) is unresponsive to antiestrogen and anti-HER2 therapies, requiring the use of cytotoxic drug combinations of anthracyclines, taxanes, cyclophosphamide, and platinum compounds. Multidrug therapies achieve pathological cure rates of only 20–40%, a consequence of drug resistance and cumulative dose limitations necessitated by the reversible cardiotoxic effects of drug therapy. Safer and more effective treatments for TNBC are required to achieve durable therapeutic responses. This study describes the mechanistic analyses of the novel anthracycline, pivarubicin, and its in vivo efficacy against human primary TNBC. Pivarubicin directly activates PKCd, triggers rapid mitochondrial-dependent apoptosis, and circumvents resistance conferred by overexpression of P-glycoprotein, Bcl-2, Bcl-X_L, and Bcr-Abl. As a consequence, pivarubicin is more cytotoxic than doxorubicin against MDA-MB-231, and SUM159 TNBC cell lines grown in both monolayer culture and tumorspheres. Comparative in vivo efficacy of pivarubicin and doxorubicin was performed in an orthotopic NSG mouse model implanted with MDA-MB-231 human TNBC cells and treated with the maximum tolerated doses (MTDs) of pivarubicin and doxorubicin. Tumor growth was monitored by digital caliper measurements and determination of endpoint tumor weight and volume. Endpoint cardiotoxicity was assessed histologically by identifying microvacuolization in ventricular cardiomyocytes. Primary tumors treated with multiple rounds of doxorubicin at MTD failed to inhibit tumor growth compared with vehicle-treated tumors. However, administration of a single MTD of pivarubicin produced significant inhibition of tumor growth and tumor regression relative to tumor volume prior to initiation of treatment. Histological analysis of hearts excised from drug- and vehicle-treated mice revealed that pivarubicin produced no evidence of myocardial damage at a therapeutic dose. These results support the development of pivarubicin as a safer and more effective replacement for doxorubicin against TNBC as well as other malignancies for which doxorubicin therapy is indicated.

Anti-cancer Activity of Centipeda minima Extract in Triple Negative Breast Cancer via Inhibition of AKT, NF-κB, and STAT3 Signaling Pathways

Breast cancer is the most commonly diagnosed cancer in females worldwide. Estimates from the World Health Organization (WHO) International Agency for Research on Cancer, suggest that globally, there were around 2.1 million new breast cancer cases and 627,000 deaths due to breast cancer in 2018. Among the subtypes of breast cancer, triple negative breast cancer (TNBC) is the most aggressive and carries the poorest prognosis, largest recurrence, and lowest survival rate. Major treatment options for TNBC patients are mainly constrained to chemotherapy, which can be accompanied by severe side effects. Therefore, development of novel and effective anti-cancer drugs for the treatment of TNBC are urgently required. Centipeda minima is a well-known traditional Chinese herbal medicine that has historically been used to treat rhinitis, sinusitis, relieve pain, and reduce swelling. Recent studies have shown that Centipeda minima exhibited efficacy against certain cancers, however, to date, no studies have been conducted on its effects in breast cancer. Here, we aimed to investigate the anti-cancer activity of the total extract of Centipeda minima (CME), and its underlying mechanism, in TNBC. In MDA-MB-231, we found that CME could significantly reduce cell viability and proliferation, induce apoptosis and inhibit cancer cell migration and invasion, in a dose and time-dependent manner. We showed that CME may potentially act via inhibition of multiple signaling pathways, including the EGFR, PI3K/AKT/mTOR, NF-κB, and STAT3 pathways. Treatment with CME also led to in vitro downregulation of MMP-9 activity and inhibition of metastasis. Further, we demonstrated that CME could significantly reduce tumor burden in MDA-MB-231 xenograft mice, without any appreciable side effects. Based on our findings, CME is a promising candidate for development as a therapeutic with high efficacy against TNBC.

Baicalein Is a Phytohormone that Signals Through the Progesterone and Glucocorticoid Receptors

While flavonoids have been studied extensively for estrogen receptor activity, they have not been well studied for their ability to modify progesterone receptor (PR) and glucocorticoid receptor (GR) signaling. Three flavonoid compounds, tangeretin, wogonin, and baicalein, were selected for testing for PR and GR activity based on their structural similarity to known phytoprogesterone-like compounds. Each compound was docked in the binding pocket of PR and GR. Of these compounds, baicalein was predicted to be most likely to bind to both receptors. A fluorescence polarization competitive binding assay for PR and GR confirmed that baicalein binds to both the PR and GR with IC₅₀ values of 15.30 μM and 19.26 μM, respectively. In Ishikawa PR-B and T47D cells, baicalein acted as a PR antagonist in a hormone response element (HRE) luciferase (Luc) assay. In OVCAR5 cells, which only express GR, baicalein was a GR agonist via an HRE/Luc assay and induced GR target genes, FKBP5 and GILZ. RU486, a PR and GR antagonist, abrogated baicalein's activity in OVCAR5 cells, confirming baicalein's activity is mediated through the GR. In vivo, baicalein administered intraperitoneally to female mice twice a week for 4 weeks at a dose of 25 mg/kg induced the GR target gene GILZ in the reproductive tract, which was blocked by RU486. In summary, baicalein has PR antagonist and GR agonist activity in vitro and demonstrates GR agonist activity in the uterus in vivo.

Structural Insight into the In Vitro Anti-Intravasative Properties of Flavonoids

We investigated the effect of 21 flavonoids in a three-dimensional in vitro system for their ability to inhibit gap formation by MCF-7 breast cancer spheroids in monolayers of lymphendothelial cells. Different representatives of the classes of flavones, flavonols, and flavanones were tested in the circular chemorepellent-induced defects (CCID)-assay. Bay11-7082, a known inhibitor of CCID formation served as the positive control. This study provides the first comparison of the potential of flavonoids to suppress features influencing the intravasation of MCF-7 breast cancer cells aggregates through the lymph endothelial barrier. The most significant effects were seen after incubation with the flavones luteolin, chrysin, and apigenin. Additional hydroxylation or methoxylation in positions 6 or 8, as expected, resulted in decreased activity. The tested flavanones remained without or low efficacy.

Molecular Targets of Genistein and Its Related Flavonoids to Exert Anticancer Effects

Increased health awareness among the public has highlighted the health benefits of dietary supplements including flavonoids. As flavonoids target several critical factors to exert a variety of biological effects, studies to identify their target-specific effects have been conducted. Herein, we discuss the basic structures of flavonoids and their anticancer activities in relation to the specific biological targets acted upon by these flavonoids. Flavonoids target several signaling pathways involved in apoptosis, cell cycle arrest, mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/AKT kinase, and metastasis. Polo-like kinase 1 (PLK1) has been recognized as a valuable target in cancer treatment due to the prognostic implication of PLK1 in cancer patients and its clinical relevance between the overexpression of PLK1 and the reduced survival rates of several carcinoma patients. Recent studies suggest that several flavonoids, including genistein directly inhibit PLK1 inhibitory activity. Later, we focus on the anticancer effects of genistein through inhibition of PLK1.

Wogonin suppresses the LPS‑enhanced invasiveness of MDA‑MB‑231 breast cancer cells by inhibiting the 5‑LO/BLT2 cascade

Wogonin, a naturally occurring bioactive monoflavonoid isolated from Scutellariae radix (roots of Scutellariae baicalensis Georgi), has known anticancer effects. However, the molecular signaling mechanism by which wogonin inhibits invasiveness in breast cancer cells remains unclear. In the present study, it was observed that wogonin exerted an inhibitory effect on the lipopolysaccha-ride (LPS)-enhanced invasiveness of MDA-MB-231 cells. In addition, wogonin inhibited the synthesis of interleukin-8 (IL-8) and matrix metallopeptidase-9 (MMP-9), which are critical for promoting invasiveness in MDA-MB-231 cells. Wogonin also suppressed the expression of leukot-riene B4 receptor 2 (BLT2) and the synthesis of its ligand, by inhibiting 5-lipoxygenase (5-LO) in LPS-stimulated MDA-MB-231 cells. Notably, wogonin attenuated the production of IL-8 and MMP-9 by inhibiting the BLT2/extracellular signal-regulated kinase (ERK)-linked cascade. Finally, in vivo, LPS-driven MDA-MB-231 cell metastasis was markedly suppressed by wogonin administration. Overall, the present results suggested that wogonin inhibited the 5-LO/BLT2/ERK/IL-8/MMP-9 signaling cascade and demonstrated that this cascade may be an important target through which wogonin exerts its anticancer effects in breast cancer.

Scutellaria: Debates on the anticancer property

The widespread use of plants as accessible anticancer agents leads to the identification of many natural source chemotherapeutic agents. Scutellaria one of the popular genus of flowering plants has been used for various human illnesses for thousands of years. Scutellaria has anti-metastatic, anti-proliferative, anti-invasion, anti-angiogenic and apoptosis effects in vitro as well as in vivo. Despite numerous reports on the cytotoxic-antitumor activity of the plant, there are still some issues need further consideration. Issues such as unjustified interpretations, lack of attention to the pharmacokinetics profile and weak study design may affect the final decision about the use of plants as anticancer agents and possibly needs reconsideration. In this review, we have summarized the potential health benefits of Scutellaria and its active components also the underlying mechanism of cytotoxicity and antitumor activity. Meanwhile we have discussed concerns may interfere with the precise conclusion.

Baicalein disturbs the morphological plasticity and motility of breast adenocarcinoma cells depending on the tumor microenvironment

During tumor invasion, cancer cells change their morphology and mode of migration based on communication with the surrounding environment. Numerous studies have indicated that paracrine interactions from non-neoplastic cells impact the migratory and invasive properties of cancer cells. Thus, these interactions are potential targets for anticancer therapies. In this study, we showed that the flavones member baicalein suppresses the motility of breast cancer cells that is promoted by paracrine interactions. First, we identified laminin-332 (LN-332) as a principle paracrine factor in conditioned medium from mammary epithelium-derived MCF10A cells that regulates the morphology and motility of breast adenocarcinoma MDA-MB-231 cells. Then, we carried out a morphology-based screen for small compounds, which showed that baicalein suppressed the morphological changes and migratory activity of MDA-MB-231 cells that were induced by conditioned medium from MCF10A cells and LN-332. We also found that baicalein caused narrower and incomplete lamellipodia formation in conditioned medium-treated MDA-MB-231 cells, although actin dynamics downstream of Rho family small GTPases were unaffected. These results suggest the importance of mammary epithelial cells in the cancer microenvironment promoting the migratory activity of breast adenocarcinoma cells and show a novel mechanism through which baicalein inhibits cancer cell motility.

Myricetin suppresses breast cancer metastasis through down-regulating the activity of matrix metalloproteinase (MMP)-2/9

Tumour metastasis is the major cause of breast cancer mortality. Myricetin, a natural polyphenol, is found in teas, wines, and berries. The pharmacodynamic action and molecular mechanism of myricetin on breast cancer metastasis remain unknown. Here, we investigated the effect of myricetin on MDA-Mb-231Br cell viability, migration, invasion, and 4T1 mouse lung metastasis mouse models. MMP-2/9 protein expression and ST6GALNAC5 expression were analysed using western blot assays and quantitative real-time polymerase chain reaction, respectively. Cell migration and invasion were detected by wound-healing and Boyden transwell assays. The antimetastatic effect in vivo was evaluated by lung metastasis model. Myricetin significantly decreased the activities of MMP-2/9 and mRNA levels of ST6GALNAC5. In addition, the migration, invasion, and adhesion were effectively inhibited in a concentration-dependent manner. On the other hand, mice treated with myricetin exhibited smaller tumour nodules compared with the vehicle mice, with only 17.78 ± 15.41% after treatment with 50 mg/kg myricetin. In conclusion, myricetin could significantly block invasion of MDA-Mb-231Br cells through suppressing the protein expression of MMP-2/9 and the expression of ST6GALNAC5, as well as lung metastasis in a mouse model, which suggests that myricetin should be developed as a potential therapeutic candidate for breast cancer.

Wogonin Suppresses the Activity of Matrix Metalloproteinase-9 and Inhibits Migration and Invasion in Human Hepatocellular Carcinoma

As one of the major active ingredients in Radix Scutellariae, wogonin has been shown to be associated with various pharmacological activities on cancer cell growth, apoptosis, and cell invasion and migration. Here, we demonstrated that wogonin may harbor potential anti-metastatic activities in hepatocarcinoma (HCC). The anti-metastasis potential of wogonin and its underlying mechanisms were evaluated by ligand–protein docking approach, surface plasmon resonance assay, and in vitro gelatin zymography studies. Our results showed that wogonin (100 μM, 50 μM) suppressed MHCC97L and PLC/PRF/5 cells migration and invasion in vitro. The docking approach and surface plasmon resonance assay indicated that the potential binding affinity between wogonin and matrix metalloproteinase-9 (MMP-9) may lead to inhibition of MMP-9 activity and further leads to suppression of tumor metastasis. This conclusion was further verified by Western blot results and gelatin zymography analysis. Wogonin might be a potent treatment option for disrupting the tumor metastasis that favors HCC development. The potential active targets from computational screening integrated with biomedical study may help us to explore the molecular mechanism of herbal medicines.

Antiangiogenic Effect of Flavonoids and Chalcones: An Update

Chalcones are precursors of flavonoid biosynthesis in plants. Both flavonoids and chalcones are intensively investigated because of a large spectrum of their biological activities. Among others, anticancer and antiangiogenic effects account for the research interest of these substances. Because of an essential role in cancer growth and metastasis, angiogenesis is considered to be a promising target for cancer treatment. Currently used antiangiogenic agents are either synthetic compounds or monoclonal antibodies. However, there are some limitations of their use including toxicity and high price, making the search for new antiangiogenic compounds very attractive. Nowadays it is well known that several natural compounds may modulate basic steps in angiogenesis. A lot of studies, also from our lab, showed that phytochemicals, including polyphenols, are potent modulators of angiogenesis. This review paper is focused on the antiangiogenic effect of flavonoids and chalcones and discusses possible underlying cellular and molecular mechanisms.

Live or let die: Neuroprotective and anti-cancer effects of nutraceutical antioxidants

Diet sources are closely involved in the pathogenesis of diverse neuropsychiatric disorders and cancers, in addition to inherited factors. Currently, natural products or nutraceuticals (commonly called medical foods) are increasingly employed for adjunctive therapy of these patients. However, the potential molecular mechanisms of the nutrient efficacy remain elusive. In this review, we summarized the neuroprotective and anti-cancer mechanisms of nutraceuticals. It was concluded that the nutraceuticals exerted neuroprotection and suppressed tumor growth possibly through the differential modulations of redox homeostasis. In addition, the balance between reactive oxygen species (ROS) production and ROS elimination was manipulated by multiple molecular mechanisms, including cell signaling pathways, inflammation, transcriptional regulation and epigenetic modulation, which were involved in the therapeutic potential of nutraceutical antioxidants against neurological diseases and cancers. We specifically proposed that ROS scavenging was integral in the neuroprotective potential of nutraceuticals, while alternation of ROS level (either increase or decrease) or disruption of redox homeostasis (ROS addiction) constituted the anti-cancer property of these compounds. We also hypothesized that ROS-associated ferroptosis, a novel type of lipid ROS-dependent regulatory cell death, was likely to be a critical mechanism for the nutraceutical antioxidants. Targeting ferroptosis is advantageous to develop new nutraceuticals with more effective and lower adverse reactions for curing patients with neuropsychiatric diseases or carcinomas.

Adipocytes and Macrophages Interplay in the Orchestration of Tumor Microenvironment: New Implications in Cancer Progression

Inflammation has been known as one of the main keys to the establishment and progression of cancers. Chronic low-grade inflammation is also a strategic condition that underlies the causes and development of metabolic syndrome and obesity. Moreover, obesity has been largely related to poor prognosis of tumors by modulating tumor microenvironment with secretion of several inflammatory mediators by tumor-associated adipocytes (TAAs), which can modulate and recruit tumor-associated macrophages. Thus, the understanding of cellular and molecular mechanisms that underlay and link inflammation, obesity, and cancer is crucial to identify potential targets that interfere with this important route. Knowledge about the exact role of each component of the tumor microenvironment is not yet fully understood, but the new insights in literature highlight the essential role of adipocytes and macrophages interplay as key factor to determine the fate of cancer progression. In this review article, we focus on the functions of adipocytes and macrophages orchestrating cellular and molecular mechanisms that lead to inflammatory modulation in tumor microenvironment, which will be crucial to cancer establishment. We also emphasized the mechanisms by which the tumor promotes itself by recruiting and polarizing macrophages, discussing the role of adipocytes in this process. In addition, we discuss here the newest possible anticancer therapeutic treatments aiming to retard the development of the tumor based on what is known about cancer, adipocyte, and macrophage polarization.

Wogonoside inhibits invasion and migration through suppressing TRAF2/4 expression in breast cancer

Background

Twist1 is involved in tumor initiation and progression, which especially contributes to tumor invasion and metastasis. Wogonoside is the main in-vivo metabolite of wogonin, and it is also a natural product with potential treatment effects against cancer.

Methods

In this study, we investigated the in-vitro anti-invasion and in-vivo anti-metastasis effects of wogonoside on breast cancer cells and uncovered its underlying mechanism.

Results

The results showed that wogonoside could suppress the growth and metastasis of breast tumor in the orthotopic model of MDA-MB-231 cells. We found that wogonoside could reduce the overexpression of TNF-α, TRAF2 and TRAF4 in later stage of tumor, and improved tumor microenvironment. Therefore, TNF-α was utilized to induce metastases of breast cancer cell in vitro. Wogonoside could inhibit invasion and migration in TNF-α-induced MDA-MB-231, MDA-MB-435, and BT-474 cells. Mechanically, wogonoside inactivated NF-κB signaling through decreasing the protein expression of TRAF2/4, which further inhibited Twist1 expression. Consequently, wogonoside could down-regulate MMP-9, MMP-2, vimentin and CD44v6 expression in TNF-α-induced MDA-MB-231 and MDA-MB-435 cells. Then, these findings were proved in TNF-α + TGF-β1-induced MCF7 cells.

Conclusions

Wogonoside might be a potential therapeutic agent for the treatment of tumor metastasis in breast cancer.

Wogonin suppresses stem cell-like traits of CD133 positive osteosarcoma cell via inhibiting matrix metallopeptidase-9 expression

Background

Several efforts have been deployed to cure osteosarcoma, a high-grade malignant bone tumour in children and adolescents. However, some challenges such as drug resistance, relapse, and tumour metastasis remain owing to the existence of cancer stem cells (CSC). There is an urgent need to develop cost-effective and safe therapies.

Methods

Wogonin, an extract from the root of Scutellaria baicalensis, has long been considered as a promising natural and safe compound for anti-tumourigenesis, particularly to inhibit tumour invasion and metastasis. Hoechst 33,342 staining, wound healing assay, sphere formation assay, western blotting, and gelatin zymography assays were performed in CD133 positive osteosarcoma cell.

Results

In this study, we examined the effect of Wogonin on the mobility of human osteosarcoma CSC. Wogonin induces apoptosis of human osteosarcoma CSC, inhibits its mobility in vitro via downregulation of MMP-9 expression, and represses its renewal ability.

Conclusions

We demonstrated that Wogonin decreases the renewal capacity of CSC. By inhibiting the formation of and reducing the size of spheres, Wogonin at a concentration of 40–80 μM effectively minimizes potential risk from CSC. Taken together, we have demonstrated a new approach for developing a potential therapy for osteosarcoma.

Baicalein, unlike 4-hydroxytamoxifen but similar to G15, suppresses 17β-estradiol-induced cell invasion, and matrix metalloproteinase-9 expression and activation in MCF-7 human breast cancer cells

Estrogen performs an important role in the growth and development of breast cancer. There are at least three major receptors, including estrogen receptor (ER)α and β, and G protein-coupled receptor 30 (GPR30), which mediate the actions of estrogen through using transcriptional and rapid non-genomic signaling pathways. Flavonoids have been considered candidates for chemopreventive agents in breast cancer. Baicalein, the primary flavonoid derived from the root of Scutellaria baicalensis Georgi, has been reported to exert an anti-estrogenic effect. In the present study, the effects of baicalein on 17β-estradiol (E2)-induced cell invasion, and matrix metalloproteinase-9 (MMP-9) expression and activation were investigated. Furthermore, its effects were compared with that of the active form of the ER modulator tamoxifen 4-hydroxytamoxifen (OHT) and the GPR30 antagonist G15 in ERα- and GPR30-positive MCF-7 breast cancer cells. The results demonstrated that OHT failed to prevent E2-induced cell invasion, upregulation and proteolytic activity of MMP-9. However, baicalein was able to significantly suppress these E2-induced effects. Furthermore, E2-stimulated invasion, and MMP-9 expression and activation were significantly attenuated following G15 treatment. In addition, baicalein significantly inhibited G-1, a specific GPR30 agonist, induced invasion, and reduced G-1 promoted expression and activity of MMP-9, consistent with effects of G15. The results of the present study suggest that baicalein is a therapeutic candidate for GPR30-positive breast cancer treatment, and besides ERα targeting the GPR30 receptor it may achieve additional therapeutic benefits in breast cancer.

Anti-tumor activity of wogonin, an extract from Scutellaria baicalensis, through regulating different signaling pathways

Wogonin is a plant flavonoid compound extracted from Scutellaria baicalensis (Huang-Qin or Chinese skullcap) and has been studied thoroughly by many researchers till date for its anti-viral, anti-oxidant, anti-cancerous and neuro-protective properties. Numerous experiments conducted in vitro and in vivo have demonstrated wogonin's excellent tumor inhibitory properties. The anti-cancer mechanism of wogonin has been ascribed to modulation of various cell signaling pathways, including serine-threonine kinase Akt (also known as protein kinase B) and AMP-activated protein kinase (AMPK) pathways, p53-dependent/independent apoptosis, and inhibition of telomerase activity. Furthermore, wogonin also decreases DNA adduct formation with a carcinogenic compound 2-Aminofluorene and inhibits growth of drug resistant malignant cells and their migration and metastasis, without any side effects. Recently, newly synthesized wogonin derivatives have been developed with impressive anti-tumor activity. This review is the succinct appraisal of the pertinent articles on the mechanisms of anti-tumor properties of wogonin. We also summarize the potential of wogonin and its derivatives used alone or as an adjunct therapy for cancer treatment. Furthermore, pharmacokinetics and side effects of wogonin and its analogues have also been discussed.

Wogonin enhances intracellular adiponectin levels and suppresses adiponectin secretion in 3T3-L1 adipocytes

As an insulin sensitizer and modulator of inflammatory responses, adiponectin has become a therapeutic target for insulin resistance, diabetes, and diabetes-related complications. Wogonin possesses anti-oxidative, anti-inflammatory, and anti-diabetic abilities. However, its effect on generation and secretion of adiponectin is ill-defined in adipocytes. Here, we demonstrated that wogonin administration augmented intracellular adiponectin levels and attenuated adiponectin release in a dose- and time-dependent manner in mature 3T3-L1 adipocytes, along with a suppression of PKCδ phosphorylation. Wogonin treatment also prevented PKCδ overexpression-induced reduction of intracellular adiponectin levels and enhancement of adiponectin release. In addition, wogonin supplementation dramatically increased AMPK phosphorylation and SirT1 expression. Inhibition of either AMPK or SirT1 mitigated wogonin action on adiponectin production and release. Furthermore, inhibition of AMPK by its specific inhibitor markedly reduced wogonin-enhanced mRNA and protein expressions of SirT1. These results suggested that wogonin regulated expression and secretion of adiponectin via PKCδ/AMPK/SirT1 signaling pathway in mature 3T3-L1 adipocytes.

Advances of wogonin, an extract from Scutellaria baicalensis, for the treatment of multiple tumors

As the major bioactive compound of Scutellaria baicalensis that has been approved to be effective as an anti-inflammatory and antiviral inhibitor in cardiovascular diseases, wogonin (WG) showed potent and promising antitumor effects both in vitro and in vivo. It has been proved that WG has the ability to inhibit the growth of tumor cells, induce apoptosis, and suppress angiogenesis. The molecular mechanisms involve reactive oxygen species, Ca²⁺, NF-κB, tumor necrosis factor-related apoptosis-inducing ligand, and tumor necrosis factor-alpha. Furthermore, the synergistic effect of WG with 5-fluorouracil, etoposide, and adriamycin to enhance chemotherapy and reverse drug resistance has also been confirmed. In this review, we summarize the advances in recent years on the antitumor effect of WG on multiple tumors; in addition, we also present information regarding the synergistic and chemosensitizing effects of WG with other drugs to illustrate its potential use in the clinic.

LZ-207, a Newly Synthesized Flavonoid, Induces Apoptosis and Suppresses Inflammation-Related Colon Cancer by Inhibiting the NF-κB Signaling Pathway

Flavonoids and flavonoid derivatives, which have significant biological and pharmacological activities, including antitumor and anti-inflammatory activities, have been widely used in human healthcare. To design a more effective flavonoid antitumor agent, we altered the flavonoid backbone with substitutions of piperazine and methoxy groups to synthesize a novel flavonoid derivative, LZ-207. The anticancer effect of LZ-207 against HCT116 colon cancer cells and the underlying mechanism of this effect were explored in this study. Specifically, LZ-207 exhibited inhibitory effects on growth and viability in several human colon cancer cell lines and induced apoptosis in HCT116 cells both in vitro and in vivo. LZ-207 treatment also suppressed the nuclear translocation of NF-κB and the phosphorylation of IκB and IKKα/β in a dose-dependent manner in both HCT116 cells and human acute monocytic leukemia THP-1 cells. Moreover, LZ-207 also reduced the secretion of the pro-inflammatory cytokine interleukin-6 (IL-6) in LPS-induced THP-1 cells, and this effect was confirmed at the transcriptional level. Furthermore, LZ-207 significantly inhibited HCT116 cell proliferation that was elicited by LPS-induced THP-1 cells in a co-culture system. These findings elucidated some potential molecular mechanisms for preventing inflammation-driven colon cancer using the newly synthesized flavonoid LZ-207 and suggested the possibility of further developing novel therapeutic agents derived from flavonoids.

LW-213 induces G2/M cell cycle arrest through AKT/GSK3β/β-catenin signaling pathway in human breast cancer cells

LW-213 is a derivative of Wogonin and the anticancer activities of Wogonin have been reported. To study whether LW-213 inhibits cancer cells and explore a possible mechanism, we investigate the compound in several cancer cell lines. We found LW-213 arrests G2/M cycle in breast cancer cells by suppression of Akt/Gsk3β/β-catenin signaling pathway. In compound treated cells, cell cycle-related proteins cyclin A, cyclin B1, p-CDK1, p-Cdc25C, and p-Chk2 (Thr68) were upregulated, and β-catenin nuclear translocation was inhibited. Electrophoretic mobility shift assay revealed LW-213 inhibits binding of β-catenin/LEF complex to DNA. GSK3β inhibitor LiCl and siRNA against GSK3β partially reversed G2/M arrest in breast cancer MCF-7 cells. These results suggest LW-213 triggered G2/M cell cycle arrest through suppression of β-catenin signaling. In BALB/c mice, growth of xenotransplanted MCF-7 tumor was also inhibited after treatment of LW-213. Regulation of cyclin A, cyclin B1, and β-catenin by LW-213 in vivo was the same as in vitro study. In conclusion, we found LW-213 exerts its anticancer effect on cell proliferation and cell cycle through repression of Akt/Gsk3β/β-catenin signaling pathway. LW-213 could be a potential candidate for anticancer drug development.

Baicalein suppresses 17-β-estradiol-induced migration, adhesion and invasion of breast cancer cells via the G protein-coupled receptor 30 signaling pathway

Flavonoids are structurally similar to steroid hormones, particularly estrogens, and therefore have been studied for their potential effects on hormone-dependent cancers. Baicalein is the primary flavonoid derived from the root of Scutellaria baicalensis Georgi. In the present study, we investigated the effects of baicalein on 17β-estradiol (E2)-induced migration, adhesion and invasion of MCF-7 and SK-BR-3 breast cancer cells. The results demonstrated that baicalein suppressed E2-stimulated wound-healing migration and cell‑Matrigel adhesion, and ameliorated E2-promoted invasion across a Matrigel-coated Transwell membrane. Furthermore, baicalein interfered with E2-induced novel G protein-coupled estrogen receptor (GPR30)-related signaling, including a decrease in tyrosine phosphorylation of epidermal growth factor receptor (EGFR) as well as phosphorylation of extracellular signal-regulated kinase (ERK) and serine/threonine kinase Akt, without affecting GPR30 expression. The results also showed that baicalein suppressed the expression of GPR30 target genes, cysteine-rich 61 (CYR61) and connective tissue growth factor (CTGF) induced by E2. Furthermore, baicalein prevented GPR30-related signaling activation and upregulation of CYR61 and CTGF mRNA levels induced by G1, a specific GPR 30 agonist. The results suggest that baicalein inhibits E2-induced migration, adhesion and invasion through interfering with GPR30 signaling pathway activation, which indicates that it may act as a therapeutic candidate for the treatment of GPR30-positive breast cancer metastasis.

Inhibitory effects of kaempferol on the invasion of human breast carcinoma cells by downregulating the expression and activity of matrix metalloproteinase-9

Matrix metalloproteinases (MMPs) have been regarded as major critical molecules assisting tumor cells during metastasis, for excessive ECM (ECM) degradation, and cancer cell invasion. In the present study, in vitro and in vivo assays were employed to examine the inhibitory effects of kaempferol, a natural polyphenol of flavonoid family, on tumor metastasis. Data showed that kaempferol could inhibit adhesion, migration, and invasion of MDA-MB-231 human breast carcinoma cells. Moreover, kaempferol led to the reduced activity and expression of MMP-2 and MMP-9, which were detected by gelatin zymography, real-time PCR, and western blot analysis, respectively. Further elucidation of the mechanism revealed that kaempferol treatment inhibited the activation of transcription factor activator protein-1 (AP-1) and MAPK signaling pathway. Moreover, kaempferol repressed phorbol-12-myristate-13-acetate (PMA)-induced MMP-9 expression and activity through suppressing the translocation of protein kinase Cδ (PKCδ) and MAPK signaling pathway. Our results also indicated that kaempferol could block the lung metastasis of B16F10 murine melanoma cells as well as the expression of MMP-9 in vivo. Taken together, these results demonstrated that kaempferol could inhibit cancer cell invasion through blocking the PKCδ/MAPK/AP-1 cascade and subsequent MMP-9 expression and its activity. Therefore, kaempferol might act as a therapeutic potential candidate for cancer metastasis.

Wogonin suppresses melanoma cell B16-F10 invasion and migration by inhibiting Ras-medicated pathways

The patients diagnosed with melanoma have a bad prognosis for early regional invasion and distant metastases. Wogonin (5,7-dihydroxy-8-methoxyflavone) is one of the active components of flavonoids that extracts from Scutellariae radix. Several previous studies reported that wogonin possesses antitumor effect against leukemia, gastrointestinal cancer and breast cancer. In this study, we used melanoma cell B16-F10 to further investigate the anti-invasive and anti-migratory activity of wogonin. Our date showed that wogonin caused suppression of cell migration, adhesion, invasion and actin remodeling by inhibiting the expression of matrix metalloproteinase-2 and Rac1 in vitro. Wogonin also reduced the number of the tumor nodules on the whole surface of the lung in vivo. Furthermore, the examination of mechanism revealed that wogonin inhibited Extracellular Regulated protein Kinases and Protein Kinase B pathways, which are both medicated by Ras. Insulin-like growth factor-1-induced or tumor necrosis factor-α-induced invasion was also inhibited by wogonin. Therefore, the inhibitory mechanism of melanoma cell invasion by wogonin might be elucidated.

Wogonin suppresses human alveolar adenocarcinoma cell A549 migration in inflammatory microenvironment by modulating the IL-6/STAT3 signaling pathway

Increasing evidence from various clinical and experimental studies has demonstrated that the inflammatory microenvironment facilitates tumor metastasis. Clinically, it will be a promising choice to suppress tumor metastasis by targeting inflammatory microenvironment. Our previous studies have demonstrated that wogonin (a bioflavonoid isolated from the traditional Chinese medicine of Huang-Qin) possesses the anti-metastatic and anti-inflammatory activity, but we have little idea about its efficacy on inflammatory-induced tumor metastasis and the mechanism underlying it. In this study, we focused on epithelial mesenchymal transition (EMT), the first step of tumor metastasis, to evaluate the effects of wogonin on tumor metastasis in inflammatory microenvironment. We found that wogonin inhibited THP-1 conditioned-medium- (CM-) and IL-6-induced EMT by inactivating STAT3 signal. And in wogonin-treated A549 cells which pretreated with THP-1 CM or IL-6, the expression level of E-cadherin, an EMT negative biomarker, increased while that of N-cadherin, Vimentin, and EMT-related transcription factors including Snail and Twist decreased. Moreover, wogonin inhibited IL-6-induced phosphorylation of STAT3, prevented p-STAT3 dimer translocation into the nucleus, and suppressed the DNA-binding activity of p-STAT3. Interestingly, similar results were obtained in the tumor xenografts mice, including downregulation of p-STAT3, N-cadherin, and Vimentin while up-regulation of E-cadherin. Wogonin also inhibit the metastasis of A549 cells in vivo. Taken all data together, we concluded that wogonin suppresses tumor cells migration in inflammatory microenvironment by inactivating STAT3 signal.

CXCL12/CXCR4 axis confers adriamycin resistance to human chronic myelogenous leukemia and oroxylin A improves the sensitivity of K562/ADM cells

This study was aimed at investigating the reversal effect of oroxylin A, a naturally bioactive monoflavonoid separated and purified from Scutellaria baicalensis Georgi, in human chronic myeloid leukemia (CML) and the underlying mechanisms. The results showed that CXCL12 could enhance the resistance of K562 cells to adriamycin (ADM) by increasing the expression of CXCR4, up-regulating the downstream PI3K/Akt pathway, and promoting translocation of NF-κB dimers into nucleus and subsequently decreasing the expression of apoptosis-related proteins in K562 cells. And we found that ADM resistance was partially reversed by CXCR4 siRNA transfection. Moreover, the sensitivity enhancement of oroxylin A was demonstrated by decreasing the expression of CXCR4 at both protein and mRNA levels, via PI3K/Akt/NF-κB pathway and triggering the apoptosis pathway in vitro. In addition, the in vivo study showed that oroxylin A increased apoptosis of leukemic cells with low systemic toxicity, and the mechanism was the same as in vitro study. In conclusion, all these results showed that oroxylin A improved the sensitivity of K562/ADM cells by increasing apoptosis in leukemic cells and decreasing the expression of CXCR4 and PI3K/Akt/NF-κB pathway, and probably served as a most promising agent for CML treatment.

LFG-500 inhibits the invasion of cancer cells via down-regulation of PI3K/AKT/NF-κB signaling pathway

Cancer cell invasion, one of the crucial events in local growth and metastatic spread of tumors, possess a broad spectrum of mechanisms, especially altered expression of matrix metalloproteinases. LFG-500 is a novel synthesized flavonoid with strong anti-cancer activity, whose exact molecular mechanism remains incompletely understood. This current study was designed to examine the effects of LFG-500 on tumor metastasis using in vitro and in vivo assays. LFG-500 could inhibit adhesion, migration and invasion of MDA-MB-231 human breast carcinoma cells. Meanwhile, it reduced the activities and expression of MMP-2 and MMP-9 via suppressing the transcriptional activation of NF-κB rather than AP-1 or STAT3. Moreover, LFG-500 repressed TNF-α induced cell invasion through inhibiting NF-κB and subsequent MMP-9 activity. Further elucidation of the mechanism revealed that PI3K/AKT but not MAPK signaling pathway was involved in the inhibitory effect of LFG-500 on NF-κB activation. LFG-500 could also suppress lung metastasis of B16F10 murine melanoma cells in vivo. Taken together, these results demonstrated that LFG-500 could block cancer cell invasion via down-regulation of PI3K/AKT/NF-κB signaling pathway, which provides new evidence for the anti-cancer activity of LFG-500.

Wogonin has multiple anti-cancer effects by regulating c-Myc/SKP2/Fbw7α and HDAC1/HDAC2 pathways and inducing apoptosis in human lung adenocarcinoma cell line A549

Wogonin is a plant monoflavonoid which has been reported to inhibit cell growth and/or induce apoptosis in various tumors. The present study examined the apoptosis-inducing activity and underlying mechanism of action of wogonin in A549 cells. The results showed that wogonin was a potent inhibitor of the viability of A549 cells. Apoptotic protein changes detected after exposure to wogonin included decreased XIAP and Mcl-1 expression, increased cleaved-PARP expression and increased release of AIF and cytotchrome C. Western blot analysis showed that the activity of c-Myc/Skp2 and HDAC1/HDAC2 pathways, which play important roles in tumor progress, was decreased. Quantitative PCR identified increased levels of c-Myc mRNA and decreased levels of its protein. Protein levels of Fbw7α, GSK3β and Thr58-Myc, which are involved in c-Myc ubiquitin-dependent degradation, were also analyzed. After exposure to wogonin, Fbw7α and GSK3β expression decreased and Thr58-Myc expression increased. However, MG132 was unable to prevent c-Myc degradation. The present results suggest that wogonin has multiple anti-cancer effects associated with degradation of c-Myc, SKP2, HDAC1 and HDAC2. Its ability to induce apoptosis independently of Fbw7α suggests a possible use in drug-resistance cancer related to Fbw7 deficiency. Further studies are needed to determine which pathways are related to c-Myc and Fbw7α reversal and whether Thr58 phosphorylation of c-Myc is dependent on GSK3β.

Curcumin inhibits TGF-β1-induced MMP-9 and invasion through ERK and Smad signaling in breast cancer MDA- MB-231 cells

OBJECTIVE

To evaluate the effects of curcumin on matrixmetalloproteinase-9 (MMP-9) and invasion ability induced by transforming growth factor-β1 (TGF-β1) in MDA-MB-231 cells and potential mechanisms.

METHODS

Human breast cancer MDA- MB-231 cells were used with the CCK-8 assay to measure the cytotoxicity of curcumin. After treatment with 10 ng/ml TGF-β1, with or without curcumin (≤10 μM), cell invasion was checked by transwell chamber. The effects of curcumin on TGF-β1-stimulated MMP-9 and phosphorylation of Smad2, extracellular-regulated kinase (ERK), and p38 mitogen activated protein kinases (p38MAPK) were examined by Western blotting. Supernatant liquid were collected to analyze the activity of MMP-9 via zymography. Following treatment with PD98059, a specific inhibitor of ERK, and SB203580, a specific inhibitor of p38MAPK, Western blotting and zymography were employed to examine MMP-9 expression and activity, respectively.

RESULTS

Low dose curcumin (≤10 μM) did not show any obvious toxicity to the cells, while 0~10 μmol/L caused a concentration-dependent reduction in cell invasion provoked by TGF-β1. Curcumin also markedly inhibited TGF-β1-regulated MMP-9 and activation of Smad2, ERK1/2 and p38 in a dose- and time-dependent manner. Additionally, PD98059, but not SB203580, showed a similar pattern of inhibition of MMP-9 expression.

CONCLUSION

Curcumin inhibited TGF-β1-stimulated MMP-9 and the invasive phenotype in MDA-MB-231 cells, possibly associated with TGF-β/Smad and TGF-β/ERK signaling.

Oridonin Induces Apoptosis, Inhibits Migration and Invasion on Highly-Metastatic Human Breast Cancer Cells

Oridonin, a natural tetracycline diterpenoid isolated from Chinese herb Rabdosia rubescens, has been reported to be a potent cytotoxic agent against a wide variety of tumors. However, its effect on highly metastatic breast cancer cells has not been addressed. In this study, we investigated the effects of oridonin on growth, migration and invasion of highly-metastatic human breast cancer cells. Our results showed that oridonin induced potent growth inhibition on human breast cancer cells MCF-7 and MDA-MB-231 in a time- and dose-dependent manner. According to the flow cytometric analysis, oridonin suppressed MCF-7 cell growth by cell cycle arrest at the G2/M phase and caused accumulation of MDA-MB-231 cells in the Sub-G1 phase. The induced apoptotic effect of oridonin was further confirmed by a morphologic characteristics assay and TUNEL assay. Oridonin triggered the reduction of Bcl-2/Bax ratio, caspase-8, NF-κB (p65), IKKα, IKKβ, phospho-mTOR, and increased expression level of cleaved PARP, Fas and PPARγ in a time-dependent manner. Immunofluorescent analysis showed that γH2AX-containing nuclear foci were significant in oridonin-treated MDA-MB-231 cells. Meanwhile, oridonin significantly suppressed MDA-MB-231 cell migration and invasion, decreased MMP-2/MMP-9 activation and inhibited the expression of Integrin β1 and FAK. In conclusion, oridonin inhibited the growth and induced apoptosis in breast cancer cells, which might be related to DNA damage and activation of intrinsic or extrinsic apoptotic pathways. Moreover, oridonin also inhibited tumor invasion and metastasis in vitro possibly via decreasing the expression of MMPs and regulating the Integrin β1/FAK pathway in MDA-MB-231 cells.

Wortmannin reduces metastasis and angiogenesis of human breast cancer cells via nuclear factor-κB-dependent matrix metalloproteinase-9 and interleukin-8 pathways

OBJECTIVE

To investigate whether inhibition of Akt phosphorylation by the phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin, reduces metastasis and angiogenesis in a human breast cancer cell line via nuclear factor (NF)-κB-dependent matrix metalloproteinase (MMP)-9 and interleukin (IL)-8 pathways.

METHODS

MDA-MB-231 cells were treated with wortmannin 0-200 nM for 4 h. Restoration of Akt activity was evaluated by transfection of cells with constitutively active myristoylated Akt (myr-Akt). NF-κB, MMP-9 and IL-8 proteins were detected by electrophoretic mobility shift assay, Western blot or enzyme-linked immunosorbent assay. The chicken embryo chorio-allantoic membrane assay, cell motility and migration assays were used to evaluate angiogenesis and invasion in vitro. A mouse pseudo metastatic breast cancer model was used to assess the effects of wortmannin on metastasis and angiogenesis in vivo.

RESULTS

Wortmannin inhibited the phosphorylation of Akt, upregulation of NF-κB, MMP-9, IL-8, and in vitro cell invasion and angiogenesis, in a dose-dependent manner. Transfection of myr-Akt reversed the cellular and biochemical effects of wortmannin in vitro. Wortmannin also significantly inhibited tumour metastasis and angiogenesis in vivo.

CONCLUSION

The findings of the present study suggest that wortmannin inhibits metastasis and angiogenesis in breast cancer cells via PI3K/Akt/NF-κB-mediated MMP-9 and IL-8 signalling pathways.

Resveratrol induces MMP-9 and cell migration via the p38 kinase and PI-3K pathways in HT1080 human fibrosarcoma cells

Trans-3,4',5-trihydroxystilbene (resveratrol) is a grape polyphenol present in various plants, food products, red wine and grapes. Resveratrol has anti-inflammatory, anticarcinogenic, anti-oxidant and anti-aging properties. Matrix metalloproteinases (MMPs) are key enzymes involved in the degradation of the extracellular matrix, and their expression may be regulated in cancer metastasis. In the present study, we aimed to evaluate the effect of resveratrol on MMPs and cell migration, and to understand the mechanism of action in HT1080 human fibrosarcoma cells. We found that resveratrol inhibited HT1080 cell viability at various concentrations as detected by the MTT assay and FACS analysis. However, resveratrol dramatically increased the activation and expression of MMP-9 in a dose- and time-dependent manner, as determined by gelatin zymography assay and western blot analysis. We also discovered that resveratrol enhanced the migratory ability of HT1080 cells, as determined by the wound healing assay, and decreased the phosphorylation of p38 kinase. Moreover, the Akt kinase was inhibited by resveratrol in the HT1080 cells. The inhibition of p38 and Akt kinases with SB203580 and LY294002 further increased resveratrol-induced MMP-9 as well as cell migration in the HT1080 cells. Our results suggest that resveratrol regulates MMP-9 and migratory abilities through the p38 kinase and PI-3K pathways in HT1080 human fibrosarcoma cells.

Luteolin exerts anti-tumor activity through the suppression of epidermal growth factor receptor-mediated pathway in MDA-MB-231 ER-negative breast cancer cells

This study investigated the inhibitory effect of luteolin on MDA-MB-231 estrogen receptor (ER) negative breast tumor growth both in vitro and in vivo. Study results showed that luteolin suppresses (3)H thymidine incorporation indicating cell growth inhibition, and this was accompanied by cell cycle arrest at the G2/M and S stages and apoptotic activity. Further analyses showed that luteolin exhibited cell cycle arrest and apoptotic activity by decreasing AKT, PLK1, cyclin B(1), cyclin A, CDC2, CDK2, and Bcl-xL expression and increasing p21 and Bax expression. Underlying mechanisms of action exerted by luteolin included the down-regulation. EGFR mRNA expression followed by the inhibition of EGF-induced MAPK activation, including the phosphorylation of ERK, p38 and AKT. Luteolin-supplementation at 0.01% or 0.05% significantly reduced tumor burden in nude mice inoculated with MDA-MB-231 cells. In conclusion, luteolin effectively suppresses MDA-MB-231 ER-negative breast cancer cell growth, and its anticancer activity may be partly derived from inhibitory effects on EGFR-mediated cell survival.