Epigallocatechin-3-gallate (EGCG) downregulates gelatinase-B (MMP-9) by involvement of FAK/ERK/NFkappaB and AP-1 in the human breast cancer cell line MDA-MB-231

Role of Epigallocatechin Gallate in Selected Malignant Neoplasms in Women

Tea is a significant source of flavonoids in the diet. Due to different production processes, the amount of bioactive compounds in unfermented (green) and (semi-)fermented tea differs. Importantly, green tea has a similar composition of phenolic compounds to fresh, unprocessed tea leaves. It consists primarily of monomeric flavan-3-ols, known as catechins, of which epigallocatechin gallate (EGCG) is the most abundant. Thanks to its antioxidant, antiproliferative, and antiangiogenic properties, EGCG has attracted the scientific community's attention to its potential use in preventing and/or combating cancer. In this review article, we summarize the literature reports found in the Google Scholar and PubMed databases on the anticancer effect of EGCG on selected malignant neoplasms in women, i.e., breast, cervical, endometrial, and ovarian cancers, which have been published over the last two decades. It needs to be emphasized that EGCG concentrations reported as effective against cancer cells are typically higher than those found in plasma after polyphenol administration. Moreover, the low bioavailability and absorption of EGCG appear to be the main reasons for the differences in the effects between in vitro and in vivo studies. In this context, we also decided to look at possible solutions to these problems, consisting of combining the polyphenol with other bioactive components or using nanotechnology. Despite the promising results of the studies conducted so far, mainly in vitro and on animal models, there is no doubt that further, broad-based activities are necessary to unequivocally assess the potential use of EGCG in oncological treatment to combat cancer in women.

An updated review summarizing the anticancer potential of flavonoids via targeting NF-kB pathway

Nuclear factor-κB (NF-κB) cell signaling pathway is essential for the progression and development of numerous human disorders, including cancer. NF-κB signaling pathway regulates a wide range of physiological processes, such as cell survival, growth, and migration. Deregulated NF-kB signaling resulted in unregulated cell proliferation, viability, movement, and invasion, thus promoting tumor development. Recent findings have increasingly shown that plant derived phytochemicals that inhibit NF-κB signaling have the potential to be employed in cancer therapeutics. Flavonoids are a group of polyphenolic natural compounds present in various plants and their fruits, vegetables, and leaves. These compounds have numerous medicinal properties owing to their antioxidant, anti-inflammatory, antiviral, and antitumor characteristics. The main mechanism by which these flavonoids exhibit their anticancer potential is via potent antioxidative and immunomodulatory actions. Current research reports have demonstrated that these flavonoids exhibited their anticancer effects via suppressing the NF-κB signaling. Based on these facts, we have comprehensively outlined the cancer promoting role of NF-κB pathway in various processes including tumor progression, drug resistance, angiogenesis and metastasis. In addition to these, we also summarize the anticancer potential of flavonoids by specifically targeting the NF-κB pathway in various types of cancers.

Emerging Combinatorial Drug Delivery Strategies for Breast Cancer: A Comprehensive Review

Breast cancer remains the second most prevalent cancer among women in the United States. Despite advancements in surgical, radiological, and chemotherapeutic techniques, multidrug resistance continues to pose significant challenges in effective treatment. Combination chemotherapy has emerged as a promising approach to address these limitations, allowing multiple drugs to target malignancies via distinct mechanisms of action. Increasingly, the use of phytoconstituents alongside chemotherapeutic agents has shown promise in enhancing treatment outcomes. This combination therapy acts on key signaling pathways such as Hedgehog, Notch, Wnt/β- catenin, tyrosine kinases, and phosphatidylinositol 3-kinase (PI3K), which play critical roles in cellular proliferation, apoptosis, angiogenesis, differentiation, invasion, and metastasis. This review explores various signaling pathways involved in breast cancer progression, discusses conventional treatment methods like surgery, adjuvant radiotherapy, hormonal therapy, and chemotherapy, and highlights emerging nanocarrier-based drug delivery systems (DDS). Liposomes, dendrimers, exosomes, polymeric micelles, and nanoparticles (organic, inorganic, gold, magnetic, carbon-based, and quantum dots) are examined as innovative strategies for enhancing drug delivery efficacy. Furthermore, stimuli-responsive DDSs, including reactive oxygen species (ROS), enzyme-, and hypoxia- responsive systems, are presented as cutting-edge approaches to overcoming drug resistance. Special emphasis is placed on the co-delivery of chemotherapeutic agents and plant-based compounds, particularly in estrogen receptor-positive (ER+) breast cancer. This review aims to provide a comprehensive overview of novel combinatorial strategies and advanced nanocarriers for the effective and targeted treatment of breast cancer.

In Silico Investigations on the Synergistic Binding Mechanism of Functional Compounds with Beta-Lactoglobulin

Piceatannol (PIC) and epigallocatechin gallate (EGCG) are polyphenolic compounds with applications in the treatment of various diseases such as cancer, but their stability is poor. β-lactoglobulin (β-LG) is a natural carrier that provides a protective effect to small molecule compounds and thus improves their stability. To elucidate the mechanism of action of EGCG, PIC, and palmitate (PLM) in binding to β-LG individually and jointly, this study applied molecular docking and molecular dynamics simulations combined with in-depth analyses including noncovalent interaction (NCI) and binding free energy to investigate the binding characteristics between β-LG and compounds of PIC, EGCG, and PLM. Simulations on the binary complexes of β-LG + PIC, β-LG + EGCG, and β-LG + PLM and ternary complexes of (β-LG + PLM) + PIC, (β-LG + PLM) + EGCG, β-LG + PIC) + EGCG, and (β-LG + EGCG) + PIC were performed for comparison and characterizing the interactions between binding compounds. The results demonstrated that the co-bound PIC and EGCG showed non-beneficial effects on each other. However, the centrally located PLM was revealed to be able to adjust the binding conformation of PIC, which led to the increase in binding affinity with β-LG, thus showing a synergistic effect on the co-bound PIC. The current study of β-LG co-encapsulated PLM and PIC provides a theoretical basis and research suggestions for improving the stability of polyphenols.

Insight into the Biological Roles and Mechanisms of Phytochemicals in Different Types of Cancer: Targeting Cancer Therapeutics

Cancer is a hard-to-treat disease with a high reoccurrence rate that affects health and lives globally. The condition has a high occurrence rate and is the second leading cause of mortality after cardiovascular disorders. Increased research and more profound knowledge of the mechanisms contributing to the disease’s onset and progression have led to drug discovery and development. Various drugs are on the market against cancer; however, the drugs face challenges of chemoresistance. The other major problem is the side effects of these drugs. Therefore, using complementary and additional medicines from natural sources is the best strategy to overcome these issues. The naturally occurring phytochemicals are a vast source of novel drugs against various ailments. The modes of action by which phytochemicals show their anti-cancer effects can be the induction of apoptosis, the onset of cell cycle arrest, kinase inhibition, and the blocking of carcinogens. This review aims to describe different phytochemicals, their classification, the role of phytochemicals as anti-cancer agents, the mode of action of phytochemicals, and their role in various types of cancer.

Effects of Epigallocatechin-3-Gallate on Matrix Metalloproteinases in Terms of Its Anticancer Activity

Epidemiological studies have shown that the consumption of green tea has beneficial effects against cancer. Basic studies have provided evidence that epigallocatechin gallate (EGCG) is a major contributor to these effects. Matrix metalloproteinases (MMPs) are zinc-dependent metalloproteinases with the ability to degrade the extracellular matrix proteins and are involved in various diseases including cancer in which MMPs have a critical role in invasion and metastasis. In this review, we discuss the effects of EGCG on several types of MMPs in the context of its anticancer activity. In the promoter region, MMPs have binding sites for at least one transcription factor of AP-1, Sp1, and NF-κB, and EGCG can downregulate these transcription factors through signaling pathways mediated by reactive oxygen species. EGCG can also decrease nuclear ERK, p38, heat shock protein-27 (Hsp27), and β-catenin levels, leading to suppression of MMPs' expression. Other mechanisms by which EGCG inhibits MMPs include direct binding to MMPs to prevent their activation and downregulation of NF-κB to suppress the production of inflammatory cytokines such as TNFα and IL-1β. Findings from studies on EGCG presented here may be useful in the development of more effective anti-MMP agents, which would give beneficial effects on cancer and other diseases.

Therapeutic Effects of Green Tea Polyphenol (‒)-Epigallocatechin-3-Gallate (EGCG) in Relation to Molecular Pathways Controlling Inflammation, Oxidative Stress, and Apoptosis

(‒)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea. Thanks to multiple interactions with cell surface receptors, intracellular signaling pathways, and nuclear transcription factors, EGCG possesses a wide variety of anti-inflammatory, antioxidant, antifibrotic, anti-remodelation, and tissue-protective properties which may be useful in the treatment of various diseases, particularly in cancer, and neurological, cardiovascular, respiratory, and metabolic disorders. This article reviews current information on the biological effects of EGCG in the above-mentioned disorders in relation to molecular pathways controlling inflammation, oxidative stress, and cell apoptosis.

Potential Focal Adhesion Kinase Inhibitors in Management of Cancer: Therapeutic Opportunities from Herbal Medicine

Focal adhesion kinase (FAK) is a multifunctional protein involved in cellular communication, integrating and transducing extracellular signals from cell-surface membrane receptors. It plays a central role intracellularly and extracellularly within the tumor microenvironment. Perturbations in FAK signaling promote tumor occurrence and development, and studies have revealed its biological behavior in tumor cell proliferation, migration, and adhesion. Herein we provide an overview of the complex biology of the FAK family members and their context-dependent nature. Next, with a focus on cancer, we highlight the activities of FAK signaling in different types of cancer and how knowledge of them is being used for screening natural compounds used in herbal medicine to fight tumor development.

Plants as a Source of Anticancer Agents: From Bench to Bedside

Cancer is the second leading cause of death after cardiovascular diseases. Conventional anticancer therapies are associated with lack of selectivity and serious side effects. Cancer hallmarks are biological capabilities acquired by cancer cells during neoplastic transformation. Targeting multiple cancer hallmarks is a promising strategy to treat cancer. The diversity in chemical structure and the relatively low toxicity make plant-derived natural products a promising source for the development of new and more effective anticancer therapies that have the capacity to target multiple hallmarks in cancer. In this review, we discussed the anticancer activities of ten natural products extracted from plants. The majority of these products inhibit cancer by targeting multiple cancer hallmarks, and many of these chemicals have reached clinical applications. Studies discussed in this review provide a solid ground for researchers and physicians to design more effective combination anticancer therapies using plant-derived natural products.

Therapeutic Potential of Natural Products in the Treatment of Renal Cell Carcinoma: A Review

Renal cell carcinoma (RCC) is a common cancer of the urinary system. The potential therapeutic effects of certain natural products against renal cell carcinoma have been reported both in vivo and in vitro, but no reviews have been published classifying and summarizing the mechanisms of action of various natural products. In this study, we used PubMed and Google Scholar to collect and screen the recent literature on natural products with anti-renal-cancer effects. The main mechanisms of action of these products include the induction of apoptosis, inhibition of angiogenesis, inhibition of metastasis and reduction of drug resistance. In total, we examined more than 30 natural products, which include kahweol acetate, honokiol, englerin A and epigallocatechin-3-gallate, among others, have demonstrated a variety of anti-renal-cancer effects. In conclusion, natural products may have a wider application in kidney cancer than previously believed and are potential candidates for treatment in RCC.

Effects of Polyphenols on ncRNAs in cancer - An update

In recent years, oncotherapy has received considerable attention concerning plant polyphenols. Increasing evidence suggests that due to the efficiency of polyphenols, they may have antitumor effects in various cancers. However, their regulatory structures remain elusive. Long non-coding RNAs (LncRNAs) have been identified in the regulation of various forms of tumorigenesis and tumor development. Long non-coding RNAs (LncRNAs) have recently emerged as regulatory eukaryotic transcripts and therapeutic targets with important and diverse functions in health and diseases. LncRNAs may be associated with the initiation, development, and progression of cancer. This review summarizes the research on the modulatory effects of LncRNAs and their roles in mediating cellular processes. The mechanisms of action of polyphenols underlying their therapeutic effects on cancers are also discussed. Based on our review, polyphenols might facilitate a significant epigenetic modification as part of their tissue-/cell-related biological effects. This finding may be attributed to their interaction with cellular signaling pathways involved in chronic diseases. Certain LncRNAs might be the target of specific polyphenols, and some critical signaling processes involved in the intervention of cancers might mediate the therapeutic roles of polyphenols. This article is protected by copyright. All rights reserved.

The Potential of Natural Products in the Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that lacks receptors for targeted therapy. Consequently, chemotherapy is currently the mainstay of systemic treatment options. However, the enrichment of cancer stem cells (CSC, a subpopulation with stem-cell characteristics and tumor-initiating propensity) promotes chemo-resistance and tumorigenesis, resulting in cancer recurrence and relapse. Furthermore, toxic side effects of chemotherapeutics reduce patient wellbeing. Natural products, specifically compounds derived from plants, have the potential to treat TNBC and target CSCs by inhibiting CSC signaling pathways. Literature evidence from six promising compounds were reviewed, including sulforaphane, curcumin, genistein, resveratrol, lycopene, and epigallocatechin-3-gallate. These compounds have been shown to promote cell cycle arrest and apoptosis in TNBC cells. They also could inhibit the epithelial-mesenchymal transition (EMT) that plays an important role in metastasis. In addition, those natural compounds have been found to inhibit pathways important for CSCs, such as NF-κB, PI3K/Akt/mTOR, Notch 1, Wnt/β-catenin, and YAP. Clinicals trials conducted on these compounds have shown varying degrees of effectiveness. Epidemiological case-control studies for the compounds commonly consumed in certain human populations have also been summarized. While in vivo and in vitro data are promising, further basic and clinical investigations are required. Likely, natural products in combination with other drugs may hold great potential to improve TNBC treatment efficacy and patient outcomes.

Methacrylation of epigallocatechin-gallate for covalent attachment with a dental polymer

OBJECTIVE

Synthesize novel epigallocatechin-gallate (EGCG) methacrylate monomers with the ability to copolymerize with dental methacrylate resins.

METHODS

EGCG was reacted with 1/3 (E33), 2/3 (E67) and 1 (E100) molar equivalents of methacyloyl chloride introducing three degrees of polymerizablility. EGCG-methacrylates were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). E33, E67, E100 and neat EGCG were incorporated into TEGDMA at 0.5-20% ratios (m/m). Copolymers were tested for degree of conversion (%DC), EGCG release, gel content (%GC), degree of swelling (%DS), flexural properties and bacterial viability (Streptococcus mutans, baseline/30-days). Neat TEGDMA and TEGDMA passively loaded with EGCG (E0) were used as controls. Data were analysed by one-way ANOVA, Tukey, and Dunnett's method (α=5%). Two-way ANOVA and Bonferroni were used to investigate factor interaction.

RESULTS

FTIR/NMR confirmed synthesis of desired compounds. All of E100 incorporated ratios had %DC similar to TEGDMA. Remaining groups had reduction in %DC at 2% in E0, 10% in E33 and 20% in E67 ratios. EGCG was stable within ECGC-methacrylate copolymers. Release of EGCG from E0 significantly increased with higher EGCG ratios. Except for E100, higher EGCG or EGCG-methacrylate ratios led to decreased %CG and %DS. At baseline, E0 had the lowest bacterial survival rates (1-10% survival) at all ratios compared to E33, E67, E100, and neat TEGDMA. However, E33, E67 and E100 still had statistically lower survival rates (7-53%) compared with neat TEGDMA. After 30-days, all compounds had similar survival rates for all ratios, which were lower than that of neat TEGDMA.

SIGNIFICANCE

Demonstration of methacrylate functionalized EGCG- with inherited antibacterial activity for improved restoration longevity.

Interaction of epigallocatechin-gallate and chlorhexidine with Streptococcus mutans stimulated odontoblast-like cells: Cytotoxicity, Interleukin-1β and co-species proteomic analyses

OBJECTIVES

The dentin therapeutic agent chlorhexidine has inflammatory and cytotoxic characteristics urging investigation of alternatives like the natural compound epigallocatechin-gallate. The aim is to verify the effect of epigallocatechin-gallate and chlorhexidine on viability, interleukin-1β (IL-1β) and differential protein expression of MDPC-23 odontoblast-like cells stimulated by Streptococcus mutans.

DESIGN

Cells were stimulated with heat-killed S. mutans at multiplicity of infection (MOI) of 100-1000 and subsequently treated with 100-1 µM of epigallocatechin-gallate. Cells with no treatment or chlorhexidine were controls. Combined stimulated/treated cells were tested for cytotoxicity (Alamar-Blue, N = 3, n = 3), total protein (N = 3, n = 3), IL-1β (ELISA, N = 3, n = 3), and differential protein expression by liquid chromatography-tandem mass spectrometry (LC-MS/MS, n = 2).

RESULTS

Cells stimulated at MOI 100/1000 and treated with 10 µM epigallocatechin-gallate and chlorhexidine did not present cytotoxicity. IL-1β significantly increased in both un-stimulated and stimulated chlorhexidine 10 µM groups when compared to un-treated control (p < 0.05). MOI 100 chlorhexidine 10 µM group significantly increased IL-1β compared to un-stimulated chlorhexidine 10 µM and epigallocatechin-gallate 10 µM groups, as well as to MOI 100 epigallocatechin-gallate 10 µM group (p < 0.05). LC-MS/MS revealed S. mutans and mammalian proteins, with tooth-specific proteins exhibiting different abundance levels, depending on the tested condition.

CONCLUSIONS

Odontoblast-like cells stimulated with S. mutans at different MOI combined with epigallocatechin-gallate treatment did not cause cytotoxicity. S. mutans stimulation combined with chlorhexidine 100 µM treatment decreased cell viability, while treatment with chlorhexidine 10 µM concentration significantly increased IL-1β. S. mutans stimulation and treatment of cells resulted in varied protein expression.

Role of Phytochemicals in Cancer Chemoprevention: Insights

Cancer is a condition where the body cells multiply in an uncontrollable manner. Chemoprevention of cancer is a broad term that describes the involvement of external agents to slow down or suppress cancer growth. Synthetic and natural compounds are found useful in cancer chemoprevention. The occurrence of global cancer type varies, depending on many factors such as environmental, lifestyle, genetic etc. Cancer is often preventable in developed countries with advanced treatment modalities, whereas it is a painful death sentence in developing and low-income countries due to the lack of modern therapies and awareness. One best practice to identify cancer control measures is to study the origin and risk factors associated with common types. Based on these factors and the health status of patients, stage, and severity of cancer, type of treatment is decided. Even though there are well-established therapies, cancer still stands as one of the major causes of death and a public health burden globally. Research shows that most cancers can be prevented, treated, or the incidence can be delayed. Phytochemicals from various medicinal plants were reported to reduce various risk factors associated with different types of cancer through their chemopreventive role. This review highlights the role of bioactive compounds or natural products from plants in the chemoprevention of cancer. There are many plant based dietary factors involved in the chemoprevention process. The review discusses the process of carcinogenesis and chemoprevention using plants and phytocompounds, with special reference to five major chemopreventive phytocompounds. The article also summarizes the important chemopreventive mechanisms and signaling molecules involved in the process. Since the role of antioxidants in chemoprevention is inevitable, an insight into plant-based antioxidant compounds that fight against this dreadful disease at various stages of carcinogenesis and disease progression is discussed. This will fill the research gap in search of chemopreventive natural compounds and encourage scientists in clinical trials of anticancer agents from plants.

The Role of EGCG in Breast Cancer Prevention and Therapy

BACKGROUND

Breast cancer is the most frequent cancer in women. Green tea has been studied for breast cancer chemopreventive and possibly chemotherapeutic effects due to its high content in polyphenolic compounds, including epigallocatechin-3-gallate (EGCG).

METHOD

This review is based on literature research that included papers registered on the Medline® database. The research was conducted through PubMed, applying the following query: "EGCG"AND "breast cancer". The result was a total of 88 articles in which this review stands on.

RESULTS

In vitro, EGCG shows antioxidant or pro-oxidant properties, depending on the concentration and exposure time. EGCG blocks cell cycle progression and modulates signaling pathways that affect cell proliferation and differentiation. EGCG also induces apoptosis, negatively modulates different steps involved in metastasis, and targets angiogenesis by inhibiting VEGF transcription. In vivo investigations have shown that oral administration of EGCG results in the reduction of tumor growth and in antimetastatic and antiangiogenic effects in animal xenograft and allograft models.

DISCUSSION

Much remains unknown about the molecular mechanisms involved in the protective effects of EGCG on mammary carcinogenesis. In addition, more studies in vivo are necessary to determine the potential toxicity of EGCG at higher doses and to elucidate its interactions with other drugs.

CONCLUSION

A protective effect of EGCG has been shown in different experimental models and under different experimental conditions, suggesting clinical implications of EGCG for breast cancer prevention and therapy. The data presented in this review support the importance of further investigations.

S-adenosyl-L-homocysteine Hydrolase: Its Inhibitory Activity Against Plasmodium falciparum and Development of Malaria Drugs

Parasite Plasmodium falciparum is continuously giving a challenge to human beings by changing itself against most of the antimalarial drugs and its consequences can be seen in the form of a huge number of deaths each year especially in the poor and developing country. Due to its drug resistance ability, new drugs are regularly needed to kill the organism. Many new drugs have been developed based on different mechanisms. One of the potential mechanisms is to hamper protein synthesis by blocking the gene expression. S-Adenosyl-L-homocysteine (SAH) hydrolase is a NAD+ dependent tetrameric enzyme, which is responsible for the reversible hydrolysis of AdoHcy to adenosine and L-homocysteine, has been recognized as a new target for antimalarial agents since the parasite has a specific SAH hydrolase. The inhibition of SAH hydrolase causes the intracellular accumulation of S-Adenosyl-L-homocysteine, elevating the ratio of SAH to S-adenosylmethionine (SAM) and inhibiting SAM-dependent methyltransferase that catalyzes methylation of the capped structure at the 5'-terminus of mRNA, and other methylation reaction which is essential for parasite proliferation. In other words, S-Adenosyl-Lhomocysteine hydrolase regulates methyltransferase reactions. In this way, SAH hydrolase inhibitors can be used for the treatment of different diseases like malaria, cancer, viral infection, etc. by ultimately stopping the synthesis of protein. Many antiviral drugs have been synthesized and marketed which are based on the inhibition of SAH hydrolase. This review summarises the development of SAH inhibitors developed over the last 20 years and their potentiality for the treatment of malaria.

Proliferation of MDA-MB-231 can be suppressed by dimeric-epigallocatechin gallate through competitive inhibition of amphiregulin-epidermal growth factor receptor signaling

Triple-negative breast cancer (TNBC) is highly aggressive, with high rates of early relapse and very poor overall prognosis. Amphiregulin (AREG) is the most abundant epidermal growth factor receptor (EGFR) agonist in MDA-MB-231 TNBC cells, whose proliferation can be inhibited by (-)-epigallocatechin gallate (EGCG), a constituent of green tea that is prone to oxidative polymerization. The effect of dimeric-EGCG, a dimer of oxidized and polymerized EGCG, on MDA-MB-231 cell the proliferation warrants further exploration. In the present study, MTT, flow cytometry, migration scratch, transwell, western blotting, and surface plasmon resonance assays were used to evaluate the effect of dimeric-EGCG on MDA-MB-231 cells and explore the underlying mechanism. MDA-MB-231 cell proliferation and migration were significantly inhibited by dimeric-EGCG at concentrations as low as 10 μM. Levels of EGFR and p44/42 MAPK phosphorylation in MDA-MB-231 cells were significantly reduced by treatment with 10 μM dimeric-EGCG (P < 0.01). In addition, the levels of phosphorylation induced by exogenous AREG were also inhibited by dimeric-EGCG (P < 0.01); however, no significant effects of dimeric-EGCG were observed on epidermal growth factor or transforming growth factor-alpha signaling. Surface plasmon resonance analysis demonstrated that 10 μM dimeric-EGCG bound directly to the extracellular domain of EGFR, competitively inhibiting the binding of AREG to EGFR. These results suggest a novel mechanism underlying the inhibitory effect of dimeric-EGCG on MDA-MB-231 cells, with potential application in the development of drugs for the treatment of TNBC.

Potential Role of Phytochemicals Against Matrix Metalloproteinase Induced Breast Cancer; An Explanatory Review

World Health Organization (WHO) estimated breast cancer as one of the most prevailed malignancy around the globe. Its incident cases are gradually increasing every year, resulting in considerable healthcare burden. The heterogeneity of breast cancer accounts for its differential molecular subtyping, interaction between pathways, DNA damaging, and chronic inflammation. Matrix metalloproteinases (MMPs) are a group of zinc-containing, calcium dependent endopeptidases which play a substantial role in breast carcinogenesis through several mechanisms. These mechanisms include remodeling of extracellular matrix (ECM), cell proliferation, and angiogenesis which promote metastasis and result in tumor progression. In this context, compounds bearing MMP inhibitory potential can serve as potent therapeutic agents in combating MMPs provoked breast cancer. Current systematic review aimed to encompass the details of potent natural lead molecules that can deter MMPs-provoked breast cancer. Following the critical appraisal of literature, a total of n = 44 studies that explored inhibitory effect of phytochemicals on MMPs were included in this review. These phytoconstituents include alkaloids (n = 11), flavonoids (n = 23), terpenoids (n = 7), and lignans (n = 2). The most common inhibitory methods used to evaluate efficacy of these phytoconstituents included Gelatin Zymography, Western Blotting, and real time polymerase chain reaction (RT-PCR) analysis. Moreover, current limitations, challenges, and future directions of using such compounds have been critically discussed. This review underscores the potential implications of phytochemicals in the management of breast cancer which could lessen the growing encumbrance of disease.

Natural Marine and Terrestrial Compounds as Modulators of Matrix Metalloproteinases-2 (MMP-2) and MMP-9 in Alzheimer's Disease

Several studies have reported neuroprotective effects by natural products. A wide range of natural compounds have been investigated, and some of these may play a beneficial role in Alzheimer's disease (AD) progression. Matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases, have been implicated in AD. In particular, MMP-2 and MMP-9 are able to trigger several neuroinflammatory and neurodegenerative pathways. In this review, we summarize and discuss existing literature on natural marine and terrestrial compounds, as well as their ability to modulate MMP-2 and MMP-9, and we evaluate their potential as therapeutic compounds for neurodegenerative and neuroinflammatory diseases, with a focus on Alzheimer's disease.

Nuclear factor-κB plays an important role in Tamarixetin-mediated inhibition of matrix metalloproteinase-9 expression

Flavonoids possess a broad spectrum of pharmacological properties, including anti-cancer, anti-oxidant and immunomodulatory activities. The current study explored the potential of some less-studied flavonoids in inhibiting Matrix Metalloproteinase-9 (MMP-9), a prominent biomarker, upregulated in a variety of cancers and known to promote migration and invasion of cancer cells. Amongst these, Tamarixetin, a naturally occurring flavonoid derivative of Quercetin, demonstrated significant dose-dependent inhibition of MMP-9 expression. Furthermore, a substantial inhibition of migration, invasion and clonogenic potential of HT1080 cells was also observed in the presence of Tamarixetin, which further suggests its role as a potential anti-cancer agent. It is noteworthy that Tamarixetin inhibits nuclear translocation as well the activity of nuclear factor kappa B (NFκB), both of which are functions essential for the activation of MMP-9 in promoting tumorigenesis. Additionally, the endogenous regulators of MMP-9 that tightly control its activity were also modulated by Tamarixetin, as evident from the 1.9 fold increase in the expression of Tissue Inhibitor of Metalloproteinase-1 (TIMP-1), with a concomitant 2.2 fold decrease in Matrix Metalloproteinase-14 (MMP-14) expression. The results obtained were further corroborated in three dimensional (3D) tumor models, which showed significant inhibition of MMP-9 activity as well as reduced invasive potential in the presence of Tamarixetin. Taken together, our observations demonstrate for the first time, the anti-invasive potential of Tamarixetin in cancer cells, indicating its possible use as a template for novel therapeutic applications.

Protective Effects of Epigallocatechin Gallate (EGCG) on Endometrial, Breast, and Ovarian Cancers

Green tea and its major bioactive component, (-)-epigallocatechin gallate (EGCG), possess diverse biological properties, particularly antiproliferation, antimetastasis, and apoptosis induction. Many studies have widely investigated the anticancer and synergistic effects of EGCG due to the side effects of conventional cytotoxic agents. This review summarizes recent knowledge of underlying mechanisms of EGCG on protective roles for endometrial, breast, and ovarian cancers based on both in vitro and in vivo animal studies. EGCG has the ability to regulate many pathways, including the activation of nuclear factor erythroid 2-related factor 2 (Nrf2), inhibition of nuclear factor-κB (NF-κB), and protection against epithelial-mesenchymal transition (EMT). EGCG has also been found to interact with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which affect epigenetic modifications. Finally, the action of EGCG may exert a suppressive effect on gynecological cancers and have beneficial effects on auxiliary therapies for known drugs. Thus, future clinical intervention studies with EGCG will be necessary to more and clear evidence for the benefit to these cancers.

Mapping Pharmacological Network of Multi-Targeting Litchi Ingredients in Cancer Therapeutics

Considerable pharmacological studies have demonstrated that the extracts and ingredients from different parts (seeds, peels, pulps, and flowers) of Litchi exhibited anticancer effects by affecting the proliferation, apoptosis, autophagy, metastasis, chemotherapy and radiotherapy sensitivity, stemness, metabolism, angiogenesis, and immunity via multiple targeting. However, there is no systematical analysis on the interaction network of “multiple ingredients-multiple targets-multiple pathways” anticancer effects of Litchi. In this study, we summarized the confirmed anticancer ingredients and molecular targets of Litchi based on published articles and applied network pharmacology approach to explore the complex mechanisms underlying these effects from a perspective of system biology. The top ingredients, top targets, and top pathways of each anticancer function were identified using network pharmacology approach. Further intersecting analyses showed that Epigallocatechin gallate (EGCG), Gallic acid, Kaempferol, Luteolin, and Betulinic acid were the top ingredients which might be the key ingredients exerting anticancer function of Litchi, while BAX, BCL2, CASP3, and AKT1 were the top targets which might be the main targets underling the anticancer mechanisms of these top ingredients. These results provided references for further understanding and exploration of Litchi as therapeutics in cancer as well as the application of “Component Formula” based on Litchi’s effective ingredients.

Quercetin Triggers Induction of Apoptotic and Lysosomal Death of Sensitive and Multidrug Resistant Leukaemia HL60 Cells

Multidrug resistance (MDR) constitutes the major cause of the failure in anticancer therapy. One of the most important mechanisms leading to the occurrence of MDR is related to the modulation of cellular death pathways. The aim of this study was to determine the effect of quercetin (Q) on triggering the programed death of human promyelocytic leukemia sensitive cells HL60 as well as multidrug resistant HL60/VINC cells overexpressing P-glycoprotein and HL60/MX2 cells characterized by the presence of mutated α isoform of topoisomerase II and the absence of β isoform of this enzyme. Q exerted comparable cytotoxic activities toward sensitive HL60 cells and their MDR counterparts. It was also found that this compound modulated the cellular level of reactive oxygen species (ROS) and led to the marked decrease in cellular GSH level. Furthermore, it was demonstrated that Q used at IC₅₀ and IC₉₀ significantly increased the percentage of sub-G1 subpopulation of all studied leukemia cells causing oligonucleosomal DNA fragmentation. The present study also indicated that Q used at IC₉₀ triggers predominantly programed cell death of sensitive HL60 cells and their MDR counterparts by induction of apoptosis occurring with the involvement of caspase-3 and caspase-8 as well as by lysosome membrane permeabilization-dependent mechanisms.

Anti-cancer activity of Conyza blinii saponin against cervical carcinoma through MAPK/TGF-β/Nrf2 signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Conyza blinii H.Lév. is a type of natural plant distributed in southwest of China. Its dried overground section can be used in traditional Chinese medicine (TCM) for treating infections, inflammations and occasionally cancers. CBS (Conyza blinii saponin), mainly composed of triterpenoidal saponins of Conyza blinii H.Lév. CBS is considered as the major active fraction of this species. The current investigation have focused on the mechanisms of CBS with regard to its anti-cancer activity. Hence it is of high relevance of identifying the anti-cancer efficacy of ethnomedicine.

AIM OF THE STUDY

To understand the anti-cancer mechanism of CBS using both in vitro and in vivo experiments.

MATERIALS AND METHODS

CBS (Conyza blinii saponin) was obtained as described previously. We tested the anti-cancer activity of CBS using in vitro HeLa cell models and in vivo animal models. We adopted immunoblot, RT-PCR (reverse transcription polymerase chain reaction), luciferase reporter assay and flow cytometry to study relevant proteins, genes, pathways and cellular ROS (reactive oxygen species) responsible for anti-cancer activity of CBS. More, 24 tumour-xenografted mice were grouped randomly as 'control', 'cisplatin' (as positive control), 'low dose' and 'high dose' groups. The IL-1β, TNF-α, PGE2 and IL-2 in the blood serum and the tumour tissue of mice were measured.

RESULTS AND CONCLUSIONS

We have found that CBS is capable of inducing apoptotic cancer cell death via both caspase-dependent and -independent pathways. CBS inhibits the activation of TGF-β signaling pathway in a dose- and time-dependent manner. Phospho-ERK, phospho-JNK and phospho-p38 MAPK are significantly suppressed by CBS. Furthermore, some inflammation mediators including IL-1β, TNF-α and PGE2 from animal samples were found decreased in CBS-treated mice models. In contrast, the level of IL-2, a cytokine commonly used for treating cancers, increased reversely. Last, we have discovered that CBS is able to decrease the expression of Nrf2, inhibit the activation of ARE and increase ROS level in HeLa cells. In summary, we have confirmed that the anti-cancer activity of CBS is possibly related to its TGF-β, MAPK, Nrf2 signaling pathways as well as some cancer related inflammation mediators and cytokines.

Increasing the low lipid phosphate phosphatase 1 activity in breast cancer cells decreases transcription by AP-1 and expressions of matrix metalloproteinases and cyclin D1/D3

Metastasis is the leading cause of mortality in breast cancer patients and lysophosphatidate (LPA) signaling promotes this process. LPA signaling is attenuated by lipid phosphate phosphatase-1 (LPP1) whose activity is decreased in cancers. Consequently, increasing LPP1 levels suppresses breast tumor growth and metastasis. This study shows that increasing LPP1 in breast cancer cells decreases transcription through cFos and cJun. This decreases production of cyclin D1/D3 and matrix metalloproteinases (MMPs), which provides new insights into the role of LPP1 in controlling tumor growth and metastasis. Methods: Invasiveness was determined by a Matrigel invasion assay. MMP expression was measured by qPCR, multiplex LASER bead technology and gelatin zymography. Levels of cJUN, cFOS, FRA1, cyclin D1, and cyclin D3 were determined by qPCR and western blotting. Collagen was determined by Picro-Sirius Red staining. Results: Increasing LPP1 expression inhibited invasion of MDA-MB-231 breast cancer cells through Matrigel. This was accompanied by decreases in expression of MMP-1, -3, -7, -9, -10, -12 and -13, which are transcriptionally regulated by the AP-1 complex. Increasing LPP1 attenuated the induction of mRNA of MMP-1, -3, cFOS, and cJUN by EGF or TNFα, but increased FRA1. LPP1 expression also decreased the induction of protein levels for cFOS and cJUN in nuclei and cytoplasmic fractions by EGF and TNFα. Protein levels of cyclin D1 and D3 were also decreased by LPP1. Although FRA1 in total cell lysates or cytoplasm was increased by LPP1, nuclear FRA1 was not affected. LPP1-induced decreases in MMPs in mouse tumors created with MDA-MB-231 cells were accompanied by increased collagen in the tumors and fewer lung metastases. Knockdown of LPP1 in MDA-MB-231 cells increased the protein levels of MMP-1 and -3. Human breast tumors also have lower levels of LPP1 and higher levels of cJUN, cFOS, MMP-1, -7, -8, -9, -12, -13, cyclin D1, and cyclin D3 relative to normal breast tissue. Conclusion: This study demonstrated that the low LPP1 expression in breast cancer cells is associated with high levels of cyclin D1/D3 and MMPs as a result of increased transcription by cFOS and cJUN. Increasing LPP1 expression provides a novel approach for decreasing transcription through AP-1, which could provide a strategy for decreasing tumor growth and metastasis.

The Role of Polyphenol (Flavonoids) Compounds in the Treatment of Cancer Cells

Cancer remains a second leading cause of deaths and major public health problem. It occurs due to extensive DNA damage caused by ultraviolet radiations, ionizing radiations, environmental agents, therapeutic agents, etc. Among all cancers, the most frequently diagnosed cancers are lung (12.7%), breast (10.9%), colorectal (9.7%), and gastric cancer (7.81%). Natural compounds are most favorable against cancer on the count of their anti-cancerous ability, easy to avail and efficient. Among natural compounds, polyphenols (flavonoids, catechin, hesperetin, flavones, quercetin, phenolic acids, ellagic acid, lignans, stilbenes, etc.) represent a large and diverse group used in the prevention and treatment of cancer. Natural flavonoids are derived from different plant sources and from various medicinal plants including Petroselinum crispum, Apium graveolens, Flemingia vestita, Phyllanthus emblica, etc. Natural flavonoids possess antioxidant, anti-inflammation, as well as anti-cancerous activities through multiple pathways, they induce apoptosis in breast, colorectal, and prostate cancers, lower the nucleoside diphosphate kinase-B activity in lung, bladder and colon cancers, inhibit cell-proliferation and cell cycle arrest by suppressing the NF-kB pathway in various cancers, etc. The current review summarized the anticancer activities of natural polyphenols and their mechanisms of action.

Increased Expression of MicroRNA 551a by c-Fos Reduces Focal Adhesion Kinase Levels and Blocks Tumorigenesis

Breast cancer is a recurrent type of cancer among women worldwide. Despite remarkable progress in the prevention, detection, and treatment of breast cancer, it still remains a major chronic problem worldwide and poses significant challenges, like metastasis to distant organs, demanding the need for novel biomarkers and therapeutic targets. Focal adhesion kinase (FAK), a member of the protein tyrosine kinases, has been shown to be expressed in high levels in breast tumors. Of late, FAK has emerged as an impending curative target in breast carcinoma, with few of the small molecular inhibitors reaching the clinical trial stage. In the current study, we established that microRNA 551a (miR-551a) precisely regulates FAK by binding to the complementary sequences in the 3' untranslated region (UTR) of mRNAs of FAK and inhibits its expression in breast carcinoma cell lines. Further, results from human breast carcinoma samples illustrated that miR-551a levels were substantially downregulated in tumor samples, with a concurrent rise in the expression of FAK. Functional experimental studies using miR-551a-overexpressing breast cancer cells and nude mouse xenograft models revealed the tumor suppressor role of miR-551a. We also found that miR-551a expression decreased the invasion and migratory ability of breast carcinoma cells by inhibiting MMP-9 activity. Regulation studies performed utilizing promoter luciferase assays, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA) revealed that c-Fos binds to the miR-551a promoter and activates it. Further, we observed a considerable increase in the amount of miR-551a levels upon c-Fos overexpression. All of these results showed that miR-551a can be of clinical relevance in understanding the regulation of FAK in breast tumorigenesis.

The effect of resveratrol on expression of matrix metalloproteinase 9 and its tissue inhibitors in vascular smooth muscle cells

BACKGROUND

Matrix metalloproteinase 9 (MMP-9) is involved in extracellular matrix degradation and remodeling. An increase in MMP-9 expression by vascular component cells plays an important role in atherosclerotic plaque formation and rupture. Resveratrol, a polyphenolic substance, was suggested to play a role in preventing the progress of atherosclerotic disease. The aim of this study was to investigate the effect of resveratrol on MMP-9 and tissue inhibitors of metalloproteinases (TIMPs) in vascular smooth muscle cells (VSMCs) after treatment with H2O2.

METHODS

Cultured VSMCs were pre-treated with 0.2 mM of H2O2 before stimulation with different concentration of resveratrol. Expression of MMP-9, TIMP-1, and TIMP-3 genes were measured using real-time polymerase chain reaction (PCR) method, and MMP-9 protein level was detected using western blot analysis.

RESULTS

Resveratrol at 120 μmol/l concentration reduced the elevated level of MMP-9 induced by H2O2 in VSMCs as 1.85 ± 0.35 folds (P < 0.050) and 8.70 ± 1.20 folds (P < 0.050) after 24 and 48 hours, respectively. Resveratrol increased the diminished level of TIMP-1 induced by H2O2 as 2.5 ± 0.48 folds following the treatment with 120 μmol/l after 48 hours (P < 0.050).

CONCLUSION

Resveratrol as an antioxidant can decrease MMP-9 production, not only by suppressing MMP-9 expression, but also by augmenting TIMP-1 production. Altogether, resveratrol as an antioxidant can regulate the MMP-9/TIMP-1 balance, and may be considered as a preservative agent in the treatment and prevention of atherosclerosis.

Molecular Targets of Epigallocatechin-Gallate (EGCG): A Special Focus on Signal Transduction and Cancer

Green tea is a beverage that is widely consumed worldwide and is believed to exert effects on different diseases, including cancer. The major components of green tea are catechins, a family of polyphenols. Among them, epigallocatechin-gallate (EGCG) is the most abundant and biologically active. EGCG is widely studied for its anti-cancer properties. However, the cellular and molecular mechanisms explaining its action have not been completely understood, yet. EGCG is effective in vivo at micromolar concentrations, suggesting that its action is mediated by interaction with specific targets that are involved in the regulation of crucial steps of cell proliferation, survival, and metastatic spread. Recently, several proteins have been identified as EGCG direct interactors. Among them, the trans-membrane receptor 67LR has been identified as a high affinity EGCG receptor. 67LR is a master regulator of many pathways affecting cell proliferation or apoptosis, also regulating cancer stem cells (CSCs) activity. EGCG was also found to be interacting directly with Pin1, TGFR-II, and metalloproteinases (MMPs) (mainly MMP2 and MMP9), which respectively regulate EGCG-dependent inhibition of NF-kB, epithelial-mesenchimal transaction (EMT) and cellular invasion. EGCG interacts with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which modulates epigenetic changes. The bulk of this novel knowledge provides information about the mechanisms of action of EGCG and may explain its onco-suppressive function. The identification of crucial signalling pathways that are related to cancer onset and progression whose master regulators interacts with EGCG may disclose intriguing pharmacological targets, and eventually lead to novel combined treatments in which EGCG acts synergistically with known drugs.

Expression of genes modulated by epigallocatechin-3-gallate in breast cancer cells

Introduction: Breast cancer is the most common malignant cancer among women. Both drug resistance and metastasis are major problems in the treatment of breast cancer. Therefore, adjuvant therapy may improve patients’ survival and affect their quality of life. It is suggested that epigallocatechin gallate (EGCG) which is well known for its chemopreventive activity and acts on numerous molecular targets may inhibit the growth and metastasis of some cancers. Hence, discovering the metastatic molecular mechanisms for breast cancer may be useful for therapy.

Objective: The aim of the study was to determine the effect of EGGC on the mRNA expression level of genes such as ZEB1, ABCB1, MDM2, TWIST1 and PTEN in MCF-7 breast cancer cells.

Methods: MCF7/DOX were cultured in the presence of 0.2 μM DOX and EGCG (20-50 μM). The mRNA expression level was determined by real-time quantitative PCR using RealTime ready Custom Panel 96 kit.

Results: Our results showed an important increase (about 2-fold for 20 μM EGCG + 0.2 μM DOX and 2.5-fold for 50 μM EGCG + 0.2 μM DOX, p<0.05) in ZEB1 expression levels. In case of ABCB1 gene lack of influence on the mRNA level was observed (p>0.05). We also observed significant decrease of ZEB1 expression in MCF7 cells with 20 μM and 50 μM EGCG (p<0.05). In addition, EGCG (20 μM) caused an increase of MDM2 and PTEN mRNA levels in almost 100% (p<0.05) and 40% (p>0.05), respectively. Lack of the influence of EGCG was noted for the TWIST1 gene expression. In case of MCF7/DOX we showed an increase of mRNA level of PTEN gene about 50% (p<0.05).

Conclusions: These results suggest that EGCG may be potentially used in adjuvant therapy in the breast cancer treatment.

(-)-Epigallocatechin gallate derivatives reduce the expression of both urokinase plasminogen activator and plasminogen activator inhibitor-1 to inhibit migration, adhesion, and invasion of MDA-MB-231 cells

Urokinase plasminogen activator (uPA) and its inhibitor plasminogen activator inhibitor-1 (PAI-1) are established independent biomarkers for high metastasis risk in breast cancer. In this study, we investigated the regulatory activity of (-)-epigallocatechin-3-gallate (EGCG) and its derivatives on uPA and PAI-1 expression and thereby their anti-metastatic potential. EGCG showed only marginal effects on the uPA system and on the metastatic behavior of breast cancer cells (MDA-MB-231). However, the EGCG derivative 3e with a methyl-substituted carbonate substituent at the 4″-position showed potent inhibition of PAI-1 (62%) and uPA (50%) expression. The Ras-extracellular-signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), and phosphatidylinositol-3-kinase (PI3K)/Akt/NF-κB pathways, which regulate uPA and PAI-1 expression, were also affected by 3e (25%, 45%, and 25% reduction, respectively). In line with these findings, substantial reduction in metastatic behavior of MDA-MB-231 cells, such as adhesion (40%), invasion (56%), and migration (40%), was observed in the presence of 3e. It is also noteworthy that, in MDA-MB-231 cells, 3e did not exert any beneficial effect on the expression of matric metalloprotein (MMP) 2 and 9, which indicates that the anti-metastatic activity of 3e in MDA-MB-231 cells is not related to its regulation of the expression of MMPs. Taken together, we have shown that the EGCG derivative 3e could suppress the metastatic behavior of MDA-MB-231 cells through regulation of uPA and PAI-1.

Phyto-polyphenols as potential inhibitors of breast cancer metastasis

Breast cancer is the most common cancer among women as metastasis is currently the main cause of mortality. Breast cancer cells undergoing metastasis acquire resistance to death signals and increase of cellular motility and invasiveness.Plants are rich in polyphenolic compounds, many of them with known medicinal effects. Various phyto-polyphenols have also been demonstrated to suppress cancer growth. Their mechanism of action is usually pleiotropic as they target multiple signaling pathways regulating key cellular processes such as proliferation, apoptosis and differentiation. Importantly, some phyto- polyphenols show low level of toxicity to untransformed cells, but selective suppressing effects on cancer cells proliferation and differentiation.In this review, we summarize the current information about the mechanism of action of some phyto-polyphenols that have demonstrated anti-carcinogenic activities in vitro and in vivo. Gained knowledge of how these natural polyphenolic compounds work can give us a clue for the development of novel anti-metastatic agents.

In vitro Biological Effects of Sulforaphane (SFN), Epigallocatechin-3-gallate (EGCG), and Curcumin on Breast Cancer Cells: A Systematic Review of the Literature

Much of the recent research in neoplasia has been focusing on the epigenetics of cancer cells, particularly as regards the search for potential molecular biomarkers that could be used for early diagnosis, effective treatment, and prognosis of several types of cancer. Carcinogenesis often starts with mutations in oncogenes and tumor suppressor genes, and it leads to anomalies in cellular processes as vital as cell cycle regulation and apoptosis. Because malignant changes arise as a result of genetic as well as epigenetic mechanisms, one possible means of intervention involves reprogramming gene expression, so as to-at least in part-revert the molecular alterations. DNA methylation and demethylation, acetylation and deacetylation of histones, and microRNAs are a few examples of the epigenetic mechanisms responsible for tumor development and progression. Many biologically active compounds present in food-including sulforaphane, curcumin, and epigallocatechin-have been found to modulate those processes. We here systematically review information on the effects of such bioactive dietary compounds on human breast cancer cell lines, and explore the mechanisms underlying those effects with a view to their potential therapeutic application.

Absorption, metabolism, anti-cancer effect and molecular targets of epigallocatechin gallate (EGCG): An updated review

Green tea is one of the most popular beverages in the world, especially in Asian countries. Consumption of green tea has been demonstrated to possess many health benefits, which mainly attributed to the main bioactive compound epigallocatechin gallate (EGCG), a flavone-3-ol polyphenol, in green tea. EGCG is mainly absorbed in the intestine, and gut microbiota play a critical role in its metabolism prior to absorption. EGCG exhibits versatile bioactivities, with its anti-cancer effect most attracting due to the cancer preventive effect of green tea consumption, and a great number of studies intensively investigated its anti-cancer effect. In this review, we therefore, first stated the absorption and metabolism process of EGCG, and then summarized its anti-cancer effect in vitro and in vivo, including its manifold anti-cancer actions and mechanisms, especially its anti-cancer stem cell effect, and next highlighted its various molecular targets involved in cancer inhibition. Finally, the anti-cancer effect of EGCG analogs and nanoparticles, as well as the potential cancer promoting effect of EGCG were also discussed. Understanding of the absorption, metabolism, anti-cancer effect and molecular targets of EGCG can be of importance to better utilize it as a chemopreventive and chemotherapeutic agent.

Involvement of FAK-ERK2 signaling pathway in CKAP2-induced proliferation and motility in cervical carcinoma cell lines

Cervical carcinoma is the fourth most common cause of death in woman, caused by human papillomavirus (HPV) infections and arising from the cervix. Cytoskeleton-associated protein 2 (CKAP2), also known as tumor-associated microtubule-associated protein, has been linked to tumorigenic effects. In the present study, we screened CKAP2 as a new candidate gene which promotes development of cervical carcinoma, in two independent datasets (TCGA and GSE27678). Results showed that CKAP2 expression was significantly up-regulated in cervical cancerous tissues compared with normal counterparts. Gene set enrichment analysis (GSEA) showed that metastasis, cell cycle and FAK pathways were related with elevated CKAP2 expression. Knockdown of CKAP2 expression significantly inhibited cell proliferation, migration and invasion both in HeLa and C-33A cells. And depletion of CKAP2 down-regulated the expression of metastasis and cell cycle related proteins as well as the phosphorylation of ERK2 (p-ERK2), except E-cadherin. In vivo experiment revealed that knockdown of CKAP2 inhibited C-33A cells proliferation. However, FAK inhibitor PF-562271 and ERK2 inhibitor VX-11e treatment significantly inhibited CKAP2 overexpression-induced cell proliferation, migration and invasion in SiHa cells. In conclusion, our study suggests that CKAP2 acts as a functional oncogene in cervical carcinoma development and may exert its function by targeting FAK-ERK2 signaling pathway.

Recent Advances in Anticancer Activities and Drug Delivery Systems of Tannins

Tannins, polyphenols in medicinal plants, have been divided into two groups of hydrolysable and condensed tannins, including gallotannins, ellagitannins, and (-)-epigallocatechin-3-gallate (EGCG). Potent anticancer activities have been observed in tannins (especially EGCG) with multiple mechanisms, such as apoptosis, cell cycle arrest, and inhibition of invasion and metastases. Furthermore, the combinational effects of tannins and anticancer drugs have been demonstrated in this review, including chemoprotective, chemosensitive, and antagonizing effects accompanying with anticancer effect. However, the applications of tannins have been hindered due to their poor liposolubility, low bioavailability, off-taste, and shorter half-life time in human body, such as EGCG, gallic acid, and ellagic acid. To tackle these obstacles, novel drug delivery systems have been employed to deliver tannins with the aim of improving their applications, such as gelatin nanoparticles, micelles, nanogold, liposomes, and so on. In this review, the chemical characteristics, anticancer properties, and drug delivery systems of tannins were discussed with an attempt to provide a systemic reference to promote the development of tannins as anticancer agents.

Celastrol inhibits IL-1β-induced inflammation in orbital fibroblasts through the suppression of NF-κB activity

Graves' disease is an autoimmune disease of the thyroid gland, which is characterized by hyperthyroidism, diffuse goiter and Graves' ophthalmopathy (GO). Although several therapeutic strategies for the treatment of GO have been developed, the effectiveness and the safety profile of these therapies remain to be fully elucidated. Therefore, examination of novel GO therapies remains an urgent requirement. Celastrol, a triterpenoid isolated from traditional Chinese medicine, is a promising drug for the treatment of various inflammatory and autoimmune diseases. CCK‑8 and apoptosis assays were performed to investigate cytotoxicity of celastrol and effect on apoptosis on orbital fibroblasts. Reverse transcription‑polymerase chain reaction, western blotting and ELISAs were performed to examine the effect of celastrol on interleukin (IL)‑1β‑induced inflammation in orbital fibroblasts from patients with GO. The results demonstrated that celastrol significantly attenuated the expression of IL‑6, IL‑8, cyclooxygenase (COX)‑2 and intercellular adhesion molecule‑1 (ICAM‑1), and inhibited IL‑1β‑induced increases in the expression of IL‑6, IL‑8, ICAM‑1 and COX‑2. The levels of prostaglandin E2 in orbital fibroblasts induced by IL‑1β were also suppressed by celastrol. Further investigation revealed that celastrol suppressed the IL‑1β‑induced inflammatory responses in orbital fibroblasts through inhibiting the activation of nuclear factor (NF)‑κB. Taken together, these results suggested that celastrol attenuated the IL‑1β‑induced pro‑inflammatory pathway in orbital fibroblasts from patients with GO, which was associated with the suppression of NF-κB activation.

Epigallocatechin-3-gallate inhibits migration and invasion of human renal carcinoma cells by downregulating matrix metalloproteinase-2 and matrix metalloproteinase-9

The anticancer properties of epigallocatechin-3-gallate (EGCG) are documented in the treatment of several types of cancer; however, there is no relevant evidence for its efficacy in the treatment of renal cell carcinoma (RCC). In the present study, the therapeutic effects of EGCG in vitro were investigated, with particular attention to the metastatic behavior of human RCC cells. MTT assays and flow cytometry were performed to detect the effects of EGCG on the proliferation and apoptosis of RCC cells. The migration and invasion abilities of RCC cells following treatment with EGCG were assessed by wound-healing and Transwell assays, respectively. Gelatin zymography and western blot analysis were performed to analyze the effect of EGCG on matrix metalloproteinase-2 (MMP-2) and MMP-9 expression levels. The results suggested that EGCG was able to inhibit the proliferation of RCC cells, induce apoptosis and effectively suppressed the migration and invasion of RCC cells. In addition, EGCG treatment resulted in the downregulation of MMP-2 and MMP-9 in RCC cells. We hypothesize that the anticancer effect associated with EGCG may involve the downregulation of MMP-2 and MMP-9. The present results suggest the potential of EGCG as a novel therapeutic agent against RCC.

Mechanism of action of (-)-epigallocatechin-3-gallate: auto-oxidation-dependent activation of extracellular signal-regulated kinase 1/2 in Jurkat cells

AIM

(-)-Epigallocatechin-3-gallate (EGCG), a major compound of tea polyphenols, exhibited antitumor activity in previous studies. In these studies, EGCG usually inhibits EGFR, and impairs the ERK1/2 phosphorylation in tumor cells. The aim was to clarify the mechanism of ERK1/2 activation induced by EGCG.

METHOD

Jurkat and 293T cells were treated with EGCG in different culture conditions. Western Blotting (WB) was employed to analyze ERK1/2 and MEK phosphorylation. Cetuximab and FR180204 were used to inhibit cell signaling. The stability of EGCG was assessed by HPLC. The concentration of hydrogen peroxide generated by the auto-oxidation of EGCG was determined by photocolorimetric analysis.

RESULTS

Activation of ERK1/2 was observed to be both time-and dose-dependent. Stimulation of cell signaling was dependent on MEK activity, but independent of EGFR activity. Unexpectedly, EGCG was depleted within one hour of incubation under traditional culture conditions. Auto-oxidation of EGCG generated a high level of hydrogen peroxide in the medium. Addition of catalase and SOD to the acidic medium inhibited the oxidation of EGCG. However, this particular condition also prevented the phosphorylation of ERK1/2. The generation of ROS by hydrogen peroxide may also induce ERK1/2 activation in Jurkat cells.

CONCLUSION

ERK1/2 phosphorylation was caused by auto-oxidation of EGCG. Traditional culture conditions were determined to be inappropriate for EGCG research.

Epithelial-to-mesenchymal transition induced by TGF-β1 is mediated by AP1-dependent EpCAM expression in MCF-7 cells

The epithelial-to-mesenchymal transition (EMT), a process involving the breakdown of cell-cell junctions and loss of epithelial polarity, is closely related to cancer metastasis and invasion. The epithelial cell adhesion molecule (EpCAM) is a type I transmembrane protein expressed in the majority of normal epithelial tissues and overexpressed in the majority of human epithelial cancers including breast cancer. EpCAM plays an important role in cancer progression. We showed that EpCAM participated in TGF-β1-induced EMT. TGF-β1 treatment of MCF-7 breast cancer cells was shown to induce EpCAM expression, which promoted the EMT and cell migration. EpCAM overexpression further enhanced TGF-β1-induced EMT and EpCAM knockdown inhibited TGF-β1-induced EMT. We further demonstrated that TGF-β1 treatment induced the phosphorylation of JNK that was in turn responsible for the increased expression of Jun and Fos. This result suggests an important role of the JNK to AP-1 signaling to EpCAM downstream of TGF-β1 for the induction of EMT in the breast cancer cells. Collectively, our study highlights a novel function for EpCAM in TGF-β1-induced EMT process and suggests that targeting of EpCAM may be an attractive strategy to treat breast cancer. This study implicates the potential value of EpCAM as a molecular marker for breast cancer.

Benzidine induces epithelial-mesenchymal transition in human uroepithelial cells through ERK1/2 pathway

Prolonged benzidine exposure is a known cause of urothelial carcinoma (UC). Benzidine-induced epithelial-to-mesenchymal transition (EMT) is critically involved in cell malignant transformation. The role of ERK1/2 in regulating benzidine-triggered EMT has not been investigated. This study was to investigate the regulatory role of ERK1/2 in benzidine-induced EMT. By using wound healing and transwell chamber migration assays, we found that benzidine could increase SV-HUC-1 cells invasion activity, western blotting and Immunofluorescence showed that the expression levels of Snail, β-catenin, Vimentin, and MMP-2 were significantly increased, while, the expression levels of E-cadherin, ZO-1 were decreased. To further demonstrate the mechanism in this process, we found that the phosphorylation of ERK1/2, p38, JNK and AP-1 proteins were significantly enhanced compared to the control group (*P < 0.05). Afterward, treated with MAPK pathways inhibitors, only ERK inhibitor（U0126）could reduce the expression of EMT markers in SV-HUC-1 cells, but not p38 and JNK inhibitor（SB203580, SP600125）, which indicated that benzidine induces the epithelial-mesenchymal transition in human uroepithelial cells through ERK1/2 pathway. Taken together, findings from this study could provide into the molecular mechanisms by which benzidine exerts its bladder-cancer-promoting effect as well as its target intervention.