Berberine inhibits metastasis of nasopharyngeal carcinoma 5-8F cells by targeting Rho kinase-mediated Ezrin phosphorylation at threonine 567

HTINet2: herb-target prediction via knowledge graph embedding and residual-like graph neural network

Target identification is one of the crucial tasks in drug research and development, as it aids in uncovering the action mechanism of herbs/drugs and discovering new therapeutic targets. Although multiple algorithms of herb target prediction have been proposed, due to the incompleteness of clinical knowledge and the limitation of unsupervised models, accurate identification for herb targets still faces huge challenges of data and models. To address this, we proposed a deep learning-based target prediction framework termed HTINet2, which designed three key modules, namely, traditional Chinese medicine (TCM) and clinical knowledge graph embedding, residual graph representation learning, and supervised target prediction. In the first module, we constructed a large-scale knowledge graph that covers the TCM properties and clinical treatment knowledge of herbs, and designed a component of deep knowledge embedding to learn the deep knowledge embedding of herbs and targets. In the remaining two modules, we designed a residual-like graph convolution network to capture the deep interactions among herbs and targets, and a Bayesian personalized ranking loss to conduct supervised training and target prediction. Finally, we designed comprehensive experiments, of which comparison with baselines indicated the excellent performance of HTINet2 (HR@10 increased by 122.7% and NDCG@10 by 35.7%), ablation experiments illustrated the positive effect of our designed modules of HTINet2, and case study demonstrated the reliability of the predicted targets of Artemisia annua and Coptis chinensis based on the knowledge base, literature, and molecular docking.

Berberine-mediated Ferroptosis through System Xc-/GSH/GPX4 Axis Inhibits Metastasis of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor that is highly prevalent in Southeast China, and its metastasis remains an unresolved clinical problem. Ferroptosis, a type of nonapoptotic cell death, is a critical pathway in tumor metastasis. Berberine (BBR), a plant alkaloid, has been explored as a potential anti-NPC metastatic agent; however, the underlying mechanisms are unknown. Here, we showed that BBR exerted its anti-metastasis role by inhibiting system Xc-/GSH/GPX4 axis-driven ferroptosis. The present study demonstrated for the first time that BBR induced ferroptosis in NPC cells by increasing reactive oxygen species, lipid peroxidation and cellular Fe2+ and that the ferroptosis inhibitors Ferrostatin-1 and Deferoxamine mesylate rescued BBR-induced NPC cell death. Moreover, the ferroptotic characteristics of BBR-treated NPC cells were observed using transmission electron microscopy. Mechanistically, system Xc- (SLC7A11 and SLC3A2) and GSH levels were found to be suppressed after treatment with BBR. We demonstrated that the system Xc-/GSH/GPX4 axis was a critical mediator of BBR-induced ferroptosis. Furthermore, GPX4, a key inhibitor of lipid peroxidation, was greatly suppressed by BBR at both protein and mRNA levels. Molecular docking results showed a strong interaction between GPX4 and BBR. Notably, GPX4 overexpression reversed the effect of BBR-induced ferroptosis in NPC cells. Finally, BBR-mediated inhibition of NPC metastasis was validated in vivo using a mouse model. Taken together, our data suggest that BBR induced ferroptosis of NPC cells via suppressing the system Xc-/GSH/GPX4 axis, provides new insights into the mechanism of BBR anti-NPC metastasis.

Anticancer mechanisms of Berberine: a good choice for glioblastoma multiforme therapy

The most typical malignant brain tumor, glioblastoma multiforme (GBM), seems to have a grim outcome, despite the intensive multi-modality interventions. Literature suggests that biologically active phytomolecules may exert anticancer properties by regulating several signaling pathways. Berberine, an isoquinoline alkaloid, has various pharmacological applications to combat severe diseases like cancer. Mechanistically, Berberine inhibits cell proliferation and invasion, suppresses tumor angiogenesis, and induces cell apoptosis. The effect of the antitumoral effect of Berberine in GBM is increasingly recognized. This review sheds new light on the regulatory signaling mechanisms of Berberine in various cancer, proposing its potential role as a therapeutic agent for GBM. ‎.

Anticancer activity of Nigerian medicinal plants: a review

Background

Cancer is currently the leading cause of death globally and the number of deaths from cancer is on the rise daily. Medicinal plants have been in continuous use over the years for the management of cancer, particularly, in most developing countries of the world including Nigeria. The use of synthetic drugs for the treatment of cancer is often accompanied by toxic side effects. Thus, the alternative use of readily available and inexpensive medicinal plants is the panacea to the toxic side effects associated with synthetic drugs.

Main body

The present review summarized the anticancer activity of 51 medicinal plants that are widespread in all regions of Nigeria. Furthermore, the proposed anticancer pharmacological actions as well as the anticancer bioactive compounds, the type of cancer cell inhibited, the plant parts responsible for the anticancer activity, and the nature of the extracts used for the studies were discussed in this review. The 51 Nigerian medicinal plants were reported to exhibit anticancer activities of the prostate, cervices, lung, skin, colon, esophagus, blood, ovary, central nervous system/brain, breast, stomach, pancreas, larynx, and kidney. The major classes of bioactive compounds indicated to be responsible for the anticancer activity include the polyphenols, flavonoids, alkaloids, saponins, triterpenes, tannins, and quinones. The major anticancer pharmacological actions of these bioactive compounds were antiproliferative, cytotoxic, cytostatic, antimetastatic, apoptotic, and antioxidative as well as provoked cell cycle arrest, inhibition of angiogenesis and reduction of cancer cell viability.

Conclusion

The Nigerian medicinal plants can be harnessed to provide for readily available and inexpensive anticancer drugs in the future because the plants reported in this review showed promising anticancer activity.

Berberine inhibits proliferation and migration of colorectal cancer cells by downregulation of GRP78

Human colorectal cancer (CRC), a highly malignant and metastatic carcinoma, is resistant to many present anticancer therapies. The inhibition of tumor survival and growth through receptor suppression is a promising way to treat CRC. The study aimed to investigate the effect of a natural plant triterpenoid, berberine (BBR), on SW480 cells and whether its role is mediated by Glucose-regulated protein 78 (GRP78). MTT assay, wound healing assay, and Annexin V-FITC assay were used to measure the effect of BBR on the proliferation, migration, and apoptosis of SW480 cells, respectively. Immunofluorescence and western blotting were used to evaluate both the downregulation of BBR on GRP78 and the role of GRP78 in the effect of BBR on SW480 cells. Our results revealed that BBR inhibited the proliferation and migration, as well as induced the apoptosis of SW480 cells, in a dose-dependent manner. BBR induced the dose-dependent inhibition of cell proliferation in HT-29 cells. BBR inhibited the expression of GRP78 and its localization on the cell surface. Moreover, BBR inhibited the expression of Bax, Bcl-2, c-Myc, and Vimentin and up-regulated the cytokeratin expression in SW480 cells. In addition, we found that the effects of BBR on cell proliferation, migration, and apoptosis in SW480 cells were reversed by the overexpression of GRP78. Our findings demonstrated that BBR inhibited the proliferation and migration and induced the apoptosis of SW480 cells by downregulating the expression of GRP78, and targeting GRP78 might be a potential way to develop the effective anticancer therapy.

Health-promoting role of dietary bioactive compounds through epigenetic modulations: a novel prophylactic and therapeutic approach

The epigenome is an overall epigenetic state of an organism, which is as important as that of the genome for normal development and functioning of an individual. Epigenetics involves heritable but reversible changes in gene expression through alterations in DNA methylation, histone modifications and regulation of non-coding RNAs in cells, without any change in the DNA sequence. Epigenetic changes are owned by various environmental factors including pollution, microbiota and diet, which have profound effects on epigenetic modifiers. The bioactive compounds present in the diet mainly include curcumin, resveratrol, catechins, quercetin, genistein, sulforaphane, epigallocatechin-3-gallate, alkaloids, vitamins, and peptides. Bioactive compounds released during fermentation by the action of microbes also have a significant effect on the host epigenome. Besides, recent studies have explored the new insights in vitamin's functions through epigenetic regulation. These bioactive compounds exert synergistic, preventive and therapeutic effects when combined as well as when used with chemotherapeutic agents. Therefore, these compounds have potential of therapeutic agents that could be used as "Epidrug" to treat many inflammatory diseases and various cancers where chemotherapy results have many side effects. In this review, the effect of diet derived bioactive compounds through epigenetic modulations on in vitro and in vivo models is discussed.

Repurposing of plant alkaloids for cancer therapy: Pharmacology and toxicology

Drug repurposing (or repositioning) is an emerging concept to use old drugs for new treatment indications. Phytochemicals isolated from medicinal plants have been largely neglected in this context, although their pharmacological activities have been well investigated in the past, and they may have considerable potentials for repositioning. A grand number of plant alkaloids inhibit syngeneic or xenograft tumor growth in vivo. Molecular modes of action in cancer cells include induction of cell cycle arrest, intrinsic and extrinsic apoptosis, autophagy, inhibition of angiogenesis and glycolysis, stress and anti-inflammatory responses, regulation of immune functions, cellular differentiation, and inhibition of invasion and metastasis. Numerous underlying signaling processes are affected by plant alkaloids. Furthermore, plant alkaloids suppress carcinogenesis, indicating chemopreventive properties. Some plant alkaloids reveal toxicities such as hepato-, nephro- or genotoxicity, which disqualifies them for repositioning purposes. Others even protect from hepatotoxicity or cardiotoxicity of xenobiotics and established anticancer drugs. The present survey of the published literature clearly demonstrates that plant alkaloids have the potential for repositioning in cancer therapy. Exploitation of the chemical diversity of natural alkaloids may enrich the candidate pool of compounds for cancer chemotherapy and -prevention. Their further preclinical and clinical development should follow the same stringent rules as for any other synthetic drug as well. Prospective randomized, placebo-controlled clinical phase I and II trials should be initiated to unravel the full potential of plant alkaloids for drug repositioning.

Coptidis Rhizoma: a comprehensive review of its traditional uses, botany, phytochemistry, pharmacology and toxicology

CONTEXT

Coptidis rhizome (CR), also known as Huanglian in Chinese, is the rhizome of Coptis chinensis Franch., C. deltoidea C.Y. Cheng et Hsiao, or C. teeta Wall (Ranunculaceae). It has been widely used to treat bacillary dysentery, diabetes, pertussis, sore throat, aphtha, and eczema in China.

OBJECTIVES

The present paper reviews the latest advances of CR, focusing on the botany, phytochemistry, traditional usages, pharmacokinetics, pharmacology and toxicology of CR and its future perspectives.

METHODS

Studies from 1985 to 2018 were reviewed from books; PhD. and MSc. dissertations; the state and local drug standards; PubMed; CNKI; Scopus; the Web of Science; and Google Scholar using the keywords Coptis, Coptidis Rhizoma, Huanglian, and goldthread.

RESULTS

Currently, 128 chemical constituents have been isolated and identified from CR. Alkaloids are the characteristic components, together with organic acids, coumarins, phenylpropanoids and quinones. The extracts/compounds isolated from CR cover a wide pharmacological spectrum, including antibacterial, antivirus, antifungal, antidiabetic, anticancer and cardioprotective effects. Berberine is the most important active constituent and the primary toxic component of CR.

CONCLUSIONS

As an important herbal medicine in Chinese medicine, CR has the potential to treat various diseases. However, further research should be undertaken to investigate the clinical effects, toxic constituents, target organs and pharmacokinetics, and to establish criteria for quality control, for CR and its related medications. In addition, the active constituents, other than alkaloids, in both raw and processed products of CR should be investigated.

Modulation of Multiple Signaling Pathways of the Plant-Derived Natural Products in Cancer

Natural compounds are highly effective anticancer chemotherapeutic agents, and the targets of plant-derived anticancer agents have been widely reported. In this review, we focus on the main signaling pathways of apoptosis, proliferation, invasion, and metastasis that are regulated by polyphenols, alkaloids, saponins, and polysaccharides. Alkaloids primarily affect apoptosis-related pathways, while polysaccharides primarily target pathways related to proliferation, invasion, and metastasis. Other compounds, such as flavonoids and saponins, affect all of these aspects. The association between compound structures and signaling pathways may play a critical role in drug discovery.

An Insight Into the Molecular Mechanism of Berberine Towards Multiple Cancer Types Through Systems Pharmacology

Over the past several decades, natural products with poly-pharmacological profiles have demonstrated promise as novel therapeutics for various complex diseases, including cancer. Berberine (PubChem CID: 2353), a soliloquies quaternary alkaloid, has been validated to exert powerful effects in many cancers. However, the underlying molecular mechanism is not yet fully elucidated. In this study, we summarized the molecular effects of berberine against multiple cancers based on current available literatures. Furthermore, a systems pharmacology infrastructure was developed to discover new cancer indications of berberine and explore their molecular mechanisms. Specifically, we incorporated 289 high-quality protein targets of berberine by integrating experimental drug-target interactions (DTIs) extracted from literatures and computationally predicted DTIs inferred by network-based inference approach. Statistical network models were developed for identification of new cancer indications of berberine through integration of DTIs and curated cancer significantly mutated genes (SMGs). High accuracy was yielded for our statistical models. We further discussed three typical cancer indications (hepatocarcinoma, lung adenocarcinoma, and bladder carcinoma) of berberine with new mechanisms of actions (MOAs) based on our systems pharmacology framework. In summary, this study systematically provides a powerful strategy to identify potential anti-cancer effects of berberine with novel mechanisms from a systems pharmacology perspective.

MICAL2 Mediates p53 Ubiquitin Degradation through Oxidating p53 Methionine 40 and 160 and Promotes Colorectal Cancer Malignance

Molecule interacting with CasL2 (MICAL2), a microtubule-associated monooxygenase, is highly expressed in various cancers and is involved in cancer pathogenesis, but the mechanisms underlying its regulation in carcinogenesis are unclear. In this study, we aim to clarify the mechanism by which MICAL2 participates in colorectal cancer (CRC) and identify novel markers for predicting prognosis of CRC patients. Methods: The value of MICAL2 in CRC prognosis was determined by immunohistochemical analysis of a CRC biopsy array. A short hairpin RNA target MICAL2 (shMICAL2) was designed to knock down MICAL2 expression and observe MICAL2's function on CRC cell growth. mRNA expression array was used to screen target molecules of MICAL2. HCT116 p53+/+ and HCT116 p53-/- cells were used to confirm whether MICAL2 exerts its oncogenic effect through p53. The in vivo effect of MICAL2 on CRC growth was assessed by subcutaneously injecting MICAL2-knockout CRC cells into the dorsal flank of each mouse. Immunofluorescence was used to observe the effect of MICAL2 on p53 cellular location. Reverse-phase nano ESI-LCMS analysis was used to investigate if MICAL2 mediates p53 oxidation. Results: MICAL2 was found to be highly expressed in CRC tissues, and its expression was associated with CRC carcinogenesis and poor patient outcome. MICAL2-knockdown decreased growth and colony formation of CRC cells, which was linked with cell cycle arrest and apoptosis. MICAL2 physically interacted with p53 and retained p53 in the cytoplasm. MICAL2 shortened the half-life of p53, and ectopic MICAL2 expression decreased p53 protein stability through ubiquitin degradation. MICAL2 was also found to oxidize p53 at methionine 40 and 160, which mediated p53 ubiquitin degradation. MICAL2-promoted CRC growth in vivo was confirmed in nude mice. Conclusion: MICAL2 binds to p53, retains p53 in the cytoplasm and oxidizes it at Met 40 and 160, promotes p53 ubiquitination, and decreases p53 function. MICAL2-reduced p53 promotes CRC development.

Effects of berberine on tumor growth and intestinal permeability in HCT116 tumor-bearing mice using polyamines as targets

The prognosis of colorectal cancer (CRC) is seriously affected by high intestinal mucosal permeability accompanied by increasing tumor load. Berberine, a natural plant-derived product, can protect the intestinal mucosal barrier and suppress tumor growth, but its effects on the intestinal mucosal barrier dysfunction of CRC have not yet been evaluated. Herein, we assessed the effects of berberine on the intestinal mucosal permeability of HCT116 tumor-bearing mice and the underlying mechanism. Berberine (6.25, 12.5, 25 mg/kg) was administered to tumor-bearing mice for 3 weeks by intraperitoneal injection, and saline was given to controls and models. Compared with the control group, tumor-bearing mice had increased intestinal mucosal permeability in the third week. Meanwhile, the body weight decreased by 4%-7%, the concentration of D-lactic acid in plasma increased, and the expressions of ZO1 and Occludin were down-regulated. The intestinal mucosa was impaired. Compared with the model group, berberine inhibited tumor growth in a dose-dependent manner (6.25, 12.5, 25 mg/kg), reduced the permeability of intestinal mucosa, and alleviated intestinal mucosal damage. HPLC showed that berberine decreased the content of polyamines in tumor tissue, whereas increased that in intestinal mucosa tissue. Western blot showed that berberine inhibited the expressions of ODC, C-MYC and HIF-1α, but up-regulated those of OAZ1 and SSAT. In short, berberine may exert antitumor effects by suppressing tumor growth and elevating the intestinal mucosal permeability.

Studies on the Dual Cytotoxicity and Antioxidant Properties of Berberis vulgaris Extracts and Its Main Constituent Berberine

The present study attempts to investigate the cytotoxic activity of ethanol and ethyl acetate extracts of the Moroccan Berberis vulgaris and its major component berberine, together with exploring their antioxidant properties. It also consists of studying the combination effect of berberine and S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO) donor, against the human breast adenocarcinoma cell line (MCF-7). Using the MTT assay, we report a differential cytotoxic effect of ethanol and ethyl acetate extracts since the ethanol extract is more cytotoxic than the ethyl acetate one, with IC₅₀ = 3.54 μg/mL and 596.71 μg/mL, respectively. Interestingly, no cytotoxic effect was observed against normal cells. Furthermore, these extracts showed a remarkable antioxidant activity as measured by the DPPH free radicals scavenging assay. In fact, the IC₅₀ values are 69.65 μg/mL and 77.75 μg/mL for the ethanol and ethyl acetate extracts, respectively. In addition, several concentrations of berberine, when combined with the NO donor used at IC₃₀, induced a synergistic cytotoxic activity at concentrations ranging from 8.40 μM to 33.60 μM, as revealed by the combination index values, using the Chou–Talalay method. However, at the other concentrations tested, an antagonistic effect was observed. The observed cytotoxicity was related to apoptosis induction as demonstrated by the annexin-V-streptavidin FITC-staining analysis.

Berberine-induced autophagic cell death by elevating GRP78 levels in cancer cells

Berberine, an isoquinoline alkaloid extracted from Coptidis Rhizoma, has been shown to induce cancer cell autophagic death. Glucose regulated protein 78 (GRP78) is associated with stress-induced autophagy. However, the related mechanisms between berberine-induced cancer cell autophagy and GRP78 remain to be elucidated. Here, we report that berberine can induce autophagic cancer cell death by elevating levels of GRP78. These results further demonstrated that berberine enhanced GRP78 by suppression of ubiquitination / proteasomal degradation of GRP78 and activation of ATF6. Moreover, fluorescence spectrum assay revealed that berberine could bind to GRP78 and form complexes. Finally, co-IP analysis showed that the ability of GRP78 to bind to VPS34 was increased with berberine treatment. Taken together, our results suggest that berberine induces autophagic cancer cell death via enhancing GRP78 levels and the ability of GRP78 to bind to VPS34.

IGF-I regulates HT1080 fibrosarcoma cell migration through a syndecan-2/Erk/ezrin signaling axis

Fibrosarcoma is a tumor of mesenchymal origin, originating from fibroblasts. IGF-I is an anabolic growth factor which exhibits significant involvement in cancer progression. In this study, we investigated the possible participation of syndecan-2 (SDC-2), a cell membrane heparan sulfate (HS) proteoglycan on IGF-I dependent fibrosarcoma cell motility. Our results demonstrate that SDC-2-deficient HT1080 cells exhibit attenuated IGF-I-dependent chemotactic migration (p < 0.001). SDC-2 was found to co-localize to IGF-I receptor (IGF-IR) in a manner dependent on IGF-I activity (P ≤ 0.01). In parallel, the downregulation of SDC-2 significantly inhibited both basal and due to IGF-I action ERK1/2 activation, (p < 0.001). The phosphorylation levels of ezrin (Thr567), which is suggested to act as a signaling bridge between the cellular membrane receptors and actin cytoskeleton, were strongly enhanced by IGF-I at both 1h and 24h (p < 0.05; p < 0.01). The formation of an immunoprecipitative complex revealed an association between SDC2 and ezrin which was enhanced through IGF-I action (p < 0.05). Immunoflourescence demonstrated a co-localization of IGF-IR, SDC2 and ezrin upregulated by IGF-I action. IGF-I enhanced actin polymerization and ezrin/actin specific localization to cell membranes. Finally, treatment with IGF-I strongly increased SDC2 expression at both the mRNA and protein level (p < 0.001). Therefore, we propose a novel SDC2-dependent mechanism, where SDC2 is co-localized with IGF-IR and enhances its' IGFI-dependent downstream signaling. SDC2 mediates directly IGFI-induced ERK1/2 activation, it recruits ezrin, contributes to actin polymerization and ezrin/actin specific localization to cell membranes, ultimately facilitating the progression of IGFI-dependent fibrosarcoma cell migration.

Berberine Inhibited the Proliferation of Cancer Cells by Suppressing the Activity of Tumor Pyruvate Kinase M2

Berberine, an isoquinoline alkaloid extracted from coptis, exerts anti-proliferation and anticancer properties. Pyruvate kinase M2 (PKM2) is a key enzyme of aerobic glycolysis and considered as the potential anticancer target. However, the inhibition effects and interaction action between Berberine and PKM2 is not well known. In this study, berberine showed antitumor activity of HCT-116 and HeLa cells with the suppression of cell proliferation. Moreover, berberine inhibited the enzyme activity of PKM2 in cancer cells, but had no impact on PKM2 expression. Further research showed that the interaction between berberine and PKM2 was dynamic fluorescence quenching and the main intermolecular force was hydrogen bonding. These findings revealed that berberine may serve as a therapeutic drug for cancer chemotherapy.

Berberine sensitizes nasopharyngeal carcinoma cells to radiation through inhibition of Sp1 and EMT

Nasopharyngeal carcinoma (NPC) is a tumor of epithelial origin with radiotherapy as its standard treatment. However, radioresistance remains a critical issue in the treatment of NPC. This study aimed to investigate the effect of berberine on the proliferation, cell cycle regulation, apoptosis, radioresistance of NPC cells and whether specificity protein 1 (Sp1) is a functional target of berberine. Our results showed that treatment with berberine reduced the proliferation and viability of CNE-2 cells in a dose- and time‑dependent manner. Berberine induced cell cycle arrest in the G0/G1 phase and apoptosis. In CNE-2 cells exposed to gamma‑ray irradiation, berberine reduced cell viability at various concentrations (25, 50, 75 and 100 µmol/l). Berberine significantly decreased mRNA and protein expression of Sp1 in the CNE-2 cells. Mithramycin A, a selective Sp1 inhibitor, enhanced the radiosensitivity and the rate of apoptosis in the CNE-2 cells. Berberine inhibited transforming growth factor-β (TGF-β)-induced tumor invasion and suppressed epithelial-to-mesenchymal transition (EMT) process, as evidenced by increased E-cadherin and decreased vimentin proteins. Sp1 may be required for the TGF-β1-induced invasion and EMT by berberine. In conclusion, berberine demonstrated the ability to suppress proliferation, induce cell cycle arrest and apoptosis, and enhance radiosensitivity of the CNE-2 NPC cells. Sp1 may be a target of berberine which is decreased during the radiosensitization of berberine.

Advances in the study of berberine and its derivatives: a focus on anti-inflammatory and anti-tumor effects in the digestive system

It has been widely recognized that inflammation, particularly chronic inflammation, can increase the risk of cancer and that the simultaneous treatment of inflammation and cancer may produce excellent therapeutic effects. Berberine, an alkaloid isolated from Rhizoma coptidis, has broad applications, particularly as an antibacterial agent in the clinic with a long history. Over the past decade, many reports have demonstrated that this natural product and its derivatives have high activity against both cancer and inflammation. In this review, we summarize the advances in studing berberine and its derivatives as anti-inflammatory and anti-tumor agents in the digestive system; we also discuss their structure-activity relationship. These data should be useful for the development of this natural product as novel anticancer drugs with anti-inflammation activity.

Natural Compounds as Modulators of Cell Cycle Arrest: Application for Anticancer Chemotherapies

Natural compounds from various plants, microorganisms and marine species play an important role in the discovery novel components that can be successfully used in numerous biomedical applications, including anticancer therapeutics. Since uncontrolled and rapid cell division is a hallmark of cancer, unraveling the molecular mechanisms underlying mitosis is key to understanding how various natural compounds might function as inhibitors of cell cycle progression. A number of natural compounds that inhibit the cell cycle arrest have proven effective for killing cancer cells in vitro, in vivo and in clinical settings. Significant advances that have been recently made in the understanding of molecular mechanisms underlying the cell cycle regulation using the chemotherapeutic agents is of great importance for improving the efficacy of targeted therapeutics and overcoming resistance to anticancer drugs, especially of natural origin, which inhibit the activities of cyclins and cyclin-dependent kinases, as well as other proteins and enzymes involved in proper regulation of cell cycle leading to controlled cell proliferation.

Cdk3-promoted epithelial-mesenchymal transition through activating AP-1 is involved in colorectal cancer metastasis

Cyclin dependent kinase-3 (Cdk3) is a positive regulator of the G1 mammalian cell cycle phase. Cdk3 is involved in cancer progression, but very little is known about its mechanism in cancer development and progression. Herein, we found that Cdk3 increased colorectal cancer metastasis through promoting epithelial-mesenchymal transition (EMT) shift. Cdk3 was found to highly express in metastatic cancer and induce cell motility and invasion. Cdk3 was shown to phosphorylate c-Jun at Ser 63 and Ser 73 in vitro and ex vivo. Cdk3-phosphorylated c-Jun at Ser 63 and Ser 73 resulted in an increased AP-1 activity. Ectopic expression of Cdk3 promoted colorectal cancer from epithelial to mesenchymal transition conjugating AP-1 activation, while AP-1 inhibition dramatically decreased Cdk3-increased EMT shift. These results showed that the Cdk3/c-Jun signaling axis mediating epithelial-mesenchymal transition plays an important role in colorectal cancer metastasis.

NLRP3 inflammasome as a target of berberine in experimental murine liver injury: interference with P2X7 signalling

Berberine (BRB) is commonly used in herbal medicine, but its mechanisms of action are poorly understood. In the present study, we tested BRB in steatohepatitis induced by a methionine- and choline-deficient (MCD) diet, in acute acetaminophen intoxication and in cultured murine macrophages. BRB markedly improved parameters of liver injury and necroinflammation induced by the MCD diet, although increased mortality was observed by mechanisms independent of bacterial infections or plasma levels of BRB. The MCD diet induced up-regulation of all components of the NLRP3 (NACHT, LRR and PYD domain-containing protein 3) inflammasome, and increased hepatic levels of mature IL-1β (interleukin 1β). All of these parameters were significantly reduced in mice treated with BRB. In mice administered an acetaminophen overdose, a model dependent on inflammasome activation, BRB reduced mortality and ALT (alanine aminotransferase) elevation, and limited the expression of inflammasome components. In vitro, LPS (lipopolysaccharide)-induced activation of NLRP3 inflammasome in RAW264.7 murine macrophages was markedly decreased by pre-incubation with BRB. BRB significantly limited the activation of the purinergic receptor P2X7, involved in the late phases of inflammasome activation. Upon P2X7 knockdown, the ability of BRB to block LPS-induced secretion of IL-1β was lost. These data indicate that administration of BRB ameliorates inflammation and injury in two unrelated murine models of liver damage. We demonstrate for the first time that BRB interferes with activation of the NLRP3 inflammasome pathway in vivo and in vitro, through a mechanism based on interference with activation of P2X7, a purinergic receptor involved in inflammasome activation.

Berberine and Coptidis Rhizoma as potential anticancer agents: Recent updates and future perspectives

ETHNOPHARMACOLOGICAL RELEVANCE

The antineoplastic property of Coptidis Rhizoma and berberine was correlated with its traditional use of clearing internal fire, removing damp-heat and counteracting toxic pathogens.

AIM OF THE STUDY

The anti-tumor effect of Coptidis Rhizoma and berberine was extensively studied since our last comprehensive review in 2009. This study aims to summarize the recent updates and give rise to perspectives of Coptidis Rhizoma and berberine as potential novel antineoplastic agents.

METHODS

Quality studies in recent 5 years were retrieved from PubMed, Medline and CNKI with keywords including Coptis, Coptidis Rhizoma, huanglian, berberine, tumor and cancer. Studies were focused on the pharmacological actions of Coptidis Rhizoma and berberine in cancer progression.

RESULTS

It was shown that Coptidis Rhizoma extract and berberine may repress tumor progression by regressing abnormal cell proliferation, arresting cell cycle and inducing cell death. Studies also highlighted the actions of Coptidis Rhizoma extract and berberine in inhibiting tumor cell invasion and angiogenesis, which in turn abolish cancer metastasis. Some studies have also been conducted to reveal the potential effect of Coptidis Rhizoma extract and berberine in regulating tumor stromal microenvironment, as well as in preventing carcinogenesis. Most of the results have been demonstrated with in vivo models, but results of high-quality clinical trials are not yet available. Unspecified cancer type and staging, fluctuated dose information and variants of targets across studies of berberine/ Coptidis Rhizoma impede their clinical use for cancer treatment.

CONCLUSION

Recent advances highlighted by this review may shed light on future direction of studies featuring Coptidis Rhizoma and berberine as novel antineoplastic agents, which should be repeatedly proven in future animal and clinical studies. Although more evidences on its specificity and clinical efficacy are necessary to support its clinical use, Coptidis Rhizoma and berberine are highly expected to be effective, safe and affordable treatments for cancer patients.

Berberine, a natural compound, suppresses Hedgehog signaling pathway activity and cancer growth

Background

Berberine (BBR), a natural alkaloid compound, is used as a non-prescription drug in China for treating diarrhea and gastroenteritis. Many studies have revealed that BBR possesses anticancer effect. However, the molecular mechanisms underlying its anticancer action is far from being fully elucidated. This study is aimed to determine the effect of BBR on the hedgehog (Hh) activity and the growth of cancers addiction to Hh activity.

Methods

The Hh activity was determined by dual luciferase assays and quantitative RT-PCR analyses. The growth inhibition of BBR on medulloblastoma which was obtained from ptch+/−;p53−/− mice was analyzed by 5-bromo-2-deoxyuridine (Brdu) assays and by allografting the medulloblastoma into nude mice. The data were statistically analyzed by one-way analysis of variance (ANOVA), and multiple comparison between the groups was performed using Dunnett’s method.

Results

In this study, we found that BBR significantly inhibited the Hh pathway activity. Meanwhile, we observed that BBR failed to affect the transcriptional factors activities provoked by tumor necrosis factor-α (TNF-α) and Prostaglandin E2 (PGE2), thus suggesting its unique property against Hh pathway activity. Further studies revealed that BBR inhibited the Hh pathway activity by potentially targeting the critical component Smoothened (Smo) and most likely shared the same binding site on Smo with cyclopamine, a classical Smo inhibitor. Finally, we demonstrated that BBR obviously suppressed the Hh-dependent medulloblastoma growth in vitro and in vivo.

Conclusion

Collectively, our study uncovered a novel molecular mechanism responsible for the anticancer action of BBR, thus opening the way for the usage of BBR for therapeutics of cancers addiction to aberrant Hh pathway activity.

Rho Kinase Inhibitor Fasudil Suppresses the Vasculogenic Mimicry of B16 Mouse Melanoma Cells Both In Vitro and In Vivo

The aim of this study was to investigate the biologic role of the Rho kinase inhibitor fasudil in the vasculogenic mimicry (VM) of B16 mouse melanoma cells. It was previously reported that RhoA plays a critical role in angiogenesis by coordinating endothelial cell cytoskeleton remodeling and promoting endothelial cell motility. Although RhoA has been implicated in the regulation of angiogenesis, little has been described regarding its control of these tumor cell-lined channels. In this study, we established an in vitro model of VM using 3-dimensional cell culturing of mouse B16 melanoma cells and studied VM in vivo by transplanting B16 cells into C57/BL mice. Next, we explored the effect of RhoA and Rho-associated, coiled-coil containing protein kinase (ROCK) on VM formation using the Rho kinase inhibitor fasudil. We provide direct evidence that fasudil leads to reduced vascular-like channels in Matrigel. Additional experiments suggested that fasudil prevents both initial cellular architecture changes and cell migration in vitro. Finally, we provide in-depth evidence for the underlying mechanisms of fasudil-induced VM destruction using the Rho-GTPase agonist lysophosphatidic acid. In vivo studies revealed that fasudil reduced B16 melanoma cell xenograft tumor growth without causing significant toxicity in mice. Fasudil-treated tumors also displayed fewer VM channels. These results suggest that fasudil may be an emerging therapeutic option for targeting cancer VM.

Dinitrosopiperazine-mediated phosphorylated-proteins are involved in nasopharyngeal carcinoma metastasis

N,N'-dinitrosopiperazine (DNP) with organ specificity for nasopharyngeal epithelium, is involved in nasopharyngeal carcinoma (NPC) metastasis, though its mechanism is unclear. To reveal the pathogenesis of DNP-induced metastasis, immunoprecipitation was used to identify DNP-mediated phosphoproteins. DNP-mediated NPC cell line (6-10B) motility and invasion was confirmed. Twenty-six phosphoproteins were increased at least 1.5-fold following DNP exposure. Changes in the expression levels of selected phosphoproteins were verified by Western-blotting analysis. DNP treatment altered the phosphorylation of ezrin (threonine 567), vimentin (serine 55), stathmin (serine 25) and STAT3 (serine 727). Furthermore, it was shown that DNP-dependent metastasis is mediated in part through ezrin at threonine 567, as DNP-mediated metastasis was decreased when threonine 567 of ezrin was mutated. Strikingly, NPC metastatic tumors exhibited a higher expression of phosphorylated-ezrin at threonine 567 than the primary tumors. These findings provide novel insight into DNP-induced NPC metastasis and may contribute to a better understanding of the metastatic mechanisms of NPC tumors.

Berberine alters epigenetic modifications, disrupts microtubule network, and modulates HPV-18 E6-E7 oncoproteins by targeting p53 in cervical cancer cell HeLa: a mechanistic study including molecular docking

Increased evidence of chemo-resistance, toxicity and carcinogenicity necessitates search for alternative approaches for determining next generation cancer therapeutics and targets. We therefore tested the efficacy of plant alkaloid berberine on human papilloma virus (HPV) -18 positive cervical cancer cell HeLa systematically-involving certain cellular, viral and epigenetic factors. We observed disruptions of microtubule network and changes in membrane topology due to berberine influx through confocal and atomic force microscopies (AFM). We examined nuclear uptake, internucleosomal DNA damages, mitochondrial membrane potential (MMP) alterations and cell migration assays to validate possible mode of cell death events. Analytical data on interactions of berberine with pBR322 through fourier transform infrared (FTIR) and gel migration assay strengthen berberine׳s biologically significant DNA binding abilities. We measured cellular uptake, DNA ploidy and DNA strand-breaks through fluorescence activated cell sorting (FACS). To elucidate epigenetic modifications, in support of DNA binding associated processes, if any, we conducted methylation-specific restriction enzyme (RE) assay, methylation specific-PCR (MSP) and expression studies of histone proteins. We also analyzed differential interactions and localization of cellular tumor suppressor p53 and viral oncoproteins HPV-18 E6-E7 through siRNA approach. We further made in-silico approaches to determine possible binding sites of berberine on histone proteins. Overall results indicated cellular uptake of berberine through cell membrane depolarization causing disruption of microtubule networks and its biological DNA binding abilities that probably contributed to epigenetic modifications. Results of modulation in p53 and viral oncoproteins HPV-18 E6-E7 by berberine further proved its potential as a promising chemotherapeutic agent in cervical cancer.

Sequence specific binding of beta carboline alkaloid harmalol with deoxyribonucleotides: binding heterogeneity, conformational, thermodynamic and cytotoxic aspects

BACKGROUND

Base dependent binding of the cytotoxic alkaloid harmalol to four synthetic polynucleotides, poly(dA).poly(dT), poly(dA-dT).poly(dA-dT), poly(dG).poly(dC) and poly(dG-dC).poly(dG-dC) was examined by various photophysical and calorimetric studies, and molecular docking.

METHODOLOGY/PRINCIPAL FINDINGS

Binding data obtained from absorbance according to neighbor exclusion model indicated that the binding constant decreased in the order poly(dG-dC).poly(dG-dC)>poly(dA-dT).poly(dA-dT)>poly(dA).poly(dT)>poly(dG).poly(dC). The same trend was shown by the competition dialysis, change in fluorescence steady state intensity, stabilization against thermal denaturation, increase in the specific viscosity and perturbations in circular dichroism spectra. Among the polynucleotides, poly(dA).poly(dT) and poly(dG).poly(dC) showed positive cooperativity where as poly(dG-dC).poly(dG-dC) and poly(dA-dT).poly(dA-dT) showed non cooperative binding. Isothermal calorimetric data on the other hand showed enthalpy driven exothermic binding with a hydrophobic contribution to the binding Gibbs energy with poly(dG-dC).poly(dG-dC), and poly(dA-dT).poly(dA-dT) where as harmalol with poly(dA).poly(dT) showed entropy driven endothermic binding and with poly(dG).poly(dC) it was reported to be entropy driven exothermic binding. The study also tested the in vitro chemotherapeutic potential of harmalol in HeLa, MDA-MB-231, A549, and HepG2 cell line by MTT assay.

CONCLUSIONS/SIGNIFICANCE

Studies unequivocally established that harmalol binds strongly with hetero GC polymer by mechanism of intercalation where the alkaloid resists complete overlap to the DNA base pairs inside the intercalation cavity and showed maximum cytotoxicity on HepG2 with IC50 value of 14 µM. The results contribute to the understanding of binding, specificity, energetic, cytotoxicity and docking of harmalol-DNA complexation that will guide synthetic efforts of medicinal chemists for developing better therapeutic agents.

Berberine, an epiphany against cancer

Alkaloids are used in traditional medicine for the treatment of many diseases. These compounds are synthesized in plants as secondary metabolites and have multiple effects on cellular metabolism. Among plant derivatives with biological properties, the isoquinoline quaternary alkaloid berberine possesses a broad range of therapeutic uses against several diseases. In recent years, berberine has been reported to inhibit cell proliferation and to be cytotoxic towards cancer cells. Based on this evidence, many derivatives have been synthesized to improve berberine efficiency and selectivity; the results so far obtained on human cancer cell lines support the idea that they could be promising agents for cancer treatment. The main properties of berberine and derivatives will be illustrated.

Targets and mechanisms of berberine, a natural drug with potential to treat cancer with special focus on breast cancer

Breast cancer is the most common cancer among women worldwide and novel therapeutic agents are needed to treat this disease. The plant-based alkaloid berberine has potential therapeutic applications for breast cancer, although a better understanding of the genes and cellular pathways regulated by this compound is needed to define the mechanism of its action in cancer treatment. In this review, the molecular targets of berberine in various cancers, particularly breast cancer, are discussed. Berberine was shown to be effective in inhibiting cell proliferation and promoting apoptosis in various cancerous cells. Some signaling pathways affected by berberine, including the MAP (mitogen-activated protein) kinase and Wnt/β-catenin pathways, are critical for reducing cellular migration and sensitivity to various growth factors. This review will discuss recent studies and consider the application of new prospective approaches based on microRNAs and other crucial regulators for use in future studies to define the action of berberine in cancer. The effects of berberine on cancer cell survival and proliferation are also outlined.

Identification of novel signaling components in N,N'-dinitrosopiperazine-mediated metastasis of nasopharyngeal carcinoma by quantitative phosphoproteomics

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a highly invasive and metastatic cancer. N,N'-dinitrosopiperazine (DNP), a carcinogen with specificity for nasopharyngeal epithelium, facilitates NPC metastasis. However, the underlying mechanism is not known.

METHODS

Quantitative phosphoproteomics, using stable isotope labeling of amino acids in cell cultures, was employed to identify phosphoproteins associated with NPC metastasis mediated by DNP. NPC cell line 6-10B, which is relatively less metastatic, was used to investigate DNP-mediated metastasis. Boyden chamber invasion assay was used to measure DNP-induced motility and invasion, and nude mice were used to verify DNP-mediated metastasis in vivo. Several different phosphoproteins detected by proteomics analysis were verified by immunoblotting. DNP-mediated metastasis facilitated by lysine-rich CEACAM1 co-isolated protein (LYRIC) phosphorylation at serine 568 was confirmed using mutations targeting the phosphorylation site of LYRIC. DNP-mediated metastasis through LYRIC phosphorylation was confirmed in the NPC cell line CNE1. DNP-mediated LYRIC phosphorylation at serine 568 was also verified in metastatic tumors of BABL/c nude mice.

RESULTS

Boyden chamber invasion assay indicated that DNP mediated cell motility and invasion of NPC cell 6-10B in vitro, and experiments with nude mice indicated that DNP increased 6-10B metastasis in vivo. In the phosphoproteomics analysis, we detected 216 phosphorylation sites on 130 proteins; among these, 48 phosphorylation sites on 30 unique phosphopeptides were modulated by DNP by at least 1.5-fold. DNP mediated the expression of phosphorylated GTPase, ferritin, LYRIC, and RNA polymerase, and it decreased the expression of phosphorylated torsin-1A protein 1. Furthermore, DNP induced LYRIC phosphorylation at serine 568 to facilitate cell motility and invasion, whereas DNP-mediated motility and invasion was decreased when serine 568 in LYRIC was mutated. In another NPC cell line, CNE1, DNP also mediated cell motility and invasion followed by enhanced phosphorylation of LYRIC at serine 568. Finally, phosphorylated-LYRIC expression at serine 568 was significantly increased in metastatic tumors induced by DNP.

CONCLUSION

DNP regulates multiple signaling pathways through protein phosphorylation, including the phosphorylation of LYRIC at serine 568, and mediates NPC metastasis. These findings provide insights on the complexity and dynamics of DNP-facilitated metastasis, and may help to gain a better understanding of the mechanisms by clarifying NPC-induced metastasis.

Berberine suppresses tumorigenicity and growth of nasopharyngeal carcinoma cells by inhibiting STAT3 activation induced by tumor associated fibroblasts

Background

Cortidis rhizoma (Huanglian) and its major therapeutic component, berberine, have drawn extensive attention in recent years for their anti-cancer properties. Growth inhibitory effects of berberine on multiple types of human cancer cells have been reported. Berberine inhibits invasion, induces cell cycle arrest and apoptosis in human cancer cells. The anti-inflammatory property of berberine, involving inhibition of Signal Transducer and Activator of Transcription 3 (STAT3) activation, has also been documented.

Methods

In this study, we have examined the effects of berberine on tumorigenicity and growth of nasopharyngeal carcinoma (NPC) cells and their relationship to STAT3 signaling using both in vivo and in vitro models.

Results

Berberine effectively inhibited the tumorigenicity and growth of an EBV-positive NPC cell line (C666-1) in athymic nude mice. Inhibition of tumorigenic growth of NPC cells in vivo was correlated with effective inhibition of STAT3 activation in NPC cells inside the tumor xenografts grown in nude mice. In vitro, berberine inhibited both constitutive and IL-6-induced STAT3 activation in NPC cells. Inhibition of STAT3 activation by berberine induced growth inhibition and apoptotic response in NPC cells. Tumor-associated fibroblasts were found to secret IL-6 and the conditioned medium harvested from the fibroblasts also induced STAT3 activation in NPC cells. Furthermore, STAT3 activation by conditioned medium of tumor-associated fibroblasts could be blocked by berberine or antibodies against IL-6 and IL-6R.

Conclusions

Our observation that berberine effectively inhibited activation of STAT3 induced by tumor-associated fibroblasts suggests a role of berberine in modulating the effects of tumor stroma on the growth of NPC cells. The effective inhibition of STAT3 activation in NPC cells by berberine supports its potential use in the treatment of NPC.

ß1 integrin binding phosphorylates ezrin at T567 to activate a lipid raft signalsome driving invadopodia activity and invasion

Extracellular matrix (ECM) degradation is a critical process in tumor cell invasion and requires matrix degrading protrusions called invadopodia. The Na⁺/H⁺ exchanger (NHE1) has recently been shown to be fundamental in the regulation of invadopodia actin cytoskeleton dynamics and activity. However, the structural link between the invadopodia cytoskeleton and NHE1 is still unknown. A candidate could be ezrin, a linker between the NHE1 and the actin cytoskeleton known to play a pivotal role in invasion and metastasis. However, the mechanistic basis for its role remains unknown. Here, we demonstrate that ezrin phosphorylated at T567 is highly overexpressed in the membrane of human breast tumors and positively associated with invasive growth and HER2 overexpression. Further, in the metastatic cell line, MDA-MB-231, p-ezrin was almost exclusively expressed in invadopodia lipid rafts where it co-localized in a functional complex with NHE1, EGFR, ß1-integrin and phosphorylated-NHERF1. Manipulation by mutation of ezrins T567 phosphorylation state and/or PIP2 binding capacity or of NHE1s binding to ezrin or PIP2 demonstrated that p-ezrin expression and binding to PIP2 are required for invadopodia-mediated ECM degradation and invasion and identified NHE1 as the membrane protein that p-ezrin regulates to induce invadopodia formation and activity.

Podoplanin-mediated cell adhesion through extracellular matrix in oral squamous cell carcinoma

Podoplanin (PDPN), one of the representative mucin-like type-I transmembrane glycoproteins specific to lymphatic endothelial cells, is expressed in various cancers including squamous cell carcinoma (SCC). On the basis of our previous studies, we have developed the hypothesis that PDPN functions in association with the extracellular matrix (ECM) from the cell surface side. The aim of this study was to elucidate the molecular role of PDPN in terms of cell adhesion, proliferation, and migration in oral SCC cells. Forty-four surgical specimens of oral SCC were used for immunohistochemistry for PDPN, and the expression profiles were correlated with their clinicopathological properties. Using ZK-1, a human oral SCC cell system, and five other cell systems, we examined PDPN expression levels by immunofluorescence, western blotting, and real-time PCR. The effects of transient PDPN knockdown by siRNA in ZK-1 were determined for cellular functions in terms of cell proliferation, adhesion, migration, and invasion in association with CD44 and hyaluronan. Cases without PDPN-positive cells were histopathologically classified as less-differentiated SCC, and SCC cells without PDPN more frequently invaded lymphatics. Adhesive properties of ZK-1 were significantly inhibited by siRNA, and PDPN was shown to collaborate with CD44 in cell adhesion to tether SCC cells with hyaluronan-rich ECM of the narrow intercellular space as well as with the stromal ECM. There was no siRNA effect in migration. We have demonstrated the primary function of PDPN in cell adhesion to ECM, which is to secondarily promote oral SCC cell proliferation.

Sphingolipid regulation of ezrin, radixin, and moesin proteins family: implications for cell dynamics

A key but poorly studied domain of sphingolipid functions encompasses endocytosis, exocytosis, cellular trafficking, and cell movement. Recently, the ezrin, radixin and moesin (ERM) family of proteins emerged as novel potent targets regulated by sphingolipids. ERMs are structural proteins linking the actin cytoskeleton to the plasma membrane, also forming a scaffold for signaling pathways that are used for cell proliferation, migration and invasion, and cell division. Opposing functions of the bioactive sphingolipid ceramide and sphingosine-1-phosphate (S1P), contribute to ERM regulation. S1P robustly activates whereas ceramide potently deactivates ERM via phosphorylation/dephosphorylation, respectively. This recent dimension of cytoskeletal regulation by sphingolipids opens up new avenues to target cell dynamics, and provides further understanding of some of the unexplained biological effects mediated by sphingolipids. In addition, these studies are providing novel inroads into defining basic mechanisms of regulation and action of bioactive sphingolipids. This review describes the current understanding of sphingolipid regulation of the cytoskeleton, it also describes the biologies in which ERM proteins have been involved, and finally how these two large fields have started to converge. This article is part of a Special Issue entitled New Frontiers in Sphingolipid Biology.

Berberine enhances tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in breast cancer

Berberine (BBR) has been used for the treatment of bacterial and fungal infections and also for cancer-associated symptoms such as diarrhea. Furthermore, it has been reported that BBR may have direct antitumor effects. Although evidence supports the theory that tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a promising candidate for treating cancer, its usage may be limited due to the resistance to the TRAIL-induced apoptosis of cancer cells. In the present study, the effect of BBR on TRAIL-induced antitumor effects was investigated in vitro using recombinant TRAIL and in vivo using a 4T1 murine breast cancer model in combination with anti-DR5 (death-inducing TRAIL receptor) monoclonal antibody therapy. BBR sensitized human breast cancer cell lines to TRAIL-mediated apoptosis in vitro. The combination of BBR and recombinant TRAIL significantly activated caspase-3 and PARP cleavage in TRAIL-resistant MDA-MB-468 cells. Furthermore, BBR in combination with TRAIL more effectively induced apoptosis compared with coptisine (COP), which is structurally related to BBR. In a murine 4T1 breast cancer model, BBR treatment enhanced the efficacy of anti-DR5 antibody therapy against primary tumor growth and lung metastasis. Thus, BBR may become a new adjuvant for overcoming the resistance of cancer cells to TRAIL/DR5-mediated therapy.

Ethanolic extract of the Goldenseal, Hydrastis canadensis, has demonstrable chemopreventive effects on HeLa cells in vitro: Drug-DNA interaction with calf thymus DNA as target

This study tested chemotherapeutic potential of Hydrastis canadensis (HC) extract in HeLa cells in vitro, with emphasis on its drug-DNA interaction and apoptosis induction ability. Nuclear uptake of HC by DAPI, Ao/Eb staining and internucleosomal DNA damage by comet assay was studied through fluorescence microscopy. Possible changes in MMP and apoptotic signalling events were critically analyzed. Cell cycle progression studied through FACS and fragmented DNA through "TUNEL" assay were critically analyzed. RT-PCR studies were conducted for analyzing Cyt-C and Bax translocation in mitochondrial and cytosolic extracts, and Caspase 3 in whole cell lysate. Role of p53-mediated regulation of NF-κβ and TNF-α was elucidated by Western blot analysis. Data of CD and Tm profile of CT-DNA were analyzed. Overall results indicated anti-cancer potential of HC through its ability to induce apoptosis, and interaction with CT-DNA that changed structural conformation of DNA, proving HC to be a promising candidate for chemoprevention.

Molecular approaches towards development of purified natural products and their structurally known derivatives as efficient anti-cancer drugs: current trends

Several natural products and their derivatives, either in purified or structurally identified form, exhibit immense pharmacological and biological properties, some of them showing considerable anticancer potential. Although the molecular mechanisms of action of some of these products are yet to be elucidated, extensive research in this area continues to generate new data that are clinically exploitable. Recent advancement in molecular biology, high throughput screening, biomarker identifications, target selection and genomic approaches have enabled us to understand salient interactions of natural products and their derivatives with cancer cells vis-à-vis normal cells. In this review we highlight the recent approaches and application of innovative technologies made to improve quality as well as efficiency of structurally identified natural products and their derivatives, particularly in small molecular forms capable of being used in "targeted therapies" in oncology. These products preferentially involve multiple mechanistic pathways and overcome chemo-resistance in tumor types with cumulative action. We also mention briefly a few physico-chemical features that compare natural products with drugs in recent natural product discovery approaches. We further report here a few purified natural products as examples that provide molecular interventions in cancer therapeutics to give the reader a glimpse of the current trends of approach for discovering useful anticancer drugs.

N,N'-dinitrosopiperazine--mediated heat-shock protein 70-2 expression is involved in metastasis of nasopharyngeal carcinoma

N,N′-Dinitrosopiperazine (DNP) is invovled in nasopharyngeal carcinoma (NPC) development and metastasis, and it shows organ specificity to the nasopharyngeal epithelium. Herein, we demonstrate that DNP induces heat-shock protein (HSP) 70-2 expression in NPC cells (6-10B) at a non-cytotoxic concentration. DNP induced HSP70-2 expression in a dose- and time- dependent manner, but showed no effect on other HSP70 family members. Furthermore, DNP also increased HSP70-2 RNA transcription through directly binding to the hypoxia-responsive elements (HRE) and heat shock elements (HSE) located in the HSP70-2 promoter. DNP-mediated HSP70-2 expression might act through enhancing the transcription of HSP70-2 RNA. Importantly, DNP induced motility and invasion of 6-10B cells dose- and time-dependently, and DNP-mediated NPC metastasis was confirmed in nude mice, which showed high HSP70-2 expression in the metastatic tumor tissue. However, the motility and invasion of NPC cells that were stably transfected using short interfering RNA against HSP70-2 could not effectively induce DNP. These results indicate that DNP induces HSP70-2 expression through increasing HSP70-2 transcription, increases the motility and invasion of cells, and promotes NPC tumor metastasis. Therefore, DNP mediated HSP70-2 expression may be an important factor of NPC-high metastasis.

Berberine inhibits the growth of human colorectal adenocarcinoma in vitro and in vivo

Berberine is an alkaloid isolated from the Chinese herbal medicine Huanglian, and has long been used as an antibiotic. Its antineoplastic properties were subsequently discovered in vitro. The purpose of this study was to investigate the effects of berberine on the growth of human colorectal carcinoma cells in vitro and in vivo. The results showed that berberine inhibited human colorectal adenocarcinoma (LoVo) cell growth in a time- and dose-dependent manner. A WST-1 assay showed that the IC50 value after 72 h was 40.79 ± 4.11 μM. Cell cycle analysis of 40 μM berberine-treated LoVo cells by flow cytometry showed accumulation of cells in the G2/M phase. The inhibition of LoVo cell growth by berberine was associated with the suppression of cyclin B1, cdc2, and cdc25c proteins. Berberine at a dose of 50 mg kg(-1) day(-1) showed inhibitory rates of 45.3% in a human colorectal adenocarcinoma xenograft in nude mice. The combination of berberine and 5-fluorouracil (5-FU) had a higher inhibitory rate (59.8%) than the berberine group (36.4%, P = 0.01), but no significant difference was observed between the 5-FU group (43.0%, P = 0.06) and the combination group. These results support the possibility that berberine may be useful as an alternative therapy for colorectal carcinoma.

The invasion inhibitor sarasinoside A1 reverses mesenchymal tumor transformation in an E-cadherin-independent manner

During metastatic progression, an aberrant epithelial-to-mesenchymal transformation (EMT) that is most often driven by the loss of the cell-cell adhesion molecule E-cadherin generates noncohesive tumor cells that are highly invasive. We used mesenchymally transformed, E-cadherin-negative MDA-MB-231 breast carcinoma cells in a natural product screen and determined that the triterpenoid saponin sarasinoside A1 inhibited their invasion and the invasion of a number of other tumor cell lines. Sarasinoside A1 also caused MDA-MB-231 cells to become cohesive in a three-dimensional basement membrane and collagen gel cultures. In two-dimensional culture, sarasinoside A1 initiated a morphologic re-epithelialization of MDA-MB-231 cells wherein preexisting nonepithelial cadherins and the junction-associated proteins β-catenin and ZO-1 all relocalized to sites of cell-cell contact. In addition, the intercellular space between neighboring cells narrowed considerably, the stability of polymerized actin at cell-cell contact sites increased, and there was a recruitment and stabilization of nectin-based adhesion complexes to these sites, all of which strongly suggested that functional cell-cell junctions had formed. Importantly, sarasinoside A1 induced nascent cell-cell junction formation that did not require changes in gene expression and was not associated with an induction of E-cadherin but resulted in increased activation of Rap GTPases. Therefore, our findings with sarasinoside A1 suggest that it may be possible to re-epithelialize metastatic tumor cells with phenotypic consequence even when E-cadherin is completely absent.