Triterpenes from Ganoderma Lucidum induce autophagy in colon cancer through the inhibition of p38 mitogen-activated kinase (p38 MAPK)

The discovery of kinase inhibitors by a combination of diversity-oriented synthesis and selective screening

An efficient strategy for the discovery of kinase inhibitors by a combination of diversity-oriented synthesis and selective screening was presented.

Submerged fermentation production and characterization of intracellular triterpenoids from Ganoderma lucidum using HPLC-ESI-MS

As the main bioactive metabolites of Ganoderma lucidum, triterpenoids have various pharmacological effects. In this paper, the nutritional requirements and culture conditions of a submerged culture of G. lucidum were optimized using the response surface methodology; maximum mycelia biomass and intracellular triterpenoid production reached 1.87 g/100 ml and 93.21 mg/100 ml, respectively, for a culture consisting of wort 4.10% (0.041 g/ml) and yeast extract 1.89% (0.0189 g/ml), pH 5.40. For the first time, we established that wort, which is cheap and abundant, can replace the more commonly used glucose as the sole source of carbohydrate. Using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS), 10 major ganoderic acids were tentatively identified based on the predominant fragmentation pathways with the elimination of H2O and CO2, as well as cleavage of the D-ring.

Methanolic Extract of Ganoderma lucidum Induces Autophagy of AGS Human Gastric Tumor Cells

Ganoderma lucidum is one of the most widely studied mushroom species, particularly in what concerns its medicinal properties. Previous studies (including those from some of us) have shown some evidence that the methanolic extract of G. lucidum affects cellular autophagy. However, it was not known if it induces autophagy or decreases the autophagic flux. The treatment of a gastric adenocarcinoma cell line (AGS) with the mushroom extract increased the formation of autophagosomes (vacuoles typical from autophagy). Moreover, the cellular levels of LC3-II were also increased, and the cellular levels of p62 decreased, confirming that the extract affects cellular autophagy. Treating the cells with the extract together with lysossomal protease inhibitors, the cellular levels of LC3-II and p62 increased. The results obtained proved that, in AGS cells, the methanolic extract of G. lucidum causes an induction of autophagy, rather than a reduction in the autophagic flux. To our knowledge, this is the first study proving that statement.

Distinct Responses of Cytotoxic Ganoderma lucidum Triterpenoids in Human Carcinoma Cells

The medicinal mushroom Ganoderma lucidum is well recognized for its effective cancer-preventative and therapeutic properties, while specific components responsible for these anticancer effects are not well studied. Six triterpenoids that are ganolucidic acid E, lucidumol A, ganodermanontriol, 7-oxo-ganoderic acid Z, 15-hydroxy-ganoderic acid S, and ganoderic acid DM were isolated and identified from an extract of the mushroom. All compounds reduced cell growth in three human carcinoma cells (Caco-2, HepG2, and HeLa cells) dose dependently with LC50s from 20.87 to 84.36 μM. Moreover, the six compounds induced apoptosis in HeLa cells with a maximum increase (22%) of sub-G1 accumulations and 43.03% apoptotic cells in terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay (15-hydroxy-ganoderic acid S treatment). Apoptosis was further confirmed by annexin-V staining. Four of the compounds also caused apoptosis in Caco-2 cells with maximum 9.5% increase of sub-G1 accumulations (7-oxo-ganoderic acid Z treatment) and maximum 29.84% apoptotic cells in TUNEL assay (ganoderic acid DM treatment). Contrarily, none of the compounds induced apoptosis in HepG2 cells. The different responses of the three cell lines following these treatments indicated that the bioactive properties of these compounds may vary from cells of different sites of origin and are likely acting under diverse regulatory mechanisms.

Rhus coriaria induces senescence and autophagic cell death in breast cancer cells through a mechanism involving p38 and ERK1/2 activation

Here, we investigated the anticancer effect of Rhus coriaria on three breast cancer cell lines. We demonstrated that Rhus coriaria ethanolic extract (RCE) inhibits the proliferation of these cell lines in a time- and concentration-dependent manner. RCE induced senescence and cell cycle arrest at G1 phase. These changes were concomitant with upregulation of p21, downregulation of cyclin D1, p27, PCNA, c-myc, phospho-RB and expression of senescence-associated β-galactosidase activity. No proliferative recovery was detected after RCE removal. Annexin V staining and PARP cleavage analysis revealed a minimal induction of apoptosis in MDA-MB-231 cells. Electron microscopy revealed the presence of autophagic vacuoles in RCE-treated cells. Interestingly, blocking autophagy by 3-methyladenine (3-MA) or chloroquine (CQ) reduced RCE-induced cell death and senescence. RCE was also found to activate p38 and ERK1/2 signaling pathways which coincided with induction of autophagy. Furthermore, we found that while both autophagy inhibitors abolished p38 phosphorylation, only CQ led to significant decrease in pERK1/2. Finally, RCE induced DNA damage and reduced mutant p53, two events that preceded autophagy. Our findings provide strong evidence that R. coriaria possesses strong anti-breast cancer activity through induction of senescence and autophagic cell death, making it a promising alternative or adjunct therapeutic candidate against breast cancer.

From 2000years of Ganoderma lucidum to recent developments in nutraceuticals

Medicinal mushrooms have been used for centuries as nutraceuticals to improve health and to treat numerous chronic and infectious diseases. One such mushroom is Ganoderma lucidum, commonly known as Lingzhi, a species revered as a medicinal mushroom for treating assorted diseases and prolonging life. The fungus is found in diverse locations, and this may have contributed to confusion regarding the correct taxonomic classification of the genus Ganoderma. G. lucidum was first used to name a specimen found in England and thereafter was naively applied to a different Ganoderma species found in Asia, commonly known as Chinese Lingzhi. Despite the taxonomic confusion, which has largely been uncorrected, the popularity of Lingzhi has escalated across the globe. The current taxonomic situation is now discussed accurately in this Special Issue on Ganoderma. Today it is a multi-billion dollar industry wherein Lingzhi is cultivated or collected from the wild and consumed as a tea, in alcoholic beverages, and as a nutraceutical to confer numerous health benefits. Consumption of nutraceuticals has grown in popularity, and it is becoming increasingly important that active ingredients be identified and that suppliers make substantiated health claims about their products. The objective of this article is to present a review of G. lucidum over the past 2000 years from prized ancient "herbal" remedy to its use in nutraceuticals and to the establishment of a 2.5 billion $ (US) industry.

Tissue invasion and metastasis: Molecular, biological and clinical perspectives

Cancer is a key health issue across the world, causing substantial patient morbidity and mortality. Patient prognosis is tightly linked with metastatic dissemination of the disease to distant sites, with metastatic diseases accounting for a vast percentage of cancer patient mortality. While advances in this area have been made, the process of cancer metastasis and the factors governing cancer spread and establishment at secondary locations is still poorly understood. The current article summarizes recent progress in this area of research, both in the understanding of the underlying biological processes and in the therapeutic strategies for the management of metastasis. This review lists the disruption of E-cadherin and tight junctions, key signaling pathways, including urokinase type plasminogen activator (uPA), phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene (PI3K/AKT), focal adhesion kinase (FAK), β-catenin/zinc finger E-box binding homeobox 1 (ZEB-1) and transforming growth factor beta (TGF-β), together with inactivation of activator protein-1 (AP-1) and suppression of matrix metalloproteinase-9 (MMP-9) activity as key targets and the use of phytochemicals, or natural products, such as those from Agaricus blazei, Albatrellus confluens, Cordyceps militaris, Ganoderma lucidum, Poria cocos and Silybum marianum, together with diet derived fatty acids gamma linolenic acid (GLA) and eicosapentanoic acid (EPA) and inhibitory compounds as useful approaches to target tissue invasion and metastasis as well as other hallmark areas of cancer. Together, these strategies could represent new, inexpensive, low toxicity strategies to aid in the management of cancer metastasis as well as having holistic effects against other cancer hallmarks.

Elaborating the role of natural products-induced autophagy in cancer treatment: achievements and artifacts in the state of the art

Autophagy is a homeostatic process that is highly conserved across different types of mammalian cells. Autophagy is able to relieve tumor cell from nutrient and oxidative stress during the rapid expansion of cancer. Excessive and sustained autophagy may lead to cell death and tumor shrinkage. It was shown in literature that many anticancer natural compounds and extracts could initiate autophagy in tumor cells. As summarized in this review, the tumor suppressive action of natural products-induced autophagy may lead to cell senescence, provoke apoptosis-independent cell death, and complement apoptotic cell death by robust or target-specific mechanisms. In some cases, natural products-induced autophagy could protect tumor cells from apoptotic death. Technical variations in detecting autophagy affect data quality, and study focus should be made on elaborating the role of autophagy in deciding cell fate. In vivo study monitoring of autophagy in cancer treatment is expected to be the future direction. The clinical-relevant action of autophagy-inducing natural products should be highlighted in future study. As natural products are an important resource in discovery of lead compound of anticancer drug, study on the role of autophagy in tumor suppressive effect of natural products continues to be necessary and emerging.

A methanolic extract of Ganoderma lucidum fruiting body inhibits the growth of a gastric cancer cell line and affects cellular autophagy and cell cycle

Ganoderma lucidum is one of the most extensively studied mushrooms as a functional food and as a chemopreventive agent due to its recognized medicinal properties. Some G. lucidum extracts have shown promising antitumor potential. In this study, the bioactive properties of various extracts of G. lucidum, from both the fruiting body and the spores, were investigated. The most potent extract identified was the methanolic fruiting body extract, which inhibited the growth of a gastric cancer cell line (AGS) by interfering with cellular autophagy and cell cycle.

Ganoderma lucidum for cancer treatment: we are close but still not there

The medicinal fungus Ganoderma lucidum has been used in traditional Chinese medicine for millennia to improve health and promote longevity. The idea of using G. lucidum for cancer treatment is based on numerous laboratory and preclinical studies with cancer and immune cells as well as animal models demonstrating various biological activities in vitro and in vivo. For example, G. lucidum possesses cytotoxic, cytostatic, antimetastatic, anti-inflammatory, and immunomodulating activities. Limited clinical studies, including case reports and randomized controlled trials, suggest G. lucidum as an alternative adjunct therapy for stimulating the immune system in cancer patients. To confirm the efficacy of G. lucidum in cancer treatment, systematic translational research programs should be started worldwide. In addition, only standardized preclinically evaluated, biologically active G. lucidum extracts should be used in alternative treatments. This approach will lead to the development of standardized G. lucidum preparations with specific chemical fingerprint-associated anticancer activities.

Effects of metformin on retinoblastoma growth in vitro and in vivo

Recent studies suggest that the anti-diabetic drug metformin may reduce the risk of cancer and have anti-proliferative effects for some but not all cancers. In this study, we examined the effects of metformin on human retinoblastoma cell proliferation in vitro and in vivo. Two different human retinoblastoma cell lines (Y79, WERI) were treated with metformin in vitro and xenografts of Y79 cells were established in nu/nu immune-deficient mice and used to assess the effects of pharmacological levels of metformin in vivo. Metformin inhibited proliferation of the retinoblastoma cells in vitro. Similar to other studies, high concentrations of metformin (mM) blocked the cell cycle in G0‑G1, indicated by a strong decrease of G1 cyclins, especially cyclin D, cyclin-dependent kinases (4 and 6), and flow cytometry assessment of the cell cycle. This was associated with activation of AMPK, inhibition of the mTOR pathways and autophagy marker LC3B. However, metformin failed to suppress growth of xenografted tumors of Y79 human retinoblastoma cells in nu/nu mice, even when treated with a maximally tolerated dose level achieved in human patients. In conclusion, suprapharmacological levels (mM) of metformin, well above those tolerated in vivo, inhibited the proliferation of retinoblastoma cells in vitro. However, physiological levels of metformin, such as seen in the clinical setting, did not affect the growth of retinoblastoma cells in vitro or in vivo. This suggests that the potential beneficial effects of metformin seen in epidemiological studies may be limited to specific tumor types or be related to indirect effects/mechanisms not observed under acute laboratory conditions.

Ganoderma lucidum Polysaccharides Reduce Lipopolysaccharide-Induced Interleukin-1 β Expression in Cultured Smooth Muscle Cells and in Thoracic Aortas in Mice

The expression of inflammatory cytokines on vascular walls is a critical event in vascular diseases and inflammation. The aim of the present study was to examine the effects of an extract of Ganoderma lucidum (Reishi) polysaccharides (EORPs), which is effective against immunological disorders, on interleukin- (IL-) 1β expression by human aortic smooth muscle cells (HASMCs) and the underlying mechanism. The lipopolysaccharide- (LPS-) induced IL-1β expression was significantly reduced when HASMCs were pretreated with EORP by Western blot and immunofluorescent staining. Pretreatment with 10 μg/mL EORP decreased LPS-induced ERK, p38, JNK, and Akt phosphorylation. But the increase in IL-1β expression with LPS treatment was only inhibited by pretreatment with the ERK1/2 inhibitor, while the JNK and p38 inhibitors had no effect. In addition, EORP reduced the phosphorylation and nuclear translocation of nuclear factor- (NF-) κB p65 in LPS-treated HASMCs. Furthermore, in vivo, IL-1β expression was strongly expressed in thoracic aortas in LPS-treated mice. Oral administration of EORP decreased IL-1β expression. The level of IL-1β expression in LPS-treated or in LPS/EORP-treated group was very low and was similar to that of the saline-treated group in toll-like receptor 4-deficient (TLR4^−/−) mice. These findings suggest that EORP has the anti-inflammatory property and could prove useful in the prevention of vascular diseases and inflammatory responses.

Ghrelin inhibits doxorubicin cardiotoxicity by inhibiting excessive autophagy through AMPK and p38-MAPK

Doxorubicin (DOX) is a wide spectrum antitumor drug, but its clinical application is limited by the cardiotoxicity. Ghrelin, a multi-functional peptide hormone with metabolic regulation in energy homeostasis, plays important roles in cardiovascular protection. Now, the underlying mechanisms of ghrelin against DOX-induced cardiomyocyte apoptosis and atrophy are still not clear. In the present study, we revealed an autophagy-dependent mechanism involved in ghrelin's protection against DOX-induced cardiomyocyte death and size decrease. We observed that DOX insult induced remarkable mortality and cardiac dysfunction in mice, and increase in LDH leakage, cardiomyocyte apoptosis and decrease in cell viability and size in mouse hearts and H9c2 cell cultures, which were effectively improved by ghrelin supplement. We further observed that the strong autophagy stirred by DOX exposure was paralleling with the serious apoptosis and size decrease in cardiomyocytes. Ghrelin, like an autophagy inhibitor, 3-MA, inhibited the DOX-induced autophagy and attenuated cardiomyocyte apoptosis and size decrease. Furthermore, ghrelin significantly reduced the intercellular oxidative stress level, a strong autophagy trigger, partly by augmenting the expression and activities of the endogenous anti-oxidative enzymes. After the further investigation in the post signaling pathways of ghrelin receptors in H9c2 cells, including ERK, p38/MAPK, JNK, AMPK and Akt, we observed that ghrelin supplement only reduced the DOX-activated AMPK and augmented the DOX-down regulated p38-MAPK and mTOR phosphorylation. Our results indicated that ghrelin effectively improved the cardiomyocyte survival and size maintenance by suppressing the excessive autophagy through both ROS inhibition and mTOR induction through suppressing AMPK activity and stimulating p38-MAPK activity.

Ganoderic Acid and Lucidenic Acid (Triterpenoid)

Ganoderma species is known as a functional mushroom used in many Asian countries. Triterpenoids, ganoderic acids, and lucidenic acids have been isolated from Ganoderma species (Ganodermataceae family), such as Ganoderma lucidum. Triterpenoids have been investigated for their biological activities, including antibacterial, antiviral, antitumor, antiosteoclastic differentiation activity, anti-HIV-1, hepatoprotection, antioxidation, antihypertension, cholesterol reduction, and antiaggregation functions. In this chapter, the sources, biosynthesis, biological functions (including cell cytotoxicity, cell apoptosis, cell cycle arrest, anti-invasion, autophagy, anti-inflammation, antiosteoclastogenesis, antiasthma, and antihepatitis B activity), and pharmacokinetics of lucidenic acids and ganoderic acids are considered in detail here. This chapter briefly summarizes the multiple functions of lucidenic acids and ganoderic acids and their potential for fighting against human diseases.

Triterpene-loaded microemulsion using Coix lacryma-jobi seed extract as oil phase for enhanced antitumor efficacy: preparation and in vivo evaluation

Ganoderma lucidum triterpene-loaded microemulsions (TMEs) using Coix lacryma-jobi (adlay) seed oil as oil phase were prepared, characterized, and evaluated for enhanced antitumor activity. Ternary phase diagrams for the TMEs were constructed and the optimal preparation was developed. Transmission electron microscopy and dynamic light scattering showed that this formulation had a well defined spherical shape, a homogeneous distribution, a small size, and a narrow polydispersity index. The drug-loading rate was determined to be 9.87% by ultraviolet spectrophotometry, and acceptable stability under various stimulations in vitro was confirmed. Importantly, the TME formulation showed a significantly greater antiproliferative effect towards human lung carcinoma (A549) cells and murine lung tumor (Lewis) cells in comparison with suspension formulations containing triterpene and adlay seed oil as a positive control. The half-maximal inhibitory concentration of the TMEs was about 0.62 mg crude drug per mL, being 2.5-fold improved relative to that of the corresponding suspension formulation, but no significant cytotoxicity was observed for the bare microemulsion in A549 cells and Lewis cells. In vivo, the TME formulation showed markedly enhanced antitumor efficacy in a xenograft model of Lewis lung cancer after intragastric administration. Compared with cyclophosphamide, the TME formulation showed similar antitumor activity but less general toxicity. These results indicate the feasibility of using a microemulsion to increase the solubility of triterpene and adlay. TMEs hold promise as an efficient drug delivery system for the treatment of lung cancer.

p38 and JNK MAPK pathways control the balance of apoptosis and autophagy in response to chemotherapeutic agents

The Mitogen Activated Protein Kinase (MAPK) signaling plays a critical role in the outcome and the sensitivity to anticancer therapies. Activated MAPK can transmit extracellular signals to regulate cell growth, proliferation, differentiation, migration, apoptosis and so on. Apoptosis as well as macroautophagy (hereafter referred to as autophagy) can be induced by extracellular stimuli such the treatment of chemotherapeutic agents, resulting in different cell response to these drugs. However, the molecular mechanisms mediating these two cellular processes remain largely unknown. Recently, several studies provide new insights into p38 and JNK MAPK pathways function in the control of the balance of autophagy and apoptosis in response to genotoxic stress. Our increased understanding of the role of p38 and JNK MAPK pathways in regulating the balance of autophagy and apoptosis will hopefully provide prospective strategies for cancer therapy.

Inhibition of autophagy promotes CYP2E1-dependent toxicity in HepG2 cells via elevated oxidative stress, mitochondria dysfunction and activation of p38 and JNK MAPK

Autophagy has been shown to be protective against drug and alcohol-induced liver injury. CYP2E1 plays a role in the toxicity of ethanol, carcinogens and certain drugs. Inhibition of autophagy increased ethanol-toxicity and accumulation of fat in wild type and CYP2E1 knockin mice but not in CYP2E1 knockout mice as well as in HepG2 cells expressing CYP2E1 (E47 cells) but not HepG2 cells lacking CYP2E1 (C34 cells). The goal of the current study was to evaluate whether modulation of autophagy can affect CYP2E1-dependent cytotoxicity in the E47 cells. The agents used to promote CYP2E1 -dependent toxicity were a polyunsaturated fatty acid, arachidonic acid (AA), buthionine sulfoximine (BSO), which depletes GSH, and CCl4, which is metabolized to the CCl3 radical. These three agents produced a decrease in E47 cell viability which was enhanced upon inhibition of autophagy by 3-methyladenine (3-MA) or Atg 7 siRNA. Toxicity was lowered by rapamycin which increased autophagy and was much lower to the C34 cells which do not express CYP2E1. Toxicity was mainly necrotic and was associated with an increase in reactive oxygen production and oxidative stress; 3-MA increased while rapamycin blunted the oxidative stress. The enhanced toxicity and ROS formation produced when autophagy was inhibited was prevented by the antioxidant N-Acetyl cysteine. AA, BSO and CCl4 produced mitochondrial dysfunction, lowered cellular ATP levels and elevated mitochondrial production of ROS. This mitochondrial dysfunction was enhanced by inhibition of autophagy with 3-MA but decreased when autophagy was increased by rapamycin. The mitogen activated protein kinases p38 MAPK and JNK were activated by AA especially when autophagy was inhibited and chemical inhibitors of p38 MAPK and JNK lowered the elevated toxicity of AA produced by 3-MA. These results show that autophagy was protective against the toxicity produced by several agents known to be activated by CYP2E1. Since CYP2E1 plays an important role in the toxicity of ethanol, drugs and carcinogens and is activated under various pathophysiological conditions such as diabetes, NASH and obesity, attempts to stimulate autophagy may be beneficial in preventing/lowering CYP2E1/ethanol liver injury.

Anti-lung cancer activity through enhancement of immunomodulation and induction of cell apoptosis of total triterpenes extracted from Ganoderma luncidum (Leyss. ex Fr.) Karst

Ganoderma luncidum (Leyss. ex Fr.) Karst. (GLK) has been used traditionally for the prevention and treatment of cancers or tumors for a long time in Traditional Chinese Medicine. The triterpenes as main effective components of GLK have been found to be beneficial for the efficacy. The purpose of this study was to examine the anti-lung cancer activity of triterpenes of GLK in vitro and in vivo and to explore their anti-lung cancer effects and potential mechanisms. A549 cells and Lewis tumor-bearing mice were used to evaluate the inhibition effects of triterpenes on cell proliferation and tumor growth. The IC₅₀ of triterpenes of GLK on A549 cells was 24.63 μg/mL. Triterpenes of GLK could significantly inhibit tumor growth in mice (30, 60 and 120 mg/kg). The immune organs indexes including spleen and thymus were increased remarkedly by the treatment with triterpenes. Moreover, they were able to stimulate the immune response by increasing the expressions of IL-6 and TNF-α. Flow cytometric analysis revealed that cell arrest caused by triterpenes treatment (7.5, 15 and 30 μg/mL) was in the G2/M phase in A549 cells. Triterpenes induced apoptosis by decreasing the expression of the antiapoptotic protein Bcl-2 and pro-caspase 9 and increasing the levels of cleaved-caspase 9. Our findings suggested that the triterpenes of GLK have anti-lung cancer activity in vitro and in vivo via enhancement of immunomodulation and induction of cell apoptosis. The study provides insights into the mechanism of GLK in the prevention and treatment of lung cancer.

Autophagy therapeutic potential of garlic in human cancer therapy

Cancer is one of the deadliest diseases against humans. To tackle this menace, humans have developed several high-technology therapies, such as chemotherapy, tomotherapy, targeted therapy, and antibody therapy. However, all these therapies have their own adverse side effects. Therefore, recent years have seen increased attention being given to the natural food for complementary therapy, which have less side effects. Garlic (Dà Suàn; Allium sativum), is one of most powerful food used in many of the civilizations for both culinary and medicinal purpose. In general, these foods induce cancer cell death by apoptosis, autophagy, or necrosis. Studies have discussed how natural food factors regulate cell survival or death by autophagy in cancer cells. From many literature reviews, garlic could not only induce apoptosis but also autophagy in cancer cells. Autophagy, which is called type-II programmed cell death, provides new strategy in cancer therapy. In conclusion, we wish that garlic could be the pioneer food of complementary therapy in clinical cancer treatment and increase the life quality of cancer patients.

Anti-colorectal cancer effects of traditional Chinese herbal medicine: Research progress

Colorectal cancer is a common malignant tumor of the digestive system, and its incidence has an upward trend in China. In recent years, the role of traditional Chinese herbal medicine in treatment of colorectal cancer has attracted the attention of researchers. Traditional Chinese medicine exerts anti-colorectal cancer effects by inhibiting tumor cell proliferation and migration, inducing cell apoptosis and autophagy, reducing telomerase activity and vascular endothelial growth factor production, and arresting cell cycle progression. This paper summarizes the progress in research of anti-colorectal cancer effects of traditional Chinese herbal medicine in terms of mechanisms of action and clinical applications.

Regulation of cell cycle transition and induction of apoptosis in HL-60 leukemia cells by the combination of Coriolus versicolor and Ganoderma lucidum

Medicinal mushrooms have served as the mainstay of treatment for a variety of human illnesses in Asian countries, mostly as supplements by cancer patients. Extracts prepared from Trametes versicolor under the trade name of I'm-Yunity exhibit anti-tumorigenic activities, as supported by inhibition of the proliferation and induction of apoptosis in malignant cells. Similar effects have also been observed for the Reishi mushroom Ganoderma lucidum. The two mushrooms exert their medicinal activities primarily through a family of polysaccharo-peptides. Despite the common identity in their bioactive ingredients, whether their combination might elicit an expanded efficacy and mechanism has not been investigated. In the present study, we investigated similarities and differences between extracts prepared from I'm-Yunity and from a formulation denoted I'm-Yunity-Too combining I'm-Yunity and Ganoderma lucidum. By assaying their anti-proliferative and anti-apoptotic effects using human promyelocytic HL-60 cells, we found that the ethanolic extract of I'm-Yunity-Too was more active in inducing cell death compared to I'm-Yunity, based on measured changes in the expression of caspase 3 and Bax. Moreover, ethanolic extracts of I'm-Yunity-Too exhibited more potent activity compared to its aqueous extracts with regard to suppression of the growth and induction of apoptosis, as assayed by the more pronounced downregulation of phosphorylation of Rb and increased cleavage of poly(ADP‑ribose) polymerase (PARP) from its native 112-kDa form to the inactive 89-kDa product. These results suggested that the chemopreventive potential of I'm-Yunity may be enhanced by adding Ganoderma lucidum and that their bioactive ingre-dients potentially exhibit mechanistic synergism suggesting a more efficacious adjunct in chemotherapy.

Glucose induces autophagy under starvation conditions by a p38 MAPK-dependent pathway

Autophagy is a natural process of 'self-eating' that occurs within cells and can be either pro-survival or can cause cell death. As a pro-survival mechanism, autophagy obtains energy by recycling cellular components such as macromolecules or organelles. In response to nutrient deprivation, e.g. depletion of amino acids or serum, autophagy is induced and most of these signals converge on the kinase mTOR (mammalian target of rapamycin). It is commonly accepted that glucose inhibits autophagy, since its deprivation from cells cultured in full medium induces autophagy by a mechanism involving AMPK (AMP-activated protein kinase), mTOR and Ulk1. However, we show in the present study that under starvation conditions addition of glucose produces the opposite effect. Specifically, the results of the present study demonstrate that the presence of glucose induces an increase in the levels of LC3 (microtubule-associated protein 1 light chain)-II, in the number and volume density of autophagic vacuoles and in protein degradation by autophagy. Addition of glucose also increases intracellular ATP, which is in turn necessary for the induction of autophagy because the glycolysis inhibitor oxamate inhibits it, and there is also a good correlation between LC3-II and ATP levels. Moreover, we also show that, surprisingly, the induction of autophagy by glucose is independent of AMPK and mTOR and mainly relies on p38 MAPK (mitogen-activated protein kinase).

The synergistic effects of traditional Chinese herbs and radiotherapy for cancer treatment

Traditional Chinese medicine (TCM) has been demonstrated to have potent cytotoxic activity against certain malignant tumors. Ionizing radiation (IR) is one of the most effective methods used in the clinical treatment of cancer. The drawback of a single formula is that it limits the treatment efficacy for cancer, while comprehensive strategies require additional theoretical support. However, a combination of different antitumor treatment modalities is advantageous in restricting the non-specific toxicity often observed with an extremely high dose of a single regimen. The induction of apoptotic cell death is a significant process in tumor cells following radiotherapy or chemotherapy, and resistance to these treatments has been linked to a low propensity for apoptosis. Autophagy is a response of cancer cells to IR or chemotherapy, and involves the prominent formation of autophagic vacuoles in the cytoplasm. In this review, the synergistic effects of TCM and radiotherapy are summarized and the underlying mechanisms are illustrated, providing new therapeutic strategies for cancer.

Lanostanoids from fungi: a group of potential anticancer compounds

Lanostanes are a group of tetracyclic triterpenoids derived from lanosterol. They have relevant biological and pharmacological properties, such as their cytotoxic effects via induction of apoptosis. This review compiles the most relevant lanostanoids studied from 2000 to 2011, principally those isolated from Ganoderma lucidum and other related fungi, such as Poria cocos, Laetiporus sulphureus, Inonotus obliquus, Antrodia camphorata, Daedalea dickinsii, and Elfvingia applanata, which have great potential as anticancer agents because of their cytotoxic or apoptotic effects. The compounds were selected on the basis of their proapoptotic mechanisms, through their ability to modify transcriptional activities via nuclear factors or genes and the activation or inhibition of pro- or antiapoptotic proteins; studies based only on their cytotoxicity were excluded from this review in the absence of complementary studies on their mechanisms of action. A total of 81 compounds from Ganoderma lucidum and other species from this genus are included, as well as 96 compounds isolated from other fungi, principally Poria cocos. Some of these compounds were found to arrest the cell cycle in the G1 phase, increase levels of p53 and Bax, or inhibit the phosphorylation of Erk1/2 or the activation of NF-κB and AP-1. Other lanostanes have inhibitory effects on the growth of androgen prostate carcinoma through increasing the expression of p21, which activates the tumor suppressor protein p53, while other compounds have been shown to selectively inhibit topo II activity without affecting topo I. General considerations concerning the chemical structure-biological activities of these compounds are also discussed.

14-3-3 Proteins are Regulators of Autophagy

14-3-3 proteins are implicated in the regulation of proteins involved in a variety of signaling pathways. 14-3-3-dependent protein regulation occurs through phosphorylation-dependent binding that results, in many cases, in the release of survival signals in cells. Autophagy is a cell digestion process that contributes to overcoming nutrient deprivation and is initiated under stress conditions. However, whether autophagy is a cell survival or cell death mechanism remains under discussion and may depend on context. Nevertheless, autophagy is a cellular process that determines cell fate and is tightly regulated by different signaling pathways, some of which, for example MAPK, PI3K and mTOR, are tightly regulated by 14-3-3 proteins. It is therefore important to understand the role of 14-3-3 protein in modulating the autophagic process. Within this context, direct binding of 14-3-3 to mTOR regulatory proteins, such as TSC2 and PRAS40, connects 14-3-3 with autophagy regulatory processes. In addition, 14-3-3 binding to human vacuolar protein sorting 34 (hVps34), a class III phosphatidylinositol-3-kinase (PI3KC3), indicates the involvement of 14-3-3 proteins in regulating autophagosome formation. hVps34 is involved in vesicle trafficking processes such as autophagy, and its activation is needed for initiation of autophagy. Chromatography and overlay techniques suggest that hVps34 directly interacts with 14-3-3 proteins under physiological conditions, thereby maintaining hVps34 in an inactive state. In contrast, nutrient starvation promotes dissociation of the 14-3-3–hVps34 complex, thereby enhancing hVps34 lipid kinase activity. Thus, 14-3-3 proteins are regulators of autophagy through regulating key components of the autophagic machinery. This review summarizes the role of 14-3-3 protein in the control of target proteins involved in regulating the master switches of autophagy.

Regulation of autophagy by glucose in Mammalian cells

Autophagy is an evolutionarily conserved process that contributes to maintain cell homeostasis. Although it is strongly regulated by many extracellular factors, induction of autophagy is mainly produced by starvation of nutrients. In mammalian cells, the regulation of autophagy by amino acids, and also by the hormone insulin, has been extensively investigated, but knowledge about the effects of other autophagy regulators, including another nutrient, glucose, is more limited. Here we will focus on the signalling pathways by which environmental glucose directly, i.e., independently of insulin and glucagon, regulates autophagy in mammalian cells, but we will also briefly mention some data in yeast. Although glucose deprivation mainly induces autophagy via AMPK activation and the subsequent inhibition of mTORC1, we will also comment other signalling pathways, as well as evidences indicating that, under certain conditions, autophagy can be activated by glucose. A better understanding on how glucose regulates autophagy not only will expand our basic knowledge of this important cell process, but it will be also relevant to understand common human disorders, such as cancer and diabetes, in which glucose levels play an important role.

Active lipids of Ganoderma lucidum spores-induced apoptosis in human leukemia THP-1 cells via MAPK and PI3K pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Ganoderma lucidum (Lingzhi) is traditionally drug, which has been traditionally effective used in the treatment of chronic hepatopathy, hypertension, hyperglycemia and cancer.

MATERIALS AND METHODS

THP-1 and HL-60 apoptosis induced by active lipids of Ganoderma lucidum spores was quantified by flow cytometry using FITC-conjugated annexin V and PI; MAPK and Akt were measured by Western blot, and caspase-3, -8 and -9 activities were also detected by spectrophotometric assay.

RESULTS

Our results showed that active lipids of Ganoderma lucidum spores decreased phosphorylation-ERK1/2 (P-ERK1/2), P-Akt and increased P-JNK1/2, but did not affect expressions of P-p38 MAPK in THP-1 cells. Moreover, treatment of THP-1 cells with active lipids of Ganoderma lucidum spores resulted in activation of caspase-3, -8 and -9. Furthermore, LY294002 (Akt inhibitor) or PD98059 (ERK1/2 inhibitor) significantly enhanced active lipids of Ganoderma lucidum spores-induced apoptosis in THP-1 cells, whereas caspase inhibitors or SP600125 (JNK inhibitor), decreased apoptosis in THP-1 cells.

CONCLUSION

Taken together, our study for the first time suggests that active lipids of Ganoderma lucidum spores is able to enhance apoptosis in THP-1 cells, at least in part, through inhibition of ERK1/2, Akt and activation of JNK1/2 signaling pathways. Moreover, it also triggers caspase-3, -8 and -9 activation mediated apoptotic induction.

Semisynthesis and biological evaluation of ganodermanontriol and its stereoisomeric triols

The first synthesis of ganodermanontriol, a bioactive lanostane triterpene from the medicinal mushroom Ganoderma lucidum, has been achieved in 15.3% yield over nine steps, along with its three stereoisomeric triols and ganoderol A. The key steps leading to this family of isomers involve the reconstruction of the trisubstituted alkene by stereoselective and chemoselective phosphonate reactions and the formation of the unusual Δ7,9(11)-diene core by the mild acidic opening of a lanosterone-derived epoxide. Ganodermanontriol showed promising activity on the inhibition and proliferation of breast cancer cells. The effect of ganodermanontriol and its isomers on cell proliferation was assayed; IC50 values of 5.8 and 9.7 μM on breast cancer cell lines MCF-7 and MDA-MB-231, respectively, were found for ganodermanontriol.

β-Elemene induces apoptosis as well as protective autophagy in human non-small-cell lung cancer A549 cells

OBJECTIVES

β-Elemene, a novel traditional Chinese medicine, has been shown to be effective against a wide range of tumours. In this study, the antitumour effect of β-elemene on human non-small-cell lung cancer (NSCLC) A549 cells and the mechanism involved have been investigated.

METHODS

Cell viability and apoptosis were measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. Protein expression was assayed by Western blotting. Autophagy was evaluated under fluorescence microscopy and transmission electron microscopy.

KEY FINDINGS

β-Elemene inhibited the viability of A549 cells in a dose-dependent manner. This suppression of cell viability was due to the induction of apoptosis. Further study showed that β-elemene inhibited the activity of the PI3K/Akt/mTOR/p70S6K1 signalling pathway, and at the same time it triggered a robust autophagy. The autophagy was characterized by the accumulation of punctate LC3 dots in the cytoplasm, morphological changes, and the increased levels of LC3-II as well as Atg5-Atg12 conjugated proteins. Inhibition of autophagy with chlorochine significantly enhanced the antitumour effect of β-elemene.

CONCLUSIONS

Our data indicated that β-elemene inhibited the activity of the PI3K/Akt/mTOR/p70S6K1 signalling pathway in human NSCLC A549 cells, which resulted in apoptosis as well as protective autophagy. A combination of β-elemene with autophagy inhibitor might be an effective therapeutic option for advanced NSCLC.

Ganodermanontriol (GDNT) exerts its effect on growth and invasiveness of breast cancer cells through the down-regulation of CDC20 and uPA

Ganoderma lucidum is a medicinal mushroom that has been recognized by Traditional Chinese Medicine (TCM). Although some of the direct anticancer activities are attributed to the presence of triterpenes-ganoderic and lucidenic acids-the activity of other compounds remains elusive. Here we show that ganodermanontriol (GDNT), a Ganoderma alcohol, specifically suppressed proliferation (anchorage-dependent growth) and colony formation (anchorage-independent growth) of highly invasive human breast cancer cells MDA-MB-231. GDNT suppressed expression of the cell cycle regulatory protein CDC20, which is over-expressed in precancerous and breast cancer cells compared to normal mammary epithelial cells. Moreover, we found that CDC20 is over-expressed in tumors when compared to the tissue surrounding the tumor in specimens from breast cancer patients. GDNT also inhibited invasive behavior (cell adhesion, cell migration, and cell invasion) through the suppression of secretion of urokinase-plasminogen activator (uPA) and inhibited expression of uPA receptor. In conclusion, mushroom GDNT is a natural agent that has potential as a therapy for invasive breast cancers.

Antihyperglycemic effect of ganoderma lucidum polysaccharides on streptozotocin-induced diabetic mice

The current study evaluated the glucose-lowering effect of ganoderma lucidum polysaccharides (Gl-PS) in streptozotocin (STZ)-induced diabetic mice. The diabetic mice were randomly divided into four groups (8 mice per group): diabetic control group, low-dose Gl-PS treated group (50 mg/kg, Gl-PS), high-dose Gl-PS treated group (150 mg/kg, Gl-PS) and positive drug control treated group (glibenclamide, 4 mg/kg), with normal mice used as the control group. Body weights, fasting blood glucose (FBG), serum insulin and blood lipid levels of mice were measured. After 28 days of treatment with Gl-PS, body weights and serum insulin levels of the Gl-PS treated groups was significantly higher than that of the diabetic control group, whereas FBG levels was significantly lower. Moreover, total cholesterol (TC), triglyceride (TG) and low density lipoprotein cholesterol (LDL-C) levels of the Gl-PS treated groups had dropped, whereas the high density lipoprotein cholesterol (HDL-C) levels had increased. In addition, according to acute toxicity studies, Gl-PS did not cause behavioral changes and any death of mice. These data suggest that Gl-PS has an antihyperglycemic effect. Furthermore, considering the Gl-PS effects on lipid profile, it may be a potential hypolipidaemic agent, which will be a great advantage in treating diabetic conditions associated with atherosclerosis or hyperlipidemia.

ReishiMax, mushroom based dietary supplement, inhibits adipocyte differentiation, stimulates glucose uptake and activates AMPK

Background

Obesity is a health hazard which is closely associated with various complications including insulin resistance, hypertension, dyslipidemia, atherosclerosis, type 2 diabetes and cancer. In spite of numerous preclinical and clinical interventions, the prevalence of obesity and its related disorders are on the rise demanding an urgent need for exploring novel therapeutic agents that can regulate adipogenesis. In the present study, we evaluated whether a dietary supplement ReishiMax (RM), containing triterpenes and polysaccharides extracted from medicinal mushroom Ganoderma lucidum, affects adipocyte differentiation and glucose uptake in 3T3-L1 cells.

Methods

3T3-L1 pre-adipocytes were differentiated into adipocytes and treated with RM (0-300 μg/ml). Adipocyte differentiation/lipid uptake was evaluated by oil red O staining and triglyceride and glycerol concentrations were determined. Gene expression was evaluated by semi-quantitative RT-PCR and Western blot analysis. Glucose uptake was determined with [³H]-glucose.

Results

RM inhibited adipocyte differentiation through the suppresion of expression of adipogenic transcription factors peroxisome proliferator-activated receptor-γ (PPAR-γ), sterol regulatory element binding element protein-1c (SREBP-1c) and CCAAT/enhancer binding protein-α (C/EBP-α). RM also suppressed expression of enzymes and proteins responsible for lipid synthesis, transport and storage: fatty acid synthase (FAS), acyl-CoA synthetase-1 (ACS1), fatty acid binding protein-4 (FABP4), fatty acid transport protein-1 (FATP1) and perilipin. RM induced AMP-activated protein kinase (AMPK) and increased glucose uptake by adipocytes.

Conclusion

Our study suggests that RM can control adipocyte differentiation and glucose uptake. The health benefits of ReishiMax warrant further clinical studies.

Ganoderma lucidum (Reishi) inhibits cancer cell growth and expression of key molecules in inflammatory breast cancer

Inflammatory breast cancer (IBC) is the most lethal and least understood form of advanced breast cancer. Its lethality originates from its nature of invading the lymphatic system and absence of a palpable tumor mass. Different from other metastatic breast cancer cells, IBC cells invade by forming tumor spheroids that retain E-cadherin-based cell-cell adhesions. Herein we describe the potential of the medicinal mushroom Ganoderma lucidum (Reishi) as an attractive candidate for anti-IBC therapy. Reishi contains biological compounds that are cytotoxic against cancer cells. We report the effects of Reishi on viability, apoptosis, invasion, and its mechanism of action in IBC cells (SUM-149). Results show that Reishi selectively inhibits cancer cell viability although it does not affect the viability of noncancerous mammary epithelial cells. Apoptosis induction is consistent with decreased cell viability. Reishi inhibits cell invasion and disrupts the cell spheroids that are characteristic of the IBC invasive pathology. Reishi decreases the expression of genes involved in cancer cell survival and proliferation (BCL-2, TERT, PDGFB), and invasion and metastasis (MMP-9), whereas it increases the expression of IL8. Reishi reduces BCL-2, BCL-XL, E-cadherin, eIF4G, p120-catenin, and c-Myc protein expression and gelatinase activity. These findings suggest that Reishi is an effective anti-IBC therapeutic.

Regulation of autophagy by kinases

Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets.

β-Elemene-induced autophagy protects human gastric cancer cells from undergoing apoptosis

Background

β-Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anti-cancer effects against a broad spectrum of tumors. The mechanism by which β-elemene kills cells remains unclear. The aim of the present study is to investigate the anti-tumor effect of β-elemene on human gastric cancer cells and the molecular mechanism involved.

Results

β-Elemene inhibited the viability of human gastric cancer MGC803 and SGC7901 cells in a dose-dependent manner. The suppression of cell viability was due to the induction of apoptosis. A robust autophagy was observed in the cells treated with β-elemene; it was characterized by the increase of punctate LC3 dots, the cellular morphology, and the increased levels of LC3-II protein. Further study showed that β-elemene treatment up-regulated Atg5-Atg12 conjugated protein but had little effect on other autophagy-related proteins. PI3K/Akt/mTOR/p70S6K1 activity was inhibited by β-elemene. Knockdown of Beclin 1 with small interfering RNA, or co-treatment with the autophagy inhibitor, 3-methyladenine or chlorochine enhanced significantly the antitumor effects of β-elemene.

Conclusions

Our data provides the first evidence that β-elemene induces protective autophagy and prevents human gastric cancer cells from undergoing apoptosis. A combination of β-elemene with autophagy inhibitor might thus be a useful therapeutic option for advanced gastric cancer.

Possible role of autophagy in the treatment of pancreatic cancer with histone deacetylase inhibitors

Pancreatic cancer is a lethal disease and notoriously difficult to treat. Only a small proportion is curative by surgical resection, whilst standard chemotherapy for patients with advanced disease has only a modest effect with substantial toxicity. Clearly there is a need for the continual development of novel therapeutic agents to improve the current situation. Currently, there is a bulk of data indicating the important function of autophagy in cancer. While genetic evidence indicates that autophagy functions as a tumor suppressor, it is also apparent that autophagy can promote the survival of established tumors under stress conditions and in response to chemotherapy. This review provides a spectrum of potential pharmacological agents and autophagic approaches to enhance cell killing in pancreatic cancer.