CDC20 associated with cancer metastasis and novel mushroom‑derived CDC20 inhibitors with antimetastatic activity

Aberrant expression of cell division cycle 20 (CDC20) is associated with malignant progression and poor prognosis in various types of cancer. The development of specific CDC20 inhibitors may be a novel strategy for the treatment of cancer with elevated expression of CDC20. The aim of the current study was to elucidate the role of CDC20 in cancer cell invasiveness and to identify novel natural inhibitors of CDC20. The authors found that CDC20 knockdown inhibited the migration of chemoresistant PANC‑1 pancreatic cancer cells and the metastatic MDA‑MB‑231 breast cancer cell line. By contrast, the overexpression of CDC20 by plasmid transfection promoted the metastasizing capacities of the PANC‑1 cells and MCF‑7 breast cancer cells. It was also identified that a triterpene mixture extracted from the mushroom Poria cocos (PTE), purified triterpenes dehydropachymic acid, and polyporenic acid C (PPAC) downregulated the expression of CDC20 in PANC‑1 cells dose‑dependently. Migration was also suppressed by PTE and PPAC in a dose‑dependent manner, which was consistent with expectations. Taken together, the present study is the first, to the best of our knowledge, to demonstrate that CDC20 serves an important role in cancer metastasis and that triterpenes from P. cocos inhibit the migration of pancreatic cancer cells associated with CDC20. Further investigations are in progress to investigate the specific mechanism associated with CDC20 and these triterpenes, which may have future potential use as natural agents in the treatment of metastatic cancer.

Abstract B12: Effect of Ganoderma lucidum on DNA damage and DNA repair in colorectal cancer cell lines

Colorectal carcinoma (CRC) is the third most common type of cancer in the world and second most common cause of cancer related deaths in Europe. Countries of Central Europe (Czech Republic, Slovakia and Hungary) have one of the highest rates both for incidence and mortality of CRC and this disease therefore possesses a serious health, social and economic problem.

CRC is a complex disease that develops as consequence of environmental and health risk factors with particular involvement of suboptimal DNA repair, resulting in accumulation of DNA damage. Reactive oxygen species (ROS) represent a group of highly reactive molecules tightly controlled by cellular antioxidant system. Disturbance of the prooxidation–antioxidation homeostasis can lead to ROS accumulation and consequently to DNA damage and apoptosis. Many natural compounds possess anti-cancer activities with the generation of ROS. Cancer cells are more sensitive to oxidative DNA damage than non-malignant cells. Modulation of oxidative DNA damage and DNA repair pathways by natural compounds may lead to selective cancer cell-death and to sensitization of cancer cells to treatment. Ganoderma Lucidum (GLC) (Reishi, Ling-Zhi) is a mushroom used in Chinese medicine for thousands of years for prevention or therapy of many different disorders including cancer.

The aim of our study is to define the effect of Ganoderma lucidum (GLC) extract on DNA damage and DNA repair machinery in colorectal cancer cell lines (HTC116, HCT116p53-/-, HT29, SW480).

Our results showed that 6hrs GLC treatment in colorectal cancer cells (0.5µg/µl) inhibits activity of superoxid dismutase 1 (25%, p<0.01) and enzymatic activity of glutathione peroxidase (20%, p<0.01), followed by abnormal ROS accumulation (1,5-fold, p<0.05). Furthermore the specific oxidative DNA damage increased (10-fold, p<0.01) after GLC treatment, whereas the base excision DNA repair process was supressed (40%, p<0.001). Finally, above events resulted in cell cycle arrest (HCT116) or apoptosis (HCTp53-/-) and subsequent decrease of colorectal cancer cell survival (25%, p<0.05).

Our results suggest that GLC extract decreases activity of the cellular antioxidant system, which leads to oxidative DNA damage and subsequently to genotoxic effects of GLC extract in colorectal cancer cell lines. These data indicate that specific oxidative DNA damage caused by natural compounds may become a potential tool for improvement of anti-cancer treatment.

Acknowledgement: AMVIS LH13061 and GACR 15-14789S, AZV 15-27580A

Citation Format: Alena Opattova, Andrea Cumova, Sona Vodenkova, Peter Macinga, Jozef Horak, Daniel Sliva, Pavel Vodicka. Effect of Ganoderma lucidum on DNA damage and DNA repair in colorectal cancer cell lines [abstract]. In: Proceedings of the AACR Special Conference on DNA Repair: Tumor Development and Therapeutic Response; 2016 Nov 2-5; Montreal, QC, Canada. Philadelphia (PA): AACR; Mol Cancer Res 2017;15(4_Suppl):Abstract nr B12.

Trimeric and Tetrameric A-Type Procyanidins from Peanut Skins

Peanut skins are a rich source of oligomeric and polymeric procyanidins. The oligomeric fractions are dominated by dimers, trimers, and tetramers. A multistep chromatographic fractionation led to the isolation of four new A-type procyanidins of tri- and tetrameric structures. The structures of the new trimers were defined by NMR, electronic circular dichroism, and MS data as epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→8,2β→O→7)-catechin, peanut procyanidin B (3), and epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→6)-catechin, peanut procyanidin C (4). The new tetramers were defined as epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→6)-epicatechin-(4β→8,2β→O→7)-catechin, peanut procyanidin E (1), and epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→6)-epicatechin-(4β→8,2β→O→7)-epicatechin, peanut procyanidin F (2). In addition, both A-type dimers A1, epicatechin-(4β→8,2β→O→7)-catechin, and A2, epicatechin-(4β→8,2β→O→7)-epicatechin, as well as two known peanut trimers, ent-epicatechin-(4β→6)-epicatechin-(4β→8,2β→O→7)-catechin, peanut procyanidin A (5), and epicatechin-(4β→8)-epicatechin-(4β→8,2β→O→7)-catechin, peanut procyanidin D (6), were also isolated. Dimer A1, the four trimers, and two tetramers were evaluated for anti-inflammatory activity in an in vitro assay, in which LPS-stimulated macrophages were responding with secretion of TNF-α, a pro-inflammatory cytokine. Tetramer F (2) was the most potent, suppressing TNF-α secretion to 82% at 8.7 μM (10 μg/mL), while tetramer E (1) at the same concentrations caused a 4% suppression. The results of the TNF-α secretion inhibition indicate that small structural differences, as in peanut procyanidin tetramers E and F, can be strongly differentiated in biological systems.

BreastDefend enhances effect of tamoxifen in estrogen receptor-positive human breast cancer in vitro and in vivo

BACKGROUND

Tamoxifen (TAM) has been widely used for the treatment of estrogen receptor (ER)-positive breast cancer and its combination with other therapies is being actively investigated as a way to increase efficacy and decrease side effects. Here, we evaluate the therapeutic potential of co-treatment with TAM and BreastDefend (BD), a dietary supplement formula, in ER-positive human breast cancer.

METHODS

Cell proliferation and apoptosis were determined in ER-positive human breast cancer cells MCF-7 by MTT assay, quantitation of cytoplasmic histone-associated DNA fragments and expression of cleaved PARP, respectively. The molecular mechanism was identified using RNA microarray analysis and western blotting. Tumor tissues from xenograft mouse model were analyzed by immunohistochemistry.

RESULTS

Our data clearly demonstrate that a combination of 4-hydroxytamoxifen (4-OHT) with BD lead to profound inhibition of cell proliferation and induction of apoptosis in MCF-7 cells. This effect is consistent with the regulation of apoptotic and TAM resistant genes at the transcription and translation levels. Importantly, TAM and BD co-treatment significantly enhanced apoptosis, suppressed tumor growth and reduced tumor weight in a xenograft model of human ER-positive breast cancer.

CONCLUSION

BD sensitized ER-positive human breast cancer cells to 4-OHT/TAM treatment in vitro and in vivo. BreastDefend can be used in an adjuvant therapy to increase the therapeutic effect of tamoxifen in patients with ER-positive breast cancer.

Designing a broad-spectrum integrative approach for cancer prevention and treatment

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are not reliant upon the same mechanisms as those which have been targeted). To address these limitations, an international task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspects of relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a wide range of high-priority targets (74 in total) that could be modified to improve patient outcomes. For these targets, corresponding low-toxicity therapeutic approaches were then suggested, many of which were phytochemicals. Proposed actions on each target and all of the approaches were further reviewed for known effects on other hallmark areas and the tumor microenvironment. Potential contrary or procarcinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixed evidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of the relationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. This novel approach has potential to be relatively inexpensive, it should help us address stages and types of cancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for future research is offered.

Ganoderma Lucidum(Reishi) in Cancer Treatment

The popular edible mushroom Ganoderma lucidum(Reishi) has been widely used for the general promotion of health and longevity in Asian countries. The dried powder of Ganoderma lucidumwas popular as a cancer chemotherapy agent in ancient China. The authors recently demonstrated that Ganoderma luciduminhibits constitutively active transcription factors nuclear factor kappa B (NF-.B) and AP-1, which resulted in the inhibition of expression of urokinasetype plasminogen activator (uPA) and its receptor uPAR. Ganoderma lucidumalso suppressed cell adhesion and cell migration of highly invasive breast and prostate cancer cells, suggesting its potency to reduce tumor invasiveness. Thus, Ganoderma lucidumclearly demonstrates anticancer activity in experiments with cancer cells and has possible therapeutic potential as a dietary supplement for an alternative therapy for breast and prostate cancer. However, because of the availability of Ganoderma lucidum from different sources, it is advisable to test its biologic activity.

Abstract 5562: BreastDefend enhances the effects of tamoxifen in estrogen receptor-positive human breast cancer in vitro and animal models in vivo

In this study we evaluated the combined effects of the natural product/dietary supplement BreastDefend (BD) and tamoxifen (TAM) on MCF-7 estrogen receptor-positive (ER+) human breast cancer cells in vitro and an orthotopic mouse model in vivo. BD has been studied previously in preclinical models, and shown to exert significant effects on MDA-MB-231 triple-negative breast cancer cells. The proliferation of MCF-7 cells was evaluated using MTT assays, whereas the expression of genes involved in the molecular mechanisms of cancer was evaluated using DNA microarrays. MCF-7 cells were stimulated with estradiol (10 nM) and treated with TAM (1 μM), BD (10 μg/ml), and the combination of TAM and BD for 3 days and 6 days. Compared with control, BD enhanced the anti-proliferative activity of TAM significantly (P < 0.05), and the combination of BD and TAM induced apoptosis. The results of DNA microarray analyses suggested that the pro-apoptotic activity of BD and TAM in MCF-7 cells was associated with the significant upregulation of BRAF (an oncogene that can block proliferation and induce apoptosis) and downregulation of BCL2 (an apoptosis inhibitor) and FN1 (fibronectin, a glycoprotein involved in tumorigenesis and metastasis) expression. In the orthotopic model MCF-7 cells were implanted into the mammary fat pads of female ovariectomized nude mice (n = 12-13). The mice received subcutaneous pellets that released estradiol and TAM, whereas BD was administered orally via intragastric gavage. All groups, including control, received estradiol. The combination of BD and TAM suppressed tumor size in vivo markedly compared with the BD and TAM alone groups. The inhibition of tumor growth was associated with the induction of the cell cycle inhibitor protein p21 in MCF-7-generated breast tumors. In summary, this study suggests that BD could be considered for use in clinical studies as an adjuvant therapy in conjunction with TAM for the treatment of ER+ human breast cancer.

Citation Format: Shujie Cheng, Mark Alvarado, Jagadish Loganathan, Victor Castillo, Georg Sandusky, Isaac Eliaz, Daniel Sliva. BreastDefend enhances the effects of tamoxifen in estrogen receptor-positive human breast cancer in vitro and animal models in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5562. doi:10.1158/1538-7445.AM2015-5562

Pachymic acid inhibits growth and induces apoptosis of pancreatic cancer in vitro and in vivo by targeting ER stress

Pachymic acid (PA) is a purified triterpene extracted from medicinal fungus Poria cocos. In this paper, we investigated the anticancer effect of PA on human chemotherapy resistant pancreatic cancer. PA triggered apoptosis in gemcitabine-resistant pancreatic cancer cells PANC-1 and MIA PaCa-2. Comparative gene expression array analysis demonstrated that endoplasmic reticulum (ER) stress was induced by PA through activation of heat shock response and unfolded protein response related genes. Induced ER stress was confirmed by increasing expression of XBP-1s, ATF4, Hsp70, CHOP and phospho-eIF2α. Moreover, ER stress inhibitor tauroursodeoxycholic acid (TUDCA) blocked PA induced apoptosis. In addition, 25 mg kg-1 of PA significantly suppressed MIA PaCa-2 tumor growth in vivo without toxicity, which correlated with induction of apoptosis and expression of ER stress related proteins in tumor tissues. Taken together, growth inhibition and induction of apoptosis by PA in gemcitabine-resistant pancreatic cancer cells were associated with ER stress activation both in vitro and in vivo. PA may be potentially exploited for the use in treatment of chemotherapy resistant pancreatic cancer.

Honokiol suppresses metastasis of renal cell carcinoma by targeting KISS1/KISS1R signaling

Renal cell carcinoma (RCC) is a common urological cancer worldwide and is known to have a high risk of metastasis, which is considered responsible for more than 90% of cancer associated deaths. Honokiol is a small-molecule biphenol isolated from Magnolia spp. bark and has been shown to be a potential anticancer agent involved in multiple facets of signal transduction. In this study, we demonstrated that honokiol inhibited the invasion and colony formation of highly metastatic RCC cell line 786-0 in a dose-dependent manner. DNA-microarray data showed the significant upregulation of metastasis-suppressor gene KISS1 and its receptor, KISS1R. The upregulation was confirmed by qRT-PCR analysis. Overexpression of KISS1 and KISS1R was detected by western blotting at the translation level as well. Of note, the decreased invasive and colonized capacities were reversed by KISS1 knockdown. Taken together, the results first indicate that activation of KISS1/KISS1R signaling by honokiol suppresses multistep process of metastasis, including invasion and colony formation, in RCC cells 786-0. Honokiol may be considered as a natural agent against RCC metastasis.

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.

Abstract 3203: Honokiol inhibits growth and migration of renal cell carcinoma

Renal cell carcinoma (RCC) is a common urological cancer worldwide and is known to the high risk of recurrence and metastasis. Approximately 70% of patients with RCC will develop recurrence after surgical resection, and 25%-30% of patients will eventually develop progression to distant metastasis. Honokiol is a small-molecule polyphenol isolated from the genus Magnolia, which has been shown to be a potential anticancer agent in multiple facets of signal transduction. Here we demonstrate that honokiol inhibits proliferation of RCC cells 786-0 and A498 without affecting cell viability. Moreover, honokiol also significantly inhibited migration of 786-0 cells in a dose-dependent manner. DNA microarray analysis showed that honokiol regulated expression of many genes related to human tumor metastasis in 786-0 cells. Real time PCR analysis confirmed that the expression of metastasis suppressor KISS1 and its receptor, KISS1R, were upregulated in 786-0 cells after treatment with honokiol. In addition, the shape changes and excessive formation of actin stress fibers were identified in 786-0 cells treated with honokiol. This phenomenon disappeared when treated cells with the pharmacological Rho-kinase inhibitor Y-27632 and honokiol. This inhibition can also be identified in 786-0 cells treated with Y-27632 only. Our present results demonstrated that honokiol could inhibit the growth and migration of RCC, which is likely to be regulated by the Rho and Rho-Associated Kinase (ROCK) pathway. In conclusion, honokiol is a biologically active natural compound which can be considered for the alternative treatment of RCC. The investigation of detailed mechanisms and molecular targets are in progress.

Citation Format: Shujie Cheng, Matt Welty, Isaac Eliaz, Victor Castillo, Daniel Sliva. Honokiol inhibits growth and migration of renal cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3203. doi:10.1158/1538-7445.AM2014-3203

The mushroom Ganoderma lucidum suppresses breast-to-lung cancer metastasis through the inhibition of pro-invasive genes

Breast cancer metastasis is one of the major reasons for the high morbidity and mortality of breast cancer patients. In spite of surgical interventions, chemotherapy, radiation therapy and targeted therapy, some patients are considering alternative therapies with herbal/natural products. In the present study, we evaluated a well-characterized extract from the medicinal mushroom Ganoderma lucidum (GLE) for its affects on tumor growth and breast-to-lung cancer metastasis. MDA-MB-231 human breast cancer cells were implanted into the mammary fat pads of nude mice. GLE (100 mg/kg/every other day) was administered to the mice by an oral gavage for 4 weeks, and tumor size was measured using microcalipers. Lung metastases were evaluated by hematoxylin and eosin (H&E) staining. Gene expression in MDA-MB-231 cells was determined by DNA microarray analysis and confirmed by quantitative PCR. Identified genes were silenced by siRNA, and cell migration was determined in Boyden chambers and by wound-healing assay. Although an oral administration of GLE only slightly suppressed the growth of large tumors, the same treatment significantly inhibited the number of breast-to-lung cancer metastases. GLE also downregulated the expression of genes associated with invasive behavior (HRAS, VIL2, S100A4, MCAM, I2PP2A and FN1) in MDA-MB-231 cells. Gene silencing of HRAS, VIL2, S100A4, I2PP2A and FN1 by siRNA suppressed migration of MDA-MB‑231 cells. Our study suggests that an oral administration of GLE can inhibit breast-to-lung cancer metastases through the downregulation of genes responsible for cell invasiveness. The anti-metastatic benefits of GLE warrant further clinical studies.

Triterpenes from Poria cocos suppress growth and invasiveness of pancreatic cancer cells through the downregulation of MMP-7

Poria cocos is a medicinal mushroom that is widely used in traditional Asian medicine. Here, we show that a characterized mixture of triterpenes extracted from P. cocos (PTE) and three purified triterpenes: pachymic acid (PA), dehydropachymic acid (DPA) and polyporenic acid C (PPAC) suppress the proliferation of the human pancreatic cancer cell lines Panc-1, MiaPaca-2, AsPc-1 and BxPc-3. Moreover, the most effective compound, PA, only slightly affects the proliferation of HPDE-6 normal pancreatic duct epithelial cells. The anti-proliferative effects of PTE on BxPc-3 cells are mediated by the cell cycle arrest at G0/G1 phase. DNA microarray analysis demonstrated that PTE significantly downregulates the expression of KRAS and matrix metalloproteinase-7 (MMP-7) in BxPc-3 cells. In addition, PTE and PA suppress the invasive behavior of BxPc-3 cells. The inhibition of invasiveness by PTE and PA was associated with the reduction of MMP-7 at the protein level and the role of MMP-7 further confirmed by the gene silencing of MMP-7 which also suppressed the invasiveness of BxPc-3 cells. In conclusion, triterpenes from P. cocos demonstrate anticancer and anti-invasive effects on human pancreatic cancer cells and can be considered as new therapeutic agents in the treatment of pancreatic cancer.

Mushroom Ganoderma lucidum prevents colitis-associated carcinogenesis in mice

BACKGROUND

Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT). The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice.

METHODS/PRINCIPAL FINDINGS

Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP]) and inflammation (dextran sodium sulfate [DSS]) in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF) formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue.

CONCLUSIONS

Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer.

BreastDefend™ prevents breast-to-lung cancer metastases in an orthotopic animal model of triple-negative human breast cancer

We have recently demonstrated that a natural dietary supplement BreastDefend (BD), which contains extracts from medicinal mushrooms (Coriolus versicolor, Ganoderma lucidum, Phellinus linteus), medicinal herbs (Scutellaria barbata, Astragalus membranaceus, Curcuma longa), and purified biologically active nutritional compounds (diindolylmethane and quercetin), inhibits proliferation and metastatic behavior of MDA-MB-231 invasive human breast cancer cells in vitro. In the present study, we evaluated whether BD suppresses growth and breast-to lung cancer metastasis in an orthotopic model of human breast cancer cells implanted in mice. Oral application of BD (100 mg/kg of body weight for 4 weeks) by intragastric gavage did not affect body weight or activity of liver enzymes and did not show any sign of toxicity in liver, spleen, kidney, lung and heart tissues in mice. Moreover, BD significantly decreased the change in tumor volume over time compared to the control group (p=0.002). BD treatment also markedly decreased the incidence of breast-to-lung cancer metastasis from 67% (control) to 20% (BD) (p<0.05) and the number of metastases from 2.8 (0.0, 48.0) in the control group to 0.0 (0.0, 14.2) in the BD treatment group (p<0.05). Finally, anti-metastatic activity of BD in vivo was further confirmed by the downregulation of expression of PLAU (urokinase plasminogen activator, uPA) and CXCR4 (C-X-C chemokine receptor-4) genes in breast tumors. In conclusion, BD may be considered as a biological therapeutic agent against invasive breast cancers.

Synergistic and additive effects of modified citrus pectin with two polybotanical compounds, in the suppression of invasive behavior of human breast and prostate cancer cells

AIM

The objective of this study was to evaluate the combined effect of a known galectin-3 inhibitor, PectaSol-C modified citrus pectin (MCP), and 2 novel integrative polybotanical compounds for breast and prostate health, BreastDefend (BD) and ProstaCaid (PC), on invasive behavior in human breast and prostate cancer cells in vitro, respectively.

METHODS

The effect of MCP and BD and of MCP and PC on invasiveness was assessed by cell adhesion, cell migration, and cell invasion assays. Secretion of urokinase plasminogen activator (uPA) was determined by Western blot analysis.

RESULTS

Although low concentrations of MCP (0.25-1.0 mg/mL) do not suppress cell adhesion of breast or prostate cancer cells, the combination of MCP with BD or PC synergistically inhibits adhesion of these cells. Dose-dependent inhibition of breast and prostate cancer cell migration by MCP (0.25-1.0 mg/mL) is synergistically enhanced by BD (20 µg/mL) and PC (10 µg/mL), respectively. BD or PC did not further inhibit the invasion of breast and prostate cancer cells by MCP; however, the combination of MCP with BD or PC suppressed secretion of uPA from breast and prostate cancer cells, respectively.

CONCLUSION

The combination of MCP with BD and of MCP with PC synergistically inhibits the metastatic phenotypes of human breast and prostate cancer cells, respectively. Further studies confirming these observations in animal models of breast and prostate cancer metastasis are warranted.

ProstaCaid inhibits tumor growth in a xenograft model of human prostate cancer

We have recently demonstrated that the dietary supplement ProstaCaid (PC) inhibits growth and invasive behavior of PC-3 human prostate cancer cells in vitro. In the present study, we evaluated toxicity and whether PC suppresses growth of prostate cancer in a xenograft model of human prostate cancer cells implanted in mice. Here, we show that an oral administration of PC (100, 200 and 400 mg/kg) did not affect body weight or activity of liver enzymes (ALT, AST) and did not show any sign of toxicity in liver, spleen, kidney, lung and heart tissues in mice. In addition, PC treatment resulted in the inhibition of tumor volumes (1024.6 ± 378.6 vs. 749.3 ± 234.3, P<0.001) in a xenograft model of prostate cancer with human hormone refractory (independent) PC-3 prostate cancer cells. Moreover, qRT-PCR analysis demonstrated significant upregulation of expression of CDKN1A (p21) and inhibition of expression of IGF2, NR2F2 and PLAU (uPA) genes by an oral administration of PC in prostate cancer xenografts. Our study demonstrates that the concentrations of the dietary supplement ProstaCaid tested did not show signs of toxicity, and its oral application has significant anticancer activity in vivo and can be considered as an alternative treatment for prostate cancer patients.

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.

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.

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.

Anti-inflammatory activity of edible oyster mushroom is mediated through the inhibition of NF-κB and AP-1 signaling

Background

Mushrooms are well recognized for their culinary properties as well as for their potency to enhance immune response. In the present study, we evaluated anti-inflammatory properties of an edible oyster mushroom (Pleurotus ostreatus) in vitro and in vivo.

Methods

RAW264.7 murine macrophage cell line and murine splenocytes were incubated with the oyster mushroom concentrate (OMC, 0-100 μg/ml) in the absence or presence of lipopolysacharide (LPS) or concanavalin A (ConA), respectively. Cell proliferation was determined by MTT assay. Expression of cytokines and proteins was measured by ELISA assay and Western blot analysis, respectively. DNA-binding activity was assayed by the gel-shift analysis. Inflammation in mice was induced by intraperitoneal injection of LPS.

Results

OMC suppressed LPS-induced secretion of tumor necrosis factor-α (TNF-α, interleukin-6 (IL-6), and IL-12p40 from RAW264.7 macrophages. OMC inhibited LPS-induced production of prostaglandin E2 (PGE₂) and nitric oxide (NO) through the down-regulation of expression of COX-2 and iNOS, respectively. OMC also inhibited LPS-dependent DNA-binding activity of AP-1 and NF-κB in RAW264.7 cells. Oral administration of OMC markedly suppressed secretion of TNF-α and IL-6 in mice challenged with LPS in vivo. Anti-inflammatory activity of OMC was confirmed by the inhibition of proliferation and secretion of interferon-γ (IFN-γ), IL-2, and IL-6 from concanavalin A (ConA)-stimulated mouse splenocytes.

Conclusions

Our study suggests that oyster mushroom possesses anti-inflammatory activities and could be considered a dietary agent against inflammation. The health benefits of the oyster mushroom warrant further clinical studies.

Suppression of growth and invasive behavior of human prostate cancer cells by ProstaCaid™: mechanism of activity

Since the use of dietary supplements as alternative treatments or adjuvant therapies in cancer treatment is growing, a scientific verification of their biological activity and the detailed mechanisms of their action are necessary for the acceptance of dietary supplements in conventional cancer treatments. In the present study we have evaluated the anti-cancer effects of dietary supplement ProstaCaid™ (PC) which contains mycelium from medicinal mushrooms (Ganoderma lucidum, Coriolus versicolor, Phellinus linteus), saw palmetto berry, pomegranate, pumpkin seed, green tea [40% epigallocatechin-3-gallate (EGCG)], Japanese knotweed (50% resveratrol), extracts of turmeric root (BCM-95®), grape skin, pygeum bark, sarsaparilla root, Scutellaria barbata, eleuthero root, Job's tears, astragalus root, skullcap, dandelion, coptis root, broccoli, and stinging nettle, with purified vitamin C, vitamin D3, selenium, quercetin, citrus bioflavonoid complex, β sitosterolzinc, lycopene, α lipoic acid, boron, berberine and 3.3'-diinodolymethane (DIM). We show that PC treatment resulted in the inhibition of cell proliferation of the highly invasive human hormone refractory (independent) PC-3 prostate cancer cells in a dose- and time-dependent manner with IC50 56.0, 45.6 and 39.0 µg/ml for 24, 48 and 72 h, respectively. DNA-microarray analysis demonstrated that PC inhibits proliferation through the modulation of expression of CCND1, CDK4, CDKN1A, E2F1, MAPK6 and PCNA genes. In addition, PC also suppresses metastatic behavior of PC-3 by the inhibition of cell adhesion, cell migration and cell invasion, which was associated with the down-regulation of expression of CAV1, IGF2, NR2F1, and PLAU genes and suppressed secretion of the urokinase plasminogen activator (uPA) from PC-3 cells. In conclusion, the dietary supplement PC is a promising natural complex with the potency to inhibit invasive human prostate cancer.

Apurinic/Apyrimidinic endonuclease 1 regulates inflammatory response in macrophages

The multi-functional apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) DNA repair and redox signaling protein has been shown to have a role in cancer growth and survival, however, little has been investigated concerning its role in inflammation. In this study, an APE1 redox-specific inhibitor (E3330) was used in lypopolysaccharide (LPS)-stimulated macrophages (RAW264.7). E3330 clearly suppressed secretion of inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin (IL-6) and IL-12 and inflammatory mediators nitric oxide (NO) as well as prostaglandin E(2) (PGE(2)) from the LPS-stimulated RAW264.7 cells. These data were supported by the down-regulation of the LPS-dependent expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) genes in the RAW264.7 cells. The effects of E3330 were mediated by the inhibition of transcription factors nuclear factor-κB (NF-κB) and activator protein 1 (AP-1) in the LPS-stimulated macrophages, both known targets of APE1. In conclusion, pharmacological inhibition of APE1 by E3330 suppresses inflammatory response in activated macrophages and can be considered as a novel therapeutic strategy for the inhibition of tumor-associated macrophages.

Ganodermanontriol, a lanostanoid triterpene from Ganoderma lucidum, suppresses growth of colon cancer cells through ß-catenin signaling

Colorectal cancer is one of the most common cancers in men and women in the world. Previous molecular studies have revealed that deregulation of the ß-catenin signaling pathway plays a crucial role in the progression of colorectal cancer. Therefore, modulation of the ß-catenin pathway offers a strategy to control colorectal cancer progression. The medicinal mushroom Ganoderma lucidum (GL) is a rich source of triterpenes with anticancer properties. Here, we show that ganodermanontriol (GNDT), a purified triterpene from GL, inhibited proliferation of HCT-116 and HT-29 colon cancer cells without a significant effect on cell viability. Moreover, GNDT inhibited transcriptional activity of ß-catenin and protein expression of its target gene cyclin D1 in a dose-dependent manner. A marked inhibition effect was also seen on Cdk-4 and PCNA expression, whereas expression of Cdk-2, p21 and cyclin E was not affected by the GNDT treatment. In addition, GNDT caused a dose-dependent increase in protein expression of E-cadherin and ß-catenin in HT-29 cells. Finally, GNDT suppressed tumor growth in a xenograft model of human colon adenocarcinoma cells HT-29 implanted in nude mice without any side-effects and inhibited expression of cyclin D1 in tumors. In conclusion, our data suggest that ganodermanontriol might be a potential chemotherapeutic agent for the treatment of cancer.

Suppression of Proliferation and Invasive Behavior of Human Metastatic Breast Cancer Cells by Dietary Supplement BreastDefend

Aim: The study was to evaluate the effect of the dietary supplement BreastDefend (BD) on the proliferation and invasive behavior of highly metastatic human breast cancer cells in vitro. Methods: Cell proliferation and cytotoxicity of BD was evaluated in MDA-MB-231 cells treated with BD (0-40 μg/mL) by MTT assay and trypan blue staining, respectively. Expression of cell cycle regulatory genes were determined by DNA-microarray analysis. Effect of BD on invasiveness was assessed by cellular adhesion, migration, and invasion assays. Results: BD treatment of cells MDA-MB-231 resulted in the cytostatic inhibition of cell proliferation with IC50 22.2, 19.1, and 17.5 μg/mL for 24, 48, and 72 hours, respectively. The inhibition of proliferation was mediated by the upregulation expression of CCNG1, CHEK1, CDKN1C, GADD45A, and E2F2, whereas BD downregulated expression of CCNA1 and CDK6 genes. The induction of expression of GADD45A and inhibition of expression of cyclin A1 (gene CCNA1) by BD was also confirmed on the protein level. BD treatment suppressed the invasive behavior of MDA-MB-231 cells by the inhibition of cellular adhesion, migration, and invasion. This inhibition of invasiveness was mediated by the suppression of secretion of urokinase plasminogen activator (uPA), and by the downregulation of expression of CXCR4 in breast cancer cells treated with BD. Conclusion: BD inhibits proliferation and invasive behavior of the highly metastatic human breast cancer cells in vitro. BD may have a therapeutic potential for prevention or treatment of highly metastatic breast cancers.

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

Medicinal mushroom Ganoderma lucidum is one of the most esteemed natural products that have been used in the traditional Chinese medicine. In this article, we demonstrate that G. lucidum triterpene extract (GLT) suppresses proliferation of human colon cancer cells HT-29 and inhibits tumor growth in a xenograft model of colon cancer. These effects of GLT are associated with the cell cycle arrest at G0/G1 and the induction of the programmed cell death Type II-autophagy in colon cancer cells. Here, we show that GLT induces formation of autophagic vacuoles and upregulates expression of Beclin-1 (1.3-fold increase) and LC-3 (7.3-fold increase) proteins in colon cancer cells and in tumors in a xenograft model (Beclin-1, 3.9-fold increase; LC-3, 1.9-fold increase). Autophagy is mediated through the inhibition of p38 mitogen-activated protein kinase (p38 MAPK) because p38 MAPK inhibitor, SB202190, induces autophagy and expression of Beclin-1 (1.2-fold increase) and LC-3 (7.4-fold increase), and GLT suppresses phosphorylation of p38 MAPK ( approximately 60% inhibition) in colon cancer cells. Taken together, our data demonstrate a novel mechanism responsible for the inhibition of colon cancer cells by G. lucidum and suggest GLT as natural product for the treatment of colon cancer.

Medicinal mushroom Phellinus linteus as an alternative cancer therapy

Alternative cancer treatment with nutritional/dietary supplements containing a wide variety of herbal products is on the rise in Western countries. Recent epidemiological studies have suggested that mushrooms may prevent against different types of cancers. Phellinus linteus is a well-known Oriental medicinal fungus with a variety of biological activities, including immunomodulatory or direct antitumor activities. The activity of P. linteus and its extracts is associated with the presence of polysaccharides, their peptide/protein complexes and other low molecular weight complexes. Polysaccharide fractions isolated from P. linteus were found to be related to the increased activity of immune cells such as the production of cytokines by macrophages and B-cells or the increased cytotoxic activity of natural killer cells. Moreover, P. linteus was found to modulate the expression or activity of various genes involved in cell proliferation, apoptosis, angiogenesis, invasive behavior and chemoprevention. Finally, P. linteus extracts demonstrated tumor regression in three independent case reports, suggesting that an extract from P. linteus or a dietary supplement based on the extract from P. linteus may have potential use for the alternative treatment of cancer.

Pleurotus ostreatus inhibits proliferation of human breast and colon cancer cells through p53-dependent as well as p53-independent pathway

In spite of the global consumption of mushrooms, only two epidemiological studies demonstrated an inverse correlation between mushroom intake and the risk of cancer. Therefore, in the present study we evaluated whether extracts from edible mushrooms Agaricus bisporus (portabella), Flammulina velutipes (enoki), Lentinula edodes (shiitake) and Pleurotus ostreatus (oyster) affect the growth of breast and colon cancer cells. Here, we identified as the most potent, P. ostreatus (oyster mushroom) which suppressed proliferation of breast cancer (MCF-7, MDA-MB-231) and colon cancer (HT-29, HCT-116) cells, without affecting proliferation of epithelial mammary MCF-10A and normal colon FHC cells. Flow cytometry revealed that the inhibition of cell proliferation by P. ostreatus was associated with the cell cycle arrest at G0/G1 phase in MCF-7 and HT-29 cells. Moreover, P. ostreatus induced the expression of the tumor suppressor p53 and cyclin-dependent kinase inhibitor p21(CIP1/WAF1), whereas inhibited the phosphorylation of retinoblastoma Rb protein in MCF-7 cells. In addition, P. ostreatus also up-regulated expression of p21 and inhibited Rb phosphorylation in HT-29 cells, suggesting that that P. ostreatus suppresses the proliferation of breast and colon cancer cells via p53-dependent as well as p53-independent pathway. In conclusion, our results indicated that the edible oyster mushroom has potential therapeutic/preventive effects on breast and colon cancer.

Suppression of cancer invasiveness by dietary compounds

Tumor invasion and cancer metastasis are interrelated processes involving cell growth, cell adhesion, cell migration and proteolytic degradation of tissue barriers, which are mediated by aberrant intracellular signaling in cancer cells. Natural (green tea polyphenols, soy isoflavones) or dietary compounds (mushroom G. lucidum) markedly decreased AP-1 and NF-kappaB signaling and suppressed invasiveness of cancer cells. This review will summarize alternative approaches for the inhibition of invasive behavior of cancer cells by dietary compounds, which can be considered in adjuvant or combination therapy for the prevention and treatment of cancer metastasis.

Ganoderic acids suppress growth and invasive behavior of breast cancer cells by modulating AP-1 and NF-kappaB signaling

Structurally related lanostane-type triterpenes, ganoderic acid A, F and H (GA-A, GA-F, GA-H), were identified in an oriental medicinal mushroom Ganoderma lucidum. In the present study we evaluated the effect of GA-A, GA-H and GA-F on highly invasive human breast cancer cells. We showed that GA-A and GA-H suppressed growth (cell proliferation and colony formation) and invasive behavior (adhesion, migration and invasion) of MDA-MB-231 cells. Our results suggest that GA-A and GA-H mediate their biological effects through the inhibition of transcription factors AP-1 and NF-kappaB, resulting in the down-regulation of expression of Cdk4 and the suppression of secretion of uPA, respectively. Furthermore, the activity of ganoderic acids is linked to the hydroxylation in the position 7 and 15 (GA-A) and 3 (GA-H) in their triterpene lanostane structure. In conclusion, hydroxylated triterpenes from G. lucidum could be promising natural agents for the therapy of invasive breast cancers.

Combined effect of green tea and Ganoderma lucidum on invasive behavior of breast cancer cells

Epidemiological studies have suggested that consumption of green tea may decrease the risk of a variety of cancers. In addition, mushroom Ganoderma lucidum has been used for the promotion of health, longevity and treatment of cancer in traditional Chinese medicine. In the present study we show that extract from green tea (GTE) increased the anticancer effect of G. lucidum extract (GLE) on cell proliferation (anchorage-dependent growth) as well as colony formation (anchorage-independent growth) of breast cancer cells. This effect was mediated by the down-regulation of expression of oncogene c-myc in MDA-MB-231 cells. Although individual GTE and GLE independently inhibited adhesion, migration and invasion of MDA-MB-231 cells, their combination demonstrated a synergistic effect, which was mediated by the suppression of secretion of urokinase plasminogen activator (uPA) from breast cancer cells. Our study suggests the potential use of combined green tea and G. lucidum extracts for the suppression of growth and invasiveness of metastatic breast cancers.

Synthesis and screening of N-alkyl hydroxamates for inhibition of cancer cell proliferation

A small library of N-alkylated amino acid-derived sulfonamide hydroxamates was synthesized on solid phase and tested for inhibition of proliferation of the highly invasive breast cancer cell line MDA-MB-231. The most active compound 4317 inhibited cell growth at IC(50) 30 microM. N-alkylation of N-H hydroxamate-based MMP inhibitors, a modification known to eliminate MMP activity, enhanced cell proliferation inhibition potency.

Inhibition of oxidative stress-induced invasiveness of cancer cells by Ganoderma lucidum is mediated through the suppression of interleukin-8 secretion

Epidemiological studies suggest that the intake of natural/nutrient products is inversely related to cancer risk. While oxidative stress, generating reactive oxygen species, has been linked to cancer initiation and progression, dietary antioxidants have reduced the risk of certain cancers. Experimental studies have demonstrated that antioxidants and phytochemicals could prevent cancer metastasis, and antioxidants were suggested as adjuvants in cancer therapy. Ganoderma lucidum is an Asian medicinal mushroom that has been used for the past two thousand years for the treatment of various diseases, including cancer. G. lucidum is currently popular as a dietary supplement in the form of tea, powder or extract. We have previously demonstrated that G. lucidum suppresses growth, angiogenesis and invasiveness of highly invasive and metastatic breast cancer cells. The present study was undertaken to evaluate the effect of G. lucidum on oxidative stress-induced metastatic behavior of poorly-invasive MCF-7 breast cancer cells. We show that G. lucidum inhibits oxidative stress-induced migration of MCF-7 cells by the down-regulation of MAPK signaling. G. lucidum suppressed oxidative stress stimulated phosphorylation of extracellular signal-regulated protein kinases (Erk1/2), which resulted in the down-regulation of expression of c-fos, and in the inhibition of transcription factors AP-1 and NF-kappaB. The biological effect of G. lucidum on cell migration was mediated by the suppression of secretion of interleukin-8 from MCF-7 cells exposed to oxidative stress. In summary, our results suggest that G. lucidum inhibits the oxidative stress-induced invasive behavior of breast cancer cells by modulating Erk1/2 signaling and can be potentially considered as an antioxidant in adjuvant cancer therapy.

Ganoderma lucidum inhibits proliferation of human breast cancer cells by down-regulation of estrogen receptor and NF-kappaB signaling

Ganoderma lucidum, an oriental medical mushroom, has been used in Asia for the prevention and treatment of a variety of diseases, including cancer. We have previously demonstrated that G. lucidum inhibits growth and induces cell cycle arrest at G0/G1 phase through the inhibition of Akt/NF-kappaB signaling in estrogen-independent human breast cancer cells. However, the molecular mechanism(s) responsible for the inhibitory effects of G. lucidum on the proliferation of estrogen-dependent (MCF-7) and estrogen-independent (MDA-MB-231) breast cancer cells remain to be elucidated. Here, we show that G. lucidum inhibited the proliferation of breast cancer MCF-7 and MDA-MB-231 cells by the modulation of the estrogen receptor (ER) and NF-kappaB signaling. Thus, G. lucidum down-regulated the expression of ERalpha in MCF-7 cells but did not effect the expression of ERbeta in MCF-7 and MDA-MB-231 cells. In addition, G. lucidum inhibited estrogen-dependent as well as constitutive transactivation activity of ER through estrogen response element (ERE) in a reporter gene assay. G. lucidum decreased TNF-alpha-induced (MCF-7) as well as constitutive (MDA-MB-231) activity of NF-kappaB. The inhibition of ER and NF-kappaB pathways resulted in the down-regulation of expression of c-myc, finally suppressing proliferation of estrogen-dependent as well as estrogen-independent cancer cells. Collectively, these results suggest that G. lucidum inhibits proliferation of human breast cancer cells and contain biologically active compounds with specificity against estrogen receptor and NF-kappaB signaling, and implicate G. lucidum as a suitable herb for chemoprevention and chemotherapy of breast cancer.