Niu Y, Chang TM, Yeh S, Ma WL, Wang YZ, Chang C (2010) Differential androgen receptor signals in different cells explain why androgen-deprivation therapy of prostate cancer fails. Oncogene 29, 3593-3604.
Prostate cancer is one of the major causes of cancer-related death in the western world. Androgen-deprivation therapy (ADT) for the suppression of androgens binding to the androgen receptor (AR) has been the norm of prostate cancer treatment. Despite early success to suppress prostate tumor growth, ADT eventually fails leading to recurrent tumor growth in a hormone-refractory manner, even though AR remains to function in hormone-refractory prostate cancer. Interestingly, some prostate cancer survivors who received androgen replacement therapy had improved quality of life without adverse effect on their cancer progression. These contrasting clinical data suggest that differential androgen/AR signals in individual cells of prostate tumors can exist in the same or different patients, and may be used to explain why ADT of prostate cancer fails. Such a hypothesis is supported by the results obtained from transgenic mice with selective knockout of AR in prostatic stromal vs epithelial cells and orthotopic transplants of various human prostate cancer cell lines with AR over-expression or knockout. These studies concluded that AR functions as a stimulator for prostate cancer proliferation and metastasis in stromal cells, as a survival factor of prostatic cancer epithelial luminal cells, and as a suppressor for prostate cancer basal intermediate cell growth and metastasis. These dual yet opposite functions of the stromal and epithelial AR may challenge the current ADT to battle prostate cancer and should be taken into consideration when developing new AR-targeting therapies in selective prostate cancer cells.
Johnson BM, Doonan BP, Radwan FF, Haque A (2010). Ganoderic Acid DM: An Alternative Agent for the Treatment of Advanced Prostate Cancer. Open Prost Cancer J 3,78-85.
Prostate cancer is the most commonly diagnosed cancer in men and accounts for significant morbidity and mortality in the western world. While traditional therapies are effective at clearing early stage cancer, they often fail to treat late stage metastatic disease. Thus, an effective therapy that targets prostate tumor growth and metastasis is desired for alleviating the disease and improving patient outcomes. Natural extracts have been the focus of recent investigation, particularly those with reduced cellular toxicity to healthy tissue. In this review, we discuss one potential candidate, ganoderic acid, an extract from the Ganoderma lucidum mushroom that has been tested in multiple cancer models. Interestingly, ganoderic acid DM (GA-DM) has shown toxicity to both androgen-dependent and independent prostate cancer cells with reduced osteoclastogenesis in late stage metastatic disease. This review will discuss the current knowledge on this GA-DM extract and the potential benefit in treating advanced prostate cancer. We will also provide an overview on the targeted delivery of GA-DM through nanoparticles that would reduce bystander toxicity and improve the drug's effectiveness. An improved understanding of this drug and its uses will advance the field of natural chemotherapeutics, particularly in treating advanced prostate cancer.
Jiang J, Grieb B, Thyagarajan A, Sliva D (2008). Ganoderic acids suppress growth and invasive behavior of breast cancer cells by modulating AP-1 and NF-kappaB signaling. Int J Mol Med 21, 577–84.
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.
Zheng J, Yang B, Yu Y, Chen Q, Huang T, Li D (2012). Ganoderma lucidum polysaccharides exert anti-hyperglycemic effect on streptozotocin-induced diabetic rats through affecting β-cells. Comb Chem High Throughput Screen 15(7):542-50.
Previous studies have demonstrated that Ganoderma lucidum polysaccharides (Gl-PS) exhibited potential antihyperglycemic effect in rats. The aim of the present study was to investigate the mechanism of the hypoglycemic effect of a low- molecular-weight Gl-PS in streptozotocin (STZ)-induced diabetic Sprague-Dawley (SD) rats. Gl-PS was extracted and purified from Ganodema lucidum fruiting body. 50 male SD rats were included in the study; 10 were taken as healthy controls; 40 were induced to diabetes by a single injection of 65 mg/kg STZ, of which 30 were selected as successful diabetic rat models. The 30 diabetic rats were divided into three groups: Gl-PS (200 mg/kg Gl-PS), metformin (100 mg/kg metformin) and diabetic control (n = 10 per group). After eight weeks' oral administration, plasma concentrations of fasting glucose, triacylglyceride, total cholesterol and nitric oxide were significantly decreased in Gl-PS and metformin groups. Pancreatic superoxide dismutase, catalase and glutathione peroxidase were significantly increased in Gl-PS and metformin groups. Histopathological results showed that Gl-PS and metformin had protective effect on β-cells. The mRNA expressions of Bcl-2 and PDX-1 in pancreas were up-regulated, but Bax, iNOS and Casp-3 down-regulated in Gl- PS and metformin groups compared to diabetic control group. The present results suggested that Gl-PS had a hypoglycemic effect in STZ-induced diabetic rats through preventing apoptosis of pancreatic β-cells and enhancing β-cells regeneration.
Suppression of the inflammatory response by triterpenes isolated from the mushroom Ganoderma lucidum
In conclusion, the anti-inflammatory and anti-proliferative effects of GLT on macrophages are mediated through the inhibition of NF-κB and AP-1 signaling pathways.
Ganoderma lucidum extract attenuates the proliferation of hepatic stellate cells by blocking the PDGF receptor.
These results indicated that G. lucidum inhibits PDGF-BB-activated HSC proliferation possibly through blocking PDGFbetaR phosphorylation, thereby indicating its efficacy for preventing and treating hepatic fibrosis.
Antifibrotic activity a fermentation filtrate of Ganoderma lucidum
The effects of a fermentation filtrate of Ganoderma lucidum (FGL) on carbon tetrachloride (CCl4)-induced hepatic fibrosis were investigated in rats. Male Sprague-Dawley rats were orally administered with FGL (20 or 100 mg/kg) for 33 days, and orally administered with CCl4 (1.0 mL/kg; 2 mL/kg of 50% in corn oil) at 3-day intervals 1 h after FGL treatment. Body and liver weights, blood and histopathological findings in accordance with hydroxyproline concentrations were analyzed. Chronic exposure to CCl4 reduced the body weight gain, but increased liver weights and fibrosis, resulting in 3.35-fold increase in hydroxyproline level. Although FGL did not significantly reduce the CCl4-induced body and liver weight changes, it attenuated the increases in the hepatic fibrosis and hydroxyproline contents. Taken together, it is suggested that FGL might prevent hepatic fibrosis, and that FGL or its ingredient could be a potential candidate for the prevention of chronic hepatic disorders.
An update on plant derived anti-androgens.
Anti-androgens are an assorted group of drugs and compounds that reduce the levels or activity of androgen hormones within the human body. Disease states in which this is relevant include polycystic ovarian syndrome, hirsutism, acne, benign prostatic hyperplasia, and endocrine related cancers such as carcinoma of the prostate. We provide an overview and discussion of the use of anti-androgen medications in clinical practice and explore the increasing recognition of the benefits of plant-derived anti-androgens, for example, spearmint tea in the management of PCOS, for which some evidence about efficacy is beginning to emerge. Other agents covered include red reishi, which has been shown to reduce levels 5-alpha reductase, the enzyme that facilitates conversion of testosterone to dihydrotestosterone (DHT); licorice, which has phytoestrogen effects and reduces testosterone levels; Chinese peony, which promotes the aromatization of testosterone into estrogen; green tea, which contains epigallocatechins and also inhibits 5-alpha reductase, thereby reducing the conversion of normal testosterone into the more potent DHT; black cohosh, which has been shown to kill both androgenresponsive and non-responsive human prostate cancer cells; chaste tree, which has a reduces prolactin from the anterior pituitary; and saw palmetto extract, which is used as an anti-androgen although it shown no difference in comparison to placebo in clinical trials.