Antioxidant and Antiproliferative Effect of Pleurotus ostreatus

In this study, ethanol extract of an edible mushroom Pleurotus ostreatus cultivated under the laboratory condition was investigated for its antioxidant and anticancer property in vitro. To confirm the total antioxidant activity, ABTS, DPPH free radical-scavenging assay was carried, along with total phenolic and flavonoid concentration. The ethanolic extract showed a potent antioxidant activity against both DPPH and ABTS radicals, with the EC50 value of 0.202±0.55 mg/mL and 6.42±0.261 mg/mL. Antioxidant components like total flavonoids were 1.82±0.15 µg/mg (Quercetin equivalent) and the total phenols were 8.52±0.6 mg/g (Catechin equivalent). Against the cancer cell (HL-60) in vitro P. ostreatus extracts exhibited the cytotoxic effect. The HL-60 cells treated with ethanol extract was further stained with propidium iodide and analyzed through flow cytometry, to identify whether the cytotoxicity induction was due to apoptosis or necrocis. The results of the flow cytometry confirm the cytotoxic effect of the mushroom extract was found to be mediated by the induction of apoptosis. In conclusion, our results supported the consumption of edible mushroom that act as a good dietary supplement and functional food

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) i

Mushroom \u3ci\u3eGanoderma lucidum\u3c/i\u3e 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 downregulated 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

Deubiquitinase UCHL1 Maintains Protein Homeostasis through the PSMA7–APEH–Proteasome Axis in High-grade Serous Ovarian Carcinoma

High-grade serous ovarian cancer (HGSOC) is characterized by chromosomal instability, DNA damage, oxidative stress, and high metabolic demand that exacerbate misfolded, unfolded, and damaged protein burden resulting in increased proteotoxicity. However, the underlying mechanisms that maintain protein homeostasis to promote HGSOC growth remain poorly understood. This study reports that the neuronal deubiquitinating enzyme, ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), is overexpressed in HGSOC and maintains protein homeostasis. UCHL1 expression was markedly increased in HGSOC patient tumors and serous tubal intraepithelial carcinoma (HGSOC precursor lesions). High UCHL1 levels correlated with higher tumor grade and poor patient survival. UCHL1 inhibition reduced HGSOC cell proliferation and invasion, as well as significantly decreased the in vivo metastatic growth of ovarian cancer xenografts. Transcriptional profiling of UCHL1-silenced HGSOC cells revealed downregulation of genes implicated with proteasome activity along with upregulation of endoplasmic reticulum stress–induced genes. Reduced expression of proteasome subunit alpha 7 (PSMA7) and acylaminoacyl peptide hydrolase (APEH), upon silencing of UCHL1, resulted in a significant decrease in proteasome activity, impaired protein degradation, and abrogated HGSOC growth. Furthermore, the accumulation of polyubiquitinated proteins in the UCHL1-silenced cells led to attenuation of mTORC1 activity and protein synthesis, and induction of terminal unfolded protein response. Collectively, these results indicate that UCHL1 promotes HGSOC growth by mediating protein homeostasis through the PSMA7–APEH–proteasome axis.This study identifies the novel links in the proteostasis network to target protein homeostasis in HGSOC and recognizes the potential of inhibiting UCHL1 and APEH to sensitize cancer cells to proteotoxic stress in solid tumors

Effect of GLT on the PhIP/DSS induced colon carcinogenesis and inflammation.

<p>Tumor incidence are summarized using percentage of animals with tumors and compared across groups using Fisher's exact test and the Bonferonni correction for multiple comparisons: ^a p<0.001 PhIP/DSS vs control, PhIP, DSS; ^b p<0.02 PhIP/DSS+500 GLT vs PhIP/DSS.</p><p>Tumor multiplicity are summarized using mean ± SD and compared across all group using Kruskal-Wallis one way analysis of variance on ranks and the Dunn's method for the multiple comparisons: ^a p<0.05 PhIP/DSS vs control PhIP, DSS; ^b p<0.05 PhIP/DSS+500 GLT vs PhIP/DSS.</p><p>Neoplastic index is summarized using median (min, max) and compared across groups using the Kruskal-Wallis test. Comparisons of each group to control performed using Mann-Whitney U tests with significance levels adjusted using the Bonferroni correction: ^a p<0.001 control vs PhIP; ^b p<0.001 control vs PhIP/DSS.</p><p>Data for colon length summarized using mean ± SD and compared across all group using ANOVA and Dunnett's post hoc test: ^ap<0.001 control vs DSS, control vs PhIP/DSS; ^bp<0.001 PhIP/DSS vs PhIP/DSS+100 GLT, PhIP/DSS vs PhIP/DSS+500 GLT.</p

GLT suppresses PhIP/DSS induced formation of colon tumors and inhibits focal hyperplasia and ACF formation.

<p>(A) Schematic of the animal treatment. The details of the treatment are described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047873#s4" target="_blank"><i>Materials and Methods</i></a>. (B) Body weight of control animals (black circle), animals treated with PhIP (white square), DSS (black square), PhIP/DSS (white circle), PhIP/DSS+GLT 100 mg/kg of body weight (black triangle), and PhIP/DSS+GLT 500 mg/kg of body weight (white traingle) during the experiment. (C) H&E staining of representative samples from animal experiments described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047873#pone-0047873-g001" target="_blank">Figure 1A</a>. (D) Focal hyperplasia was evaluated by the histological analysis after H&E staining in colon tissue samples as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047873#s4" target="_blank"><i>Materials and Methods</i></a>. Results are means ± SD (n = 6–9 mice/per group). (E) ACF formation was evaluated after methylene blue staining as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047873#s4" target="_blank"><i>Materials and Methods</i></a>. Results are means ± SD (n = 10 foci/3 mice/per group), *p<0.05 by ANOVA.</p

GLT down-regulates expression of COX-2 in colon tissue.

<p>(A) Immunohistochemistry and (B) quantification of COX-2 positive cells were performed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047873#s4" target="_blank"><i>Materials and Methods</i></a>. Box plots represent 5^th/10^th percentiles, horizontal bars represent median values, and whiskers indicate minimum to maximum values. Significant differences (*p<0.05) were observed among PhIP/DSS vs. control, PhIP/DSS vs PhIP/DSS+GLT 100, and PhIP/DSS vs. PhIP/DSS+GLT 100.</p

Effect of GLT on the lipid metabolism.

<p>Values are Mean ± S.D. (n = 6), HDL, high-density lipoprotein. No significant difference from the control group.</p