Synergistic Effect of Exercise and Phellodendron Amurense on Muscle Mass Preservation in a Prostate Cancer Mouse Model

Muscle loss has detrimental effects on the body. It leads to a reduction in physical function, strength, endurance, and quality of life. In men with prostate cancer (PCa), a large percentage of men will suffer from muscle loss, a debilitating adverse effect caused by both the chronic illnesses or from the treatment of these illnesses. Studies have shown that the implementation of a routine exercise elicits muscle preservation in patients with PCa. Previously, our group has found that the natural product phellodendron amurense (PA) preserves muscle mass similar to exercise. PURPOSE: The purpose of this study is to test the hypothesis that combining PA and exercise will have a synergistic effect on muscle preservation and strength. METHOD: Twenty-four, 10-week-old transgenic adenocarcinoma of the mouse prostate (TRAMP) mice were randomized into one of four study groups: Exercise (running wheel) group, PA group, exercise plus PA, or no treatment control. PA was pelleted into the feed at a dose of 600 mg/kg and provided ad lib. Body mass was measured each week. Fore limb and all limb grip strength was measured at baseline and end of study (Columbus Instruments, Columbus, OH). Mice completed 10 repetitions on the apparatus with the first five repetitions using only the forelimbs and the last five repetitions using all four limbs. After euthanasia, the right gastrocnemius and soleus were collected, cleaned and weighted. One way and two-way analysis of variance was performed with tukey’s post-hoc test. Significance was set at pRESULTS: Analysis of body weight revealed significant differences between groups (F(3,20) = 2.93, P = 0.0311). Post hoc analysis revealed significantly lower body mass at the end of the study in the combination exercise plus PA group (25.83 ± 1.72 g) compared to the control group (28.70 ± 1.70 g; p=0.03). Higher soleus mass was found in the mice from the exercise only (11.6 ± 5 mg) and combination exercise plus PA (11.5 ± 3.271 mg) groups compared to the no treatment control group (10.33 ± 3.445 mg), however, these results did not reach significance. No statistical significance was found in the measurement of forelimb or all limb grip strength. CONCLUSION: Our initial hypothesis of synergy was not supported, however, there is preliminary evidence that exercise and PA independently reduces the loss of slow twitch skeletal muscle induced by cancer. Future research is required to validate these results

Activation of AKR1C1/ERβ induces apoptosis by downregulation of c-FLIP in prostate cancer cells: A prospective therapeutic opportunity

We provide first-time evidence for ERβ-mediated transcriptional upregulation of c-FLIP as an underlying mechanism in the development of castrate-resistant cancer. While androgens inhibit apoptosis partly through transcriptional upregulation of the anti-apoptotic protein, c-FLIP in androgen-responsive cells, they downregulate c-FLIP in androgen-independent cells. We found that although Sp1 and p65 trans-activate c-FLIP, the combination of Sp1 and p65 has differential effects in a cellular context-dependent manner. We show that activation of the androgen metabolism enzyme, aldo-keto reductase, AKR1C1, relieves androgen independence through activation of 3β-Adiol-mediated upregulation of ERβ. ERβ competes with Sp1 and Sp3 to transcriptionally downregulate c-FLIP in the absence of consensus estrogen-response element in androgen-independent cells. Forced expression of AR in androgen-independent cells show that ERβ-mediated growth inhibition occurs under conditions of androgen independence. Reactivation of ERβ with the estrogenic metabolite, 2-methoxyestradiol, decreased enrichment ratio of Sp1/Sp3 at the c-FLIP promoter with concomitant effects on cell growth and death. Expression of Sp1 and c-FLIP are elevated while AKR1C1, ERβ and Sp3 are significantly low in human prostate tumor samples. ERβ is epigenetically silenced in prostate cancer patients, therefore our results suggest that combination of ERβ agonists with ADT would benefit men stratified on the basis of high estrogen levels

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Abstract 1660: Therapeutic targeting cross talk between ROS/autophagy and apoptosis for pancreatic cancer by a herbal extract.

Abstract 5-year survival for pancreatic cancer (PanCA) continuous to be lower than any other solid tumor due to late stage diagnosis combined with lack of effective therapeutic options. Therefore developing novel strategies possibly based on molecular targets is critical for successful management of PanCA. Recent studies from our laboratory show potential anti-pancreatic cancer activity for NexrutineR (Nx), a bark extract isolated from traditional Chinese medicine Phellodendron amurense. These studies also show that Nx reduces pancreatic fibrosis in preclinical animal model through targeting two critical oncogenic transcription factors including NF-κB and Stat3. Nonetheless, the precise molecular mechanism associated with the observed biological activity is unclear. We investigated whether Nx inhibits pancreatic cell proliferation and pancreatic fibrosis via reactive oxygen species (ROS)-mediated activation of autophagy. Our data show that Nx can induce autophagy at earlier time points (4h) but inhibit autophagy at later time points (24h) in human pancreatic cancer cell lines Capan-2 and BxPC-3 as evidenced by autophagosome formation, alteration in the expression and levels of various autophagy related genes. Interestingly Nx also induced apoptosis at 24h time point but not at 4h suggesting that autophagy precedes apoptosis. Further under these experimental conditions, treatment of pancreatic cancer cells with Nx enhanced intracellular production of ROS implicating a cross talk between Nx-induced ROS, autophagy and apoptosis. Overall, our findings divulge an important role for ROS/autophagy/apoptosis in Nx-mediated anti-pancreatic cancer effects. Supported by NCCAM (APK). Citation Format: Gong Jingjing, Addanki P. Kumar. Therapeutic targeting cross talk between ROS/autophagy and apoptosis for pancreatic cancer by a herbal extract. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1660. doi:10.1158/1538-7445.AM2013-1660</jats:p

Abstract 3047: 2-Methoxyestradiol inhibits proliferation and induces apoptosis through modulation of miR-7/FLIP signaling in prostate cancer cells

Abstract Prostate cancer is the second most common cause of death related to cancer in Western societies. 2-Methoxyestradiol (2-ME2), an endogenous metabolite of 17-β estradiol inhibits tumor cell proliferation in various cancer cells, including in the prostate. Previous studies from our laboratory showed that 2-ME2 (i) inhibits proliferation of both androgen responsive and independent cells through induction of apoptosis involving G2/M check point block; (ii) prevents the development of prostate tumors in transgenic adenocarcinoma of mouse prostate (TRAMP) model. Although various molecular targets have been proposed, the mechanism of action behind its antiproliferative activity is still uncertain. Here we investigated the hypothesis that 2-ME2 may induce apoptosis in prostate cancer cells through modulation of microRNA (miRNAs). MicroRNAs are small non-coding RNAs that down regulate gene expression during cellular processes including proliferation and apoptosis. These studies led to the identification of miR-7 and −10 as predominantly up-regulated in response to 2-ME2 treatment in prostate cancer cell lines. Knock-down of miR-7 and −10 using mercury LNA probes showed resistance to 2-ME2-induced proliferation of prostate cancer cells. Additional studies to assess the effect of miR-7 knock-down to regulate apoptosis gene expression identified FLIP (FLICE -inhibitory protein) as one of the downstream targets of miR-7. We have shown that high grade prostate tumors express FLIP at higher levels compared to low grade and inhibition of prostate tumor development by 2-ME2 in preclinical animal model is associated with down regulation of FLIP. In addition overexpression of FLIP has been shown to contribute to resistance to apoptosis. We interpret our findings to suggest that up regulation of miR-7 following treatment with 2-ME2 inhibits FLIP leading to reduced proliferation and induction of apoptosis. Therefore our results may provide a molecular basis for the ability of 2-ME2 to suppress proliferation and to induce apoptosis in prostate cancer cells through modulation of miR-7 mediated inhibition of antiapoptotic genes including FLIP. Supported by ACS RSG-04-169 and NIH CA 135451 (APK). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3047.</jats:p

Abstract 4951: 2-Methoxyestradiol (2-ME2) induces microRNA alterations in prostate cancer cells: Role for miRs in 2-ME2-induced biological effects

Abstract Prostate cancer is the second most common cause of death related to cancer in Western societies. 2-Methoxyestradiol (2-ME2), an endogenous metabolite of 17-β estradiol inhibits tumor cell proliferation in various cancer cells, including the prostate. Previous studies from our laboratory showed that 2-ME2 (i) inhibits proliferation of both androgen responsive and independent cells through induction of apoptosis involving G2/M check point block; (ii) prevents the development of prostate tumors in transgenic adenocarcinoma of mouse prostate (TRAMP) model. Although various molecular targets have been proposed, the mechanism of action behind its antiproliferative activity is still uncertain. Here we investigated the possible role for 2-ME2 induced antiproliferative activity by examining the altered regulation of microRNA (miRNAs). MicroRNAs are small non-coding RNAs that down regulate gene expression during cellular processes including proliferation and apoptosis. We compared the microRNA profile in non-tumorigenic (RWPE-1), androgen responsive (LNCaP) and androgen independent (PC-3) cells in response to 2-ME2 treatment in the presence and absence of androgen-stimulation (only in LNCaP cells) using the stem-loop RT-PCR based Taqman® Array Human MicroRNA Cards (Array A and B) representing 754 unique assays specific to human mature miRNAs (Applied Biosystems, Foster City, CA). Analysis of these data identified expression of only 50% of miRs in prostate cancer cells. About 26% and 12% of these are upregulated; 20.5% and 26% were down regulated in LNCaP and PC-3 cells respectively. However androgen stimulation of LNCaP cells resulted in upregulation of 34.2% and 15% down regulation of miRs whereas 2-ME2 treatment down regulated 28.7% of miRs. Target transcripts for these miRs have been identified. To the best of our knowledge this is the first study to report in-depth investigation of global miR changes in response to 2-ME2 induced biological effects. These data demonstrate that 2-ME2 suppresses proliferation and induces apoptosis in prostate cancer cells through modulation of microRNA signature. Supported by NIH CA 135451 (APK). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4951. doi:10.1158/1538-7445.AM2011-4951</jats:p

Abstract 2921: NAD(P)H quinone oxidoreductase 1 regulates pro-inflammatory mediators associated with prostate tumorigenesis.

Abstract Oxidative stress and inflammation are both important in the neoplastic transformation of the prostate. NAD(P)H Quinone Oxidoreductase 1 (NQO1) is a key antioxidant enzyme that protects against quinone-derived reactive intermediates and maintains a cellular pool of antioxidants. Various studies conducted using NQO1 knockout mice suggested its potential role in carcinogenesis. However the role of NQO1 has not been fully explored in prostate cancer. Here we show that NQO1 silencing by a specific shRNA (shNQO1) increased cell survival, proliferation, colony formation, migration and hormone-independent survival in hormone-responsive human prostate cancer cells LNCaP. Genome wide array revealed that NQO1 blockade significantly upregulated pro-inflammatory mediators (e.g., IL-32, CCL2, IL-8, IL-17C, IL-10RA, CXCR2, CXCR7, NOS3) associated with prostate tumorigenesis. Cytokine profiling further confirmed the increased IL-8 production in conditioned-media from NQO1 knockdown cells compared to the parental cells. However, enforced expression of NQO1 in these cells did not alter IL-8 and other inflammatory mediators. Our data indicate that inflammatory mediators produced by NQO1 knockdown LNCaP cells may be responsible for the hormone-independent survival. Since these inflammatory mediators influence prostate cancer development and castration resistance, strategies modulating cellular antioxidants to regulate NQO1 and other important players in NQO1-signaling may provide multifaceted opportunities for prostate cancer prevention. Supported by a postdoctoral fellowship from CPRIT (DT) and RO1 CA 149516 (RG). Citation Format: Dinesh Thapa, Addanki P. Kumar, Rita Ghosh. NAD(P)H quinone oxidoreductase 1 regulates pro-inflammatory mediators associated with prostate tumorigenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2921. doi:10.1158/1538-7445.AM2013-2921</jats:p

Abstract LB-427: Differential effects of resveratrol-induced SIRT1 in prostate cancer: A novel therapeutic target

Abstract Silence information regulator (SIRT1) is a Nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase that regulates various biological processes including cell survival, apoptosis, metabolism and aging. Given the role for calorie restriction (CR) in delaying the onset of aging and age-related disorders including cancers, efforts are under way to develop CR mimetics as therapeutic agents. Resveratrol, a CR mimetic activates SIRT1 and has been shown to extend life span. Further, resveratrol has been shown to prevent tumor development and cancer cell proliferation in a wide variety of models including prostate. However the precise role of SIRT1 in prostate cancer development and progression remains unexplored. Towards developing SIRT1 targeted preventive approaches, we conducted studies using human prostate cancer cell lines and a preclinical animal model that develops high grade prostatic intraepithelial neoplasia (HGPIN) in response to hormone stimulation. Our studies show that androgen independent prostate cancer cell lines (DU145 and PC-3) express higher levels of SIRT1 compared to non tumorigenic RWPE-1 consistent with the published results. Resveratrol-mediated inhibition of cell proliferation was associated with reduction in the levels of pAkt (Ser473 and Thr308), SIRT1and Cyclin D1 in PC-3 cells but not in DU145. Most interestingly we did not detect SIRT1 enzymatic activation following resveratrol treatment. Further pretreatment of prostate cancer cells with known pharmacological SIRT1 inhibitor (Nicotinamide) enhanced resveratrol mediated proliferation inhibition. Dietary intervention with increasing doses of resveratrol for 3 weeks showed no protective effect on the development of PIN lesions or chronic inflammation or atrophy in rats stimulated with hormones. Our studies show for the first time that (i) SIRT1 may not be a direct target of resveratrol; (ii) combination of resveratrol and SIRT1inhibitor may provide a new approach to prevent development and progression of prostate cancer. Supported by CA 137518 (APK). Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-427.</jats:p