Multimodal Biomarkers That Predict the Presence of Gleason Pattern 4: Potential Impact for Active Surveillance

PURPOSE

Latent grade group ≥2 prostate cancer can impact the performance of active surveillance protocols. To date, molecular biomarkers for active surveillance have relied solely on RNA or protein. We trained and independently validated multimodal (mRNA abundance, DNA methylation, and/or DNA copy number) biomarkers that more accurately separate grade group 1 from grade group ≥2 cancers.

MATERIALS AND METHODS

Low- and intermediate-risk prostate cancer patients were assigned to training (n=333) and validation (n=202) cohorts. We profiled the abundance of 342 mRNAs, 100 DNA copy number alteration loci, and 14 hypermethylation sites at 2 locations per tumor. Using the training cohort with cross-validation, we evaluated methods for training classifiers of pathological grade group ≥2 in centrally reviewed radical prostatectomies. We trained 2 distinct classifiers, PRONTO-e and PRONTO-m, and validated them in an independent radical prostatectomy cohort.

RESULTS

PRONTO-e comprises 353 mRNA and copy number alteration features. PRONTO-m includes 94 clinical, mRNAs, copy number alterations, and methylation features at 14 and 12 loci, respectively. In independent validation, PRONTO-e and PRONTO-m predicted grade group ≥2 with respective true-positive rates of 0.81 and 0.76, and false-positive rates of 0.43 and 0.26. Both classifiers were resistant to sampling error and identified more upgrading cases than a well-validated presurgical risk calculator, CAPRA (Cancer of the Prostate Risk Assessment; P < .001).

CONCLUSIONS

Two grade group classifiers with superior accuracy were developed by incorporating RNA and DNA features and validated in an independent cohort. Upon further validation in biopsy samples, classifiers with these performance characteristics could refine selection of men for active surveillance, extending their treatment-free survival and intervals between surveillance.

Total Quality Management in higher education: a literature review on barriers, customers and accreditation

Purpose

The purpose of this paper is to analyze the evolution of Total Quality Management (TQM) in terms of barriers, customers and accreditation in higher education (HE) over the last three decades (1991–2020) using literature review to establish the current state.

Design/methodology/approach

A total of 137 articles across 55 journals were consolidated for this review specifically focused on TQM (barriers, customers and accreditation) in HE. The investigations were carried out to identify the chronological growth of articles, research streams and methodologies. The articles were classified based on four research approaches and three research streams which have been reviewed in detail.

Findings

Considering the rapid growth in the HE sector and the concerns over reduction in quality of education especially in developing countries, the importance of TQM in HE is immense. The findings include identification of the barriers to successful TQM implementation, the need for alignment of TQM objectives of higher educational institutions (HEIs) and identified target customer(s) with the selected model/framework and the impact of accreditation/certification in the attainment of TQM.

Originality/value

This study which tries to bring a perspective to the main trends in TQM application to HE with respect to barriers, customers and accreditation over the last three decades is expected to add to the body of knowledge in this area and help future researchers to focus on the relevant areas identified in this paper.

Multimodal biomarkers overcome sampling bias to predict presence of aggressive localized prostate cancer

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Background: Histopathologic investigation of diagnostic prostate biopsies both confirms the presence of disease and estimates its potential for distal spread via tumour grade. The accuracy of biopsy grading is limited by intra-tumoral heterogeneity, inter-observer variability, and other factors. To improve risk stratification at the time of diagnosis, we sought to create objective molecular biomarkers of radical prostatectomy grade that are resistant to sampling error and should be useful when applied to biopsy tissue. Methods: We developed and validated a robust objective biomarker of prostate cancer grade using pathologic grading of prostatectomy tissues as the gold standard. We created training (333 patients) and validation (202 patients) cohorts of Cancer of the Prostate Risk Assessment (CAPRA) low- and intermediate-risk prostate cancer patients. To address intra-tumoral heterogeneity, each tumor was sampled at two locations. We profiled the abundance of 342 mRNAs complemented by 100 canonical DNA copy number aberration loci (CNAs) and 14 hypermethylation events. Using the training cohort with cross-validation, we evaluated models for training classifiers of pathologic Grade Group ≥2, Restricting to strategies resulting in true negative rates ≥0.5, true positive (TP) rates ≥0.8, we selected two strategies to train classifiers, PRONTO-e and PRONTO-m. Results: The PRONTO-e classifier comprises 353 mRNA and CNA features, while the PRONTO-m classifier comprises 94 mRNA, CNA, methylation and clinical features. Both classifiers (PRONTO-e, PRONTO-m) validated in the independent cohort, with respective TP rates of 0.809 and 0.760, false positive rates of 0.429 and 0.262, F1 scores of 0.709 and 0.724, and AUCs of 0.792 and 0.818. Conclusions: Two classifiers were developed and validated in separate cohorts, each achieved excellent performance by integrating different types of molecular data. Implementation of classifiers with these performance characteristics could markedly improve current active surveillance approaches without increasing patient morbidity and may help better inform patients on their individual need for definitive therapy versus active surveillance.

Functional validation of metabolic genes that distinguish Gleason 3 from Gleason 4 prostate cancer foci

BACKGROUND

Gleason grade is among the most powerful clinicopathological classification systems used to assess risk of lethal potential in prostate cancer, yet its biologic basis is poorly understood. Notably, pure low-grade cancers, comprised predominantly of Gleason pattern 3 (G3) are typically indolent, with lethal potential emerging with the progression of higher-grade Gleason patterns 4 (G4) or 5. One of the hallmarks of more aggressive cancer phenotypes is the stereotyped set of metabolic characteristics that transformed cells acquire to facilitate unregulated growth. In the present study, we profiled expression signatures of metabolic genes that are differentially expressed between G3 and G4 cancer foci and investigated the functional role of two of the profiled genes, PGRMC1 and HSD17B4, in prostate cancer cells.

METHODS

Gene expression profiling was conducted using 32 G3 and 32 G4 cancer foci from patients with 3+3 and ≥4+3 tumors, respectively. A 95-gene Nanostring probe set was used to probe genes associated with energy metabolism. Two out of five genes (PGRMC1 and HSD17B4) that significantly distinguish between G3 and G4 were functionally validated in vitro using established prostate cancer cells (PC3, DU145). Expression of PGRMC1 and HSD17B4 was knocked down and subsequent studies were performed to analyze cell proliferation, migration, invasion, and apoptosis. Mechanistic studies that explored the epidermal growth factor receptor (EGFR) pathway were performed by Western blot.

RESULTS

Multivariate analysis identified five metabolic genes that were differentially expressed between G3 and G4 stroma (P < .05). Functional validation studies revealed that knockdown of PGRMC1 and HSD17B4 significantly decreased cell proliferation, migration, and invasion, and increased apoptosis in PC3 and DU145 cells. Mechanistic studies showed that these effects, after PGRMC1 knockdown, were possibly mediated through alterations in downstream components of the EGFR, protein kinase B, and nuclear factor kappa-light-chain-enhancer of activated B cells pathways.

CONCLUSION

The following study provides evidence supporting the use of metabolic genes PGRMC1 and HSD17B4 as a prognostic biomarker for the distinction between G3 and G4 prostate cancers.

Abstract 4805: Cannabinoid WIN 55,212-2 induces endoplasmic reticulum stress in prostate cancer cells through CB1and CB2receptors

Cannabinoids have demonstrated anticarcinogenic properties in a variety of malignancies, including prostate cancer. WIN 55,212-2 (WIN) is a highly potent synthetic cannabinoid that binds to cannabinoid receptors (CB1 and CB2). We have previously demonstrated that WIN significantly reduces prostate cancer cell proliferation, migration, invasion, induces apoptosis, and arrests cells in the G0/G1 phase through a cannabinoid receptor 2 dependent manner. We also determined that these effects were mediated though a pathway involving cell cycle regulators p27, Cdk4, and pRb. The current study aims to examine the role of endoplasmic reticulum (ER) stress in apoptosis and investigates whether this effect is modulated by WIN and the cannabinoid receptors.

In this study, we evaluated the effect of WIN and CB receptors on ER stress induced apoptosis in established prostate cancer cells (DU145, PC3). Cells were treated with WIN, cannabinoid receptor 1 antagonist (AM251), and cannabinoid receptor 2 antagonist (AM630). Cell proliferation was determined using MTS assays. Quantitative PCR was used to examine changes in expression of ER stress related genes, including CHOP, TRIB3, and ATF4. Western blotting will be completed to determine changes in the expression of apoptotic markers after treatment with WIN and cannabinoid antagonists. Further studies are ongoing looking at the use of the ER stress inhibitor, Salubrinal, to determine whether ER stress is vital for WIN-induced apoptosis.

Our results reveal that treatment with 20μM WIN resulted in a significant reduction in the proliferation of DU145 and PC3 cells after 24 h compared to control (p&lt;0.05). In contrast, treatment with 5μM of either AM251 or AM630 did not result in any significant changes in cell proliferation. Quantitative PCR studies revealed significant upregulation of ER stress genes CHOP, TRIB3 and ATF4 in WIN treated cells (p&lt;0.05). Expression of ER stress genes were significantly downregulated after blocking CB1 and CB2 receptors (p&lt;0.05).

Interim results suggest that WIN has significant antitumoral activity and modulates ER stress-induced apoptosis in prostate cancer cells, thus, may offer a novel therapeutic strategy in the treatment of prostate cancer.

Citation Format: Domenica Roberto, Laurence H. Klotz, Vasundara Venkateswaran. Cannabinoid WIN 55,212-2 induces endoplasmic reticulum stress in prostate cancer cells through CB1and CB2receptors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4805.

Cannabinoid WIN 55,212-2 induces cell cycle arrest and apoptosis, and inhibits proliferation, migration, invasion, and tumor growth in prostate cancer in a cannabinoid-receptor 2 dependent manner

BACKGROUND

Cannabinoids have demonstrated anticarcinogenic properties in a variety of malignancies, including in prostate cancer. In the present study, we explored the anti-cancer effects of the synthetic cannabinoid WIN 55,212-2 (WIN) in prostate cancer.

METHODS

Established prostate cancer cells (PC3, DU145, LNCaP) were treated with varying concentrations of WIN. Cell proliferation was determined by the MTS assay. The anti-migration and anti-invasive potential of WIN was examined by the wound healing assay and the matrigel invasion assay. Cell cycle analysis was performed by flow cytometry, and mechanistic studies were performed by Western blot. Athymic mice (n = 10) were inoculated with human PC3 cells. Once tumors reached 100 mm³ , animals were randomized into two groups: saline control and WIN (5 mg/kg), delivered by intraperitoneal injection three times per week for 3 weeks.

RESULTS

WIN significantly reduced prostate cancer cell proliferation, migration, invasion, induced apoptosis, and arrested cells in Go/G1 phase in a dose-dependent manner. Mechanistic studies revealed these effects were mediated through a pathway involving cell cycle regulators p27, Cdk4, and pRb. Pre-treatment with a CB₂ antagonist, AM630, followed by treatment with WIN resulted in a reversal of the anti-proliferation and cell cycle arrest previously seen with WIN alone. In vivo, administration of WIN resulted in a reduction in the tumor growth rate compared to control (P < 0.05).

CONCLUSIONS

The following study provides evidence supporting the use of WIN as a novel therapeutic for prostate cancer.

Combining Desmopressin and Docetaxel for the Treatment of Castration-Resistant Prostate Cancer in an Orthotopic Model

BACKGROUND/AIM

Desmopressin is a synthetic analogue of the antidiuretic hormone vasopressin. It has recently been demonstrated to inhibit tumor progression and metastasis in breast cancer models. Docetaxel is a chemotherapy agent for castrate-resistant prostate cancer (CRPC). In this study, the ability of CRPC cells to grow and develop in vivo tumors in an animal model was evaluated, in order to investigate the anti-tumor effect of desmopressin in combination with docetaxel.

MATERIALS AND METHODS

The CRPC cell line PC3 was used for orthotopic inoculation in male athymic nude mice. The mice were randomly assigned to one of the four treatment groups: Control, docetaxel, desmopressin or combination therapy. Following the last treatment, tumors were excised and measured. Blood samples were processed for CTC analysis.

RESULTS

Docetaxel treatment resulted in a significant reduction in tumor volume compared to control. The combination therapy resulted in even more significant reduction (31.2%) in tumor volume. There was a complete absence of CTCs in the combination group.

CONCLUSION

Our pilot study demonstrated an enhanced efficacy of docetaxel-based therapy in combination with desmopressin.

Abstract 5878: Effect of cannabinoid WIN 55,212-2 on prostate cancer cell proliferation, migration, invasion, and tumor growth

Introduction and Objective: Prostate cancer (PCa) is the most commonly diagnosed cancer in men and the second leading cause of cancer related death in Canada. A large body of evidence supports a possible role for cannabinoids in certain aspects of human health and disease, acting as palliative agents and more importantly, as inhibitors of cancer cell proliferation, migration, invasion, and the angiogenesis of tumours. WIN 55,212-2 (WIN) is a highly potent synthetic cannabinoid, binding to the cannabinoid receptors 1 and 2. This study aims to determine the anti-cancer effect of WIN using preclinical models of prostate cancer.

Methodology: Human PCa cells (DU145, PC3) were treated with WIN at concentrations ranging from 1μM to 20μM and growth of cells (using the MTS assay) was assessed at various times following treatment. Wound-healing assays were conducted to investigate the migratory potential of cells following exposure to treatment, and trans-well invasion assays were performed to explore the influence of WIN on cell invasion. In vivo evaluation using PC3 xenografts was performed using swiss athymic mice. Treatment was administered thrice weekly and tumor volume assessed for a total of three weeks.

Results: Treatment with 10μM WIN resulted in a significant reduction in the proliferation of DU145 and PC3 cells after 24 h compared to control (p&lt;0.05). Cell migration and invasion studies revealed a significant reduction in cell motility at 15μM WIN (p&lt;0.05) and a significant reduction in cell invasion at a concentration as low as 1μM (p&lt;0.05). Treatment with 5mg/kg WIN (ip) revealed significant differences in tumor volume compared to controls that received the vehicle (p&lt;0.05). There were no significant alterations in body weight in both groups.

Conclusion: WIN 55,212-2 is a highly potent cannabinoid, having significant influences on cell proliferation, migration, and invasion, with reduction in the growth of tumors in prostate cancer xenografts. We are the first to demonstrate the use of WIN in PC3 xenografts and provide evidence for its use as a novel therapeutic option in patients with prostate cancer.

Funding/Conflicts of Interest: None

Citation Format: Domenica Roberto, Laurence H. Klotz, Vasundara Venkateswaran. Effect of cannabinoid WIN 55,212-2 on prostate cancer cell proliferation, migration, invasion, and tumor growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5878.

Personalized risk stratification for patients with early prostate cancer (PRONTO): A Canadian team biomarker project

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Background: Current practice stratifies men with prostate cancer into risk groups based primarily on Gleason grade. When applied to biopsy samples, the Gleason grading is inaccurate due to sampling error and inter-observer variation. The result is that men either receive unnecessary surgical treatment, or they don’t receive adequate treatment, leading to worse outcomes. Previously published genomic tests have not successfully distinguished indolent low grade (G6 or GG1) cancers from their more aggressive intermediate grade (G7 or GG2 and 3) counterparts. PRONTO is specifically aimed at creating a multi-modal risk stratification tool to improve treatment stratification following a core biopsy diagnosis. Methods: PRONTO links 7 projects, each with novel diagnostic assays for risk stratification that focus on analysis of copy number variations (CNV), DNA hypermethylation, trans-differentiation, cancer metabolism, or the tumor microenvironment. We merged the best transcripts from each project into a single NanoString gene expression assay, measuring 393 transcripts, in a cohort of 365 cases of radical prostatectomy from low-to-intermediaterisk patients. To minimize sampling error, we took multiple samples, and obtained high grade, low grade and benign areas for each radical prostatectomy case. Results: Our primary goal was to develop a multivariate molecular classifier of grade that distinguished G6 from G7 (3+4 or 4+3). Cases were randomly partitioned into five equally sized groups. A supervised machine learning algorithm (random forests) was trained on samples from four of the groups, and then evaluated by testing on the fifth group. This process was repeated for each of the five groups, yielding a combined clinical and molecular classifier. DNA methylation profiles and CNV profiles are currently being integrated into our classifier Conclusions: We have developed a multivariate classifier that distinguishes low grade from intermediate grade prostate cancer. It will be clinically validated in biopsy samples from large cohorts of early prostate cancer patients.

Evaluating Metformin as a Potential Chemosensitizing Agent when Combined with Docetaxel Chemotherapy in Castration-resistant Prostate Cancer Cells

BACKGROUND/AIM

Docetaxel, the first-line chemotherapy for metastatic castration-resistant prostate cancer (mCRPC), provides certain survival benefits, but is associated with significant toxicity. A novel therapeutic approach for mCRPC is combining docetaxel with a chemosensitizing agent. We hypothesized that metformin, a potential chemosensitizer, would improve docetaxel efficacy in CRPC cells.

MATERIALS AND METHODS

MTS assays were used to determine the effect of metformin-docetaxel treatment on PC3 and DU145 cell viability. Wound-healing and ATP concentration assays were used to evaluate cell migration and intracellular ATP levels following metformin-docetaxel treatment. Western blotting was used for mechanistic evaluation.

RESULTS

Metformin-docetaxel treatment significantly reduced PC3 cell viability. Metformin-docetaxel treatment did not significantly affect cell migration or intracellular ATP levels. Western blotting revealed metformin-docetaxel treatment did not significantly change AMPK or P-AMPK expression patterns.

CONCLUSION

Metformin may be an effective chemosensitizer for certain types of CRPC cells, but further investigation is needed.

Abstract 8: Anandamide reduces cell migration, invasion, and induces apoptosis in an in vitro model of prostate cancer

Introduction and Objective: Prostate cancer (PCa) is the most commonly diagnosed cancer in men and the second leading cause of cancer related death in Canada. A large body of evidence supports a possible role for cannabinoids in certain aspects of human health and disease, acting as palliative agents as well as inhibitors of cancer cell proliferation, migration, invasion, and the angiogenesis of tumours. Anandamide (AEA) is a highly potent endogenously produced compound that acts as an agonist of the cannabinoid receptors (CB1 and CB2) as well as the transient receptor potential vanilloid receptor 1. AEA is mainly metabolized by fatty acid amide hydrolase (FAAH) and overexpression of the enzyme in PCa tissues is correlated with greater invasivity, malignancy and increasing Gleason score. Majority of studies have focused on the effect of AEA treatment on cell proliferation, without much focus on prostate cancer biology. This study aims to determine the anti-cancer effect of AEA on PCa cells. We hypothesize that anandamide will reduce migration, invasion, and induce apoptosis in PCa cells.

Methodology: Human PCa cells (DU145, LNCaP, and PC3) were treated with AEA at concentrations ranging from 1μM to 40μM and growth of cells (using the MTS assay) was assessed at various times. Wound-healing assays were conducted to investigate the migratory potential of cells following 24hr exposure to treatment, and trans-well invasion assays were performed to explore the influence of AEA on cell invasion. Flow cytometry, using the FITC Annexin V dead cell apoptosis kit, was used to detect the proportion of apoptotic versus proliferating cells following anandamide treatment.

Results: There was a significant reduction in the proliferation of DU145 cells at concentrations of 20μM and 40μM AEA compared to controls (p=0.02, 0.005). LNCaP cells on the other hand required a higher concentration of AEA to achieve this effect (p=0.05). Cell migration and invasion studies on DU145 cells revealed a significant reduction in cell motility at 20μM and 40μM AEA (p=0.006, 0.0005) as well as a significant reduction in cell invasion at 20μM and 40μM ((p=0.0002, 0.0001). Flow cytometry results indicate a significant increase in the proportion of apoptotic cells compared to control (3 fold change) when treated with 20μM and 40μM in DU145 and LNCaP cells.

Conclusion: We have shown that AEA has greatest significant influence on cell migration, invasion, and apoptosis. Further analysis on the role of AEA in these pathways is underway exploring alterations in expression levels of key proteins implicated in cell migration and apoptosis.

Funding/ Conflicts of Interest: None

Note: This abstract was not presented at the meeting.

Citation Format: Domenica Roberto, Laurence Klotz, Vasundara Venkateswaran. Anandamide reduces cell migration, invasion, and induces apoptosis in an in vitro model of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 8. doi:10.1158/1538-7445.AM2017-8

The Effect of Metformin Use during Docetaxel Chemotherapy on Prostate Cancer Specific and Overall Survival of Diabetic Patients with Castration Resistant Prostate Cancer

PURPOSE

Docetaxel is the first line chemotherapy currently used to treat patients with symptomatic metastatic castration resistant prostate cancer. Although it provides survival benefits, it is associated with significant side effects. Novel therapeutic options are needed for patients with metastatic castration resistant prostate cancer and an approach is combining docetaxel with chemosensitizing agents. Metformin has been shown to improve the survival of patients with breast, lung and endometrial cancer receiving chemotherapy, and enhance chemotherapeutic efficacy in breast cancer and colon cancer cells. However, to our knowledge the chemosensitizing effect of metformin in prostate cancer has not been explored. Therefore, the hypothesis for our study was that diabetic patients with metastatic castration resistant prostate cancer who were administered metformin during docetaxel chemotherapy would have improved prostate cancer specific and overall survival.

MATERIALS AND METHODS

This retrospective cohort study used data from several Ontario administrative health care databases. Men older than 65 years diagnosed with metastatic castration resistant prostate cancer and treated with docetaxel were stratified into groups based on diabetes status and use of antidiabetic medications. We evaluated the effect of metformin use with docetaxel on prostate cancer specific survival and overall survival using Kaplan-Meier survival curves, the log rank test and multivariate Cox proportional HRs.

RESULTS

Survival curves showed that metformin use with docetaxel did not improve prostate cancer specific survival (p = 0.9562) or overall survival (p = 0.9927). HRs showed no significant effect of metformin use with docetaxel on prostate cancer specific survival (HR = 0.96, p = 0.66) or overall survival (HR = 0.94, p = 0.39).

CONCLUSIONS

Metformin use during docetaxel chemotherapy did not significantly improve prostate cancer specific or overall survival in diabetic patients with metastatic castration resistant prostate cancer. This study indicates that metformin may not be an effective chemosensitizer for metastatic castration resistant prostate 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.

The role of lifestyle characteristics on prostate cancer progression in two active surveillance cohorts

BACKGROUND

Although much research has examined the relationship between lifestyle and prostate cancer (PCa) risk, few studies focus on the relationship between lifestyle and PCa progression. The present study examines this relationship among men initially diagnosed with low- to intermediate-risk PCa and managed with active surveillance (AS).

METHODS

Men enrolled in two separate AS programs were recruited for this study. Data regarding clinical, demographic and lifestyle characteristics were collected. Results were then compared between men whose disease remained low- to intermediate-risk and men whose disease progressed.

RESULTS

Demographic, clinical and physical characteristics were similar between comparative groups and cohorts, with the exception that age at the time of diagnosis and questionnaire was increased among men whose disease progressed. Lifestyle scores among men who remained low- to intermediate-risk were higher than those whose risk progressed; however, scores were only significant in one cohort on univariable analysis. On multivariable analysis, the only predictor of progression was age at diagnosis. Physical activity was consistently higher in both low risk groups, although this difference was insignificant. Consistent differences in other lifestyle variables were not observed.

CONCLUSIONS

Age remains an important predictor of PCa progression. Improving lifestyle characteristics among men initially managed with AS might help to reduce the risk of progression. Given the limitations of this study, more rigorous investigation is required to confirm whether lifestyle characteristics influence the progression of low- to intermediate-risk PCa.

Urinary DNA Methylation Biomarkers for Noninvasive Prediction of Aggressive Disease in Patients with Prostate Cancer on Active Surveillance

PURPOSE

Patients with prostate cancer on active surveillance are monitored by repeat prostate specific antigen measurements, digital rectal examinations and prostate biopsies. A subset of patients on active surveillance will later reclassify with disease progression, prompting definitive treatment. To minimize the risk of under treating such patients on active surveillance minimally invasive tests are urgently needed incorporating biomarkers to identify patients who will reclassify.

MATERIALS AND METHODS

We assessed post-digital rectal examination urine samples of patients on active surveillance for select DNA methylation biomarkers that were previously investigated in radical prostatectomy specimens and shown to correlate with an increasing risk of prostate cancer. Post-digital rectal examination urine samples were prospectively collected from 153 men on active surveillance who were diagnosed with Gleason score 6 disease. Urinary sediment DNA was analyzed for 8 DNA methylation biomarkers by multiplex MethyLight assay. Correlative analyses were performed on gene methylation and clinicopathological variables to test the ability to predict patient risk reclassification.

RESULTS

Using backward logistic regression a 4-gene methylation classifier panel (APC, CRIP3, GSTP1 and HOXD8) was identified. The classifier panel was able to predict patient reclassification (OR 2.559, 95% CI 1.257-5.212). We observed this panel to be an independent and superior predictor compared to current clinical predictors such as prostate specific antigen at diagnosis or the percent of tumor positive cores in the initial biopsy.

CONCLUSION

We report that a urine based classifier panel of 4 methylation biomarkers predicts disease progression in patients on active surveillance. Once validated in independent active surveillance cohorts, these promising biomarkers may help establish a less invasive method to monitor patients on active surveillance programs.

Abstract 1434: Diabetic metastatic castration-resistant prostate cancer patients administered metformin during docetaxel chemotherapy have improved prostate cancer-specific and overall survival

Introduction and Objective: Docetaxel (DTX) chemotherapy is currently one of the only treatment options for patients with metastatic castration-resistant prostate cancer (mCRPC). Although DTX treatment has been shown to provide survival benefits, it is not curative. Thus, there is a continued need to improve the therapeutic options available for mCRPC patients. One approach is combining DTX with other agents that enhance its effectiveness (i.e. chemosensitizers).

Metformin, a commonly prescribed and well-tolerated oral biguanide used to treat type II diabetes, has been shown to exert anti-neoplastic effects in several types of solid tumors, including prostate cancer. More specifically, metformin has been shown to improve the efficacy of chemotherapy in breast cancer and colon cancer models. Niraula et al (2013) evaluated the effect of metformin combined with DTX in prostate cancer patients who participated in the TAX 327 trial. Metformin did not have a statistically significant additive or synergistic effect with docetaxel, but only 38 patients were included in the analysis.

There is very limited data examining the combined effect of metformin and DTX in prostate cancer patients. Therefore, the objective of this study is to determine if diabetic mCRPC patients administered metformin during DTX treatment have improved prostate cancer-specific (PCa-specific) and overall survival (OS) when compared to nondiabetic mCRPC patients receiving DTX therapy.

Methods: The primary objective of this retrospective study is to analyze patient data from the Ontario Cancer Registry (OCR), Ontario Diabetes Database (ODD), Canadian Institute for Health Information Discharge Abstract Database (CIHI DAD), National Ambulatory Care Reporting System (NACRS), Ontario Health Insurance Plan (OHIP), and the Registered Persons Database (RPDB) evaluate whether there is a difference in PCa-specific and OS between diabetic mCRPC patients administered metformin during DTX treatment and non-diabetic mCRPC patients receiving DTX treatment. The databases described previously are all accessible through the Institute for Clinical Evaluative Sciences (ICES) in Ontario, Canada.

Data has been collected and linked at ICES and a research-ready, anonymized dataset has been provided to our research group. Since receiving access to the dataset from ICES, statistical analysis (including multivariate Cox proportional hazards regression, logrank test, and Kaplan Meier survival curves) is in progress using SAS software.

Results and Conclusions: Data analysis is currently in progress. If metformin is shown to have a chemosensitizing effect in diabetic mCRPC patients, this would indicate a novel therapeutic approach that is needed for this patient population.

Citation Format: Michelle Mayer, Laurence Klotz, Vasundara Venkateswaran. Diabetic metastatic castration-resistant prostate cancer patients administered metformin during docetaxel chemotherapy have improved prostate cancer-specific and overall survival. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1434.

Capsaicin reduces the metastatic burden in the transgenic adenocarcinoma of the mouse prostate model

BACKGROUND

Capsaicin, the active compound in chili peppers, has demonstrated anti- carcinogenic properties in vitro in a number of malignancies, including the prostate. In the present study, we investigate the chemopreventive potential of capsaicin on prostate cancer using the transgenic adenocarcinoma of the mouse prostate (TRAMP) model. The TRAMP is a murine model that resembles the progression of human disease.

METHODS

Thirty-five 6-week-old TRAMP x C57BL/6 mice were randomized between treatment with capsaicin (5 mg/kg body weight) or control (saline) three times a week by oral gavage until 30 weeks of age. Body weight of animals was recorded thrice weekly. At termination, all tumors were extracted, recorded, and analyzed for histopathological analysis. To understand the effect of capsaicin on migration and invasion, in vitro experiments were carried out using PC3 cells.

RESULTS

Mice in the control group expressed an overall trend of higher-grade disease with 37.5% poorly differentiated (PD), 18.75% moderately differentiated (MD), and 44% of well-differentiated (WD) adenocarcinoma, compared to the capsaicin-treated group with only 27.7% PD, 61.0% of WD, and 11.1% of intraepithelial neoplasia (PIN). The treatment group demonstrated a higher incidence of noncancerous PIN lesions compared to the control group. The capsaicin group also demonstrated a significant reduction (P < 0.05) in the metastatic burden compared to the controls, which correlated to a reduction in p27(Kip) (1) expression and neuroendocrine differentiation in prostate tumors. Furthermore, there were no differences in body weight between groups overtime, and no pathological toxicities in the liver and gastrointestinal tract with capsaicin consumption. In vitro studies revealed a dose-dependent reduction in the invasion and migration capacity of PC3 cells.

CONCLUSION

The following study provides evidence supporting the safety and chemopreventive effects of capsaicin in the TRAMP model.

Metformin and prostate cancer stem cells: a novel therapeutic target

Prostate cancer is the second most frequently diagnosed cancer in the world. Localized disease can be effectively treated with radiation therapy or radical prostatectomy. However, advanced prostate cancer is more difficult to treat and if metastatic, is incurable. There is a need for more effective therapy for advanced prostate cancer. One potential target is the cancer stem cell (CSC). CSCs have been described in several solid tumors, including prostate cancer, and contribute to therapeutic resistance and tumor recurrence. Metformin, a common oral biguanide used to treat type 2 diabetes, has been demonstrated to have anti-neoplastic effects. Specifically, metformin targets CSCs in breast cancer, pancreatic cancer, glioblastoma and colon cancer. Metformin acts directly on the mitochondria to inhibit oxidative phosphorylation and reduce mitochondrial ATP production. This forces tumor cells to compensate by increasing the rate of glycolysis. CSCs rely heavily on mitochondrial oxidative phosphorylation for energy production. The glycolytic switch results in an energy crisis in these cells. Metformin could be used to exploit this metabolic weakness in CSCs. This would increase CSC sensitivity to conventional cancer therapies, circumventing treatment resistance and enhancing treatment efficacy. This review will explore the characteristics of prostate CSCs, their role in tumor propagation and therapeutic resistance and the role of metformin as a potential prostate CSC sensitizer to current anticancer therapies.

A combination of desmopressin and docetaxel inhibit cell proliferation and invasion mediated by urokinase-type plasminogen activator (uPA) in human prostate cancer cells

BACKGROUND

This study was designed to assess the effectiveness of a combination treatment using both desmopressin and docetaxel in prostate cancer treatment. Desmopressin is a well-known synthetic analogue of the antidiuretic hormone vasopressin. It has recently been demonstrated to inhibit tumor progression and metastasis in in vivo models. Docetaxel is widely used for the treatment of castration resistant prostate cancer (CRPC) patients. However, durable responses have been uncommon to date. In this study, we investigated the anti-tumor effect of desmopressin in combination with docetaxel in vitro and in vivo.

METHODS

Two prostate cancer cells (PC3, LNCaP) were treated with different concentrations of desmopressin alone, docetaxel alone, and a combination of desmopressin and docetaxel. Cell proliferation was determined by MTS assay. The anti-invasive and anti-migration potential of desmopressin and in combination with docetaxel were examined by wound healing assay, migration chamber assay, and matrigel invasion assay.

RESULTS

The combination of desmopressin and docetaxel resulted in a significant inhibition of PC3 and LNCaP cell proliferation (p < 0.01). Additionally, cell migration and invasion were also inhibited by the combination when compared to that of either treatment alone in PC3 cells (p < 0.01). The anti-tumor effect of this combination treatment was associated with down-regulation of both urokinase-type plasminogen activator (uPA) and matrix metalloproteinase (MMP-2 and MMP-9) in PC3 cells.

CONCLUSIONS

We are the first to elucidate the anti-tumor and anti-metastatic potential of desmopressin in combination with docetaxel in a prostate cancer model via the uPA-MMP pathway. Our finding could potentially contribute to the therapeutic profile of desmopressin and enhance the efficacy of docetaxel based treatment for CRPC.

The effects of serum from prostate cancer patients with elevated body mass index on prostate cancer cells in vitro

We examined whether serum from obese, compared to non-obese, PCa (prostate cancer) patients creates a growth-enhancing tumor micro-environment in vitro. Serum from 80 subjects was divided into four groups: normal weight men with and without PCa and overweight/obese men with and without PCa. Cell proliferation, migration, and invasion were measured in LNCaP, and PC3 cells treated with patient serum were obtained from the above groups. The results reveal that proliferation of LNCaP cells was significantly (P = 0.05) greater with serum from non-obese (mean = 1.26 ± 0.20) compared to that from obese patients (mean = 1.16 ± 0.19). Serum from obese PCa patients compared to non-obese PCa patients induced significantly greater amounts of cell migration (P < 0.01) in PC3 cells. Serum from obese patients induced significantly (P < 0.01) lower amounts of cell invasion (mean = 8.2 ± 4.5) compared to non-obese patients (mean = 18.1 ± 5.0) when treated on PC3 cells. Serum TNF-α (tumor necrosis factor alpha) levels correlated with LNCaP cell proliferation in vitro in non-obese PCa (P < 0.01) and non-obese control groups (P = 0.05). All statistical calculations controlled for age, since the PCa patient groups were significantly older than the control groups (P < 0.01). In conclusion, serum from obese PCa patients induced greater PCa cell migration and lower cell proliferation and invasion in vitro.

Cancer prevention and therapy through the modulation of the tumor microenvironment

Cancer arises in the context of an in vivo tumor microenvironment. This microenvironment is both a cause and consequence of tumorigenesis. Tumor and host cells co-evolve dynamically through indirect and direct cellular interactions, eliciting multiscale effects on many biological programs, including cellular proliferation, growth, and metabolism, as well as angiogenesis and hypoxia and innate and adaptive immunity. Here we highlight specific biological processes that could be exploited as targets for the prevention and therapy of cancer. Specifically, we describe how inhibition of targets such as cholesterol synthesis and metabolites, reactive oxygen species and hypoxia, macrophage activation and conversion, indoleamine 2,3-dioxygenase regulation of dendritic cells, vascular endothelial growth factor regulation of angiogenesis, fibrosis inhibition, endoglin, and Janus kinase signaling emerge as examples of important potential nexuses in the regulation of tumorigenesis and the tumor microenvironment that can be targeted. We have also identified therapeutic agents as approaches, in particular natural products such as berberine, resveratrol, onionin A, epigallocatechin gallate, genistein, curcumin, naringenin, desoxyrhapontigenin, piperine, and zerumbone, that may warrant further investigation to target the tumor microenvironment for the treatment and/or prevention of cancer.

Capsaicin: a novel radio-sensitizing agent for prostate cancer

INTRODUCTION

Radio-sensitizing agents sensitize tumor cells to the lethal effects of radiotherapy (RT) allowing for use of lower doses of radiation to achieve equivalent cancer control, while minimizing adverse effects to normal tissues. Given their limited toxicity and ability to easily integrate into the diet, compounds occurring naturally in the diet make ideal potential radio-sensitizing agents. In this study, we have examined whether capsaicin, the active compound in chilli peppers, can modulate the response to RT in preclinical models of prostate cancer (PCa).

METHODS

The effects of RT (1-8 Gy) and/or capsaicin (1-10 µM) on colony formation rates in human PCa cells were assessed using clonogenic assays. Mechanistic studies were performed by Western Blot, immunocytochemistry, and flow cytometry. Athymic mice (n = 40) were inoculated with human LNCaP cells. Once tumors reached 100 mm(3) , animals were randomized into four groups: control, capsaicin alone (5 mg/kg/d), RT alone (6 Gy), and capsaicin and RT.

RESULTS

Capsaicin reduced colony formation rates and radio-sensitized human PCa cells (Sensitizer enhancement ratio = 1.3) which corresponded to the suppression of NFκB, independent of TRP-V1 receptor. Cell cycle modulation occurred following RT and capsaicin treatment independently. In vivo, oral administration of capsaicin with RT resulted in a 'greater than additive' growth delay and reduction in the tumor growth rate greater than capsaicin (P < 0.001) or RT (P < 0.03) alone. Immunohistochemical analysis revealed a reduction in proliferation and NFκB expression, and increase in DNA damage.

DISCUSSION

Our findings suggest that capsaicin acts as a radio-sensitzing agent for PCa through the inhibition of NFκB signalling.

Abstract 239: Capsaicin may reduce the metastatic burden in the transgenic adenocarcioma of the mouse prostate (TRAMP) model

Introduction and Objective: A large body of evidence supports the role of dietary factors in prostate cancer development and progression. We are interested in investigating the chemopreventive potential of capsaicin, the active compound in chilli peppers that is traditionally used topically to treat various pain-related syndromes. Recently capsaicin has been demonstrated to have anti-carcinogenic properties in vitro through a number of different mechanisms. In our study we aim to study the chemopreventive properties of capsaicin using the transgenic adenocarcinoma of the mouse prostate (TRAMP) model, a murine model that closely resembles the progression of human disease.

Methodology: Thirty-five six-week old TRAMP x C57Bk mice were randomized into two groups: control or capsaicin. Mice received either capsaicin (5 mg/kg body weight) or vehicle (saline) three times a week by oral gavage until the age of 30 weeks. Body weight was measured thrice weekly. All mice were sacrificed at 30 weeks. Body weight, genito-urinary (GU) weight, tumour burden were assessed. Prostate, seminal vesicles, lung, liver, esophagus, lymph nodes and pancreas were obtained for histological analysis. Serum was collected at the termination of the study for analysis of serum capsaicin concentration. Prostate tumours were analyzed by immunohistochemical analysis using proliferative and mechanistic markers. All tumours were scored by an on-site pathologist according to the histopathic grading scale described by Hurwitz AA, et al.

Results: Interim results revealed that higher percentage of high-grade cancer in control group (n = 18). The presence of PIN-like pre-cancerous lesions in only the treatment group and not the control group (n = 18). The capsaicin treated mice also demonstrated a reduced proportion of metastatic cancers compared to the control group. There were no significant changes in the GU wet weight between groups (n = 35). Immunohistochemical analysis of the prostate tumour is ongoing. Capsaicin was well tolerated, as there was no pathological liver or esophagus or gastrointestinal toxicities or difference in body weight between groups. Further results are currently under investigation.

Conclusion: Interim results suggest that oral administration of capsaicin is well tolerated and may reduce the metastatic burden in the TRAMP model. Ongoing studies are currently underway to delineate the mechanism of action.

Citation Format: Natalie A. Venier, Toshihiro Yamamoto, Linda Sugar, Neil Fleshner, Laurence Klotz, Vasundara Venkateswaran. Capsaicin may reduce the metastatic burden in the transgenic adenocarcioma of the mouse prostate (TRAMP) model. [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 239. doi:10.1158/1538-7445.AM2014-239

Exercise does not counteract the effects of a "westernized" diet on prostate cancer xenografts

BACKGROUND

The relationships between diet, exercise, and prostate cancer (PCa) remain unclear. We have previously reported that a "Western" diet promotes PCa tumor growth in vivo. Presently, we report the effects of sustained aerobic exercise on PCa progression in animals fed a high-fat diet versus a standard diet.

METHODS

Athymic mice (n = 43) were inoculated subcutaneously with human PCa (LNCaP) cells, fed ad libitum with either a high-fat or a standard diet, and randomized into forced exercising and non-exercising groups. Body weight, tumor volume, and food consumption were recorded tri-weekly. Terminal serum samples and tumor biopsies were obtained for analysis.

RESULTS

Body weight differences were not observed between the groups over time. The high-fat diet with exercise (HF-Ex) group showed significantly increased tumor growth rate compared to all other groups (P < 0.0007). Tumor growth rate of the standard diet with exercise (Std-Ex) group was reduced significantly compared to the high-fat diet without exercise (HF-No Ex) group (P = 0.0008). Significant differences (P ≤ 0.012) were observed in energy consumption (kcal) between the groups over time. Exercising mice consumed significantly more kcal than non-exercising mice, and the HF-Ex group consumed significantly more than each of the other three groups (P < 0.0007). The expression levels of p27 and p21 were increased in exercising animals, while AR expression was elevated in the HF-Ex group versus the Std-Ex and HF-No Ex groups.

CONCLUSIONS

Sustained aerobic exercise did not counteract the tumor-promotional effect of increased consumption of a high-fat diet, suggesting that diet is more influential in PCa progression than exercise. Combining exercise with a healthy diet reduced the rate of PCa progression in this model. This study may have implications for PCa risk reduction in humans.

Diet, obesity, and cancer progression: are adipocytes the link?

Obesity has been linked to more aggressive characteristics of several cancers, including breast and prostate cancer. Adipose tissue appears to contribute to paracrine interactions in the tumor microenvironment. In particular, cancer-associated adipocytes interact reciprocally with cancer cells and influence cancer progression. Adipokines secreted from adipocytes likely form a key component of the paracrine signaling in the tumor microenvironment. In vitro coculture models allow for the assessment of specific adipokines in this interaction. Furthermore, micronutrients and macronutrients present in the diet may alter the secretion of adipokines from adipocytes. The effect of dietary fat and specific fatty acids on cancer progression in several in vivo model systems and cancer types is reviewed. The more common approaches of caloric restriction or diet-induced obesity in animal models establish that such dietary changes modulate tumor biology. This review seeks to explore available evidence regarding how diet may modulate tumor characteristics through changes in the role of adipocytes in the tumor microenvironment.

Abstract 1591: Capsaicin enhances the effect of radiation in prostate cancer through NFκB suppression

Introduction and Objective: Radio-sensitizing agents sensitize cells to the lethal effects of ionizing radiation (IR). This permits use of lower doses of radiation to achieve equivalent cancer control thereby minimizing adverse effects to normal tissues. Given their lack of toxicity compounds occurring naturally in the diet make ideal potential radio-sensitizing agents. Capsaicin is the active compound chilli peppers. Traditionally capsaicin is used to treat chronic pain syndromes; however, recently evidence using in vitro prostate cancer (PCa) models describes its anti-carcinogenic potential. In our studies we have demonstrated that capsaicin can enhance the effect of radiation of prostate cancer in vitro and in vivo. The objective of the present study is to assess the how capsaicin enhances the effect of radiation in vitro an in vivo models.

Methods: Using clonogenic assays we assessed the effect of ionizing radiation (1-8 Gy) and/or capsaicin (1-10μM) on colony formation rates in 4 human PCa cell lines (LNCaP, PC3, PC3AR2, DU145). Western Blot and immunocytochemical analysis was performed to examine mechanistic changes. Athymic nude mice were inoculated subcutaneously with human PCa (LNCaP) cells. Once xenografts reach 100mm3 forty animals will be randomized into 4 groups (15 /group); control (no treatment), capsaicin alone, ionizing radiation (IR) alone and capsaicin and IR. Treatments were administered over a two-week time period. Capsaicin (5 mg/kg/d) or vehicle was administered 3/week by gavage. RT will be delivered to animals in sterile cages as one fraction (6 Gray). Tumours were measured thrice weekly and volumes were calculated. Tumours were fixed and stained for pathological analyses and immunohistochemical evaluation.

Results:

Exposure of cells to capsaicin (1-10μM) or IR (1-8Gy) caused significant dose-dependent inhibition of colony formation (p&lt;0.001). Combining capsaicin with IR resulted in further significant inhibition of colony formation rates (P&lt;0.001). Western Blot and IHC analysis showed that LNCaP cells treated with capsaicin and/or IR suppressed AR and NFκB, and increase DNA damage. Mice treated with capsaicin or IR alone had a significant reduction in tumour growth overtime (p &lt; 0.001). Mice treated with capsaicin and IR capsaicin had a reduction in the tumour volume greater than either capsaicin alone (p&lt;0.001) or radiation alone (p&lt;0.03). Two mice experienced mild to moderate inflammation of the stomach. No other toxicities were observed. Mechanistic studies revealed that mice administered capsaicin and radiation had an increased yH2AX expression, and significantly lower Ki67 index, AR, and NFκB expression.

Conclusion: These studies suggest that capsaicin enhances the effect of radiation through a number of mechanisms including the suppression of NFκB and AR.

Citation Format: Natalie A. Venier, Alexandra J. Colquhoun, Laurence Klotz, Neil Fleshner, Vasundara Venkateswaran. Capsaicin enhances the effect of radiation in prostate cancer through NFκB suppression. [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 1591. doi:10.1158/1538-7445.AM2013-1591

Abstract 314: Effect of dietary carbohydrates and exercise on prostate cancer progression in LNCaP xenograft model

Introduction: Prostate cancer (PCa) is the second leading cause of death among North American men. There are many risk factors for PCa, dietary as well as physical activity play a role in the development and progression of the disease. Our lab has previously reported that increased intake of dietary carbohydrates was associated with increased tumor growth and activation of signaling pathways distal to the insulin receptor in a murine model of prostate cancer. In humans, one of the most potent stimulants for insulin production is glucose consumption and carbohydrate restriction reduces serum insulin and IGF-I levels to a greater extent than dietary fat restriction. Numerous studies have also found an inverse relationship between exercise and PCa progression. For example, a study by Barnard et al (2003) demonstrated that regular physical activity in PCa patients decreased serum insulin and IGF-I levels, and also elevated IGF binding protein I. However, the exact relationships between diet, exercise and PCa, as well as their underlying mechanisms, are unclear. Herein we aim to investigate the effect of sustained aerobic exercise on PCa tumour growth in animals placed on a high carbohydrate diet.

Methods: Athymic (6 -8 week old) nude mice (n=40) were inoculated subcutaneously with 1 million LNCaP cells. Mice were fed ad libitum with a high-carbohydrate (HC) diet or a low-carbohydrate (LC) diet. Animals were randomized into four groups: HC with and without exercise, LC with and without exercise. Exercise was implemented for 5 days/week (3 x 15 mins; 2-min breaks between cycles; 2.0-10.0 m/min) using a forced exercise wheel. Exercise was performed for a period of 10 weeks. Body weights, tumour volumes, and food consumption were recorded tri-weekly. Blood samples were obtained by sephenous vein bleeding at various times during the study period. Comparisons between groups over time were performed using RANOVA Type 3 Tests of Fixed Effects.

Results: There were no significant differences in animal weight and food consumption between groups. Tumour growth, wet tumour weights were not significantly different between groups. However it was very interesting to note that animals from the exercise group had a slower tumour growth rate compared to animals from the no exercise group.

Citation Format: Xiangfeng Ge, Natalie Venier, Neil Fleshner, Laurence Klotz, Vasundara Venkateswaran. Effect of dietary carbohydrates and exercise on prostate cancer progression in LNCaP xenograft model. [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 314. doi:10.1158/1538-7445.AM2013-314

Population based study of long-term rates of surgery for urinary incontinence after radical prostatectomy for prostate cancer

PURPOSE

Urinary incontinence can be a significant complication of radical prostatectomy. It can be treated with post-prostatectomy surgical procedures. The long-term rate of patients who undergo these surgeries, including artificial urinary sphincter or urethral sling insertion, is not well described. We examined the long-term rate of post-prostatectomy incontinence surgery and factors influencing it.

MATERIALS AND METHODS

We performed a population based study of 25,346 men who underwent radical prostatectomy for prostate cancer in Ontario, Canada between 1993 and 2006. We used hospital and cancer registry administrative data to identify patients from this cohort who were later treated with surgery for urinary incontinence.

RESULTS

Of the 25,346 patients 703 (2.8%) underwent artificial urinary sphincter insertion and 282 (1.1%) underwent urethral sling placement a median of 2.9 years after prostatectomy. The probability of an artificial urinary sphincter/sling procedure increased with time from prostatectomy. Cumulative 5, 10 and 15-year Kaplan-Meier rates of an artificial urinary sphincter/sling procedure were 2.6% (95% CI 2.4-2.8), 3.8% (95% CI 3.6-4.1) and 4.8% (95% CI 4.4-5.3), respectively. Factors predicting surgery for incontinence were patient age at radical prostatectomy (HR 1.24 per decade, 95% CI 1.11-1.38, p = 0.0002), radiotherapy after surgery (HR 1.61, 95% CI 1.36-1.90, p <0.0001) and surgeon volume (49 or greater prostatectomies per year) (HR 0.59, 95% CI 0.46-0.77, p <0.0001).

CONCLUSIONS

Of patients who undergo radical prostatectomy 5% are expected to be treated with surgery for urinary incontinence during a 15-year period. Increasing patient age, radiation treatment and low surgeon volume are associated with significantly higher risk.

Abstract 1449: Spicing up radiation treatment for prostate cancer

Introduction and Objective: Radio-sensitizing agents sensitize cells to the lethal effects of ionizing radiation (IR). This permits use of lower doses of radiation to achieve equivalent cancer control thereby minimizing adverse effects to normal tissues. Given their lack of toxicity compounds occurring naturally in the diet make ideal potential radio-sensitizing agents. Capsaicin is the active compound chilli peppers. Traditionally capsaicin is used to treat chronic pain syndromes; however, recently evidence using in vitro prostate cancer (PCa) models describes its anti-carcinogenic potential. In our preliminary studies we have demonstrated the radio-sensitizing capacity of in PCa cells in vitro. Cells treated with capsaicin and/or IR to have increased expression of pro-apoptotic tumour-suppressor proteins p21 and p27 and reduced androgen-receptor. The objective of the present study is to assess the radio-sensitizing capacity in an in vivo model. Methods: Athymic nude mice were inoculated subcutaneously with human PCa (LNCaP) cells. Once xenografts reach 100mm3 forty animals will be randomized into 4 groups (15 /group); control (no treatment), capsaicin alone, ionizing radiation (IR) alone and capsaicin and IR. Treatments were administered over a two-week time period. Capsaicin (5 mg/kg/d) or vehicle was administered 3/week by gavage. RT will be delivered to animals in sterile cages as one fraction (6 Gray). Control animals were mock irradiated. Tumours were measured thrice weekly and volumes were calculated. Tumours were fixed and stained for pathological analyses and immunohistochemical evaluation. Results: There were no differences in food consumption or body weight of mice between groups. Two mice experienced mild to moderate inflammation of the stomach. No other toxicities were observed. Mice treated with capsaicin or IR alone had a significant reduction in tumour growth overtime (p &lt; 0.001). Mice treated with capsaicin and IR capsaicin had a reduction in the tumour volume greater than either capsaicin alone (p&lt;0.001) or radiation alone.(p&lt;0.03) We are currently investigating mechanism. Conclusion: These studies confirm the radio-sensitizing capacity of capsaicin in PCa xenograft model cells. Ongoing studies using are further delineating the mechanism of interaction of these treatment modalities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1449. doi:1538-7445.AM2012-1449

New variants at 10q26 and 15q21 are associated with aggressive prostate cancer in a genome-wide association study from a prostate biopsy screening cohort

PURPOSE

To identify and examine polymorphisms of genes associated with aggressive and clinical significant forms of prostate cancer among a screening cohort.

EXPERIMENTAL DESIGN

We conducted a genome-wide association study among patients with aggressive forms of prostate cancer and biopsy-proven normal controls ascertained from a prostate cancer screening program. We then examined significant associations of specific polymorphisms among a prostate cancer screened cohort to examine their predictive ability in detecting prostate cancer.

RESULTS

We found significant associations between aggressive prostate cancer and five single nucleotide polymorphisms (SNPs) in the 10q26 (rs10788165, rs10749408, and rs10788165, p value for association 1.3 × 10(-10 ) to 3.2 × 10(-11) ) and 15q21 (rs4775302 and rs1994198, p values for association 3.1 × 10(-8 ) to 8.2 × 10(-9)) regions. Results of a replication study done in 3439 patients undergoing a prostate biopsy, revealed certain combinations of these SNPs to be significantly associated not only with prostate cancer but with aggressive forms of prostate cancer using an established classification criterion for prostate cancer progression (odds ratios for intermediate to high-risk disease 1.8-3.0, p value 0.003-0.001). These SNP combinations were also important clinical predictors for prostate cancer detection based on nomogram analysis that assesses prostate cancer risk.

CONCLUSIONS

Five SNPs were found to be associated with aggressive forms of prostate cancer. We demonstrated potential clinical applications of these associations.

Prospective multi-institutional study evaluating the performance of prostate cancer risk calculators

PURPOSE

Prostate cancer risk calculators incorporate many factors to evaluate an individual's risk for prostate cancer. We validated two common North American-based, prostate cancer risk calculators.

PATIENTS AND METHODS

We conducted a prospective, multi-institutional study of 2,130 patients who underwent a prostate biopsy for prostate cancer detection from five centers. We evaluated the performance of the Sunnybrook nomogram-based prostate cancer risk calculator (SRC) and the Prostate Cancer Prevention Trial (PCPT) -based risk calculator (PRC) to predict the presence of any cancer and high-grade cancer. We examined discrimination, calibration, and decision curve analysis techniques to evaluate the prediction models.

RESULTS

Of the 2,130 patients, 867 men (40.7%) were found to have cancer, and 1,263 (59.3%) did not have cancer. Of the patients with cancer, 403 (46.5%) had a Gleason score of 7 or more. The area under the [concentration-time] curve (AUC) for the SRC was 0.67 (95% CI, 0.65 to 0.69); the AUC for the PRC was 0.61 (95% CI, 0.59 to 0.64). The AUC was higher for predicting aggressive disease from the SRC (0.72; 95% CI, 0.70 to 0.75) compared with that from the PRC (0.67; 95% CI, 0.64 to 0.70). Decision curve analyses showed that the SRC performed better than the PRC for risk thresholds of more than 30% for any cancer and more than 15% for aggressive cancer.

CONCLUSION

The SRC performed better than the PRC, but neither one added clinical benefit for risk thresholds of less than 30%. Further research is needed to improve the AUCs of the risk calculators, particularly for higher-grade cancer.

Induction of specific human cytotoxic T cells using dendritic cells transduced with an adenovector encoding rat epidermal growth factor receptor 2

This study demonstrates the ability to generate antigen-specific cytotoxic T cells (CTLs) against HER2 using a xenoantigenic immune stimulation strategy. Dendritic cells (DCs) were transduced with an adenovirus vector incorporating full-length cDNA for rat (xenoantigen) epidermal growth factor receptor 2 (Adv-HER2). Stimulation of autologous T cells with Adv-HER2 infected DCs led to enhanced HER2-specific reactivity as assessed by quantitative real-time polymerase chain reaction (qRT-PCR) for T cell IFN-γ mRNA. In ELISPOT and intracellular cytokine staining (ICS) assays, CD8+ CTLs induced by Adv-HER2 transduced DCs released IFN-γ following stimulation with irradiated autologous DCs infected with Adv-HER2 or loaded with a human prostate cancer cell line (LNCaP) lysate. DCs pulsed with HER2 peptides were less stimulatory than Adv-HER2 transduced DCs. HER2 DC induced CTL lysed HER2+ HLA-A2+ tumor cells (MCF-7); significantly reduced lysis occurred in HER2+ HLA-A2- tumor cells (SKOV-3), and the NK cell sensitive cell line K-562.

Abstract 2493: Capsaicin, a novel radiosensitizer, acts via a TRPV6 mediated mechanism

Radiosensitizing agents sensitize cells to the lethal effects of ionizing radiation (IR). This permits use of lower doses of radiation to achieve equivalent cancer control thereby minimizing adverse effects to normal tissues. Given their lack of toxicity compounds occurring naturally in the diet make ideal potential radiosensitizing agents.

Capsaicin, a compound found in the Capsicum sp. of plants, is a widely consumed food additive in areas with low PCa incidence. Traditionally capsaicin is used to treat chronic pain syndromes; however, recently evidence using in vitro PCa models describes its anti-carcinogenic potential. The transient receptor potential vanilloid-receptor (TRPV)-1 and TRPV6 cation selective channels are thought to be partly responsible for mediating these effects. TRPV-1 and TRPV-6 expression is up-regulated in PCa tissue correlating directly with increasing tumor grade. This suggests TRPV1 and/or TRPV6 may be potential therapeutic targets for capsaicin mediated interventions in PCa patients.

As IR and capsaicin both promote apoptosis and inhibit cell cycle progression in vitro we hypothesize an at least additive effect of combining these two therapies.

Using clonogenic assays we assessed the effect of ionizing radiation (1-8 Gy) and/or capsaicin (1-10μM) on colony formation rates in 4 human PCa cell lines (LNCaP, PC3, PC3AR2, DU145). Proliferative, apoptotic, TRPV-6 protein markers were assessed using Western blot analyses.

Exposure of cells to capsaicin (1-10μM) or IR (1-8Gy) caused significant dose-dependent inhibition of colony formation (p&lt;0.001). Combining capsaicin with IR resulted in further significant inhibition of colony formation rates (P&lt;0.001). Western blot analyses showed LNCaP cells treated with capsaicin and/or IR to have increased expression of pro-apoptotic proteins BAX and Bad, tumor-suppressor proteins p21 and p27 and reduced androgen-receptor. Additionally, capsaicin monotherapy caused a dramatic alteration in TRPV1 and TRPV6 expression.

These studies confirm the radiosensitizing capacity of capsaicin in PCa cells in vitro. Ongoing studies using are further delineating the mechanism of interaction of these treatment modalities.

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 2493. doi:10.1158/1538-7445.AM2011-2493

Abstract 1825: Sustained aerobic exercise alone does not counteract the tumor-promoting effects of a westernized diet on prostate cancer progression in vivo

Introduction: The influence of lifestyle behaviors on prostate cancer (PCa) is well established. Our lab has previously reported that diets high in both fat and carbohydrates – the “Westernized” diet – promote PCa tumor growth in vivo. Numerous studies have also found an inverse relationship between exercise and PCa progression. However, the exact relationships between diet, exercise and PCa, as well as their underlying mechanisms, are unclear. Herein we aim to investigate the effect of sustained aerobic exercise on PCa tumor growth in animals fed a “Westernized” diet or a normal diet.

Methods: Athymic nude mice (n=46) were inoculated subcutaneously with LNCaP cells. Mice were fed ad libitum with either a high-fat/high-carbohydrate diet (HFHC) or a standard normal diet (Normal), and randomized into exercising (Ex) and non-exercising groups (No-Ex). Exercise was undertaken 3 days per week (3 × 15 mins; 2-min breaks between cycles; 2.0-7.0 m/min) for 8 weeks, using a forced exercise wheel. Body weights, tumor volumes, and food consumption were recorded tri-weekly. Comparisons between groups over time were performed using RANOVA Type 3 Tests of Fixed Effects.

Results: There were no significant differences in body weight between the groups over time. The HFHC-Ex group (n=10) had the highest rate of tumor growth compared to all other groups (p&lt;=0.0007). No significant differences were observed between the rate of tumor growth of the HFHC-No Ex group (n=11) and the Normal-No Ex group (n=12) or between the Normal-No Ex group and the Normal-Ex group (n=10). However, the rate of tumor growth of the Normal-Ex group was reduced compared to the HFHC-No Ex group (p&lt;=0.0008). Food consumption analysis revealed significant differences (p&lt;=0.012) in energy consumption (kcal) between each of the groups over time. Mice in HFHC-Ex group consumed the most energy compared to all other groups followed by HFHC-No Ex&gt;Normal-Ex&gt;Normal-No Ex groups.

Conclusions: The results indicate that exercise stimulated an increase in food consumption. In mice fed a tumor-promoting “Westernized diet,” this enhanced the rate of tumor growth. However, in mice placed on a normal diet, this increase in energy consumption did not correspond with increased tumor growth over time, emphasizing the importance of both exercise and healthy diet in the progression of PCa. Further studies to examine the relationship between diet and exercise with respect to PCa progression are currently underway.

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 1825. doi:10.1158/1538-7445.AM2011-1825

Utilizing metformin to enhance the efficacy of androgen-deprivation therapy in the treatment of prostate cancer

22

Background: Prostate cancer (PCa) incidence varies by geographic location, with developed countries exhibiting higher levels of disease. Some attribute this to the “Westernized lifestyle” of high energy diets and limited physical activity with consequent obesity. Obesity and related diseases like diabetes, cause hyperinsulinemia, which upregulates pro-survival insulin/insulin-like growth factor signalling. Previous work shows diet-induced hyperinsulinemia enhances PCa tumor growth in vivo. Metformin, a diabetic treatment, reduces hyperinsulinemia, and also exhibits anti-neoplastic properties. We assessed the potential benefit of combining a standard PCa treatment (bicalutamide) with metformin in vitro and in vivo.

Methods: The effect of bicalutamide and/or metformin on colony formation rates was assessed in LNCaP, PC3, DU145 and PC3AR2 PCa cell lines using clonogenic assay. Western blot and cell cycle analyses were used to elucidate mechanisms of interaction between the drugs. The combination treatment regimen was assessed in vivo using a murine xenograft model.

Results: Micromolar bicalutamide or millimolar metformin caused significant dose-dependent reduction in colony formation rates (p<0.001). Combination treatment further significantly reduced colony formation rates (p<0.005). Differing mechanisms of interaction occurred in AR positive and negative cell lines. Following combination treatment LNCaP cells exhibited altered cell proliferation (decreased PCNA) and perturbed cell cycle kinetics (G1/S arrest). PC3 cells showed evidence of enhanced apoptosis (increased BAX, decreased caspase 3, phospho-Akt). Preliminary in vivo results show significantly diminished tumor growth following combination treatment (p<0.0001).

Conclusions: Combining bicalutamide and metformin significantly reduces PCa cell colony formation rates further than either monotherapy. In AR positive cells this effect is mediated by reducing cell proliferation rates, whereas in AR negative cells combination treatment promotes apoptosis. This combination drug regimen may potentially improve prostate-cancer specific survival via the direct anti-neoplastic properties outlined.

[Table: see text]

Utilizing metformin as a radiosensitizing agent in the treatment of prostate cancer

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Background: External beam radiation therapy (EBRT) is a well recognized curative prostate cancer (PCa) treatment modality utilizing ionizing radiation (IR). In addition to mediating DNA damage, IR upregulates several intracellular pro-survival pathways including the insulin- like growth factor (IGR) signaling network. This may contribute to the intrinsic radioresistance exhibited by certain tumors. Diabetic patients with PCa experience poorer outcomes following EBRT than their non-diabetic counterparts. Some attribute this to diabetes-induced chronic hyperinsulinemia with consequent upregulation of pro-survival insulin/IGF signalling. Previous work by our group showed diet-induced hyperinsulinemia to enhance PCa tumor growth in vivo. Metformin, a diabetic treatment, alleviates hyperinsulinemia, and also exhibits anti-neoplastic properties. We postulate that pre-treatment with metformin to correct hyperinsulinemia may protect cells from radiation-mediated pro-survival insulin/IGF signaling. Thus we assessed the radiosensitizing potential of metformin using in vitro and in vivo PCa models.

Methods: The effect of IR and/or metformin on colony formation rates was assessed in LNCaP, PC3, DU145 and PC3AR2 PCa cell lines using clonogenic assay. The combination treatment regimen was assessed in vivo using a murine xenograft model. Western blot and cell cycle analyses are ongoing to try and elucidate any mechanisms of interaction between metformin and IR.

Results: Monotherapy with IR (1-8Gy) or metformin (0.01-10.0mM) caused significant dose-dependent reduction in colony formation rates (p<0.001). Combination treatment further significantly reduced colony formation rates (p<0.03). Preliminary results from our in vivo study show diminished tumor growth in response to combination treatment (p<0.0001), and are currently subject to ongoing statistical analyses.

Conclusions: Our in vitro findings confirm combining metformin with IR significantly reduces PCa cell colony formation rates further than either monotherapy. Recapitulation of these results in vivo would provide justification for translating this work into a phase II clinical trial of metformin as a radiosensitizing agent.

No significant financial relationships to disclose.

Capsaicin, a novel radiosensitizer, acts via a TRPV6 mediated phenomenon

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Background: Radiosensitizing agents sensitize cells to the lethal effects of ionizing radiation (IR). This permits use of lower doses of radiation to achieve equivalent cancer control thereby minimizing adverse effects to normal tissues. Given their lack of toxicity compounds occurring naturally in the diet make ideal potential radiosensitizing agents. Capsaicin, a compound found in the Capsicum sp. of plants, is a widely consumed food additive in areas with low PCa incidence. Traditionally capsaicin is used to treat chronic pain syndromes; however, recently evidence using in vitro PCa models describes its anti-carcinogenic potential. The transient receptor potential vanilloid-receptor (TRPV)-1 and TRPV6 cation selective channels are thought to be partly responsible for mediating these effects. TRPV-1 and TRPV-6 expression is up-regulated in PCa tissue correlating directly with increasing tumor grade. This suggests TRPV1 and/or TRPV6 may be potential therapeutic targets for capsaicin mediated interventions in PCa patients. As IR and capsaicin both promote apoptosis and inhibit cell cycle progression in vitro we hypothesize an at least additive effect of combining these two therapies.

Methods: Using clonogenic assays we assessed the effect of ionizing radiation (1-8 Gy) and/or capsaicin (1-10μ M) on colony formation rates in 4 human PCa cell lines (LNCaP, PC3, PC3AR2, DU145). Proliferative, apoptotic, TRPV-6 protein markers were assessed using Western blot analyses.

Results: Exposure of cells to capsaicin (1-10μ M) or IR (1-8Gy) caused significant dose-dependent inhibition of colony formation (p<0.001). Combining capsaicin with IR resulted in further significant inhibition of colony formation rates (P<0.001). Western blot analyses showed LNCaP cells treated with capsaicin and/or IR to have increased expression of pro- apoptotic proteins BAX and Bad, tumor-suppressor proteins p21 and p27 and reduced androgen-receptor. Additionally, capsaicin monotherapy caused a dramaticalteration in TRPV1 and TRPV6 expression.

Conclusions: These studies confirm the radiosensitizing capacity of capsaicin in PCa cells in vitro. Ongoing studies are further delineating the mechanism of interaction of these treatment modalities.

No significant financial relationships to disclose.

Value addition to finger millet (Eleusine coracana) by germination and fermentation with Monascus purpureus

The present investigation has been carried out to highlight the importance of germination and fermentation of finger millet with Monascus purpureus. Finger millet was subjected to (i) germination, (ii) to fermentation with M. purpureus, and (iii) germination followed by fermentation with M. purpureus. The results of this experiment suggest that the germinated (72 h) finger millet fermented (10 days) with M. purpureus showed reduction in phytic acid and tannin contents by 88.8% and 90.1%, respectively, with an increase of 61.5% HCl-extractable minerals, reducing sugars and soluble proteins thereby supporting the production of antihypercholesterolemic metabolite, statin.

Antiproliferative mechanisms of the flavonoids 2,2'-dihydroxychalcone and fisetin in human prostate cancer cells

We have previously demonstrated the antiproliferative effect of two flavonoids-2,2'-dihydroxychalcone (DHC), a novel synthetic flavonoid, and fisetin, a naturally occurring flavonol-in prostate cancer cells. In this study, we further examine the mechanisms of these compounds on survival and proliferation pathways. DHC and fisetin (1-50 microM) caused a dose-dependent reduction in viability, a concomitant increase in apoptosis in PC3 cells at 72 h, and a decrease in clonogenic survival at 24 h treatment. DHC was considerably more potent than fisetin in these cytotoxicity assays. The mechanism of accelerated cellular senescence was not activated by either compound in PC3 or lymph node carcinoma of the prostate (LNCaP) cells. Gene expression alterations in PC3 and LNCaP cells treated with 15 muM DHC and 25 microM fisetin for 6 to 24 h were determined by oligonucleotide array. Amongst the most highly represented functional categories of genes altered by both compounds was the cell cycle category. In total, 100 cell cycle genes were altered by DHC and fisetin including 27 genes with key functions in G2/M phase that were downregulated by both compounds. Other functional categories altered included chromosome organization, apoptosis, and stress response. These results demonstrate the multiple mechanisms of antitumor activity of DHC and fisetin in prostate cancer cells in vitro.

A whole-genome SNP association study of NCI60 cell line panel indicates a role of Ca2+ signaling in selenium resistance

Epidemiological studies have suggested an association between selenium intake and protection from a variety of cancer. Considering this clinical importance of selenium, we aimed to identify the genes associated with resistance to selenium treatment. We have applied a previous methodology developed by our group, which is based on the genetic and pharmacological data publicly available for the NCI60 cancer cell line panel. In short, we have categorized the NCI60 cell lines as selenium resistant and sensitive based on their growth inhibition (GI50) data. Then, we have utilized the Affymetrix 125K SNP chip data available and carried out a genome-wide case-control association study for the selenium sensitive and resistant NCI60 cell lines. Our results showed statistically significant association of four SNPs in 5q33–34, 10q11.2, 10q22.3 and 14q13.1 with selenium resistance. These SNPs were located in introns of the genes encoding for a kinase-scaffolding protein (AKAP6), a membrane protein (SGCD), a channel protein (KCNMA1), and a protein kinase (PRKG1). The knock-down of KCNMA1 by siRNA showed increased sensitivity to selenium in both LNCaP and PC3 cell lines. Furthermore, SNP-SNP interaction (epistasis) analysis indicated the interactions of the SNPs in AKAP6 with SGCD as well as SNPs in AKAP6 with KCNMA1 with each other, assuming additive genetic model. These genes were also all involved in the Ca²⁺ signaling, which has a direct role in induction of apoptosis and induction of apoptosis in tumor cells is consistent with the chemopreventive action of selenium. Once our findings are further validated, this knowledge can be translated into clinics where individuals who can benefit from the chemopreventive characteristics of the selenium supplementation will be easily identified using a simple DNA analysis.

Micronutrients attenuate progression of prostate cancer by elevating the endogenous inhibitor of angiogenesis, platelet factor-4

Background

Longstanding evidence implicates an inadequate diet as a key factor in the onset and progression of prostate cancer. The purpose herein was to discover, validate and characterize functional biomarkers of dietary supplementation capable of suppressing the course of prostate cancer in vivo.

Methods

The Lady transgenic mouse model that spontaneously develops prostate cancer received a diet supplemented with a micronutrient cocktail of vitamin E, selenium and lycopene ad libitum. A proteomic analysis was conducted to screen for serum biomarkers of this dietary supplementation. Candidate peptides were validated and identified by sequencing and analyzed for their presence within the prostates of all mice by immunohistochemistry.

Results

Dietary supplementation with the combined micronutrients significantly induced the expression of the megakaryocyte-specific inhibitor of angiogenesis, platelet factor-4 (P = 0.0025). This observation was made predominantly in mice lacking tumors and any manifestations associated with progressive disease beyond 37 weeks of life, at which time no survivors remained in the control group (P < 0.0001). While prostates of mice receiving standard chow were enlarged and burdened with poorly differentiated carcinoma, those of mice on the supplemented diet appeared normal. Immunohistochemical analysis revealed marked amplifications of both platelet binding and platelet factor-4 within the blood vessels of prostates from mice receiving micronutrients only.

Conclusion

We present unprecedented data whereby these combined micronutrients effectively promotes tumor dormancy in early prostate cancer, following initiation mutations that may drive the angiogenesis-dependent response of the tumor, by inducing platelet factor-4 expression and concentrating it at the tumor endothelium through enhanced platelet binding.