Chemoprevention of Prostate Cancer through Dietary Agents: Progress and Promise

Abstract

Prostate cancer (CaP) is second only to lung cancer as the cause of cancer-related deaths in American men and is responsible for over 29,000 deaths per year. One promising approach to reduce the incidence of CaP is through chemoprevention, which has been recognized as a plausible and cost-effective approach to reduce cancer morbidity and mortality by inhibiting precancerous events before the occurrence of clinical disease. Indeed, CaP is an ideal candidate disease for chemoprevention because it is typically diagnosed in the elderly population with a relatively slower rate of growth and progression, and therefore, even a modest delay in the development of cancer, achieved through pharmacologic or nutritional intervention, could result in substantial reduction in the incidence of clinically detectable disease. In this review, we have summarized the recent investigations and mechanistic studies on CaP chemoprevention using dietary agents, such as selenium, vitamins D and E, lycopene, phytoestrogens, flavonoids, and green tea polyphenols. Well-designed trials are required to delineate the potential clinical usefulness of these agents through issues, such as determining the optimal period and route of administration, systemic bioavailability, optimal dosing and toxicity of the agent, and single or combinatorial approach. It is hoped that, combining the knowledge based on agents with targets, effective approaches for CaP chemoprevention can be established. (Cancer Epidemiol Biomarkers Prev 2007;16(11):2193 -203)

Carnosol, a Dietary Diterpene, Displays Growth Inhibitory Effects in Human Prostate Cancer PC3 Cells Leading to G2-Phase Cell Cycle Arrest and Targets the 5′-AMP-Activated Protein Kinase (AMPK) Pathway

“…In addition, it is becoming increasingly appreciated that cancer chemoprevention through the use of naturally occurring dietary agents may be an effective strategy for the management of PCa. (2,4,5). Consistent with the idea of chemoprevention there has been a growing increase to use dietary supplements by PCa patients to alleviate disease.…”

Suppression of NFκB and its Regulated Gene Products by Oral Administration of Green Tea Polyphenols in an Autochthonous Mouse Prostate Cancer Model

“…In the absence of satisfactory treatment options for PCa, chemoprevention could be an effective approach to reduce the incidence of the disease, an area of investigation which we recently reviewed (6 and the references therein). PCa represents an ideal candidate disease for chemoprevention because it is diagnosed in elderly males; thus even a moderate delay in the neoplastic changes achieved through pharmacologic or dietary intervention could result in a substantial reduction in the incidence of the clinically detectable disease (6)(7)(8). There is currently intense effort in identifying mechanism-based naturally occurring agents present in diet and beverages consumed by humans for their cancer chemopreventive and possibly cancer therapeutic efficacy against PCa (6)(7)(8)(9).…”

“…PCa represents an ideal candidate disease for chemoprevention because it is diagnosed in elderly males; thus even a moderate delay in the neoplastic changes achieved through pharmacologic or dietary intervention could result in a substantial reduction in the incidence of the clinically detectable disease (6)(7)(8). There is currently intense effort in identifying mechanism-based naturally occurring agents present in diet and beverages consumed by humans for their cancer chemopreventive and possibly cancer therapeutic efficacy against PCa (6)(7)(8)(9). The identification of new predictive biomarkers will be important for improving clinical management, outcome of treatment protocols, and assessing the effectiveness of chemopreventive regimens, all of which could lead to improved survival of patients with the disease.…”

“…Molecular targets for PCa, especially those that are indicative of invasiveness of the disease, will be excellent candidate targets for staging the disease and establishing effectiveness of chemoprevention of PCa. Among these agents, reports from this laboratory and elsewhere (6,7,(10)(11)(12) have shown that polyphenols derived from green tea (GTP) are potential chemopreventive agents against PCa. We have earlier shown that oral infusion of GTP to transgenic adenocarcinoma of the mouse prostate (TRAMP), inhibits the development of PCa and identified that IGF-I/IGFBP-3 signaling pathway as a prime pathway for GTP-mediated inhibition of PCa that limits the progression of cancer through inhibition of angiogenesis and metastasis (12).…”

Chemopreventive Potential of an Ethyl Acetate Fraction from Curcuma Longa is Associated with Upregulation of p57kip2and Rad9 in the PC-3M Prostate Cancer Cell Line

“…The American Cancer Society estimates that 28,660 men in the United States will die of Prostate Cancer in 2008 and accounts for about 9% of cancer related deaths in men (American Cancer Society, 2008). The epidemiological studies have shown significant correlations between prostate cancer incidence and dietary habits and the potential of dietary substances to act as chemopreventive agents against prostate cancer is increasingly appreciated (Syed et al, 2007(Syed et al, : 2008. In this regard long-term well-designed and optimized intervention trials are required to delineate the potential clinical usefulness of C. longa both in normal populations as well as in high-risk groups and warrant further studies in the treatment and prevention of human neoplasm.…”