Tomatoes, Lycopene, and Prostate Cancer: What Have We Learned from Experimental Models?

Authors

Nancy E Moran
Jennifer M Thomas-Ahner
Lei Wan
Krystle E Zuniga
John W Erdman
Steven K Clinton

Publication Date

6-9-2022

Journal

The Journal of Nutrition

DOI

10.1093/jn/nxac066

PMID

35278075

PMCID

PMC9178968

PubMedCentral® Posted Date

3-12-2022

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

Keywords

Animals, Anticarcinogenic Agents, Carcinogenesis, Carotenoids, Disease Models, Animal, Humans, Lycopene, Solanum lycopersicum, Male, Mice, Prostatic Neoplasms, preclinical models, nutrition, prostate carcinogenesis, tomato, prostate metastasis

Abstract

Human epidemiology suggests a protective effect of tomatoes or tomato phytochemicals, such as lycopene, on prostate cancer risk. However, human epidemiology alone cannot reveal causal relations. Laboratory animal models of prostate cancer provide opportunities to investigate hypotheses regarding dietary components in precisely controlled, experimental systems, contributing to our understanding of diet and cancer risk relations. We review the published studies evaluating the impact of tomatoes and/or lycopene in preclinical models of prostate carcinogenesis and tumorigenesis. The feeding of tomatoes or tomato components demonstrates anti-prostate cancer activity in both transplantable xenograft models of tumorigenesis and models of chemically- and genetically-driven carcinogenesis. Feeding pure lycopene shows anticancer activity in most studies, although outcomes vary by model system, suggesting that the impact of pure lycopene can depend on dose, duration, and specific carcinogenic processes represented in different models. Nonetheless, studies with the transgenic adenocarcinoma of the mouse prostate (TRAMP) model of carcinogenesis typically demonstrate similar bioactivity to that of tomato feeding. In general, interventions that commence earlier in carcinogenesis and are sustained tend to be more efficacious. Accumulated data suggest that lycopene is one, but perhaps not the only, anticancer bioactive compound in tomatoes. Although it is clear that tomatoes and lycopene have anti-prostate cancer activity in rodent models, major knowledge gaps remain in understanding dose-response relations and molecular mechanisms of action. Published and future findings from rodent studies can provide guidance for translational scientists to design and execute informative human clinical trials of prostate cancer prevention or in support of therapy.