Chemoprevention of prostate cancer: soy isoflavones and curcumin

Abstract

The burden of increasing morbidity and mortality due to prostate cancer imposes a need for new, effective measures of prevention in daily life. The influence of lifestyle on carcinogenesis in Asian men who migrate to Western cultures supports a causal role for dietary, environmental, and genetic factors in the epidemiology of prostate cancer. Chemoprevention, a prophylactic approach that uses nontoxic natural or synthetic compounds to reverse, inhibit, or prevent cancer by targeting specific steps in the carcinogenic pathway, is gaining traction among health care practitioners. Soy isoflavones and curcumin, staples of the Asian diet, have shown promise as functional factors for the chemoprevention of prostate cancer because of their ability to modulate multiple intracellular signaling pathways, including cellular proliferation, apoptosis, inflammation, and androgen receptor signaling. Recent evidence has revealed the DNA damage response (DDR) to be one of the earliest events in the multistep progression of human epithelial carcinomas to invasive malignancy. Soy isoflavones and curcumin activate the DDR, providing an opportunity and rationale for the clinical application of these nutraceuticals in the chemoprevention of prostate cancer.

Keywords: Chemoprevention; Curcumin; Isoflavones; Prostate neoplasms.

FIG. 1

Action of neutraceuticals on the prevention of cancer. DDR, DNA damage response; AR, androgen receptor; ER, estrogen receptor; CYP, cytochrome P450.

FIG. 2

Isoflavones and curcumin synergistically induce phosphorylation of ataxia-telangiectasia-mutated kinase (p-ATM), checkpoint kinase2 (Chk2), p53 (Ser15), and H2AX in LNCaP cells (reprinted from Ide H, et al. Cancer Sci 2011;102:468-71, with permission of John Wiley & Sons) [41].

FIG. 3

Chemopreventive actions of soy isoflavones and curcumin. DDR, DNA damage response.