Soy
isoflavones have been documented as dietary nutrients broadly classified as "natural agents" which plays important roles in reducing the incidence of
hormone-related
cancers in Asian countries, and have shown inhibitory effects on
cancer development and progression in vitro and in vivo, suggesting the
cancer preventive or therapeutic activity of soy
isoflavones against
cancers. Emerging experimental evidence shows that
isoflavones could induce
cancer cell death by regulating multiple cellular signaling pathways including Akt, NF-κB, MAPK, Wnt,
androgen receptor (AR), p53 and Notch signaling, all of which have been found to be deregulated in
cancer cells. Therefore, homeostatic regulation of these important cellular signaling pathways by
isoflavones could be useful for the activation of cell death signaling, which could result in the induction of apoptosis of both pre-cancerous and/or cancerous cells without affecting normal cells. In this article, we have attempted to summarize the current state-of-our-knowledge regarding the induction of
cancer cell death pathways by
isoflavones, which is believed to be mediated through the regulation of multiple cellular signaling pathways. The knowledge gained from this article will provide a comprehensive view on the molecular mechanism(s) by which soy
isoflavones may exert their effects on the prevention of
tumor progression and/or treatment of human
malignancies, which would also aid in stimulating further in-depth mechanistic research and foster the initiation of novel clinical trials.