**24. Isoflavone-deprived soy peptide**

NF-gammaB mediates processes of carcinogenesis related to deregulation of the normal con‐ trol of proliferation, angiogenesis, and metastasis. NF-gammaB suppression is associated with cancer chemoprevention. Heat shock protein 90 is important to NF-gammaB activation and stabilizes key proteins implicated in cell cycle control and apoptosis signaling. Adminis‐ tration of isoflavone-deprived soy peptide (3.3 g/rat/day) in the diet reduced the incidence of 7,12-dimethylbenz[alpha]anthracene (DMBA)-induced rat mammary ductal carcinomas, the number of tumors, and prolonged the latency period of tumor development compared to control diet animals. Isoflavone-deprived soy peptide downregulates the expression of heat shock protein 90, hence thwarting the signaling pathway that brings about NF-gammaB activation.It upregulates the expression of p21, p53, and caspase-3 proteins; and downregu‐ lates the expression of VEGF. In keeping with in vivo, treatment with the soy peptide inhib‐ ited growth and induced apoptosis in human breast MCF-7 tumor cells. [27].
