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Beneficial Effects of Soy Protein in the Development of DMBA‐Induced Breast Tumors in Rats
Author(s) -
Mukhopadhyay Sutapa,
Ballard Billy R,
Mukherjee Shyamali,
Kabir Syeda M,
Das Salil K
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a37-b
Subject(s) - soy protein , dmba , casein , 7,12 dimethylbenz[a]anthracene , endocrinology , medicine , immunohistochemistry , breast cancer , pathology , chemistry , cancer , food science , carcinogenesis
Soy products have anticarcinogenic properties. This study was to demonstrate by histological grading whether soy protein protects against DMBA‐induced breast tumors in female rats. At 25 days of age, rats were fed diets containing either casein or soy protein. After 25 days on diets, a single dose of DMBA in sesame oil (80 mg/kg) was administered by gavage to the animals. Control animals received the vehicle only. After 122 days of DMBA administration, the animals were sacrificed. All breast tumors were detected by palpation and at autopsy biopsy specimens were taken. Even though multiple tumors were observed in some animals of both groups, the number of tumors per rat was less in soy group than that in casein group at any time point. Incidence of tumors was less in soy protein group than that in casein group. There was no tumor in control animals. Casein group had 20% grade I, 60% grade II and 20% grade III tumors. However, the soy group had 100% grade I and no aggressive grade II or grade III tumor. There was a delay in the development of tumor in the soy protein group in comparison to the casein group. Again, unlike casein, the soy group had reduced levels of VEGF and bFGF, angiogenic markers. Furthermore, proliferative index as assessed by Ki‐67 staining was less in soy protein group than that in casein group. These findings suggest that the soy protein may protect against the development of a more aggressive breast carcinoma. (This work was supported by a grant from the US Department of Army (DAMD17‐03‐1‐0352)