Proliferative effect of whey from cows' milk obtained at two different stages of pregnancy measured in MCF-7 cells

• Published in: Journal of dairy research Vol. 79; no. 1; pp. 33 - 38
• Main Authors: Nielsen, Tina S, Andersen, Charlotte, Sejrsen, Kris, Purup, Stig
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.02.2012
• Subjects: Animal productions; Animals; Biological and medical sciences; Breast cancer; Cattle; Cell Proliferation - drug effects; Estradiol - chemistry; Estradiol - pharmacology; Estrogens; Female; Food industries; Fundamental and applied biological sciences. Psychology; Humans; MCF-7 Cells; Milk; Milk and cheese industries. Ice creams; Milk Proteins - chemistry; Milk Proteins - pharmacology; Pregnancy; Terrestrial animal productions; Vertebrates; Whey Proteins; whey; pregnancy stage; proliferative effect; Bovine milk; Bovine; Dairy product; Whey; Pregnancy; Reproduction; Vertebrata; Mammalia; Dairy industry; Cow milk; Artiodactyla; Ungulata
• ISSN: 0022-0299; 1469-7629
• DOI: 10.1017/S0022029911000689

Dietary estrogens may play a role in the etiology of hormone-dependent cancers like breast cancer. Cow's milk contains various endogenous estrogens and feed derived phytoestrogens that potentially contribute to an estrogenic effect of milk in consumers, and therefore we evaluated the effect of milk (whey) in a proliferation assay with estrogen-sensitive MCF-7 human breast cancer cells. Milk samples were obtained from 22 cows representing different stages of pregnancy (first and second half) and whey was produced from the milk. 0·1, 0·25 or 0·5% whey was included in the cell culture medium and after 6 days of treatment cell proliferation was assessed by a colorimetric method with a fluorometer. Whey induced significant (P<0·05) proliferative effects compared with control cells with no added whey at all concentrations tested. There was no difference in the proliferative effect of whey depending on the stage of pregnancy from which the milk was obtained. We did not observe anti-proliferative effects when whey was tested in the presence of 10 pm estradiol in the medium. In conclusion, these results indicate that whey, irrespective of the pregnancy stage from which the milk was obtained induced a significant proliferative response in MCF-7 cells and no anti-proliferative effect, which may be caused, at least in part, by estrogens present in milk. The implications of our findings in relation to for example breast cancer will have to be studied further in other model systems preferentially in vivo.