Wednesday, May 7, 2008

Response to anonymous regarding stem cells

There was an anonymous comment to my past blog post on "Stem Cells in discovery???" The commentor states that they did a literature search, a patent search, etc and found that Mark Cregan et al have been the only authors to publish that stem cells are present in breast milk (other than a commentary in JHL-2006).
Ruth Lawrence, author of Breastfeeding, Fourth Edition (1994) on page 78 under the topic of Synthesis of Human Milk, states, "The epithelial cells of the gland contain stem cells and highly differentiated secretory alveolar cells at the terminal ducts. The stem cells are stimulated by HGH and insulin." Human milk contains epithelial cells. Neville & Neifert in Lactation (1983) state, "the predominant cell type changes from leukocytes to sloughed epithelial cells which continue to be found in milk throughout lactation at a concentration of about ten to the fourth cells/ml." p.57
In an article about stem cells in the mammary gland at the NIH they state, "Stem cells are important medically both because of the risk they pose in carcinogenesis, and for the potential they offer for organ regeneration or replacement." Note that the mammary gland biology group from the NIH has as its symbol the statue of Romulus and Remus nursing the mother wolf.
In another review at the NIH regarding the Mammary Gland and stem cells the author Daniel Medina states: "totipotent stem cells exist throught out the mammary parenchyma tree and are not localized to just the terminal portions of the mammary tree."
The mammary tree is lined with epithelial cells (totipotent stem cells) that are sloughed off throughout lactation. This has been known for some time, just not publicly. If one looks at the literature from the NIH on stem cells and the mammary gland those studies are from the 80's and 90's. What I gather you are saying is that knowledge of stem cells was only related to information on stem cells in the mammary gland itself not the milk. I assume that Ruth Lawrence had an understanding in the 90's that human milk had stem cells but then maybe I am wrong in that assumption?
Since I have not been able to read Mark Cregan's research in Cell & Tissue Research (July 2007), I can only hope that under a conflict of interest statement (if they have one) he wrote about his patent. I do hope in his presentation to ILCA, he mentions that he has joint ownership in a patent.
If the lactation professional community wants to believe that Mark Cregan discovered that there were stem cells in breastmilk, then what more can I say at this point? People believe what they want to believe.
Copyright 2008 Valerie W. McClain

1 comment:

  1. From my limited understanding, epithelial cells are not totipotent stem cells. They are the cells that make the milk. Stem cells become them (I think). You're right that there are many previous publications on stem cells in the breast, but these relate to the tissue of the breast itself, not the milk. Herein lies the difference. Stem cells in the breast is old news, but in milk itself is the exciting part. Also, the older studies on cells in milk talk about immune and epithelial cells, and make no mention of stem cells. Mark Cregan has made the link between the two.

    I am sure, like yourself, those who spent their time thinking about human milk may have considered the possibility of stem cells being in milk, but no-one else proved it until this group from Western Australia.

    Also, this group from University of Western Australia do a lot of promotion for breastfeeding. I have seen Peter Hartmann and his group speak many times. I am sure that their patent is not intended for sinister use. It would be contrary to their interests. Indeed Prof Hartmann has received a number of awards for his positive work promoting breastfeeding, here in Australia and overseas. I doubt he would have been given these awards if he had a history of harming breastfeeding rates. From what I have seen, he is one of the most pro-breastfeeding Doctors in the world.