Only embryonic stem cells secrete cancer-busting protein

Researchers at Northwestern University in the USA have found that human embryonic stem cells secrete a protein, called Lefty, that blocks the formation of some skin cancers (e.g. melanoma) and breast cancer. Now the researchers have looked at placental cells, amniotic stem cells, cord-blood stem cells andadult haematopoietic stem cells, but none of them have been able to do what the eSCs do – prevent cancer.

From what I could gather by reading the article, the protein Lefty appears to block a protein, Nodal, produced by cancers. Nodal is hypothesised to be a protein that causes the cancer cells to continually divide, and Nodal is somehow blocked by Lefty. The researchers added tumour cells to embryonic stem cells, and within 3 days (for the melanoma) to 5 days (for the breast cancer), the tumour cells had stopped producing Nodal. Without Nodal, the cancer cells entered apoptosis (cell suicide).

So, now when asked the question “what can embryonic stem cells do anyway?”, you can respond with “Oh, nothing much. Just cure both melanoma, the cause of the majority of skin cancer deaths, as well as breast cancer, the fifth most common cause of cancer death in the world.”

(Link to Full Article not yet available, despite what the ScienceDaily summary says. I think they get confused with the other NWU story, in PNAS this week. So, look at some earlier work on Nodal pathways, similarity between embryonic cells and cancer cells and the effects of embryonic microenvirons on metastatic tumours)