04 March 2008 Human embryonic stem cells produce a protein which shows some anti-cancer properties in the lab, according to a new study.
The potential for stem-cell therapies to cause cancer is a major concern, but now researchers at Northwestern University in Chicago, US, say a protein produced by human embryonic stem cells (hESCs) can inhibit the growth and spread of breast cancer and malignant melanoma, the deadliest form of skin cancer.
They suspect that the protein, called Lefty, has similar effects on other tumor types, including those of the prostate.
The similarities between stem cells – primitive cells which can differentiate into the body’s different tissue types – and tumor cells have intrigued researchers. Both are self-renewing and have the capacity to give rise to different cells types.
The team at Northwestern previously showed that hESCs – the most versatile type of stem cell – produce chemicals that caused melanoma cells to revert to normal skin cells.
They also demonstrated that melanoma and breast cancers produce a protein called Nodal that helps tumor cells spread, and that this protein also facilitates embryonic stem cell's ability to turn into different cell types.
In the latest study they set out to find the substances produced by hESCs that have anti-cancer properties – perhaps, they believed, by blocking Nodal.
Lefty, the protein they identified, blocks the production of Nodal and therefore controls embryonic cell differentiation and development.
Mary Hendrix, who led the study, showed that unlike hESCs, however, tumor cells do not express Lefty. This allows them to produce Nodal in an unregulated manner – and to keep growing and spreading. But when the researchers exposed aggressive tumor cells to the chemical environment of hESCs, which contained Lefty, levels of Nodal production fell sharply, and the tumor cells became less invasive and even started to die.
Hendrix told New Scientist she was optimistic that anti-cancer treatments based on stem cell proteins such as Lefty would emerge.
"We now hope to interest pharmaceutical or biotech companies into developing partnerships to develop new treatments. We really believe that we are onto something important."
She adds that other stem cells proteins with anti-cancer effects probably remained to be discovered.
Significantly, Hendrix notes that Lefty is secreted only by hESCs, and not by any other stem-cell type tested – including stem cells isolated from amniotic fluid, cord blood or adult bone marrow – or placental cells.
"After all the controversy about using embryonic stem cells, this shows how potentially important such research is," she says.
Lyle Armstrong at Newcastle University in the UK says the latest study is "convincing" in showing the prominent role the Nodal protein plays in aggressive cancers. He says more research is needed to see if other types of cancer respond equally well when the pathway is switched off.
"The paper clearly shows that factors which probably promote human embryonic stem cell proliferation are important in controlling tumor cell behavior," notes Stephen Minger, director of the stem cell biology laboratory at Kings College London. "This provides a novel target for developing tumor cell therapies."
Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073__pnas.0800467105)
I've been using umbilical cord stem cells on my patients for over 15 years and I had to use a lot of them to see some results, but I never got close to the results that I see using Stemaid's stem cells.Dr C.
Thank you Stemaid. Your embryonic stem cells reduced my elevated CA-19-9 pancreatic tumour markers to normal levels and lower. So grateful.Brent J.
My PSA was at 21 when I started Stemaid's program. After two weeks of their rejuvenation protocol it was at 11.Tom F.
They said the refraction was 40 percent! My refraction hasn't been that good for at least 15 to 20 years.Randy (Heart Disease)
There isn't any doubt in my mind that Stemaid saved our daughter's life.Laura G. (Lyme Protocol)
I thank God everyday for helping me find the remarkable positive effects that were possible through Stemaid treatments.Charlene L (Heart Disease)
It was the single best decision that I have made in my life!Susan V. (Lyme Protocol)
The best stem cells in the world! Pluripotent and can message all cells in your body to regenerate. Excretes a protein that is anti-tumor and cancer. I highly recommend Stemaid.Tracy C. (Lyme Protocol)
Whether you're a patient seeking stem cell therapy or a doctor seeking stem cells for your patients, please feel free to get in touch with us.
Call Us at +357 97725404