London, March 5 : A protein that regulates development of human embryonic stem cells could also inhibit the growth and spread of deadly cancers, according to a study by researchers at Northwestern University in Chicago.
Researchers say that the protein, which they've dubbed "Lefty," inhibits the production of another protein known as Nodal, found in embryonic stem cells and cancer cells alike.
Under normal circumstances, Nodal plays a key role in helping embryonic stem cells turn into the different cells needed in the human body, such as tissue cells, skin cells, etc.
Lefty is secreted only in human embryonic stem cells (hESCs) and not in any other types of stem cells, including those isolated from amniotic fluid, umbilical cord blood or adult bone marrow, the researchers said.
In an earlier study, the Northwestern team found that aggressive melanoma and breast cancer produce a protein called Nodal, which may serve as a marker of aggressive behaviour in human cancers.
In this new study, the researchers exposed metastatic melanoma and breast cancer cells to hESCs containing Lefty and noted a dramatic reduction in Nodal production in the cancer cells, along with decreased growth and an increase in programmed cell death (apoptosis).
"The remarkable similarity of the responses of the two tumour types is likely attributable to the commonality of plasticity (for example, the aberrant and unregulated expression of Nodal) that indiscriminately unifies highly aggressive cancer cells, regardless of their tissue of origin," New Scientists magazine quoted lead author Dr. Mary J. C. Hendrix, scientific director of the Children's Memorial Research Center and professor in The Robert H. Lurie Comprehensive Cancer Center of Northwestern University and the Feinberg School of Medicine, as saying.
"Further, the tumour suppressive effects of the hESC microenvironment, by neutralizing the expression of Nodal in aggressive tumour cells, provide previously unexplored novel therapeutic modalities for cancer treatment," she added.
Hendrix further noted that 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 said.
She added that other stem cells proteins with anti-cancer effects probably remained to be discovered.
The study is published in the Proceedings of the National Academy of Sciences.