Researchers discovered a new type of stem cell that can transform into either a liver cell or one that lines liver blood vessels.
The findings could have implications for future liver cancer treatments and provide insight into how the condition develops, The Mount Sinai Hospital reported.
Humans develop from single-cells that can transform into any of the other 200 cell types that make up the fully developed human body. Stem cells multiply (proliferate) and specialize (differentiate) until they have created millions of functional cells. The early human embryo becomes three "germ" stem cells layers. In the past, researchers believed "the endoderm goes on to form the liver and other gut organs; the mesoderm the heart, muscles and blood cells; and the ectoderm the brain and skin."
"We found a stem cell that can become either a liver cell, which is thought to originate in the endoderm, or an endothelial cell that helps to from a blood vessel, which was thought to derive from the mesoderm," said Valerie Gouon-Evans, PhD, Assistant Professor in the Department of Developmental and Regenerative Biology and Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, and lead author for the study. "Our results go against traditional germ layer theory, which holds that a stem cell can only go on to become cell types in line with the germ layer that stem cell came from. Endothelial cells may arise from both the endoderm and mesoderm."
By gaining insight into stem cell processes in the liver researchers could determine what causes liver cancer to develop since fetal liver cell growth is similar to what is seen in tumors.
The newly discovered stem cell type has the ability to become new blood vessels, which can supply nutrients and oxygen to spur both liver and tumor cell growth. If this type of bi-potential progenitor cell is found in liver cancer, it could be an effective target for drugs that that keep the cancer cells and contributing blood vessels from forming.
The findigns were published Oct. 14 in the journal Stem Cell Reports.
