A protein known to be a key component of the glue that holds cells together also is involved in breaking them apart and promoting their movement when tumors begin to spread to other parts of the body, researchers at Mayo Clinic have found.
The study, published in the Sept. 18 online issue of the Journal of Cell Biology, helps illuminate the very first steps involved in metastasis, the spread of cancer that makes the disease difficult to treat, and suggests that a future designer drug might be able to block the beginning of this dangerous process, or stop it once it starts.
"Our data show that this one protein, p120 catenin, is a key player in both suppressing invasion and promoting it," says the study's senior author, Panos Anastasiadis, Ph.D., a Mayo Clinic cancer researcher. "This is very exciting, because the findings open up a whole new field of discovery for novel therapeutics that should be applicable to most types of tumors."
Their laboratory study looks at how p120 catenin interacts with different cadherin cell adhesion proteins in cancer cells. Cadherin proteins go through a cell membrane, and on the outside, they act like Velcro, sticking to other cadherin proteins on adjacent cells. On the inside of the cell membrane, cadherins bind, chain-like, to catenins, and catenins, in turn, regulate a cell's shape and function.
The best understood cadherin is E-cadherin, which provides tight connections between epithelial cells, forming a strong barrier-like layer covering the inside of organs and body cavities and the outside skin of humans. "E-cadherin holds a human's cells and tissues together," Anastasiadis says.
The other cadherins featured in this study belong to a group that collectively is called "mesenchymal" cadherins, which provide a looser bond between the cells that sparsely populate the connective tissue. "Collagen usually provides the strength to the connective tissue, so tight cell-cell adhesion i
Contact: Christine Leon
Mayo Clinic, Jacksonville