Epithelial Adhesion and Cancer Proliferation

There are more than 150 different types of epithelial cells that carry out essential functions in a wide variety of tissues. Those jobs include making our skin resilient, producing the mucus that lines and guards our airways, and helping with the absorption of nutrients in our digestive system. In a study published today in the Journal of Cell Biology, researchers identified a protein complex that regulates how epithelial cells bond together so tightly.

The research team’s focus is on how cancer cells spread throughout the body, and their new discovery is intriguing because it explains the behavior of cells that are by far the most common starting place for cancer.

“Eighty percent of cancers originate from epithelial cells, and most cancers will have to disassemble the adhesion system to grow and spread,” says senior author Rafael Garcia-Mata of the University of Toledo. “If we understand how these adhesive structures are built, we can also try to understand what happens when cancer cells disassemble them.”

Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body as well as the inner surfaces of cavities in many internal organs. Their ability to form nearly impermeable junctions enables them to establish boundaries that separate the inside of organs and other tissues from the outside environment.

The way epithelial cells link together is unique in biology and involves a large number of components that work in synchrony to control their assembly. However, the science behind how they manage to form such perfect bonds has up to now been elusive.

“The way these cells organize is very important. What we’ve identified is a new molecular mechanism that controls a lot of the properties that make the ‘right’ epithelial tissues,” Garcia-Mata explains. “Understanding how they normally function allows you to understand what happens when things go wrong.”

The implications of these findings go well beyond cancer. Garcia-Mata’s research also helps explain how cells coordinate to generate organ cavities, which may broaden our knowledge of early development and organ formation. It could add significant new pathways for explaining conditions such as asthma and inflammatory bowel disease.

“A lot of diseases are essentially leaky epithelia,” Garcia-Mata says. “Understanding how these structures are modulated may help us learn why we get some of these diseases.”