Researchers from the University of Maryland discovered a protein responsible for keeping cells in a tissue identical. The findings could be used to understand aging and cancer. The study was just published in The Journal of Cell Biology.
Different tissues require different types of cells. In order for the tissue to function properly, these cells must be identical in both structure and behavior. In cancers and some age-related diseases, one or more of the cells in a tissue grow abnormally. The researchers wanted to investigate the mechanisms that normally maintain homogeneity between cells.
While previous studies had used cultured cells, the team decided to study a whole animal. They chose a simple species called Caenorhabditis elegans, also known as the roundworm. Roundworms are ideal test subjects because their cells can be easily observed without killing the animal. The research team also used a unique experimental method called machine learning. They used computer software to analyze patterns in groups of cells. As the computer continued its analysis, it “learned” and became quicker at recognizing complicated patterns that a human would likely miss.
The research team discovered that a protein, an exonuclease called ERI-1, was responsible for maintaining uniformity between cells in a tissue. The protein controls gene expression, ensuring that each cell expresses genes in the same way. When the gene that produces ERI-1 was silenced in the roundworms, cells grew abnormally and had differing levels of gene expression.
In many age-related diseases and cancers, cells grow in irregular patterns and express genes differently than their neighbors. If researchers can pinpoint the exact mechanisms that normally regulate gene uniformity, we may be able to understand these diseases better. The authors believe that their method of using a whole animal was key to the success of the study. Complex interactions and different types of gene expression between cells can be missed when studying cultured cells. In order to understand the entire picture, it’s important to study a whole specimen such as the roundworm.
Hai H. Le et al. Tissue homogeneity requires inhibition of unequal gene silencing during development. The Journal of Cell Biology (2016).