Cancer: The role of mutations in cell-to-cell interactions

The study of cell proteins and pathways are important to cancer research. A protein molecule that receives chemical signals from outside a cell is called a protein receptor. A particular protein receptor known as the low-density lipoprotein related protein 6 (LRP6) receptor is shown to be involved in regulating the effects of a group of proteins responsible for cell-to-cell interactions. These types of interactions occur when an embryo is formed and developed. This molecular pathway is called canonical Wnt signaling, and it has been implicated in various diseases including cancer.

Wnt Signaling Pathway

The Wnt signaling pathway consists of proteins that pass signals into a cell through cell surface receptors and are critical to enable cells to develop and grow. Abnormalities in the Wnt signaling pathway can give rise to diseases such as cancer. Researchers are interested in learning more about the inner workings of how these pathways activate or deactivate so they can understand potential new strategies to prevent or treat cancer.

In a study published in a recent issue of Genes & Cancer, Dr. Sapna Vijayakumar and colleagues analyzed what happens to the Wnt pathway when mutations occur. To do this, they studied the cells of patients with a genetic disorder characterized by high cholesterol levels, called familial hypercholesteremia. In those cells, they noticed that the structure of the low-density lipoprotein related protein 6 (LRP6) receptor was similar to that of the LDL receptor (LDLR), but the function of this structure was unknown. When the researchers substituted an amino acid in the LRP6-LDLR protein structure, they saw that it had a negative impact on how the cell draws LRP6 into itself and how the Wnt signaling is activated.

These findings establish the involvement of LRP6-LDLR in directing cell activity in the embryonic stages.