Studied for decades for their essential role in making proteins within cells, several amino acids known as tRNA synthetases were recently found to have an unexpected and critical additional role in cancer metastasis in a study conducted collaboratively in the labs of Karen Lounsbury, Ph.D., University of Vermont professor of pharmacology, and Christopher Francklyn, Ph.D., UVM professor of biochemistry. The group determined that threonyl tRNA synthetase (TARS) leads a "double life," functioning as a critical factor regulating a pathway used by invasive cancers to induce angiogenesis the formation of new blood vessels and a new food supply to sustain their growth.
The teams' research was published online February 21, 2013 in Nature Scientific Reports.
According to Tamara Williams, Ph.D., first author on the study, a lecturer in nursing and postdoctoral fellow in pharmacology at UVM, cancerous tumors quickly outgrow their local blood supply. When they do, the cancer cells send out signals, TARS is secreted, and the angiogenesis process is initiated.
"In our study, we showed that TARS, once thought to only function in the housekeeping role of protein synthesis within cells, 'moonlights' as a secreted signaling agent in the endothelial cells that line vessels, in response to factors commonly produced by cancer cells," says Williams.
The study's in vivo model of angiogenesis was performed using a chick chorioallantoic membrane assay. This experiment utilizes the vascular membrane that surrounds a ten-day-old chicken embryo, which is removed from its shell. Williams and her research teammates placed small pieces of surgical sponges on the surface of the membrane and added compounds, including TARS, to the sponges. The researchers took images of the sponges and surrounding tissues every 24 hours for three days and then analyzed the images to assess the impact of the compounds on local blood vessel development around the sp
|Contact: Jennifer Nachbur|
University of Vermont