Professor Nicholas Tonks's team has discovered an antibody that can suppress an enzyme that may aid in the spread of some breast tumours. The antibody, with additional investigation, could provide a viable therapeutic treatment for the same breast tumours.
An overexpressed enzyme PTPRD
The new antibody targets PTPRD, an overexpressed enzyme in some breast tumours. PTPRD belongs to the protein tyrosine phosphatase (PTP) family of molecules, which aid in the regulation of many cellular activities. They accomplish this by interacting with kinases, which are enzymes that influence the behaviour of other proteins within cells. Kinases are enzymes that add phosphates, tiny chemical regulators, to proteins. PTPs remove them.
Phosphate addition and removal disruptions can contribute to inflammation, diabetes, and cancer. Some disturbances can be repaired with kinase inhibitors. "People have been targeting kinases for 25, 30 years," Tonks says. "It's a multibillion-dollar business. However, numerous challenges remain. Patients with cancer will respond to these types of kinase inhibitors, but resistance will develop with time." PTP activity controlling drugs might have a significant impact on human health. However, developing such drugs is a challenge.
Tonks has been researching PTPs since his discovery as a postdoctoral researcher. He refers to the enzymes as 'an untapped resource for medication discovery.' Many enzymes can be turned off using tiny compounds that latch onto and inhibit the component of the enzyme that does the work. However, that will not work for PTPs such as PTPRD, due to which alternate tactics are required.
How to stop PTPRD
Graduate student Zhe Qian developed a new PTP blocker to stop PTPRD activity. He targeted the enzyme with a synthetic antibody, a molecule that recognizes and binds to its target in a particular fashion.
PTPRD molecules sit nestled in the outer membranes of cells, with bits protruding inside and out. Qian designed his antibody to grab onto two PTPRD molecules from outside a cell simultaneously.
Qian, along with his colleagues in the Tonks lab, revealed that when the antibody binds to its target, it draws pairs of PTPRD proteins together into an inactive configuration. This not only prevents PTPRD from working but also leads to the protein's destruction. The team has shown that once this happens, breast cancer cells growing in the lab become less invasive.
(With inputs from ANI)
