Crystals made of proteins help cure cancer
Crystals made of proteins are revolutionizing cancer research and treatment. They are not the usual crystals found in nature made of minerals but are man-made in a laboratory. They are tiny, clear and colorless, barely visible to the naked eye. As they are also very fragile, they break easily. So can they really help to cure cancer?
One form of cancer, chronic myeloid leukaemia, is successfully being treated with the drug imatinib. The treatment, a chemotherapy tablet, has been shown to increase the survival rate of patients with this type of cancer from 30% to 89% five years after diagnosis. Imatinib is made of a specific protein that targets the cancer-causing Bcr-Abl fusion protein and slows or stops the growth of the cancer cells. It was designed by analyzing the crystallized structure of the Bcr-Abl fusion protein. The drug works by inhibiting proteins that cells use to signal to each other to grow, called tyrosine kinases. So blocking these chemical messengers stops the cancer cells from growing.
The human body contains over 100,000 proteins that are vital to the way we function. They repair, regulate and protect our bodies, performing such work as managing the way the body’s organs and tissues operate. For instance they form hair and fingernails, carry oxygen in the blood and enable muscle movement. Information on the three-dimensional structure of proteins is key to fully understand them in order to develop medicines that target them effectively.
Protein crystals, formed during a process called protein crystallization, have been used to develop several other drugs. The crystals provide the patterns of X-ray diffraction (the bending of light as it passes around the edge of an object) that reveal the composition of the protein. That’s important because knowing the structure of a protein helps researchers design a drug to bind to the target protein that will treat the disease.
Protein crystals are crucial in designing drugs to treat numerous diseases, including HIV and hepatitis C, heart disease, Parkinson’s disease, muscular dystrophy and diabetes.