What are Tyrosine Kinases?

Medically Reviewed By: Matthew S. Davids, MD, MMSc

Technically speaking, a tyrosine kinase is an enzyme that transfers a compound called a phosphate group from ATP — a molecule that stores energy — to a specific area on cell proteins. It helps transmit the signals that cause cells to grow and divide and to perform specific functions in the body such as burning energy. It can be thought of as part of an on-off switch for a wide range of cell functions.

Tyrosine kinases and cancer

In many types of cancer, tyrosine kinases are abnormal. They may be misshaped, overabundant, missing, overactive, underactive, or incapable of doing their job. The result can be a flood of cell-growth signals or a falloff in growth-halting signals. Any of these changes can set the stage for cancer.

Tyrosine kinases’ versatility, and the fact that they often go awry in cancer, has made them powerful targets for new cancer therapies. Blocking a malfunctioning kinase with a specially designed drug molecule offers a way to bring cell proliferation back under control, at least for a time.

In 2001, the drug imatinib became the first tyrosine kinase inhibitor to receive U.S. Food and Drug Administration approval for the treatment of cancer. Today, there are more than 40 others, for cancers ranging from lung cancer to melanoma, to leukemia, to breast cancer.

Dana-Farber researchers have taken the lead both in developing molecules that can serve as tyrosine kinase inhibitors and in testing such inhibitors as potential therapies.

This research includes:

  • A study showing that a tyrosine kinase inhibitor and immunotherapy agent significantly improve progression-free survival – the time in which cancer doesn’t worsen – in patients with advanced kidney cancer.
  • A study showing that a combination of chemotherapy and the tyrosine kinase inhibitor ibrutinib may work better than historical results with chemotherapy alone in young patients newly diagnosed with chronic lymphocytic leukemia.
  • A study showing ibrutinib can produce long-term control of the rare blood cancer Waldenström’s Macroglobulinemia.

About the Medical Reviewer

Matthew S. Davids, MD, MMSc

After obtaining an A.B. cum laude in chemistry at Harvard College, Dr. Davids completed his M.D. cum laude at Yale University School of Medicine. He served as an intern, resident, and assistant chief resident in internal medicine at New York-Presbyterian Weill Cornell Medical Center and Memorial Sloan-Kettering Cancer Center in New York City. He then completed his fellowship in hematology and oncology in Dana-Farber/Partners CancerCare, and a Masters in Medical Science (M.M.S.c.) at Harvard Medical School. He is an attending physician in the Division of Lymphoma, where he serves as the Director of Clinical Research, as well as Associate Director of the CLL Center. He is also an Associate Professor of Medicine at Harvard Medical School, and attends on the inpatient hematologic malignancies service at Brigham and Women's Hospital. Dr. Davids has an active translational research program in CLL and non-Hodgkin lymphoma, focusing on studying apoptosis (in particular Bcl-2 biology) in his laboratory, and leading clinical trials to evaluate novel therapeutic strategies in patients with CLL and other hematologic malignancies. Much of his work has focused on the clinical development of new therapeutic regimens in CLL utilizing combinations of targeted inhibitors of Bcl-2, B cell receptor pathway kinases, and other novel agents, as well as utilizing checkpoint blockade to enhance anti-tumor immunity in patients with hematologic malignancies who relapse post allogeneic hematopoietic cell transplantation.