New Way To Halt Leukemia Relapse
Published: 2020-09-18 |
Source: Hiroshima University
Researchers have identified a second path to defeating chronic myelogenous leukemia which tends to affect older adults, even in the face of resistance to existing drugs. Almost all patients with chronic myelogenous leukemia (CML), have a faulty, cancer-causing gene, or "oncogene" called BCR-ABL1. BCR-ABL1 turns a regular stem cell in the bone marrow into CML stem cell that produces malformed blood cells. And instead of the CML stem cell dying when it should be scheduled to do so, the oncogene causes it to keep producing even more of these faulty blood cells.
Advances in treatment since the turn of the millennium have been extremely successful at combating the disease in patients with this oncogene. Drugs called tyrosine kinase inhibitors (TKI) have completely transformed the prognosis of people with such leukemias, and with fewer of the side effects of other cancer treatments. In most cases, the goes into remission and patients live for many years following diagnosis.
BCR-ABL1 directs the production of an abnormal type of tyrosine kinase, an enzyme that "turns on" many types of proteins through a cascade of chemical reactions known as signal transduction--in effect communication via chemistry. Miscommunication within CML stem cells. TKI signals transduction therapy inhibits their growth and brings a halt to their production of the malformed blood cells.
However, TKIs only controls the disease, they don't cure it. Drug resistance can develop in a patient because while TKIs work well on proliferative mature CML cells that are actively reproducing, they are less effective at inducing cell death on the part of CML stem cells that are quiescent.