WEDNESDAY, Dec. 22 (HealthDay News) -- Researchers have
identified a gene mutation that may offer a target for new
treatments for a type of lymphoma.
The team found that a mutation of the MYD88 gene is one of the
most frequent genetic abnormalities in patients with this cancer,
known as large B cell lymphoma.
The MYD88 gene encodes a protein that is crucial for normal
immune response to invading microorganisms. The mutation identified
in this study can cause uncontrolled cellular signaling, resulting
in the survival of malignant cells.
A subgroup of the large B cell lymphoma that has a dismally low
cure rate -- known as the activated B cell-like (ABC) subtype --
appears particularly susceptible to the gene.
Lymphoma is a cancer of the blood that starts in white blood
cells. Diffuse large B cell lymphoma, in turn, is a type of
non-Hodgkin lymphoma, in which white blood cells known as
lymphocytes multiply out of control. There are three subtypes of
diffuse large cell lymphoma: Patients with the ABC form have the
lowest rate of three-year survival, with only 40 percent reaching
that milestone.
The researchers, led by scientists at the U.S. National Cancer
Institute (NCI), found that the mutant form of MYD88 allowed the
ABC lymphoma cells to survive but the non-mutated version did
not.
One more piece of the puzzle was unraveled through another
cell-signalling protein called IRAK4. The researchers found it
functioned as an enzyme to modify a substance called IRAK1, which
was required for the mutant MYD88 protein to promote lymphoma cell
survival.
"We believe the results of this study may provide a method to identify patients with the [ABC subtype] whose tumors may depend upon MYD88 signaling," study author Louis M. Staudt, of NCI's Center for Cancer Research, said in an NCI news release.
These patients, he said, may thus benefit from therapies
targeting "regulatory pathways that sustain the survival of these
lymphoma cells."
The study appears online Dec. 22 in the journal
Nature.
More information
The American Cancer Society has more about
non-Hodgkin lymphoma.