By Scott Gilbert, Penn State
A gene mutation is an underlying cause of LGL leukemia, according to a study published in the May 17 edition of New England Journal of Medicine and co-authored by a Penn State Hershey Cancer Institute researcher.
Tom Loughran, director of Penn State Hershey Cancer Institute, who discovered LGL leukemia in 1985, was part of the multinational study based in Finland. LGL leukemia is a rare, malignant blood disease that often is related to autoimmune diseases such as rheumatoid arthritis. The cells use the body’s own immune system to attack the body. The cause of this disease has been unknown and it was unclear if the disease is an overreaction of the immune system or a malignant blood disease.
Researchers discovered that about 40 percent of patients with LGL leukemia have a mutation in the STAT3 gene that causes the gene to always be active. STAT3 plays a role in cell signaling pathways — a cell’s way of communicating to perform basic functions. This mutation is not inherited, but is caused by an unknown reason, possibly chronic viral infection or some other longterm antigen exposure.
This finding could help in the diagnosis of patients with LGL leukemia and also in treatment. STAT3 inhibitor drugs currently are in early clinical trials.
Next, researchers will conduct a study to see if patients with rheumatoid arthritis have similar gene mutations. Patients in the current study with LGL leukemia were found more likely to also have rheumatoid arthritis.
STAT3 gene is also abnormally expressed in other cancers and autoimmune disease.
Loughran worked with researchers of the University of Helsinki, Helsinki University Central Hospital and Institute for Molecular Medicine Finland (FIMM). Besides his extensive work with LGL leukemia and the discovery in 2001 of the STAT3 gene expression, Loughran helped provide a significant number of LGL patients for the study.
“It is really exciting to see fundamental discoveries being made in a disease that you discovered, with the promise of new approaches to treatment for an incurable illness,” Loughran said.
