Drug Helps Immune System Fight Cancer
CancerWise - August 2008
Combining natural killer (NK) cells that help defend the body against disease with a new class of drugs may help the immune system fight cancer, according to a laboratory study of pediatric cancer cells.
Significance of results
The hope is that this combination could be added with little additional toxicity as an adjunct to other therapies, such as stem cell transplant or high-dose chemotherapy, says Dean Lee, M.D., Ph.D., assistant professor in the Children's Cancer Hospital at M. D. Anderson and principal investigator on the study. Lee presented the findings in May at the American Society of Pediatric Hematology/Oncology annual meeting.
“Chemotherapy drugs are often very toxic to children,” Lee says. “While they kill unhealthy fast-growing cells like cancer, they also destroy healthy fast-growing cells like hair, bone marrow and mucous membranes. We discovered that this new class of drugs, which regulates certain cells, makes cancer cells more vulnerable to the body’s natural defenses against cancer.”
The study involved MS-275, part of a class of drugs called histone deacetylase inhibitors known to affect cancerous cells. Researchers added MS-275 to human NK cells and osteosarcoma cells. Osteosarcoma is the most common pediatric bone cancer.
The addition of MS-275 made osteosarcoma cells more sensitive to NK cells and also made the NK cells more lethal to the tumor. This suggests pediatric cancers may be amenable to treatment with NK cells, and treatment may be greatly enhanced if NK cells are combined with certain other drugs, Lee says.
Lee's study found similar responses using different inhibitors in acute myelogenous leukemia, a common blood cancer in children and adults, and neuroblastoma, one of the most common solid tumors in children, usually found in the adrenal gland.
Several studies have suggested NK cells may have an effect on osteosarcoma tumors that have metastasized (spread to other parts of the body) or relapsed (returned after treatment), Lee says.
Approximately 400 young patients are diagnosed with the rare disease each year, and about one-third of these patients relapse, according to the American Cancer Society. When osteosarcoma does come back, it’s often resistant to treatment.
Lee hopes this preliminary study will lead to a clinical trial: "Incorporating the lessons from this study, we hope we can improve treatment for many cancers and make treatment less toxic.”
Additional research is being conducted on acute lymphocytic leukemia, the most common cancer in children, and medulloblastoma, the most common brain cancer in children.
— Adapted by Dawn Dorsey from an M. D. Anderson news release
M. D. Anderson resources:
- Children’s Cancer Hospital
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