High-Sensitivity Bone Marrow Aspiration Improves Leukemia Cell Detection

Superconducting quantum interference device (SQUID) technology was shown to enhance the ability to rapidly quantify the amount of nanoparticle-bound tumor cells in a sample at least 10-fold, and increased sensitivity of minimal residual disease measurements.

Results of this proof-of-concept study were published online October 6, 2009, in Cancer Research, a journal of the American Association for Cancer Research. "This promises to significantly enhance the detection for residual disease in leukemia and other cancers,” said lead scientist Richard S. Larson, M.D., Ph.D., vice president for translation research at the University of New Mexico Health Science Center (Albuquerque, USA). "Coupling nanotechnology can be employed in common techniques to enhance its utility.”

Earlier research has indicated that the magnetic needle can collect approximately 80% of leukemia cells in a bone marrow sample in a matter of minutes, according to Edward R. Flynn, Ph.D., president and CEO of Senior Scientific, LLC (Albuquerque, NM, USA).

The scientists developed this magnetic marrow biopsy needle in an effort to target tumor cells with nanoparticles and then preferentially extract the tumor cells with a magnetic needle. They used anti-CD34 antibody-loaded magnetic nanoparticles to detect CD34+ cells as an indicator of leukemia. To quantify the cells recovered, they coupled this nanoparticle-mediated fishing for leukemic cells with SQUID.

SQUID enhanced the sensitivity of measuring minimal residual disease over standard pathology methods for patients undergoing chemotherapy. "This result will determine more precisely the effect of the chemotherapy and will help to ascertain proper dosage or termination of treatment for patients,” said Dr. Flynn.

Furthermore, Dr. Larson reported that SQUID would work well with current technologies to improve the detection of leukemia cells in the bone marrow. Chi Van Dang, M.D., Ph.D., professor of medicine, cell biology, oncology, and pathology, and vice dean for research at the Johns Hopkins University School of Medicine (Baltimore, MD, USA), believes this approach is quite different from the current standard. He suggested that the sensitivity compared to polymerase chain reaction still needs to be determined.

"In the case of leukemias without clear genetic markers, the magnetic needle could be useful,” said Dr. Dang, who was not associated with this study, but is an editorial board member for Cancer Research. "It is possible that this technology could be used to detect cancer stem cells in general, if the proper antibodies with appropriate specificity are available.”

Senior Scientific is currently participating in follow-up studies to increase the efficiency of the magnetic needle further through advanced magnet configurations and theoretic calculations.

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University of New Mexico Health Science Center