Monoclonal antibody targets, kills leukemia cells

March 25, 2013
Monoclonal antibody targets, kills leukemia cells
These are chronic lymphocytic leukemia cells. Credit: UC San Diego School of Medicine

Researchers at the University of California, San Diego Moores Cancer Center have identified a humanized monoclonal antibody that targets and directly kills chronic lymphocytic leukemia (CLL) cells.

The findings, published in the online Early Edition of the Proceedings of the National Academy of Sciences on March 25, 2013 represent a potential new therapy for treating at least some patients with CLL, the most common type of blood cancer in the United States.

CLL cells express high levels of a cell-surface glycoprotein receptor called CD44. Principal investigator Thomas Kipps, MD, PhD, Evelyn and Edwin Tasch Chair in Cancer Research, and colleagues identified a monoclonal antibody called RG7356 that specifically targeted CD44 and was directly toxic to , but had little effect on normal .

Moreover, they found RG7356 induced CLL cells that expressed the protein ZAP-70 to undergo apoptosis or programmed cell death. Roughly half of CLL patients have that express ZAP-70. Such patients typically have a more aggressive form of the disease than patients with CLL cells that do not express that specific protein.

Previous research by Kipps and others has shown that CLL cells routinely undergo spontaneous or drug-induced cell death when removed from the body and cultured in the laboratory. They found that CLL cells receive survival signals from surrounding non-tumor cells that are present in the lymph nodes and bone marrow of patients with CLL. One of these survival signals appears to be transmitted through CD44. However, when CD44 is bound by the RG7356 monoclonal antibody, it seems to instead convey a death signal to the leukemia cell.

"By targeting CD44, it may be possible to kill CLL cells regardless of whether there are sufficient numbers of so-called 'effector cells,' which ordinarily are required by other to kill tumor cells," said Kipps. "We plan to initiate clinical trials using this humanized anti-CD44 monoclonal antibody in the not-too-distant future."

Explore further: Agent selectively targets malignant B cells in chronic leukemia, study shows

Related Stories

Stem cells central to pathogenesis of mature lymphoid tumors

August 15, 2011

New research suggests that blood stem cells can be involved in the generation of leukemia, even when the leukemia is caused by the abnormal proliferation of mature cells. The study, published by Cell Press in the August 16th ...

Recommended for you

Researchers discover underlying cause of myeloma

February 11, 2016

Yale Cancer Center researchers have identified what causes a third of all myelomas, a type of cancer affecting plasma cells. The findings, published Feb. 10 in the New England Journal of Medicine, could fundamentally change ...

Scientists find leukemia's surroundings key to its growth

February 10, 2016

Researchers at The University of Texas at Austin have discovered that a type of cancer found primarily in children can grow only when signaled to do so by other nearby cells that are noncancerous. The finding, published in ...

Study examines evolution of cancer

February 8, 2016

A novel Yale study answers age-old questions about how cancers spread by applying tools from evolutionary biology. The new insights will help scientists better understand the genetic origins of tumor metastases, and lead ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.