A new study of genetically modified immune cells by scientists from UCLA and the California Institute of Technology could help improve a promising treatment for melanoma, an often fatal form of skin cancer.
The research, which appears March 21 in the advance online edition of the journal Cancer Discovery, was led by James Heath, a member of UCLA's Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research and UCLA's Jonsson Comprehensive Cancer Center. Heath is a professor of molecular and medical pharmacology at UCLA and also holds the Elizabeth W. Gilloon Chair in Chemistry at Caltech.
The melanoma treatment uses T cells immune cells that play a major role in fighting infection taken from patients with melanoma. The cells are then genetically modified in the laboratory so that when they are reintroduced into a patient's bloodstream, they specifically attack melanoma tumors. In early clinical trials, this treatment was shown to shrink tumors dramatically in many patients, but the positive effects were often short-lived.
The UCLA and Caltech researchers found that after the engineered T cells were returned to patients, their efficacy faded within two to three weeks. Surprisingly, however, once the engineered cells were no longer effective, a new group of non-engineered T cells arose that had a similar tumor-killing effect that lasted even longer, the scientists discovered.
Using newly developed nanotechnology chips to perform multidimensional and multiplexed immune-monitoring assays, the researchers were able to examine at high resolution single engineered T cells taken at different times from patients undergoing the therapy, each of whom had a different level of response to the treatment.
"The engineered T cells did not recover their tumor-killing effect," Heath said, "but after one month, another group of T cells appeared that did have tumor-killing effects for another 90 days. Th
|Contact: Shaun Mason|
University of California - Los Angeles