Researchers have developed a method to produce cells that kill tumor cells and prevent new tumors from forming, according to a study published in Science (2010 Jun 10. [Epub ahead of print]).
The study led by Peng Li, a PhD student from the Wellcome Trust Sanger Institute, focused on Bcl11b, a gene essential for normal development of immune system cells. Researchers sought out to modify the developmental fate of immune system cells to produce a novel type that could be of great value in cancer treatment.
To begin the study, the research team first demonstrated that the Bcl11b gene was active only in T cells in the immune system and that its activity was needed at the earliest stages of T-cell production. When the team knocked out the Bcl11b gene, the mice produced no T cells.
“Remarkably, the mice lacking the Bcl11b gene produced a new type of immune system cell – the Induced T to Natural Killer (ITNK) cells,” explained Pentao Liu, PhD, senior author on the project from the Wellcome Trust Sanger Institute. “This is the first time we have seen these cells and the first time a gene regulator like Bcl11b has been shown to carry out such an important role in T cells.”
Researchers also reported that the ITNK cells killed melanoma and lymphoma cells in experiment test tubes and were much more efficient than unmodified Natural Killer cells in the mouse and in human.
Furthermore, when tumor cells were injected into mice, they produced at least ten-fold few tumor foci in the Bcl11b-deficient than in Bcl11b-competent mice. “The reprogrammed killer cells were effective in preventing metastasis – spread of tumor in mice,” explained Francesco Colucci, MD, from the University of Cambridge School of Clinical Medicine Department of Obstetrics & Gynecology. “The killing seems to be specific to the tumor cells and the normal cells seem to be spared.”