Knockout creates cancer killer cells

A new type of cell capable of killing tumour cells and preventing cancerous growths forming could shape the basis of a new source of cell-based anti-cancer therapies.

Researchers from the Wellcome Trust Sanger Institute developed Induced T to Natural Killer cells – or ITNK cells – by knocking out a single gene essential in pathways of development of immune cells. The gene removed was Bcl11b, whose protein acts as a master switch regulating the activity of other genes.

 “We had shown that a gene called Bcl11b was essential for normal development of the immune system – and of particular interest in the development of T cells,” said Peng Li, PhD student, “We can modify the developmental fate of immune system cells to produce a novel type that – if we can see the same effect in humans – could be of enormous value in cancer treatment.”

Researchers studied Bcl11b activity in mice and found the gene is only active in T cells in the immune system. Its activity is necessary in the early stages of T cell production. When the gene has been knocked out, the mice produced no T cells, but did produce ITNK cells.

“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,” said Dr Pentao Liu, “Even more important we can see that these reprogrammed killer cells can attack cancer cells, whether in test tubes or in mouse models.”

ITNK cells killed melanoma and lymphoma cells, and prevented metastasis in mice. The cells were specific to tumour cells – leaving normal healthy cells unaffected – and survived in mice for at least three months. Researchers hope that the technology could be transferred to humans and lead to new effective anticancer treatment.