A team of researchers from Genentech, Inc., the Howard Hughes Medical Institute and the Peter MacCallum Cancer Center, has found that cancerous tumor cells are able to survive attacks by repairing holes in their membranes caused by a protein released from T cells. In their paper published in the journal Science, the group describes how they used high resolution imaging to learn more about what happens when T cells, known as cytotoxic T lymphocytes (CTLs), attack cancerous tumor cells. Norma Andrews, with University of Maryland, College Park, has published a Perspectives piece in the same journal issue outlining the work done by the team.

Prior research has shown that the way CTLs kill cells infected by a virus or bacteria, and sometimes those that are cancerous, is by glomming onto the cell and then releasing two protein toxins: perforin and granzyme. The first, perforin, eats holes through the cell's membrane. The second then enters the cell through the holes and sets off apoptosis, which is normal programmed cell death. In this new effort, the researchers have learned how cancer cells respond to such an attack.

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