Key to cancer fight may lie in "educating" immune cells, scientists say

In a recent experiment, some Johns Hopkins scientists tested some immune cells that are known to attack a cancer of the bone marrow. The "smartest" cells – in other words, those that live near in the bone marrow near the cancer – were 90 percent more effective than those that lived in other parts of the body, the researchers say.

The experts say, then, that developing an effective cancer treatment is likely a matter of teaching the most effective cancer fighting cells where to live to do their best work.

• In efforts to educate the body to fight off cancer, researchers have found that some immune cells are "smarter" than others.
• Working with collections of human cells, Johns Hopkins Kimmel Cancer Center scientists tested kill-rates of two kinds of T-cells "primed" to home in on myeloma, a cancer of the bone marrow.
• "It is very difficult to design cancer therapies that get the body's immune system to recognize and kill cancer cells that the system has ignored for a long time," says Ivan Borrello, M.D., assistant professor of oncology and director of the research, which is published in the March 1 issue of Cancer Research.
• "Now, we have evidence that 'educating' T-cells in the bone marrow may be the most effective way to get an anti-tumor response."
• In the Hopkins study of both kinds of T-cells, those from the blood and bone marrow, scientists mixed them with magnetic beads coated with tumor antibodies, a sort of "artificial intelligence" that activated and expanded the T-cells' cancer-killing mode.
• Activated bone marrow T-cells stopped the growth of 86 percent of myeloma stem cell colonies compared to 47 percent for activated t-cells taken from circulating blood.
• The researchers' next step is to determine whether the cells' ability to limit cancer growth in culture dishes ultimately may do the same in patients.
• Kimmel Cancer Center researchers are planning studies in a small number of myeloma patients to test the activated marrow T-cells alone and in combination with a myeloma vaccine.
• "While T-cells from circulating blood traditionally are used in immunotherapy strategies because they are easy to obtain and grow, they often don't recognize the tumor," says Borrello.
• These would then be given intravenously back to patients.
• However, according to Borrello, they may find that an additional cancer vaccine may increase the overall anti-tumor effect of the marrow T-cells.
• Evidence from other research groups indicates that breast cancer patients have T-cells in their bone marrow that are specific to their tumor.