Scientists have discovered a potential new way of treating a type of blood cancer called myeloma that poisons cancer cells with their own secretions.
The research, by a team at The Institute of Cancer Research, London, found it was possible to use one of myeloma’s own weapons against it.
Myeloma cells secrete damaging substances called paraproteins into the bloodstream, often poisoning the patient’s kidneys.
But the research, published in Cancer Letters, reveals a strategy to prevent myeloma cells from getting rid of their paraproteins – making them poison themselves.
Study leader Dr Faith Davies, who leads the Myeloma Targeted Treatment Team at The Institute of Cancer Research, said:
“Myeloma cells produce these nasty proteins, ‘paraproteins’, which they secrete into the bloodstream. These proteins are extremely harmful to patients’ kidneys, and can lead to kidney failure. However, they’re also a key weakness for the myeloma cells. If the proteins aren’t folded properly, they can’t leave the cancer cell. If the cancer cell can’t get rid of the excess proteins, the build-up will kill the cell.”
Dr Davies’ team found that they could prevent these harmful paraproteins from leaving cancer cells by blocking members of a protein family called Hsp70. Hsp70 proteins help myeloma cells to fold protein correctly and destroy excess proteins before they kill the cell. They found that blocking the two major Hsp70 proteins killed myeloma cells in the lab.
Dr Davies said: “Our tests showed that blocking these Hsp70 proteins is lethal to myeloma cells, making it a promising treatment strategy. If we can keep harmful paraproteins out of the bloodstream and kill the cancer cells, it’s a win-win.”
This research, funded by Cancer Research UK and Myeloma UK, demonstrates an exciting new way to kill myeloma cells, but it will be a while before these strategies can be used in real patients. The team blocked Hsp70 proteins using laboratory compounds which have yet to be developed into clinical drugs. Drug development doesn’t happen overnight, and this research highlights the need to take powerful Hsp70 inhibitors from lab to clinic as soon as possible.