Chemotherapy is still one of the most widely used forms of treatment for cancer. It works by killing cancerous cells that divide rapidly.
In a recent study of mice with lymphoma researchers have discovered that a small number of cancer cells escape chemotherapy by hiding in the thymus—an organ where immune cells mature.
According to the lead researcher Michael Hemann, an assistant professor of biology at MIT, within the thymus, the cancer cells are bathed in growth factors that protect them for chemotherapy drugs’ effects. “Those cells are likely the source of relapsed tumors,” he said.
Hemann will be conducting further tests in mice, with drugs that are known to penetrate those protective factors. Those drugs are used to treat arthritis, and are now in clinical trials, which will be applied in combination with traditional chemotherapy. “[They] could offer a one-two punch that eliminates residual tumor cells and prevent cancer relapse,” explained the researchers.
While the biologists concur that this discovery may indeed have far-reaching implications, “It remains to be seen if the results will translate to human patients.” But the finding suggests several potential drug targets, including IL-6 and a protein called Bcl2, which is activated by IL-6 and signals other cells to stay alive.
Hemann believes the finding could help explain why tumors that have spread to other parts of the body before detection are more resistant to chemotherapy. Further research will be performed to determine whether this kind of pro-survival signal occurs in other types of cancer, including tumors that have metastasized.
