Researchers at Sandia National Laboratories, the University of Maryland and the MD Anderson Cancer Center in Houston have filed a patent application for a new drug they say could destroy the childhood disease acute lymphoblastic leukemia — and potentially other cancers as well.
According to the Mayo Clinic, acute lymphocytic leukemia is the most common type of cancer in children. Current treatments result in a good chance of a cure. However, when the disease occurs in adults survival rates are much lower.
The researchers say their drug may change that. It represents a sharp departure from the current approach.
“Most drugs have to go inside a cell to kill it,” said Sandia researcher Susan Rempe. “Instead, our method withholds an essential nutrient from the cell, essentially starving it until it self-destructs.”
One of the big drawbacks to current cancer treatments is they usually employ chemicals to kill cancer cells. While this can work, one side effect is the chemicals often make the patient sick.
The new drug focuses on a nutrient in the body called asparagine. Cells need it to survive but cancer cells can't produce it on their own. Remove cancer cells' access to asparagine and they die – it's simple as that.
Well, not quite that simple. The ideal nutrient-deprivation strategy for cancer cells requires a difficult balancing act. Doctors must remove enough asparagine from the blood to cripple the cancer, but leave enough of a chemically-similar molecule called glutamine so the patient can tolerate chemotherapy.
Using computer simulations, the researchers think they have found that right balance. When they tried it out in test tube experiments, the new drug left glutamine untouched. Follow-up tests they conducted in petri dishes showed that the mutated enzyme they created killed a variety of cancers.
There are more tests underway on laboratory mice at MD Anderson. They should be completed by early next year. If successful, Rempe says the drug will then be tested on humans.
“If we’re wrong, and keeping glutamine intact is not the answer to the cancer problem, we’ll continue investigating because we think we’re onto something,” she said.
Acute lymphocytic leukemia is a type of leukemia that starts from white blood cells in the bone marrow, which is the soft inner part of bones. It grows from cells called lymphocytes, a type of white blood cell central to the immune system. It can also develop from lymphoblasts, an immature type of lymphocyte.
Once the disease gets into the blood stream is can spread throughout the body to other organs, though it doesn't usually produce tumors like many types of cancer. It is an acute type of leukemia, which means it can progress quickly. Without treatment, the National Cancer Institute says it can be fatal within a few months.