Engineered proteins that help carry oxygen to cancer tumors may improve the odds of successful treatment for approximately half of all cancer patients. Scientists have long known that low levels of oxygen are a main source of a tumor’s resistance to radiation.
It is estimated that 50 percent of all cancer patients have tumors that exhibit insufficient oxygen levels (a state referred to as hypoxia). Now, a small startup based out of San Francisco known as Omniox is working to improve the effectiveness of current radiation treatments through the use of oxygen-carrying compounds.
Previous studies suggest that the vast majority of cancer tumors exhibit hypoxic regions. These oxygen-starved regions occur due to the rapid growth of tumor cells. As the tumor grows, it requires higher and higher levels of oxygen-rich blood to properly feed the growth of cells. To accomplish this, the tumor stimulates the growth of new blood vessels.
However, the growth of new blood vessels often has difficulty keeping up with the growth of the tumor. Such a fact reduces the effectiveness of radiation – a treatment option that relies heavily on the flow of oxygen.
Radiation therapy works by generating free radicals within the body that damage and kill tumor cells. Since free radicals require oxygen to survive, a hypoxic region often receives insufficient damage to completely kill off the tumor.
The issue of improving oxygen flow to tumors has been studied since the 1950s. Unfortunately, a variety of attempted solutions have proven unsuccessful. Omniox hopes to reverse this trend with the introduction of oxygen-carrying proteins.
These proteins have been augmented to cling to oxygen molecules and hold onto them until they have arrived inside hypoxic tissue. These proteins differ from previous oxygen-carrying options in that the proteins are not based on hemoglobin. Hemoglobin has previously been identified as unsuccessful because nitric oxide (an oxygen-killing material) also clings to such molecules.
Previous studies have shown that Onniox’s proteins effectively accumulate in the tumors of living animals and serve to improve oxygen levels in hypoxic regions.
The National Cancer Institute is working in conjunction with Omniox to further develop and research the oxygen-carrying proteins. The NCI recently awarded the startup with $3 million in funding.