Chemotherapy currently is probably the most effective treatment against most kinds of cancer. It has strong side effects though, because it is killing healthy cells also. Now scientists from the Victoria University of Wellington are moving forward in the development of the new chemotherapy drug, which would target cancer cells exclusively.
Scientists are actually mimicking evolution to reach their research goals. Essentially, they engineered special enzymes that can transform a relatively safe and non-toxic compound into a drug that is highly toxic to cancer cells exclusively. These enzymes have to be delivered to cancer cells and for that task scientists are hoping to use viruses or bacteria that are only able to replicate in tumours. Interestingly, the development of these enzymes involved quite a bit of luck. The enzyme scientists chose was already moderately active with the non-toxic compound, called PR-104A. Nature did not evolve enzymes to work with such artificial molecules, so it was a happy coincidence.
Researchers decided to use a special technique of modifying this enzyme to make it more effective for their purposes. They introduced some random mutations to the gene encoding enzyme in order to make it evolve into something that more effectively activates PR-104A. Scientists also wanted this new treatment to be more selective of its targets. This new enzyme will not only work better, but will also help keeping track of the microbes, making sure they will only attack cancer cells exclusively. This works because enzymes can trap special radioactive molecules that a full body PET scanner can identify and monitor.
Scientists are still long ways away from the clinical implementation of these findings. It will take years till therapy can be developed and tested. But even so it is a huge achievement. Current chemotherapy drugs are actually very effective. They can treat majority of the cases. However, chemotherapy is extremely toxic to healthy cells as well and soon makes the patient weak and causes a number of other side effects. That is why a new treatment would be welcome.
Someday people with cancer will be able to go through therapy without withdrawing from their normal life. Coming to a hospital regularly to get the drugs will be all that will be necessary. Scientists hope that researches like this will help achieving this goal sooner.