In some ways, cancers are very similar to resistant bacteria. Both become a problem when certain DNA changes turn the wrong genes on or off.
In bacteria, the cells become resistant to treatment. In cancers
, the cells start growing uncontrollably or ignore requests that they die. (They can also become resistant to treatment like bacterial cells but that will have to wait for another discussion.)
targets a type of
cancer called CML.
Most current cancer treatments focus on killing all growing cells. This often kills the cancer but it also causes patients to have many nasty side effects (like hair loss, nausea, anemia, etc.) because all growing cells are targeted. And these treatments don't always work.
If scientists could find the genes that are affected in specific cancers, then they could make medicines that target that gene instead of targeting all growing cells. This should decrease the number of side effects.
This approach isn't just science fiction either. Scientists have actually pulled it off with a number of different medicines. The first success story was one called Gleevec.
A certain blood cancer called CML is often caused by a DNA change called the Philadelphia chromosome
. What happens in this case is two genes called bcr
get stuck together. This new hybrid gene causes the cells to grow uncontrollably.
When scientists figured this out, they started to look for chemicals that might affect what this new gene was doing. Eventually they got to Gleevec.
Gleevec keeps this new gene from telling the cell to keep growing. This causes the cancer to stop growing. Gleevec is now one of the most effective treatments available for CML.
Until the CML becomes resistant that is. Cancer is a very slippery beast - new DNA changes crop up in the CML cells that make them resistant to Gleevec.
So scientists are uncovering those new DNA changes
and are coming up with new treatments based on what they find. And these will work until the cancers develop new DNA changes again.
These kinds of battles against cancer and resistant bacteria will rage on for the foreseeable future. Thank goodness newer technologies are giving us the weapons we need to keep these invaders at bay.