Every cell in our body is a machine
with a special function.
And, like machines everywhere,
our cells sometimes suffer damage
that interferes with their operation.
One part of a cell that can be damaged is DNA,
the genetic material that controls
just about everything a cell does.
Fortunately,
cells have several mechanisms for making repairs.
When both strands of the DNA molecule are damaged,
normal cells use genes known as
BRCA1 and BRCA2
to create proteins that help repair the breaks.
Cancer cells, also, have ways
of repairing damage to their DNA, which allows them to
continue wreaking havoc within the body.
In some cancer patients, however,
mutations in the BRCA genes
prevent the proteins from making repairs.
Without repairs, damage would pile up to the point
where DNA could no longer function,
and the cancer cells would die.
But cancer cells, have a second repair crew
that specializes in fixing damaged DNA.
The crew is led by proteins known as
poly (ADP-ribose) polymerases,
or PARPs.
These repairs allow the cancer cells
to remain alive,
and to grow and divide.
Now, doctors have a new way of attacking such cells.
Drugs known as PARP inhibitors can
knock the PARP proteins out of commission.
The loss of the PARP repair crew
allows more and more damage
to occur to the cancer cells’ DNA.
Eventually, the DNA becomes so damaged
it’s useless, and the cancer cells die.
