Looking at Cancer

     ONCE CANCER INVADES A CELL DOCTORS HAVE VERY FEW DRUGS TO FIGHT IT.
BUT YOUR BODY *DOES* HAVE IT'S OWN PROTECTION SYSTEM IN A GENE CALLED P53.
IF DNA MUTATES--ONE OF THE FIRST STEPS IN CANCER--P53 SLIPS IN AND REPAIRS THE
MISTAKES. BUT IN MANY CANCER CASES, THE P53 GENE ITSELF GETS SABOTAGED AND
IT CAN'T PERFORM THIS ALL-IMPORTANT JOB. SO, IF SCIENTISTS COULD REPAIR
DAMAGED P53 THEY MIGHT HAVE AN EFFECTIVE NEW CANCER DRUG. TOWARDS THIS
GOAL, STRUCTURAL BIOLOGIST NIKOLA PAVLETICH AT THE SLOAN KETTERING
CANCER CENTER HAS MAPPED OUT JUST WHAT THE P53 PROTEIN LOOKS LIKE. 

     Pavletich: "We know now in high detail, in high resolution, where each one of these thousands of
atoms that make up the p53 protein are in space with respect to each other." 

     PAVLETICH PRODUCED A THREE-DIMENSIONAL MAP OF P53, USING A PHYSICS
RESEARCH METHOD CALLED X-RAY CRYSTALLOGRAPHY, WHICH BOUNCES X-RAYS OFF
OF ELECTRONS IN ORDER TO FIGURE OUT THE CONSTRUCTION OF A MOLECULE. IT'S A
LITTLE LIKE HAVING A WATER HOSE IN A DARK ROOM AND TRYING TO MEASURE THE
SHAPE AND SIZE OF ALL THE FURNITURE SIMPLY BY SPRAYING WATER AROUND AND
WATCHING HOW IT BOUNCES BACK. PAVLETICH AND HIS TEAM SHOT X-RAYS AT
CRYSTALS OF P53 AND HAD A COMPUTER ANALYZE HOW THOSE X-RAYS WERE
REFLECTED. 

     Pavletich: "This process is very lengthy and elaborate. . . but in the end by using the information
from the . . . x-rays, we can reconstruct the three-dimensional structure of the protein." 

     THE SCIENTISTS FIGURED OUT THAT THERE ARE SIX HOT SPOTS ON THE PROTEIN
WHERE MUTATIONS OCCUR.  THESE SPECIALLY PLACED MUTATIONS CAN CAUSE P53 TO
COLLAPSE IN ON ITSELF LIKE SCAFFOLDING THAT HAS HAD A FEW KEY BEAMS
REMOVED. IN TIME, HOPEFULLY, SOMEONE MAY BE ABLE TO BUILD A DRUG THAT CAN
PROP THE P53 BACK UP AND KEEP IT FIGHTING THE GOOD FIGHT AGAINST CANCER
MUTATIONS.