[donocco]

Elizabeth

I looked at KRAS and got some info. KRAS is a cytoplasmic protein that activates both RAS and P13K. Therefore you get increased cancer cell growth from two signal transdution pathways. P13K stimulation to AKTto MTORC1 to cell growth. Also RAS-RAF-MEK-ERK to increased cell proliferation. Apparaently the mutation involves a single amino acid substituion in the normal protein. A glycine is changed to a Valine. Both Glycine And Valine are amino acids. Proteins are thousands of amino acids linked together in a chain like a string of colored beads. Lets say you have a chain of red-blue- purple-black-brown-green-green beads strung together in a chain repeated again and again so that their are thousands of amino acids in the protein. If a single amino acid changes in a sensitive place the protein Functions abnormlly. So in the colored beads=amino acid analogy if in the active site of the protein (enzyme, all enzymes are proteins) there is one color change (amino acid change)
the function of the enzyme is altered. The amino acid sequence that is repeated over and over again (red-blue-purple-black-brown-green-green ends in green-purple instead of green-green in one vital area. This single change makes the whole protein function change.
As DNA goes to RNA and RNA goes ultimately to an amino acid (3 DNA bases= one amino acid and this is called a codon) these abnormal amino acid substitutions (glycine changing to Valine in the KRAS mutation) are due ultimately to DNA mutations which occur all the time
(radiation, chemicals, chromosome breakages etc). This is why cancer is so complicated. I hope this makes some sense.

The KRAS mutation seems to be implicated mostly in Pancreatic cancer and colon cancer. In the brief research I did I didnt see breast cancer mentioned. Is there a KRAS mutation involved in breast cancer?

Paul

PS Here is the chemical structure of an amino acid

CH3CHNH2COOH this is the simplest one, glycine. When the amino acids link together to form proteins, the COOH part (the acid part) of one Amino Acid links to the NH2 part (Amino part) of another amino acid forming a bond.
Im sorry there is so much chemistry.