JNK

I have been devoting almost all of my time to JNK (pronounced JUNK) lately. In my last post I mentioned that I had stumbled upon something interesting. The premise of the experiment was that we would compare the levels of JNK activity in cancerous tissue to non-cancerous tissue. Not too big a deal. JNK is a multi-tasking protein. Actually there are three JNK proteins. The ones I am concerned with are JNK 1 and JNK 2. They are very similar in sequence and are usually lumped together. The phospho-antibody I have to look at activating JNK is actually designed for both JNK 1 and 2 but I have separate antibodies for the inactive forms. JNK can be involved in cell suicide (apoptosis) or cell survival depending on the stimulus and cell type. We hypothesized that JNK activity would be increased in our tumor samples. That doesn't appear to be the case at first blush. I was a little disappointed at the results but it is what it is and I accept that. The interesting part came when I stripped the antibodies off the Western blot and re-probed for the inactive versions. What I found was that JNK 1 and 2 are being differentially regulated in these tissues. Attempting to find out why that might be, I searched the published literature and found a precedent for this in a paper published 5 years ago. We are working in completely different cells but it will be interesting to see if this plays out. The published paper showed that cells lacking JNK 2 proliferated more rapidly. Our tumors appear to have reduced JNK 2 expression. This is cool.

I am going back and re-running the Westerns, this time probing for the JNKs independantly. The JNK 1 blot I finished today was not very convincing. We will see what the JNK 2 says tomorrow. This could lead to a bunch on new experiements.