circulating mRNA in serum/plasma - (May/08/2010 )

Hi,

My gene of interest is a potential tumor suppressor as its expression is reduced in most of m cancer tissues and its also demonstrated tumorr suppressive properties via invitro and in vivo experiments.

I'm now interested in looking at its expression in the serum of cancer patients. I have cloned the PCR fragmeet of my gene of interest from serum of healthy donor and have confirmed its identity. Thus, I know its present in the serum of healthy individuals.

I've been doing some literature search and I observe that

1) all papers have studied oncogenes in cancer serum vs healthy serum. But there are no studies lookininto the expresison of tumor suppressor genes in the cancer serum vs healthy serum. Howver, there are several studies that have identified methylation of tumor suppressor genes in cancer serum vs healthy serum but these studies have only lookd at methylation and not the expression by qPCR.

This literature search makes me wonder if my approach is valid i.e. to check the expression of a tumor suppressor in cancer serum vs normal serum. I have carried out a preliminary study, involving 15 healthy donor and 15 cancer patients and I see a statitically significant difference between the two groups.

All suggestions would be appreciated

Presumably this factor is not expressed in the serum, it is excreted by cells into the bloodstream, so looking at levels in serum/plasma is unlikely to tell you anything unless the protein is a signalling factor of some sort (which is quite possible).

Be careful of statistics with small sample size - use appropriate tests.

bob1 on May 10 2010, 08:20 AM said:

I doubt the mRNA in the serum will be doing anything, it needs to be in a cell for translation to take place as far as I know, therefore circulating mRNA is probably not correlated with protein levels.