Using Gene Chips in Mesothelioma Research
Using Gene Chips in Mesothelioma Research, Several researchers are pursuing some exciting lines of investigation using a device sometimes called a gene chip. The Gene Chip is actually a copyrighted name of a system made by the biotech company Affymetrix. Many people use the term gene chip more generically to mean a DNA microarray. This technology has now been in use for over 10 years and is one of a number of high tech weapons in the battle against cancer.
To learn more about how DNA microarrays work, wikipedia has a good entry. I’ll focus on some of the direct applications for Mesothelioma and cancers in general.
One application for a Gene Chip is to read the activity of individual genes in a person or in the case of a cancer, in the tumor itself. Genes are the basic building blocks of the cell, they are the “words” of the DNA. A portion of DNA that codes for a particular protein or set of proteins is essentially what a gene is. Genes can be turned on and off depending on conditions. In some cancers, genes such as tumor suppressor genes are turned off while others start pumping out gene products at much higher levels than normal. The gene chip can create a map of activity of individual genes, potentially mapping thousands at a time. When activity in cancerous cells, say tissue from a mesothelioma patient are compared to healthy tissue, scientists can start to identify potential targets for therapy or detection.
In mesothelioma, a particular protein called mesothelin is overexpressed and readily detectable with a genechip. A related protein is the basis of a new blood test, not yet licensed in the US called Mesomark.
Using the genechip technology scientists have started looking for telltale patterns in gene expression that predict the clinical outcome of a certain cancer. One pattern may indicate a relatively treatable tumor, while another may predict an aggressive tumor with poor prognosis.
Genechips have also been used to assess how treatment is working. The way treatment changes the distribution of gene products may tell a physician how well the therapy is working.
A study came out earlier this summer, building on work published in 2003. Using DNA microarrays testing for 22,000 genes, researchers at Brigham and Women’s Hospital in Boston found that they could accurately predict the disease prognosis in patients with mesothelioma using the expression rates of only 4 genes. This is a start since determining which stage of mesothelioma a patient has usually requires extensive surgery. This method allows the staging of the disease using only a small sample of the tumor. Unfortunately, this research is not widely available as an FDA licensed test. Sometimes moving from the bench to the patient can be painfully slow.
Perhaps researchers will identify a gene or set of genes that will provide the magic bullet for mesothelioma. For now the genechip is a powerful weapon in diagnosis and discovery.