Another interesting gene chip, this one for a common childhood malignancy called neuroblastoma, is being developed by scientists at The Children’s Hospital of Philadelphia and Thomas Jefferson University:
Genetics researchers have developed a customized gene chip to rapidly scan tumor samples for specific DNA changes that offer clues to prognosis in cases of neuroblastoma, a common form of children’s cancer. Rather than covering the entire genome, the microarray focuses on suspect regions of chromosomes for signs of deleted genetic material known to play a role in the cancer.
The investigators, from The Children’s Hospital of Philadelphia and Thomas Jefferson University, say their technique may be readily adapted for other types of cancer. The proof-of-principle study appears in the August issue of Genome Research.
One advantage of their technique is its flexibility, said co-author John M. Maris, M.D., a pediatric oncologist at The Children’s Hospital of Philadelphia. “As future research identifies other genes active in neuroblastoma, we can modify the microarray to include such regions,” he added…
Microarrays are silicon chips that contain tightly ordered selections of genetic material upon which sample material can be tested. When DNA bases from a sample bind to complementary sequences on the microarray, they cause fluorescent tags to shine under laser light. This is a signal that a particular gene variation is present in the sample.
“We can test DNA from peripheral blood and from the tumor, and we should see a loss of signal in the cancer,” said Dr. Fortina. He noted that the researchers can simultaneously evaluate seven chromosomal regions known to be involved in neuroblastoma.
Unlike gene expression microarrays, which detect varying levels of RNA to measure the activity levels of different genes as DNA transfers information to RNA, the current microarray directly identifies changes in DNA. “These DNA changes, involving gain or loss of genetic material, are important for neuroblastoma prognosis,” said Dr. Maris.