"Exome sequencing is a powerful tool for revealing important insights about this form of cancer that exacts such a high toll for thousands of women," said NHGRI Scientific Director Dan Kastner, M.D., Ph.D. "This study pinpoints genetic alterations that may be essential for onset and progression of uterine cancers and may eventually lead to new therapeutic targets."
Dr. Bell's team focused on the rarer, more aggressive forms of endometrial cancer. They began their study by examining serous tumor tissue and matched normal tissue from 13 patients. National Cancer Institute and Massachusetts General Hospital pathologists processed the 26 tissue samples, which subsequently underwent whole-exome sequencing at the NIH Intramural Sequencing Center.
With the exome data in hand, the researchers filtered through millions of data points to locate alterations, or mutations. They disqualified from the analysis any mutation found in a tumor and its matched healthy tissue, looking expressly for mutations that occurred exclusively in the tumor cells. They also eliminated one of the 13 tumors from analysis because its exome had hundreds more unique mutations than any other tumor.
The researchers detected more than 500 somatic mutations within the remaining 12 tumors. They next looked for genes that were mutated in more than one of the tumors. An alteration that occurs in more than one tumor is more likely to be relevant to the development of the cancer than a unique alteration.
"When you identify a set of mutations, they could either be drivers that have caused the cancer or incidental passengers that are of no consequence; our goal is to identify the drivers," Dr. Bell explained. "One way to do this is to home in on genes that are mutated in more than one tumor, because we know from experience that frequently mutated genes are often d
|Contact: Raymond MacDougall|
NIH/National Human Genome Research Institute