Mapping the Mutations: Uterine Cancer Up Close

Endometrial cancer gene mapping helps scientists discover why treatments don’t always work

(RxWiki News) Understanding cancer these days is all about understanding genetic mutations. They are the root of cancer and must be mapped out to develop new and more successful treatments.

A recent study mapped part of the genes in serous endometrial cancer.

Findings pointed to a new understanding regarding a handful of genes that apparently drive this particularly tough cancer.

Understanding what genes drive serous endometrial tumors will provide the basis for targeting treatment at those genes and their mutations.

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Daphne W. Bell, PhD, a scientist at the National Human Genome Research Institute (NHGRI), was the senior author of this study.

There are three types of uterine cancer, also known as endometrial cancer: serous, endometrioid and clear-cell. Serous is the most rare, but also the toughest endometrial cancer to successfully treat.

Dr. Bell said, “Serous endometrial tumors can account for as much as 39 percent of deaths from endometrial cancer.”

For the study, Dr. Bell’s team of researchers sequenced, or mapped out, the exomes from serous endometrial tumor cells. Exomes are a small part of the genome that is responsible for the gene’s actual code, or blue print.

Scientific Director of NHGRI, Dan Kastner, MD, PhD, said, “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.”

For the first part of the study, 13 serous endometrial tumor samples and 13 healthy tissue samples from the same person underwent whole-exome sequencing.

More than 500 mutations were found. The researchers believe not all mutations are driving the cancer; some could also be “incidental passengers” that didn’t contribute to the cancer.

By matching mutations from all of the tumors, researchers were able to identify the “driver” mutations. Dr. Bell said, “[W]e know from experience frequently mutated genes are often driver genes.”

A total of nine driver genes were found, three of which have been identified in previous studies on serous endometrial cancer genetics.

For the second part of the study, 40 new serous endometrial tumors were sequenced to have a better look at the six less studied driver genes.

Researchers found three out of those six to be mutated in 40 percent of serous endometrial tumors and in 15-26 percent of other endometrial cancer types.

Findings of this study were based on a small sample size. Further studies will be necessary to verify the results.

This study was published in October in Nature: Genetics.

Funding for this study was provided by the National Institutes of Health.

No conflicts of interest were reported.

Review Date: 
October 29, 2012