Rebekah Eliason for redOrbit.com – Your Universe Online
Researchers from Mayo Clinic have recently discovered a new type of cancer. When two perfectly harmless genes, PAX3 and MAML3, abnormally combine during recurring chromosomal mismatch, they can turn dangerous. As the two genes combine, they become a chimera, which is a gene that is made up of half of each.
This unique phenomenon causes cancerous biphenotypic sinonasal sarcoma. The tumor usually forms in the nose and continues to spread across the rest of the face. In order to save the person, often a terribly disfiguring surgery is required.
Since the Mayo Clinic pathology researchers have now discovered and described the molecular makeup of this rare tumor, there are several existing cancer drugs that can be used to target this cancer. It was in 2004 when Mayo Clinic pathologists Andre Oliveira, MD, PhD, and Jean Lewis, MD, initially noticed there was something strange about the tumor they were analyzing. They began collecting data and by 2009 had noticed the same pathology a number of times. By 2012, the team defined a new class of tumor that had never been described before.
In this most recent study, the researchers are describing the genetic structures and molecular signature of this rare and difficult to recognize type of cancer. In 75 percent of cases, this cancer affects women.
No one is sure how rare this type of cancer is since most cases the researchers examined were initially diagnosed incorrectly as other cancer types. As Mayo Clinic is considered to be one of the world’s largest referral centers for sarcoma diagnosis and treatment, they were successful at identifying and characterizing this rare tumor.
Dr. Oliveira, who subspecializes in the molecular genetics of sarcomas, said “It’s unusual that a condition or disease is recognized, subsequently studied in numerous patients, and then genetically characterized all at one place. Usually these things happen over a longer period of time and involve separate investigators and institutions. Because of Mayo’s network of experts, patient referrals, electronic records, bio repositories, and research scientists, it all happened here. And this is only the tip of the iceberg. Who knows what is in our repositories waiting to be discovered.”
Although the cancer was not formally identified until the year 2009, when Mayo Clinic’s medical records were searched, it was discovered a Mayo patient had this specific cancer in 1956. An identical description of the cancer was discovered in physician notes that were in Mayo’s computerized database.
Additionally, it was confirmed that the 1956 case was the same cancer through microscopic analysis of the tumor found preserved in Mayo’s bio repositories. Dr. Oliveira’s research confirmed the same genetic chimera in the old tumor.
Researchers are excited by this discovery because of the exciting potential disease model.
“The PAX3-MAML3 chimera we identified in this cancer has some similarities to a unique protein found in alveolar rhabdomyosarcoma, a common cancer found in children,” says Mayo Clinic molecular biologist and co-author Jennifer Westendorf, PhD. “Our findings may also lead to a better understanding of this pediatric disease for which, unfortunately, there is no specific treatment.” This study was published in the journal Nature Genetics.