Epigenetic Modification Discovered in Adult Throat Cancers

An epigenetic modification may be the cause of 15% of adult head and neck cancers that are linked to tobacco and alcohol use, according to a study published in Nature Genetics.

Although the body is made up of a large number of different types of cells—–neurons, skins cells, fat cells, immune cells–– they all have the same DNA or genome. It was not until recently that scientists discovered their differences can be explained by epigenetics.

“This discovery was absolutely unexpected since it seemed highly improbable that the kind of alterations of the epigenome that we had previously found in other types of tumors in children and young adults could also target an epithelial tumor like throat cancer that occurs only in adults,” said Dr Nada Jabado.

There are already some promising drug molecules currently on the market for other diseases that could be tested for head and neck cancers, as well as other cancer types, according to the study.

Additionally, the investigators hope that the findings could help in developing treatments for pediatric patients.

“Now that we’ve identified this cohort of patients, we can move quite quickly since the case of adults, as opposed to children, there are more patients and lots of clinical trials,” Dr Jabado said. “The medicines could then be tested on children afterward.”

Dr Jabado’s work focuses on epigenetics in pediatric cancers, particularly on the mutations of the histone H3 protein.

In particular, the investigators were interested in a 2015 publication by the Tumor Cancer Genome Atlas Consortium on head and neck cancer that included 1 of the genes that regulates H3.

“We made use of the same data but took a completely different approach,” said principal study author Dr Jacek Majewski. “Instead of concentrating on genetic mutations, we looked at the effect of these mutations on histone H3 proteins. That’s when we discovered that the histone H3 protein was abnormal or incorrectly modified in about 15% of patients with head and neck cancer. The data were there, but this fact had gone unnoticed.”

An essential part of the study was collaboration between scientists and access to the vast genomic databases of patients around the globe, according to the investigators.

“It’s crucial to have access to public data, because it allows us to advance faster and go further in our analyses,” Dr Jabado said. “In our case, this discovery revealed a sub group of patients who might benefit from a therapy that targets the epigenome. This could improve the treatment of more than 1 in 5 patients suffering from devastating oropharyngeal cancer. We are currently collaborating with 2 big groups specializing in head and neck cancer with the goal of finding treatments.”

The investigators are hopeful that the results of the study will open a variety of treatment options in the future.