Advance Treatment of Adult Cancer

The Research Institute of the McGill University Health Centre (RI-MUHC) researchers have found an epigenetic modification that might be the cause of 15% of adult cancers of the throat that are linked to alcohol and tobacco use.  The researchers are hopeful that the discovery can pave a path in the development of new, targeted and more effective treatments that could arise over the next few years.  It seemed highly improbably that the kind of alterations of the epigenome they 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, so the discovery was absolutely unexpected. Dr. Nada Jabado is a researcher at the RI-MUHC and one of the principal authors of the study that was published in Nature Genetics.

Oropharyngeal cancers, also referred to as head and neck cancers or throat cancer, often have devastating outcomes.  Radiotherapy or chemotherapy are the standard treatments as well as surgery.  The side effects of these treatments are significant and relapses are common, so oncologists are searching to develop more effective treatments that will be less harmful and have fewer deleterious effects.  The epigenetic modification discovery opens new treatment possibilities and some promising drug molecules are already on the market for other illnesses that could possibly be tested for head and neck cancers as well as other cancers like multiple myeloma and lung cancer.

Dr. Jabado is also a pediatric hemato-oncologist and has hopes that this discovery will have positive repercussions for pediatric cancers as well.  After more patients and lots of clinical trials, the medicines could then be tested on children.  Dr. Jabado focuses on epigenetics in pediatric cancers and specifically on the mutations of histone H3.  These are proteins that package the structure of our DNA and regulate the expression of our genes.  A 2015 publication by the Tumor Cancer Genome Atlas Consortium (TCGA) on head and neck cancer mentioned one of the genes that regulate H3.

The same data was used but they took a completely different approach by looking at the effect of these mutations on histone H3 proteins rather than concentrating on genetic mutations.  The discovery that the histone H3 protein was abnormal or incorrectly modified in about 15% patients with head and neck cancer was then discovered.  Public data is crucial as it allows the researchers to advance faster and go further in their analyses.  They are currently collaborating with two big groups specializing in head and neck cancer with a unified goal of finding treatments.

A large number of different types of cells such as neurons, skin cells, fat cells, immune system cells, etc. are cells that the body is composed of.  They differ, however these cells all have the same DNA or genome.  It has been recently discovered that their differences can be explained by epigenetics and is what triggers activity in each cell.

Explanations for why environmental factors like tobacco or alcohol can induce changes in the expression of our genes without actually modifying our DNA are provided through epigenetics.

Dr Fredda  Branyon