Prof John Mariadason

With more than 4,000 people dying from colon, or bowel, cancer in Australia each year, there is an urgent need to develop new treatments for this disease. Which is why Prof John Mariadason is excited about finding potential new ways of managing colon cancer.

After 15 years of research his team has homed in on a family of proteins that are required for the growth of colon cancer – and found a way to block them.

They have shown that combining drugs that target proteins called histone deacetylases with drugs that block a second pathway called MAPK, stops the cancer in its tracks; preventing the ability of the cancer cells to grow and move, and even causing their death. (A pathway is a series of actions among molecules in a cell that leads to a certain product or a change in a cell.)

“We are extremely excited by this finding as it could represent a new way of managing colon cancer. We hope that this discovery will rapidly lead to a clinical trial, aimed at stopping the spread of colon cancers around the body,” he says.

Battle against colon cancer advances on several fronts

John’s Oncogenic Transcription Laboratory, which comprises scientists, clinicians and students doing PhDs, is also involved in conducting pre-clinical work trialling newly developed drugs or drugs which are showing activity in other cancers.

They test each drug on 80 genetic versions of colon cancer nurtured in the lab. “They’re our workhorses, our tools,” he says.

By identifying which colon cancer cell lines respond best to a given drug, the researchers hope to tell oncologists which ones may provide benefits to individual patients, tailoring treatment to the needs of these patients.

John’s team is particularly interested in “epigenetic therapy”. The rapidly advancing field of epigenetics – non-genetic influences on the ways genes are expressed – is revolutionising cancer research by looking beyond the inherited mutations that cause cancer.

His team has shown that another family of proteins, bromodomain-containing proteins, is required for colon cancer growth, and demonstrated that drugs targeting them block the growth and cause death of colon cancer cells. The researchers have advanced understanding into why these drugs work more effectively in some cancers than others, using this knowledge to develop novel therapeutic combinations.