Acute myeloid leukaemia (AML) is one of the most aggressive and damaging types of cancer there is: it appears without much warning and the five-year survival rate for sufferers is just 24 percent. However, improved treatments could soon be on the way, as researchers from the Walter and Eliza Hall Institute in Melbourne, Australia have identified a protein that’s crucial to the spread of the blood cancer.
The protein in question is called the Hhex protein, and by cutting off its production, the team has shown the cancer can be stopped in its tracks – in laboratory conditions, at least. The next step is to see whether the same ‘handbrake’ mechanism would work in humans, but the initial signs are promising.
The researchers found that when the Hhex supply was cut off, the leukaemia stopped spreading uncontrollably. What’s more, the protein isn’t required in healthy blood cells, which opens the door for treatments that target Hhex specifically without the unwanted and typically very damaging side-effects that come with existing AML treatments.
“Most existing treatments for AML are not cancer cell-specific, and unfortunately kill off healthy cells in the process,” said one of the researchers, Matt McCormack. “Hhex is only essential for the leukaemic cells, meaning we could target and treat leukaemia without toxic effects on normal cells, avoiding many of the serious side-effects that come with standard cancer treatments.”
While the body does have a self-defence mechanism to switch off ‘stressed’ cells and stop them from multiplying – cells which may eventually turn cancerous – the Hhex protein disables this mechanism and thus allows the damaged cells to spread. If scientists are able to remove Hhex, the normal safety procedures built into the body can be restored and the spread of cancers such as AML can be checked.
“Hhex only regulates a small number of genes and is dispensable for normal blood cells,” says McCormack. “This gives us a rare opportunity to kill AML cells without causing many side-effects. We now hope to identify the critical regions of the Hhex protein that enable it to function, which will allow us to design much-needed new drugs to treat AML.”
Now that scientists know how AML cells grow uncontrollably, they can do something about it. And while a publicly available drug may be some way off, it could save patients from the pain and suffering associated with existing treatments, as well as improving their long-term prognosis at the same time.
The research has been published in the journal Genes & Development.