First of its kind cancer stem cell research unlocks clues to treatment resistance

The researchers showed that populations of tumour cells that had higher numbers of cancer stem cells formed larger, more aggressive tumours, and also  demonstrated that the cancer stem cells were more resistant to radiation-induced cell death.

Study lead Stephen Maher noted that "our findings strongly suggest that it is the cancer stem cell population that we need to destroy if treatment is going to be effective in our oesophageal cancer patients."

The researchers further broke down cancer stem cells into smaller groups, which had distinct radiation sensitivity profiles.

Further, levels of a powerful gene-regulating molecule, called miR-17, were found to be particularly low in the cancer stem cells that were most resistant to radiation.

Study author Niamh Lynam-Lennon noted that "in the lab we found that if we put a synthetic version of miR-17 into the resistant cells they became more sensitive to radiation. Going forward, we could use synthetic miR-17 as an addition to radiotherapy to enhance its effectiveness in patients -- this is a real possibility as a number of other synthetic miR-molecules are currently in clinical trials for treating other disease."