Professor Adrian Bracken at Trinity College Dublin has been awarded £218,000 to study a rare but highly-aggressive childhood brain cancer known as DIPG (diffuse intrinsic pontine glioma).
Worldwide Cancer Research said that work looking into rare cancers is far behind in comparison to other types, meaning outcomes for patients with those cancers can often be much worse.
Jennifer Stewart, from East Lothian in Scotland, whose eight-year-old son Luke was diagnosed with DIPG a year ago, welcomed the funding announcement.
She said: "There has been no progress towards a cure for DIPG for more than 50 years. This has to change. No child should suffer like those who are diagnosed with DIPG."
Dr Helen Rippon, chief executive of Worldwide Cancer Research, said: "The fantastic partnership we have formed with The Brain Tumour Charity means we have been able to support two international research projects that are vital to advance treatments for brain cancer.
"This is the first time both charities have joined forces to help fund cancer research and the combined support means that research projects are able to be completed that might otherwise have been missed."