Understand that it can be done as long as the tires physically fit and the direction of the rear tire is reversed. Something to do with the difference between the front and back pulling and pushing.
But looking at the Dunlop site, and assuming you are talking about the D402, their rear tires have a higher load capacity, slightly larger diameter, and deeper tread. The front tread depth is 5/32" on each model while the rear has either 9/32" or 11/32". From experience, the rear tire wears out faster, even with the deeper tread, than the front.
So, looks like you could run a front tire on the rear, where it was not designed, to save money initially and then replace it more often than you otherwise would. I'd think the economics are against you plus whatever safety issues (which are not being addressed) would arise.
Just my 2¢. Your bike, you decide.