There would be too much tension on the strings to tune them gCEA, but you could tune them differently (i.e - lower) it might sound good too, but you would have to play on your own, because if you played with other ukes you would be out of key with them unless you learned the chord shaped for your new tuning. I have a Mahalo Ukulele-Guitar, which because it has a short scale, doesn't sound good tuned EADGBE like a normal guitar (strings are too loose), but is great if lifted higher by 3 positions (like a capo on the 3rd fret of a normal guitar). Why not try it, you never know, you may find the tuning works great, but don't try gCEA, you will probably over-stretch your strings (or pull your bridge off as a worst case scenario).