Is acanthosis nigricans curable?

Possibly. If you truly have acanthosis nigricans, it's often very difficult to treat. Make sure it doesn't just wipe off with an alcohol wipe, though! if it does, you may not actually have an--see your dermatologist. Some lasers and prescription creams may help. Most importantly, the underlying cause needs to be identified and treated, as this can sometimes "cure" the skin changes as well!