Not really. Not unless you manage to make what's called a "Frankenmac." Then when you get a "Frankenmac", you have to make sure you know what are the minimum operating system, installer discs that match up with said logicboard. You'd need to get a Mac logicboard with a higher end GPU that has the same port fittings as your current MacBook Pro. And then, you'd have to make sure that the logicboard hasn't lost any of the necessary cooling gels, pads, or efficacy of the fan that's on the board from when it was in a previous Mac model. This type of work is not something I'd recommend a novice tackle, and it has a certain amount of risk involved in terms of an overheating machine, or mismatched parts. Usually though, the used and refurbished market for a newer Mac is just as expensive as the part itself for a logicboard*:
http://www.macmaps.com/usedrefurbished.html
- * Links to my pages may give me compensation.