Really depends on a number of factors e.g. the table dynamic, game flow, the stack sizes of those behind you, quality of the players behind you, what your aims for the mtt are, etc, etc. There are plenty of articles around on the tournament section of this website (the "stickies") and other websites.

Generally, tight is right UTG but you should open up your range when antes kick in. Opening for 2x or 2.2x is standard at that point.