[RegExp] Find row of uppercase letters

I’m not very good at regular Expressions, so can anyone help me find out a string test for the following sentences.

EVERY SENTENCE HAS ONE or more uppercase letters.
But not every line.

WHAT I NEED IS TO TAKE the lines which starts with two or more uppercase letters, and make them bold. If possible.

COULD ANYONE HELP me out with this. Your help is really appreciated.