General:
* Criticized
* Picked on
* Teasing
* Harassed (if it's more severe)
* Berated (if it's harsh)
* Ripped on
* Mocked
Informal:
* Busting on
* Giving a hard time
* Taken the mickey out of (British English)
* Roast (if it's friendly and humorous)
More serious:
* Bullied
* Abused
* Harassed
The best word to use will depend on the specific situation and the severity of the teasing.