Center can represent various relations involving having, finding, or turning about a center, and the choice of a preposition to accompany center depends on the meaning you want to convey. There is ample evidence for usages such as Our hope centered in the young leader, His thoughts centered on the long journey before him, and The trade is centered at Amsterdam. Center around is equally well established, as in A storm of controversy centered around the king. In this example, around seems to be the only appropriate choice. If using the phrase center around does not sit well with you, however, try revolve around instead.