($55) AJs on KK5o board -- contesting HU

Party Poker No-Limit Hold'em Tourney, Big Blind is t50 (8 handed) internettexasholdem.com

saw flop|<font color="#C00000">saw showdown</font>

BB (t1735)
UTG (t955)
Hero (t835)
MP1 (t1840)
MP2 (t1370)
CO (t1380)
Button (t930)
SB (t955)

Preflop: Hero is UTG+1 with A[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/club.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to t150</font>, <font color="#666666">5 folds</font>, BB calls t100.

Flop: (t325) 5[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets t160</font>, <font color="#CC3333">BB raises to t320</font>, Hero ??????



BB has cold called before w/ KTs and has been playing very aggressively. Winning lots of pots by making big bets, he hardly ever goes to showdown so haven't seen many of his cards.


What should Hero's play be here, and why?