Relaying has been proposed as an efficient technique to extend coverage and improve throughput in future wireless networks. However, its performance gain is degraded in the presence of co-channel interference, which is intensified as the network density keeps increasing. In this letter, we investigate interference management in a two-hop interference channel with decode-and-forward relaying. To efficiently suppress interference, we propose different relay cooperation strategies with different information exchanged between relay nodes. A high SNR analysis is used to evaluate the performance and determine the achievable degrees of freedom while demonstrating the importance of time sharing between two hops. Through performance comparison and based on the implementation complexity of each cooperation strategy, we show that a zero-forcing based approach is attractive for interference management in two-hop interference channels.