Why I cannot connect my brother printer with AirportExtreme 802.11nm? Wi-Fi

I have successfully instaled my AirpPort Extreme 802.11n Wi-Fi two weeks ago, use it as my internet connection and is working with my iPad Mini but I could not make it work with my MFC-J825DW (Wi-Fi capable) brother printer which was not the case when I had a different router. I also installed a USB cable between the printer and the Extreme thinking it might solve the problem of setting it up 'cause such an arrangement is mentioned on the Extreme for Wi-Fi setup but still I could print remotedly! Is there any suggestion that would help me in this problem?