FIGURE 3.

CDK4/6 inhibition modifies the therapeutic response of RB-positive breast cancer xenografts in vivo. A, representative α-BrdU immunohistochemical images of MDA-MB-231 xenografts treated with PD0332991, Doxorubicin or 72 h PD-pretreatment. Xenografts were harvested 7 days post treatment initiation. B, representative α-cyclin A and α-MCM7 immunohistochemical staining of tissues described in A. C, representative α-Rad51 immunofluorescence images in and quantification of MDA-MB-231 xenografts treated as described in A.