Ellen Ackerstaff1, Xiaorong Sun1,2, Mihai Coman (Deceased)1, Ya Wang1, Hung Tsung Hsiao1, Fuqiu He1, Ligang Xing1,2, Sean Carlin1, C Clifton Ling1, Jason A. Koutcher1, Gloria C. Li1
The proteasomes inhibitor Bortezomib possesses anti-angiogenic and anti-tumor properties and appears to selectively interfere in the hypoxia pathway. Our study aims to determine biomarkers characterizing treatment response. We studied in a colorectal cancer model the effects of Bortezomib on the tumor vasculature by in vivo DCE MRI and on the tumor hypoxia response ex vivo using immunohistochemistry. Our data suggest that Bortezomib treatment modifies the tumor microenvironment by decreasing tumor perfusion. Our ex vivo data indicate a reduced hypoxia response in central regions of the tumor and an increased hypoxia response in the tumor rim in response to Bortezomib treatment.