TY - JOUR
T1 - Targeting the insulin growth factor and the vascular endothelial growth factor pathways in ovarian cancer
AU - Shao, Minghai
AU - Hollar, Stacy
AU - Chambliss, Daphne
AU - Schmitt, Jordan
AU - Emerson, Robert
AU - Chelladurai, Bhadrani
AU - Perkins, Susan
AU - Ivan, Mircea
AU - Matei, Daniela
PY - 2012/7
Y1 - 2012/7
N2 - Antiangiogenic therapy is emerging as a highly promising strategy for the treatment of ovarian cancer, but the clinical benefits are usually transitory. The purpose of this study was to identify and target alternative angiogenic pathways that are upregulated in ovarian xenografts during treatment with bevacizumab. For this, angiogenesis-focused gene expression arrays were used to measure gene expression levels in SKOV3 and A2780 serous ovarian xenografts treated with bevacizumab or control. Reverse transcription-PCR was used for results validation. The insulin growth factor 1 (IGF-1) was found upregulated in tumor and stromal cells in the two ovarian xenograft models treated with bevacizumab. Cixutumumab was used to block IGF-1 signaling in vivo. Dual anti-VEGF and IGF blockade with bevacizumab and cixutumumab resulted in increased inhibition of tumor growth. Immunohistochemistry measured multivessel density, Akt activation, and cell proliferation, whereas terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay measured apoptosis in ovarian cancer xenografts. Bevacizumab and cixutumumab combination increased tumor cell apoptosis in vivo compared with therapy targeting either individual pathway. The combination blocked angiogenesis and cell proliferation but not more significantly than each antibody alone. In summary, IGF-1 activation represents an important mechanism of adaptive escape during anti-VEGF therapy in ovarian cancer. This study provides the rationale for designing bevacizumab-based combination regimens to enhance antitumor activity.
AB - Antiangiogenic therapy is emerging as a highly promising strategy for the treatment of ovarian cancer, but the clinical benefits are usually transitory. The purpose of this study was to identify and target alternative angiogenic pathways that are upregulated in ovarian xenografts during treatment with bevacizumab. For this, angiogenesis-focused gene expression arrays were used to measure gene expression levels in SKOV3 and A2780 serous ovarian xenografts treated with bevacizumab or control. Reverse transcription-PCR was used for results validation. The insulin growth factor 1 (IGF-1) was found upregulated in tumor and stromal cells in the two ovarian xenograft models treated with bevacizumab. Cixutumumab was used to block IGF-1 signaling in vivo. Dual anti-VEGF and IGF blockade with bevacizumab and cixutumumab resulted in increased inhibition of tumor growth. Immunohistochemistry measured multivessel density, Akt activation, and cell proliferation, whereas terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay measured apoptosis in ovarian cancer xenografts. Bevacizumab and cixutumumab combination increased tumor cell apoptosis in vivo compared with therapy targeting either individual pathway. The combination blocked angiogenesis and cell proliferation but not more significantly than each antibody alone. In summary, IGF-1 activation represents an important mechanism of adaptive escape during anti-VEGF therapy in ovarian cancer. This study provides the rationale for designing bevacizumab-based combination regimens to enhance antitumor activity.
UR - http://www.scopus.com/inward/record.url?scp=84863801971&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84863801971&partnerID=8YFLogxK
U2 - 10.1158/1535-7163.MCT-11-0961
DO - 10.1158/1535-7163.MCT-11-0961
M3 - Article
C2 - 22700681
AN - SCOPUS:84863801971
VL - 11
SP - 1576
EP - 1586
JO - Molecular Cancer Therapeutics
JF - Molecular Cancer Therapeutics
SN - 1535-7163
IS - 7
ER -