Bevacizumab and rapamycin inhibit tumor growth in peritoneal model of human ovarian cancer.
Ovarian cancer is the leading cause of death from gynecologic cancer. Often, the disease has spread beyond the ovary to involve the peritoneal cavity and causes ascites. Whereas mammalian target of rapamycin (mTOR) functions to regulate protein translation, cell cycle progression, and metastasis, vascular endothelial growth factor promotes tumor angiogenesis, ascites formation, and metastasis in ovarian cancer. In this study, an i.p. model of human ovarian cancer was used to determine the antitumor activity of rapamycin, bevacizumab, and rapamycin plus bevacizumab (BEV/RAPA). We report that administration of rapamycin, bevacizumab, and BEV/RAPA in mice bearing peritoneal OV-90 ovarian carcinoma resulted in 74.6%, 82.4%, and 93.3% reduction in i.p. tumor burden, respectively. BEV/RAPA-induced reduction in microvessel density and inhibition of cell proliferation were associated with significant reduction in hypoxia-inducible factor-1alpha and cyclin D1 and inactivation of downstream targets of mTOR, p70S6 kinase, S6R, and 4E-binding protein 1. BEV/RAPA treatment was not only able to prolong life of i.p. mice but also more effective than rapamycin and bevacizumab to prevent the development of peritoneal carcinomatosis in adjuvant setting and reverse ascites accumulation in heavy peritoneal disease. Our data indicate that simultaneous inhibition of the vascular endothelial growth factor receptor and mTOR pathways with BEV/RAPA or their analogues may represent a novel approach for prevention of metastasis, recurrence, and treatment of ovarian cancer.
Huynh
Hung
H
Laboratory of Molecular Endocrinology, Division of Cellular and Molecular Research, National Cancer Centre of Singapore, Singapore 169610, Singapore. cmrhth@nccs.com.sg
Teo
Ching Ching Melissa
CC
Soo
Khee Chee
KC
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001201:Ascites / Q000473:pathology; D000068258:Bevacizumab; D001835:Body Weight / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009363:Neoplasm Proteins / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000473:pathology*; D010534:Peritoneal Neoplasms / Q000473:pathology*; D020123:Sirolimus / Q000494:pharmacology*; D047368:Tumor Burden / Q000187:drug effects
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D009363:Neoplasm Proteins; D000068258:Bevacizumab; D020123:Sirolimus