title: Synergistic activity of the SRC family kinase inhibitor dasatinib and oxaliplatin in colon carcinoma cells is mediated by oxidative stress.
abstract: Chemotherapeutic regimens for the treatment of colorectal cancer generally include oxaliplatin, although inherent and acquired resistance is common. One potential mediator of oxaliplatin sensitivity is the nonreceptor protein tyrosine kinase, Src, the activity of which correlates with disease stage and patient survival. Therefore, we investigated the effects of Src inhibition using the tyrosine kinase inhibitor dasatinib on oxaliplatin sensitivity. We show that oxaliplatin acutely activates Src and that combination treatment with dasatinib is synergistic in a cell-line dependent manner, with the level of Src activation correlating with extent of synergy in a panel of six cell lines. Intracellular reactive oxygen species (ROS) are generated after oxaliplatin treatment, and ROS potently activates Src. Pretreatment with antioxidants inhibits oxaliplatin-induced Src activation. In oxaliplatin-resistant cell lines, Src activity is constitutively increased. In a mouse model of colorectal liver metastases, treatment with oxaliplatin also results in chronic Src activation. The combination of dasatinib and oxaliplatin results in significantly smaller tumors compared with single-agent treatment, corresponding with reduced proliferation and angiogenesis. Therefore, we conclude that oxaliplatin activates Src through a ROS-dependent mechanism. Src inhibition increases oxaliplatin activity both in vitro and in vivo. These results suggest that Src inhibitors combined with oxaliplatin may have efficacy in metastatic colon cancer and may provide the first indication of a molecular phenotype that might be susceptible to such combinations.
authors.affiliation: Department of Cancer Biology, The University of Texas MD Anderson Cancer Center and Program in Cancer Biology, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030-4009, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Kopetz
authors.forename: Donald P
authors.initials: DP
authors.lastname: Lesslie
authors.forename: Nikolas A
authors.initials: NA
authors.lastname: Dallas
authors.forename: Serk I
authors.initials: SI
authors.lastname: Park
authors.forename: Marjorie
authors.initials: M
authors.lastname: Johnson
authors.forename: Nila U
authors.initials: NU
authors.lastname: Parikh
authors.forename: Michael P
authors.initials: MP
authors.lastname: Kim
authors.forename: James L
authors.initials: JL
authors.lastname: Abbruzzese
authors.forename: Lee M
authors.initials: LM
authors.lastname: Ellis
authors.forename: Joya
authors.initials: J
authors.lastname: Chandra
authors.forename: Gary E
authors.initials: GE
authors.lastname: Gallick
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D048708:Cell Growth Processes / Q000187:drug effects; D003110:Colonic Neoplasms / Q000098:blood supply / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000069439:Dasatinib; D015536:Down-Regulation; D004357:Drug Synergism; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D008114:Liver Neoplasms, Experimental / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000473:pathology; D009944:Organoplatinum Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D000077150:Oxaliplatin; D018384:Oxidative Stress / Q000187:drug effects*; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D011743:Pyrimidines / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation; D017382:Reactive Oxygen Species / Q000378:metabolism; D013844:Thiazoles / Q000008:administration & dosage / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D019061:src-Family Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D009944:Organoplatinum Compounds; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D017382:Reactive Oxygen Species; D013844:Thiazoles; D042461:Vascular Endothelial Growth Factor A; D000077150:Oxaliplatin; D019061:src-Family Kinases; D000069439:Dasatinib