title: Curcumin ameliorates oxaliplatin-induced chemoresistance in HCT116 colorectal cancer cells in vitro and in vivo.
abstract: The aims of this study were to determine potency of oxaliplatin in combination with curcumin in oxaliplatin-resistant cell lines in vitro and to evaluate the efficacy of a novel curcumin formulation (Meriva®) alone and in combination with oxaliplatin in colorectal tumor-bearing mice, exploring relevant pharmacodynamic markers in vivo. Oxaliplatin-resistant HCT116 p53wt and p53(-/-) cell lines were generated, and the effects of oxaliplatin in combination with curcumin on resistance- and proliferation-associated proteins investigated. Eighty nude mice were implanted with HCT116 p53wt colorectal cancer cells before randomization into the following treatment groups: control; Meriva only; oxaliplatin only; Meriva + oxaliplatin. Tumor volume was assessed, as was the expression of Ki-67, cleaved caspase-3 and Notch-1. Curcumin in combination with oxaliplatin was able to decrease proliferative capacity of oxaliplatin-resistant p53 wildtype and p53(-/-) cell lines more effectively than oxaliplatin alone. It also decreased markers associated with proliferation. After 21 days of treatment in the xenograft model, the order of efficacy was combination > Meriva > oxaliplatin > control. The decrease in tumor volume when compared to vehicle-treated animals was 53, 35 and 16%, respectively. Ki-67 and Notch-1 immunoreactivity was decreased by the combination when compared to vehicle-treated animals, with cleaved caspase-3 rising by 4.4-fold. Meriva did not adversely affect the DNA-platinating ability of oxaliplatin. Curcumin enhanced the cytotoxicity of oxaliplatin in models of oxaliplatin resistance in vitro. In vivo, Meriva greatly enhanced oxaliplatin efficacy, without affecting the mode of action of oxaliplatin. Addition of formulated curcumin to oxaliplatin-based chemotherapy regimens has the potential for clinical benefit.
authors.affiliation: Cancer Biomarkers and Prevention Group, Cancer Studies and Molecular Medicine, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, United Kingdom. lh28@le.ac.uk
authors.forename: Lynne M
authors.initials: LM
authors.lastname: Howells
authors.forename: Stewart
authors.initials: S
authors.lastname: Sale
authors.forename: Sathya Neelature
authors.initials: SN
authors.lastname: Sriramareddy
authors.forename: Glen R B
authors.initials: GR
authors.lastname: Irving
authors.forename: Donald J L
authors.initials: DJ
authors.lastname: Jones
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Ottley
authors.forename: D Graham
authors.initials: DG
authors.lastname: Pearson
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Mann
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Manson
authors.forename: David P
authors.initials: DP
authors.lastname: Berry
authors.forename: Andreas
authors.initials: A
authors.lastname: Gescher
authors.forename: William P
authors.initials: WP
authors.lastname: Steward
authors.forename: Karen
authors.initials: K
authors.lastname: Brown
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D015179:Colorectal Neoplasms / Q000188:drug therapy*; D003474:Curcumin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D004357:Drug Synergism; D005260:Female; D045325:HCT116 Cells / Q000187:drug effects*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009944:Organoplatinum Compounds / Q000494:pharmacology; D000077150:Oxaliplatin; D011897:Random Allocation; D023041:Xenograft Model Antitumor Assays
chemical_list: D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D003474:Curcumin