title: Additive effects of Cox-1 and Cox-2 inhibition on breast cancer in vitro.
abstract: We hypothesized that combined treatment with Cox-1 and Cox-2 specific inhibitiors would exhibit synergistic effects against breast cancer in vitro. Two human breast cancer cell lines (HTB26, MCF-7) were treated with catechin (Cox-1 inhibitor) or NS398 (Cox-2 inhibitor) at 100 microM as both single and combined treatments. Reductions in cell growth were observed in both cell lines at 24 and 72 h in both single and combined treatments (p<0.001). Combined treatment produced a significantly greater inhibition as compared to single agents alone. Upon cell cycle evaluation, Cox-1 and -2 antagonism increased G1 and G2 phase fractions in MCF-7 cells (p<0.001 and p<0.05 respectively). No additive changes were observed when the two agents were combined. An increase in the G2 phase was observed in the HTB26 cells when treated with NS398 alone (p<0.001). However, a decrease in the S-phase was observed when these cells were treated with NS398, as a single agent (p<0.01) or when the two agents were combined (p<0.01). The significant and additive effects exhibited by the combination of Cox-1 and -2 inhibitors and their effects on cell cycle suggest that these agents could become an effective treatment modality for carcinoma of the breast.
authors.affiliation: Department of Surgery, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA. dmcfadden@hsc.wvu.edu
authors.forename: David W
authors.initials: DW
authors.lastname: McFadden
authors.forename: Dale R
authors.initials: DR
authors.lastname: Riggs
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Jackson
authors.forename: Cynthia
authors.initials: C
authors.lastname: Cunningham
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D051545:Cyclooxygenase 1 / Q000187:drug effects*; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004357:Drug Synergism; D005260:Female; D006801:Humans; D008565:Membrane Proteins / Q000037:antagonists & inhibitors*
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human