Effect of a Cyclooxygenase-2 Inhibitor in Combination with (−)-Epigallocatechin Gallate or Polyphenon E on Cisplatin-Induced Lung Tumorigenesis in A/J Mice

We investigated the effects of celecoxib combined with (−)-epigallocatechin-3-gallate (EGCG) or polyphenon E in a cisplatin-induced lung tumorigenesis model. Four-week-old female A/J mice were divided into seven groups: (i) Control, (ii) 150 mg/kg celecoxib (150Cel), (iii) 1,500 mg/kg celecoxib (1500Cel), (iv) EGCG+150 mg/kg celecoxib (EGCG+150Cel), (v) EGCG+1,500 mg/kg celecoxib (EGCG+1500Cel), (vi) polyphenon E+150 mg/kg celecoxib (PolyE+150Cel), and (vii) polyphenon E+1,500 mg/kg celecoxib (PolyE+1500Cel). All mice were administered cisplatin (1.62 mg/kg of body weight, i.p.) 1×/week for 10 weeks and sacrificed at week 30; the numbers of tumors on the lung surface were then determined. The tumor incidence and multiplicity (no. of tumors/mouse, mean±SD) were respectively 95% and 2.15±1.50 in Control, 95% and 2.10±1.29 in 150Cel, 86% and 1.67±1.20 in 1500Cel, 71% and 1.38±1.24 in EGCG+150Cel, 67% and 1.29±1.38 in EGCG+1500Cel, 80% and 1.95±1.36 in PolyE+150Cel, and 65% and 1.05±0.10 in PolyE+1500Cel. The combination of high-dose celecoxib with EGCG or polyphenon E significantly reduced multiplicity in cisplatin-induced lung tumors.