Growth inhibition of HNSCC cells in vitro with curcumin Growth inhibition of HNSCC cells in vitro with curcumin. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were done on CCL23 (A), CAL27 (B), and UM-SCC1 (C) cells following treatment with increasing doses of curcumin dissolved in DMSO. DM... Growth inhibition of HNSCC cells in vitro with curcumin. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were done on CCL23 (A), CAL27 (B), and UM-SCC1 (C) cells following treatment with increasing doses of curcumin dissolved in DMSO. DMSO alone has some inhibitory effect; however, curcumin has a significantly greater cytotoxic effect in all three cell lines (P < 0.0001). There is near-complete cell death with 150 μmol/L of curcumin in CCL23 and UM-SCC1 cell lines, and a concentration of 400 μmol/L is required to achieve complete cell killing in CAL27 cells. Maria M. LoTempio et al. Clin Cancer Res 2005;11:6994-7002 ©2005 by American Association for Cancer Research