title: Curcumin: a new radio-sensitizer of squamous cell carcinoma cells.
abstract: OBJECTIVE
  Curcumin, a potential chemopreventive agent, was found to inhibit cancer cells in S/G2M phases of the cell cycle, when radiation is more effective. The purpose of the current study was to investigate whether curcumin can sensitize squamous cell carcinoma (SCC) cells to the ionizing effects of irradiation.
  
  
  METHODS
  Curcumin (3.5 microM) was added for 48 hours to an SCC cell line prior to irradiation. Cell growth (counts) and colony-formation (colonogenic assay) were examined after radiation.
  
  
  RESULTS
  Incubation with curcumin only (3.75 microM) for 48 hours did not decrease the number of cells or the ability to form colonies in the absence of radiation. However, in plates that were exposed to 1-5 Gy of radiation, cell counts dropped significantly if pretreated with curcumin with a maximal effect at 2.5 Gy (where the cell counts dropped from 1240 to 1017, P < 0.001). The colonogenic assay revealed a significant decrease in the ability to form colonies following pretreatment with curcumin in all radiation doses ( P < 0.05).
  
  
  CONCLUSIONS
  Given the appropriate doses, curcumin exhibits radio-sensitizing effects on SCC cells in vitro.
authors.affiliation: Department of Otolaryngology, Tel-Aviv Sourasky Medical Center, Israel. avironit@Bezeqint.net
authors.forename: Avi
authors.initials: A
authors.lastname: Khafif
authors.forename: Robert
authors.initials: R
authors.lastname: Hurst
authors.forename: Kimberly
authors.initials: K
authors.lastname: Kyker
authors.forename: Dan M
authors.initials: DM
authors.lastname: Fliss
authors.forename: Ziv
authors.initials: Z
authors.lastname: Gil
authors.forename: Jesus E
authors.initials: JE
authors.lastname: Medina
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D002452:Cell Count; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor / Q000187:drug effects / Q000528:radiation effects; D003474:Curcumin / Q000494:pharmacology*; D016195:G2 Phase / Q000187:drug effects; D006801:Humans; D009062:Mouth Neoplasms / Q000532:radiotherapy*; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D016196:S Phase / Q000187:drug effects; D014410:Tumor Stem Cell Assay
chemical_list: D011838:Radiation-Sensitizing Agents; D003474:Curcumin