Curcumin: a new radio-sensitizer of squamous cell carcinoma cells.
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.
Khafif
Avi
A
Department of Otolaryngology, Tel-Aviv Sourasky Medical Center, Israel. avironit@Bezeqint.net
Hurst
Robert
R
Kyker
Kimberly
K
Fliss
Dan M
DM
Gil
Ziv
Z
Medina
Jesus E
JE
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
D011838:Radiation-Sensitizing Agents; D003474:Curcumin