Curcumin: a potential radio-enhancer in head and neck cancer.
OBJECTIVE
To investigate whether curcumin enhances the cytotoxic effect of radiotherapy in head and neck squamous cell carcinoma (HNSCC).


METHODS
HNSCC cell lines SCC-1, SCC-9, KB, as well as A431 cell line were treated with curcumin, irradiation, or their combination. Cell viability was evaluated by XTT assay. Cyclooxygenase-2 (COX-2), epithelial growth factor receptor (EGFR), and p-Erk1/2 were measured by Western blot analysis. CD-1 athymic nude mice with orthotopic implanted SCC-1 cells, were treated with control diet, curcumin containing diet, local single-dose radiation, or combination.


RESULTS
Curcumin (IC50 range, 15-22 microM) and radiation inhibited cell viability in all cell lines were tested. The combination of curcumin and radiation resulted in additive effect. Curcumin decreased COX-2 expression and inhibited phosphorylation of EGFR in SCC-1 cells. In tumor-bearing mice the combination regimen showed a decrease in both tumor weight (25%, P = .09) and tumor size (15%, P = .23) compared to the nontreated mice.


CONCLUSIONS
: Curcumin inhibited HNSCC cell growth and augmented the effect of radiation in vitro and in vivo. A possible mechanism is inhibition of COX-2 expression and EGFR phosphorylation.
Khafif
Avi
A
Department of Otolaryngology, Tel Aviv Sourasky Medical Center and Tel Aviv University School of Medicine, 6 Weizmann Street, Tel Aviv, Israel.
Lev-Ari
Shahar
S
Vexler
Akiva
A
Barnea
Itai
I
Starr
Alex
A
Karaush
Vicki
V
Haif
Sasha
S
Ben-Yosef
Rami
R
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003474:Curcumin / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D066246:ErbB Receptors / Q000378:metabolism; D005434:Flow Cytometry; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D051379:Mice; D008819:Mice, Nude; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects
D000894:Anti-Inflammatory Agents, Non-Steroidal; D051546:Cyclooxygenase 2; D066246:ErbB Receptors; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D003474:Curcumin