Inhibitory effects of dietary glucosylceramides on squamous cell carcinoma of the head and neck in NOD/SCID mice.
BACKGROUND
Sphingolipids, components of cellular membranes in eukaryotic cells, have roles in the regulation of tumor growth, inflammation, angiogenesis, and immunity. We investigated the effects of dietary glucosylceramides, sphingolipids isolated from rice bran, on tumor growth of human head and neck squamous cell carcinoma.


METHODS
The tumor cell line SCCKN cells isolated from well-differentiated human head and neck cancer were subcutaneously inoculated into the right flank of NOD/SCID mice, to establish an SCCKN xenograft model. Rice bran glucosylceramides (300 mg/kg/day) were administered orally to the mice for 14 consecutive days.


RESULTS
Dietary glucosylceramides significantly inhibited the growth of the xenograft tumor in comparison with the control group. The TUNEL stain revealed that treatment of mice with glucosylceramides increased the number of apoptotic cells in the implanted tumor tissues and that apoptosis induction was accompanied by the formation of active/cleaved caspase-3.


CONCLUSIONS
These results suggest that dietary glucosylceramides possibly exert anti-tumor activity by inducing apoptosis of head and neck squamous cell carcinoma. Therefore, their potential usefulness in treatment and prevention of human head and neck squamous cell carcinoma warrants further investigation.
Division of Otolaryngology, Head and Neck Surgery, Faculty of Medicine, Tottori University, Nishi-Machi 86, Yonago 683-8503, Japan. kfujiwa@grape.med.tottori-u.ac.jp
Kazunori
K
Fujiwara
Kazuyuki
K
Kitatani
Kei
K
Fukushima
Hiroaki
H
Yazama
Hisanori
H
Umehara
Mitsunori
M
Kikuchi
Yasuyuki
Y
Igarashi
Hiroya
H
Kitano
Toshiro
T
Okazaki
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002277:Carcinoma / Q000188:drug therapy / Q000378:metabolism; D002294:Carcinoma, Squamous Cell; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D005260:Female; D005963:Glucosylceramides / Q000494:pharmacology*; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D018307:Neoplasms, Squamous Cell / Q000188:drug therapy / Q000378:metabolism; D000077195:Squamous Cell Carcinoma of Head and Neck; D023041:Xenograft Model Antitumor Assays / Q000379:methods
D005963:Glucosylceramides; D053148:Caspase 3