Altered cytokeratin expression during chemoprevention of experimental hamster buccal pouch carcinogenesis by garlic.
BACKGROUND
Cytokeratins (also known as keratins (K)) are members of the family of intermediate filaments and form major components of the mammalian epithelial cell cytoskeleton. Cytokeratins have emerged as reliable cellular markers of oral cancer development and chemoprevention because of their abundance, stability and high antigenicity.


METHODS
We investigated the effect of aqueous garlic extract on cytokeratin expression during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Hamsters were divided into four groups of six animals. Animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin, on the right buccal pouches, three times a week for 14 weeks. Group 2 animals were painted with DMBA as in group 1 and also received 250 mg/kg body weight aqueous garlic extract orally on alternate days to the DMBA application. Group 3 animals received garlic extract only, as in group 2. Group 4 animals received neither DMBA nor garlic extract and served as the control. The hamsters were killed after an experimental period of 14 weeks.


RESULTS
Cytokeratin expression was studied using human monoclonal antibodies AE1 and AE3, which react with type I and II keratins. In DMBA-induced squamous cell carcinomas, decreased expression of high molecular weight keratins was observed. Administration of garlic extract to animals painted with DMBA suppressed HBP carcinomas and restored normal cytokeratin expression.


CONCLUSIONS
The results of the present study suggest that inhibition of HBP carcinogenesis by garlic may be due to its regulatory effects on differentiation, tumour invasiveness, migratory and metastatic potential. We suggest that one of the mechanisms of tumour inhibition by garlic is an influence on cellular differentiation.
Balasenthil
S
S
Department of Biochemistry, Faculty of Science, Annamalai University, Annamalainagar-608,002, Tamil Nadu, India.
Rao
K S
KS
Nagini
S
S
D000818:Animals; D000911:Antibodies, Monoclonal; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage*; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000378:metabolism* / Q000517:prevention & control*; D002454:Cell Differentiation / Q000187:drug effects; D002610:Cheek; D018890:Chemoprevention; D006224:Cricetinae; D004220:Disulfides; D004591:Electrophoresis, Polyacrylamide Gel; D005737:Garlic; D006801:Humans; D007633:Keratins / Q000096:biosynthesis*; D008297:Male; D008647:Mesocricetus; D009062:Mouth Neoplasms / Q000139:chemically induced / Q000378:metabolism* / Q000517:prevention & control*; D008517:Phytotherapy; D011897:Random Allocation; D013441:Sulfinic Acids / Q000008:administration & dosage*
D000911:Antibodies, Monoclonal; D000972:Antineoplastic Agents, Phytogenic; D004220:Disulfides; D013441:Sulfinic Acids; C006452:allicin; D007633:Keratins