Sulindac prevents carcinogen-induced intrahepatic cholangiocarcinoma formation in vivo.
BACKGROUND
Intrahepatic cholangiocarcinoma (ICC) incidence and mortality are increasing in the United States and worldwide. ICC etiologies involve chronic inflammation. We hypothesize that the nonsteroidal anti-inflammatory agent sulindac may prevent ICC by targeting cyclooxygenase-1 and -2 (COX-1, -2) as well as COX-independent pathways.


METHODS
ICC was induced with the carcinogen N-nitrosobis(2-oxopropyl)amine (BOP) in Syrian golden hamsters. Cholangiocarcinogenesis was accelerated by a choline-deficient diet and administration of DL-ethionine and L-methionine. Hamsters were gavaged twice daily for 10 wk with vehicle or sulindac 25, 50, or 75 mg/kg/dose. Harvested livers underwent gross and histopathological examinations. Tissues were analyzed by immunostaining, Western blot, and enzyme-linked immunosorbent assay (ELISA).


RESULTS
ICC incidence and multiplicity were decreased in sulindac treatment groups versus control (P < 0.05). In addition, ICC and nontumor lesion sizes decreased in treatment versus control animals. Proliferative indices (Ki-67 immunostaining) decreased and apoptosis (ApopTag immunostaining) increased in treatment versus control (P < 0.05). No changes in COX-1 and -2 protein levels were detected by Western blot. Furthermore, prostaglandin E(2) (PGE(2)) levels were unchanged in treatment and control serum and liver tissues (P > 0.05), suggesting that the antitumor effects of sulindac are mediated by COX-independent mechanisms. Nuclear p65 (activated NF-kappaB) immunostaining decreased (P < 0.05), and protein levels of the NF-kB inhibitor IkappaB-alpha increased in treatment versus control groups. p65 ELISA of liver extracts confirmed decreased NF-kappaB binding activity in sulindac-treated versus control animals (P < 0.05).


CONCLUSIONS
Sulindac effectively prevents experimental cholangiocarcinogenesis, in part by inhibiting the NF-kappaB pathway.
Wentz
Sabrina C
SC
Department of Surgery, Indiana University School of Medicine, Indianapolis, USA.
Yip-Schneider
Michele T
MT
Gage
Earl A
EA
Saxena
Romil
R
Badve
Sunil
S
Schmidt
C Max
CM
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001650:Bile Duct Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D001652:Bile Ducts / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000473:pathology; D002273:Carcinogens / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D018281:Cholangiocarcinoma / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D006224:Cricetinae; D051545:Cyclooxygenase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D005260:Female; D020672:I-kappa B Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D008647:Mesocricetus; D000072000:NF-KappaB Inhibitor alpha; D009602:Nitrosamines / Q000494:pharmacology; D013467:Sulindac / Q000494:pharmacology*; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000970:Antineoplastic Agents; D002273:Carcinogens; D020672:I-kappa B Proteins; D009602:Nitrosamines; D051996:Transcription Factor RelA; D000072000:NF-KappaB Inhibitor alpha; D013467:Sulindac; C013622:nitrosobis(2-oxopropyl)amine; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015232:Dinoprostone