Inhibition of 11beta-hydroxysteroid dehydrogenase type II selectively blocks the tumor COX-2 pathway and suppresses colon carcinogenesis in mice and humans.
Colorectal cancer (CRC) is a leading cause of cancer death, yet primary prevention remains the best approach to reducing overall morbidity and mortality. Studies have shown that COX-2-derived PGE2 promotes CRC progression, and both nonselective COX inhibitors (NSAIDs) and selective COX-2 inhibitors (such as glucocorticoids) reduce the number and size of colonic adenomas. However, increased gastrointestinal side effects of NSAIDs and increased cardiovascular risks of selective COX-2 inhibitors limit their use in chemoprevention of CRC. We found that expression of 11beta-hydroxysteroid dehydrogenase type II (11betaHSD2), which converts active glucocorticoids to inactive keto-forms, increased in human colonic and Apc+/min mouse intestinal adenomas and correlated with increased COX-2 expression and activity. Furthermore, pharmacologic inhibition or gene silencing of 11betaHSD2 inhibited COX-2-mediated PGE2 production in tumors and prevented adenoma formation, tumor growth, and metastasis in mice. Inhibition of 11betaHSD2 did not reduce systemic prostacyclin production or accelerate atherosclerosis in mice, thereby avoiding the major cardiovascular side effects seen with systemic COX-2 inhibitors. Therefore, 11betaHSD2 inhibition represents what we believe to be a novel approach for CRC chemoprevention and therapy by increasing tumor glucocorticoid activity, which in turn selectively blocks local COX-2 activity.
Zhang
Ming-Zhi
MZ
Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA. ming-zhi.zhang@vanderbilt.edu
Xu
Jie
J
Yao
Bing
B
Yin
Huiyong
H
Cai
Qiuyin
Q
Shrubsole
Martha J
MJ
Chen
Xiwu
X
Kon
Valentina
V
Zheng
Wei
W
Pozzi
Ambra
A
Harris
Raymond C
RC
D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2 / Q000037:antagonists & inhibitors* / Q000235:genetics; D000230:Adenocarcinoma / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control / Q000556:secondary; D000236:Adenoma / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control; D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology / Q000517:prevention & control*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D052246:Cyclooxygenase 2 Inhibitors / Q000009:adverse effects / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020868:Gene Silencing; D017491:Genes, APC; D019695:Glycyrrhizic Acid / Q000494:pharmacology; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains; D008954:Models, Biological; D009389:Neovascularization, Pathologic / Q000517:prevention & control; D034741:RNA, Small Interfering / Q000235:genetics; D011965:Receptors, Glucocorticoid / Q000187:drug effects / Q000378:metabolism
D052246:Cyclooxygenase 2 Inhibitors; D004791:Enzyme Inhibitors; D034741:RNA, Small Interfering; D011965:Receptors, Glucocorticoid; D019695:Glycyrrhizic Acid; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human