Loss of cannabinoid receptor 1 accelerates intestinal tumor growth.
Although endocannabinoid signaling is important for certain aspects of gastrointestinal homeostasis, the role of the cannabinoid receptors (CB) in colorectal cancer has not been defined. Here we show that CB1 expression was silenced in human colorectal cancer due to methylation of the CB1 promoter. Our genetic and pharmacologic studies reveal that loss or inhibition of CB1 accelerated intestinal adenoma growth in Apc(Min/+) mice whereas activation of CB1 attenuated intestinal tumor growth by inducing cell death via down-regulation of the antiapoptotic factor survivin. This down-regulation of survivin by CB1 is mediated by a cyclic AMP-dependent protein kinase A signaling pathway. These results indicate that the endogenous cannabinoid system may represent a potential therapeutic target for prevention or treatment of colorectal cancer.
Wang
Dingzhi
D
Departments of Medicine, Vanderbilt University Medical Center, Nashville, Tenessee, USA.
Wang
Haibin
H
Ning
Wei
W
Backlund
Michael G
MG
Dey
Sudhansu K
SK
DuBois
Raymond N
RN
D000818:Animals; D001483:Base Sequence; D019175:DNA Methylation; D017931:DNA Primers; D015536:Down-Regulation; D016147:Genes, Tumor Suppressor; D051034:Inhibitor of Apoptosis Proteins; D007414:Intestinal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D043884:Receptor, Cannabinoid, CB1 / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins; D015398:Signal Transduction; D000077022:Survivin
C117749:Birc5 protein, mouse; D017931:DNA Primers; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D043884:Receptor, Cannabinoid, CB1; D012097:Repressor Proteins; D000077022:Survivin