Cannabinoid CB₁ receptor is downregulated in clear cell renal cell carcinoma.
Several studies in cell cultures and in animal models have demonstrated that cannabinoids have important antitumoral properties. Because many of these effects are mediated through cannabinoid (CB) receptors CB₁ and CB₂, the study of their expression in human neoplasms has become of great interest in recent years. Fresh and formalin-fixed tissue samples of 20 consecutive clear cell renal cell carcinomas (CCRCCs) were collected prospectively and analyzed for the expression of both CB receptors by using RT-PCR, Western blot (WB), and immunohistochemical techniques. RT-PCR assays demonstrated the expression of mRNA encoding the CB₁ in tumor tissue and in adjacent non-neoplastic kidney. Conversely, WB and IHC revealed a marked downregulation of CB₁ protein in tumor tissue; CB₂ was not expressed. The obtained data suggest a possible implication of the endocannabinoid system in renal carcinogenesis. A posttranscriptional downregulation of CB₁ and the absence of expression of CB₂ characterize CCRCC.
Larrinaga
Gorka
G
Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Leioa, Bizkaia, Spain.
Sanz
Begoña
B
Pérez
Itxaro
I
Blanco
Lorena
L
Cándenas
María L
ML
Pinto
Francisco M
FM
Gil
Javier
J
López
José I
JI
D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation / Q000235:genetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D043884:Receptor, Cannabinoid, CB1 / Q000235:genetics* / Q000378:metabolism*; D043885:Receptor, Cannabinoid, CB2 / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2