A Role for GPR55 in Multistage Mouse Skin Carcinogenesis

Abstract

Our results show that GPR55-deficient mice are significantly more resistant to DMBA/TPA-induced papilloma and carcinoma formation than their wt littermates. Different in vitro and in vivo approaches show that GPR55 confers oncogenic properties on cancer cells. Specifically, GPR55 increases (i) cancer cell proliferation (as indicated by the resistance of GPR55-deficient mice to TPA-induced epidermal hyperproliferation and by the co-localization of GPR55 with endogenous markers of proliferation), (ii) anchorage-independent growth and invasiveness in vitro, and (iii) tumorigenicity in vivo. Finally, GPR55 is upregulated both in human squamous cell carcinomas and mouse skin tumors compared to nontumoral tissue