The Expression And Significance Of Cannabinoid Receptor 2 In Malignant Cutaneous Tumors

BackgroundMarijuana as a medicine was used in thousands years, and cannabinoids, active components of marijuana and their derivatives, are anti-inflammatory and have inhibitory effects on the proliferation of a number of tumorigenic cell lines, some of which are mediated via cannabinoid receptors. Two different cannabinoid receptors have been found: the cannabinoid receptor 1(CB1), mostly expressed in central nervous system, and the cannabinoid receptor 2 (CB2), mostly expressed in the immune system. Activation of CB2 decreases growth, proliferation, angiogenesis and metastasis, and increased apoptosis, of cutaneous tumors. Currently, there is an intense renaissance in the study of the effects of cannabinoid receptor 2 focused on the genesis, development and metastasis of cutaneous tumors.ObjectiveTo investigate the expression and its significance of CB2 in human normal skin and malignant cutaneous tumors, analyze its relation with genesis and development of malignant cutaneous tumors.MethodsWe detected the expression of CB2 in protein level and mRNA level in human normal skin, malignant melanoma, basal cell carcinoma and squamous cell carcinoma using the method of immunohistochemical staining, in situ hybridization and RT-PCR.ResultsHuman normal skin, malignant melanoma, basal cell carcinoma and squamous cell carcinoma all expressed CB2. It was chiefly expressed in basal cell layer and prickle cell layer in human skin, and subcutaneous tissue expressed little. The distinction of malignant cutaneous tumors and human normal skin tissues showed statistical significances (P<0.05), moreover, malignant melanoma compared with normal skin, basal cell carcinoma and squamous cell carcinoma over-expression showed statistical significances (P<0.05), but basal cell carcinoma and squamous cell carcinoma showed no statistical significances (P>0.05).ConclusionCB2 were all expressed in normal skin, malignant melanoma, basal cell carcinoma and squamous cell carcinoma. Malignant cutaneous tumors over-expressed CB2 in protein level and mRNA level. The intension of expression in normal skin was significantly lower than malignant cutaneous tumors, and melanoma was the highest, but basal cell carcinoma and squamous cell carcinoma had no significant difference. High expression of CB2 in malignant cutaneous tumors suggests that it probably play an important role in the origin and development of skin tumors.