Anti-Mu Opioid Receptor monoclonal antibody

The mu-opioid receptor gene, OPRM1, undergoes extensive alternative splicing, creating an array of splice variants that are conserved from rodent to human. Both mouse and human OPRM1 have five exon 5-associated seven transmembrane full-length carboxyl terminal variants, MOR-1B1, MOR-1B2, MOR-1B3, MOR-1B4, and MOR-1B5, all of which are derived from alternative 3 ' splicing from exon 3 to alternative sites within exon 5. The functional relevance of these exon 5-associated MOR-1Bs has been demonstrated in mu agonist-induced G protein coupling, adenylyl cyclase activity, receptor internalization and desensitization, and post-endocytic sorting, as well as region-specific expression at the mRNA level. In the present study, we mapped a polyadenylation site for both mouse and human MOR-1Bs that defines the 3 '-untranslated regions (3 '-UTR) of MOR-1Bs and stabilizes mMOR-1Bs mRNAs. We identified a conserved miR378a-3p sequence in the 3 '-UTR of both mouse and human MOR-1B(S) transcripts through which miR-378a-3p can regulate the expression of MOR-1Bs at the mRNA level. Chronic morphine treatment significantly increased the miR-378-3p level in Be(2)C cells and the brainstem of the morphine tolerant mice, contributing to the decreased expression of the mouse and human MOR-1B3 and MOR-1B4. Our study provides new insights into the role of miRNAs and Oprm1 splice variants in morphine tolerance.

Distribution of A118G single nucleotide polymorphism (SNP) in the mu-opioid receptor 1 gene (OPRM1) differs with ethnicity. We assessed the distribution of this SNP in Korean women with breast cancer and compared it with that in women of other ethnicities with breast cancer. Distribution of SNP genotypes was as follows: 49.8% for AG genotype, 40.6% for AA genotype, and 9.6% for GG genotype. Logistic regression analysis showed a negative association between the presence of the G allele at position 118 of OPRM1 and breast cancer in the studied population (odds ratios [OR], 0.635; p=0.002). However, the AG and GG genotypes were not associated with breast cancer in the studied population (OR, 0.719; p=0.130). The proportions of the AG and GG genotypes of the OPRM1 SNP were higher in Korean women with breast cancer than in those of other ethnicities.