Research Group of Natural Materials and Metabolism, Korea Food Research Institute, Wanju 55365, Korea.
Department of Food Science and Engineering, Ewha Womans University, Seoul 03760, Korea.
Sensors (Basel). 2021 May 16;21(10):3468. doi: 10.3390/s21103468.
Olfactory receptors (ORs) account for 49% of all G protein-coupled receptors (GPCRs), which are important targets for drug discovery, and hence ORs may also be potential drug targets. Various ORs are expressed in breast cancer cells; however, most of them are orphan receptors, and thus, their functions are unknown. Herein, we present an experimental strategy using a surface plasmon resonance (SPR) system and a cell-based assay that allowed the identification of orphan OR6M1 as a new anticancer target in the MCF-7 breast cancer cell line. After the construction of stable OR6M1-expressing cells, the SPR-based screening of 108 chemicals for ligand activity was performed against OR6M1-expressing whole cells (primary screening) or membrane fragments (secondary screening). As a result, anthraquinone (AQ) and rutin were discovered to be new OR6M1 ligands. Based on calcium imaging in OR6M1-expressing Hana3A cells, AQ and rutin were classified as an OR6M1 agonist and antagonist, respectively. Cell viability and live/dead assays showed that AQ induced the death of MCF-7 cells, which was inhibited by rutin. Therefore, OR6M1 may be considered an anticancer target, and AQ may be considered a chemotherapeutic agent. This combined method can be widely used to discover the ligands and functions of other orphan GPCRs.
嗅觉受体（ORs）占所有 G 蛋白偶联受体（GPCRs）的 49%，是药物发现的重要靶点，因此 ORs 也可能成为潜在的药物靶点。各种 ORs 在乳腺癌细胞中表达；然而，它们中的大多数是孤儿受体，因此它们的功能尚不清楚。在此，我们提出了一种使用表面等离子体共振（SPR）系统和基于细胞的测定的实验策略，该策略允许鉴定孤儿 OR6M1 作为 MCF-7 乳腺癌细胞系中的新抗癌靶标。在构建稳定表达 OR6M1 的细胞后，针对表达 OR6M1 的整个细胞（初步筛选）或膜片段（二次筛选）进行了针对 108 种化学物质配体活性的基于 SPR 的筛选。结果发现蒽醌（AQ）和芦丁是新的 OR6M1 配体。基于在表达 OR6M1 的 Hana3A 细胞中的钙成像，AQ 和芦丁分别被归类为 OR6M1 激动剂和拮抗剂。细胞活力和死活检测表明，AQ 诱导 MCF-7 细胞死亡，而芦丁可抑制该作用。因此，OR6M1 可被视为抗癌靶标，AQ 可被视为化疗药物。这种组合方法可广泛用于发现其他孤儿 GPCR 的配体和功能。
