FBXL19介导μ-阿片受体泛素化抑制非小细胞肺癌转移的研究

μ-opioid receptor is responsible for mediating the clinically beneficial effect of opioids, including analgesia such as morphine and fentanyl. However, it is reported on the role of promoting angiogenesis, growth, and metastatic spread in human non-small cell lung cancer. Recently, we have shown that FBXL19, substrate of Skp1-Cullin-1-F-box (SCF) E3 ubiquitin ligases, targets ST2L、Rac1、RhoA、Rac3 for ubiquitination and degradation to regulate IL-33-induced pulmonary inflammation、cell mobility、cell proliferation and rearrangement of cytoskeleton、esophageal cancer metastasis. And at the same time, we reveal that FBXL19 can mediate μ-opioid receptor ubiquitination and degradation. Here, we study the molecular mechanism of opioids-induced human non-small cell lung cancer metastasis with immunological and molecular biology methods by vivo and vitro to confirm that MOR plays an important role during the non-small cell lung cancer growth and metastasis. The F-box protein complex FBXL19 can suppress cancer metastasis through mediatingμ-opioid receptor ubiquitination and degradation. It is important to illuminate the molecular mechanism of opioids-induced cancer metastasis and provide trail for clinic treatment.

μ-阿片受体是芬太尼、吗啡等阿片类麻醉镇痛药的主要靶受体，负责介导阿片类药物临床镇痛作用同时，可促进非小细胞肺癌新生血管生成、肿瘤细胞生长转移。本课题前期研究发现，FBXL19作为泛素化连接酶重要亚单位之一，不仅可以介导ST2L、Rac1、RhoA、Rac3泛素化和降解，进而调控肺部炎症、细胞运动性及食道癌转移，还可介导μ-阿片受体泛素化和降解。前期结果提示FBXL19可能通过介导μ-阿片受体泛素化和降解进而抑制非小细胞肺癌转移。本课题拟在前期工作基础上，采用分子生物学技术通过体内、外实验开展FBXL19介导μ-阿片受体泛素化抑制非小细胞肺癌转移的研究，揭示FBXL19介导μ-阿片受体泛素化的机制及FBXL19抑制非小细胞肺癌转移的信号通路。所得的结果不仅可揭示FBXL19调控非小细胞肺癌转移的机制，还可为μ-阿片受体介导非小细胞肺癌转移防治手段的研制提供新的理论基础。

阿片类药物被广泛应用于临床用来缓解急、慢性疼痛，而阿片类药物是通过激活μ-阿片受体1（MOR1）进而达到其生物学效应。大多数研究关注于激动剂诱导的MOR1磷酸化、泛素化和内化，而激动剂介导的MOR1降解对阿片受体的稳定性是至关重要的，但却研究甚少。HECT家族的E3泛素连接酶Smurf2被认为可以调节MOR1的泛素化和内化效应，然而其对MOR1降解的作用研究较少。本项研究中，我们发现Smurf2可以调节DAMGO 诱导的MOR1泛素化和降解；DAMGO在泛素蛋白酶体系统中降低MOR1的表达量；MOR1在多泛素化链赖氨酸48被修饰；过表达Smurf2可以介导MOR1泛素化和加速DAMGO诱发的MOR1降解效应；下调Smurf2降低MOR1的降解。而且，本研究表明DAMGO可以增加肺泡上皮细胞的迁移和增殖，并且过表达Smurf2可削弱细胞的迁移和增殖。总之，本项研究揭示了Smurf2可通过降低MOR1稳定性进而负向调节MOR1的活性，同时研究提示了MOR1 在肺泡上皮细胞中尚未被发现的生物学作用。DAMGO/MOR1促性肺泡上皮细胞增殖和迁移的基础研究为临床肺损伤后的肺修复和重建提供新的治疗策略。