IL-8：miRNA调控轴在肺癌骨转移中的功能机制研究

Lung cancer is one of the malignancies that cause high morbidity and mortality, about 30%-40% lung cancer patients develop with bone metastasis. Bone metastasis is the main reason of reducing the quality of life and increasing cancer-related-death in lung cancer patients. However, the molecular mechanisms underlying lung cancer bone metastasis remain largely unclear. Our preliminary results showed that the proinflammatory cytokine IL-8 is dramatically elevated in the serum of patients with lung cancer bone metastasis, and that miR-93 and miR-182 were markedly up-regulated in bone metastatic lung cancer cells A549-BM newly generated in the laboratory. Intriguingly, we found that IL-8 treatment potently enhanced the levels of miR-93 and miR-182 in A549 cells. More importantly, our functional studies showed that miR-93 and miR-182 significantly promoted the bone localization of A549-BM cells in nude mice. In this research plan, we will further study the function and mechanisms of IL-8, miR-93 and miR-182 in bone metastasis of lung cancer from the aspects of molecular biology, cell biology and animal experiments. We propose three aims for this project: first, we will dissect the IL-8 signaling pathways that modulate the expression of miR-93 and miR-182 by the approaches of computational prediction, RNAi, overexpression, and reporter assays; second, we will identify the functional targets of miR-93 and miR-182 in regulating bone metastasis of lung cancer cells by site-directed mutagenesis, immunoblotting, and reporter analyses; third, we will study the function and mechanism of miR-93 and miR-182 as well as its upstream and downstream components in lung cancer bone metastasis. Data generated from these studies will advance our understanding of the molecular connections between the inflammation-miRNA regulatory axis and lung cancer bone metastasis, and provide useful information for the strategies of effective lung cancer bone metastasis prevention, diagnosis and therapy.

骨转移是肺癌的主要并发症之一，占肺癌患者的30%-40%，是影响肺癌患者生活质量和致死率的重要原因，但目前对肺癌骨转移发生机理的了解还极其有限。我们的前期研究发现，促炎性细胞因子IL-8在肺癌骨转移患者血清中显著升高，miR-93和miR-182在我们筛选到的骨转移型肺癌细胞中表达上调，而IL-8处理肺癌细胞可激活miR-93和miR-182表达；功能实验表明，在裸鼠模型中miR-93和miR-182均促进肺癌细胞骨组织定位。在本申请项目中，我们将在前期研究基础上，深入研究IL-8、miR-93和miR-182在肺癌骨转移中的功能，调查IL-8调控miR-93和miR-182的分子机制，鉴定miR-93和miR-182调控肺癌骨转移的功能靶基因，揭示炎症-miRNA通路在肺癌骨转移中的调控功能与分子机制。项目研究获得结果将促进对肺癌骨转移发生机理的认识，并为肺癌骨转移预防和诊治提供新靶点。

骨转移是肺癌的主要并发症之一，占肺癌患者的30%-40%，是影响肺癌患者生活质量和致死率的重要原因，但目前对肺癌骨转移发生机理的了解还极其有限。我们的前期研究发现，促炎性细胞因子IL-8在肺癌骨转移患者血清中显著升高，通过本项目的研究，我们发现，IL-8通过stat3通路正向调控miR-182，并且KLHL21是miR-182的靶基因，miR-182通过负向调控KLHL21调控NF-B信号通路进而上调IL-8的表达和分泌。IL-8促进骨微环境中破骨细胞分化进而影响骨稳态。进一步，我们发现IL-8中和抗体可以显著降低肺癌细胞在骨微环境中的增殖，为肺癌骨转移的预防和诊断治疗提供了新分子靶点。