Roles of oxidized LDL receptor and TLR4 signaling in lung metastasis

肿瘤转移是包括转移前阶段形成在内的多个步骤的结果。在转移前的肺中，已观察到髓系抑制细胞的聚集和S100A8和SAA3表达的上调，但详细的分子机制尚不完全清楚。本研究重点研究氧化型低密度脂蛋白受体和TLR/MD-2复合体在肺内皮细胞和肺内皮细胞中的表达及其与其潜在的内源性配体S100A8和SAA3的关系。通过使用纯化的蛋白质和过度表达系统，研究发现SAA3与MD-2结合，但不与TLR4结合。此外，某些SAA3变异体与氧化型低密度脂蛋白受体结合。

Tumor metastasis happens results of various steps including formation of pre-matastatic phase. In the pre-metastatic lungs, accumulations of myeloid derived suppressor cells and upregulations of S100A8 and SAA3 expressions have been observed, but detailed molecular mechanisms are not fully understood. This study focused on oxidized LDL receptor and TLR/MD-2 complex, both express in lung endothelial cells and epithelial cells in relation with their potential endogenous ligands, S100A8 and SAA3. By using purified proteins and overexpression sytems, the research identified that SAA3 binds MD-2 but not TLR4. In addition certain SAA3 variant binds oxidized LDL receptor.