未折叠蛋白反应调控胶质瘤细胞自噬促进肿瘤适应微环境的实验研究

To have a better understanding of the interdynamics between cancer cells and their microenvironment is of great importance for cancer therapy. Hypoxia and nutrients deprivation are major features of solid tumors including glioma. Under such stress conditions, activation of unfolded protein response (UPR) is necessary for cancer cell survival and tumor development, while the biological importance and mechanisms of UPR in glioma is still unclear. . Autophagy confers important protection against stress in vivo for tumor cells and inhibition of autophagy results in glioma cell apoptosis. It is known that UPR is tightly linked with autophagy. All the 3 arms of UPR have potential impact on autophagy. Based on the above information, we for the first time hypothesize that UPR has important role on regulating autophagy thus adapt glioma cells to the stress in vivo. In this study, we will investigate the relationship between UPR activation and glioma cell proliferation, apoptosis, invasion, and response to therapy; discover the regulatory mechanisms of UPR on autophagy of glioma; clarify the linkage of UPR, autophagy and biological behaviors of glioma; and reveal whether UPR’s positive impact on glioma cells is via the regulation on autophagy. . This study for the first time links the glioma microenvironment, UPR and autophagy, and will provide novel insights into the understanding of stress regulation mechanisms of glioma cells under tumor microenvironment.

理解肿瘤与微环境的相互作用对肿瘤治疗具有重要意义。低氧和营养物质缺乏是胶质瘤等实体肿瘤微环境的重要特征，肿瘤组织在体内应激微环境下激活未折叠蛋白反应（UPR）是保护细胞生存、促进其发展的生物行为。自噬是肿瘤细胞在体内应激环境存活的重要保护机制，抑制胶质瘤细胞自噬可促使肿瘤细胞走向凋亡。研究表明UPR 与细胞自噬关系密切，其分支信号参与调控自噬，然而胶质瘤中UPR 的生物学意义及详细作用机制不明确。本次实验针对UPR 可通过调控胶质瘤细胞自噬而促进其在体内微环境存活的假说，我们将探索UPR 激活在胶质瘤中的发生位点及与肿瘤增殖、凋亡、侵袭、治疗反应等的关系；明确UPR 对胶质瘤细胞自噬的影响及调控机制；深入研究UPR、细胞自噬与胶质瘤生物学行为之间的关系；揭示UPR调控胶质瘤是否通过自噬途径来实现。本次研究将UPR、胶质瘤微环境和自噬联系起来，对理解胶质瘤在微环境下的应激调控机制提供新思路。

本实验针对UPR 可通过调控胶质瘤细胞自噬而促进其在体内微环境存活的假说，我们将探索UPR 激活在胶质瘤中的发生位点及与肿瘤增殖的关系，明确UPR 对胶质瘤细胞自噬的影响及调控机制，揭示UPR调控胶质瘤是否通过自噬途径来实现。紫花前胡素在多发性骨髓瘤、非小细胞性肺癌、乳腺癌、黑色素瘤、前列腺癌中均具有抑制肿瘤生长的作用，可能会抑制胶质瘤细胞的UPR。.方法 观察U87、U251增殖和活性与紫花前胡素的剂量及时间的相关性，检测U87、U251迁移能力与紫花前胡素的时间相关性，观察经紫花前胡素处理后的U87、U251中的ERS/UPR相关蛋白表达情况，检测经紫花前胡素处理后的U87、U251中的自噬相关蛋白Beclin-1和LC3的表达情况。.结果 紫花前胡素抑制U87、U251增殖和活性具有浓度依赖性和时间依赖性；紫花前胡素抑制U87、U251迁移能力具有时间依赖性；紫花前胡素使U87、U251中的ERS/UPR相关蛋白表达水平降低；紫花前胡素诱导U87、U251中的自噬相关蛋白Beclin-1和LC3的表达水平降低。.结论 本次研究将UPR、胶质瘤微环境和自噬联系起来，证实中药紫花前胡素能够降低ERS/UPR及下调自噬，从而抑制胶质瘤细胞生长。