ΔNp63α/Notch轴介导莱菔硫烷干预慢性吸烟暴露诱导肺支气管上皮细胞向肺癌干细胞转化的机制研究

Cigarette smoke is the most important risk factor of lung cancer. Cancer stem cells (CSCs) play crucial role in the formation and development of cancer. To date, the action of cigarette smoke on the induction of lung CSCs, the underlying mechanisms as well as sulforaphane intervention has not been defined. In our preliminary studies we found that chronic cigarette smoke exposure induced malignant transformation of normal human bronchial epithelial (HBE) cells to lung CSCs, along with upregulation of ΔNp63α, and activation of Notch signaling pathway. We also showed that sulforaphane inhibited the sphere formation of malignant transformated HBE cells cultured in serum-free-medium, reduced the lung CSCs markers’expression, suppressed the expression of ΔNp63α and prevented the activation of Notch pathway. However, the role and regulation of ΔNp63α/Notch axis in chronic cigarette smoke-induced lung cancer stem cell and sulforaphane intervention is totally unknown. Using both in vitro and nude mouse models, the proposed research will for the first time investigate the role of ΔNp63α/Notch in cigarette smoke-induced lung CSCs and its regulatory mechanism. Furthermore, this research will illustrate the function of ΔNp63α/Notch in the interventional effects of sulforaphane on cigarette smoke-induced lung CSCs. Findings from this research will provide new insights into the molecular mechanisms of ΔNp63α/Notch in regulating cigarette smoke-induced lung CSCs as well as its target intervention.

吸烟是引起肺癌的最重要因素。肿瘤干细胞对肿瘤的发生、发展起决定性作用。目前从肺癌干细胞角度探讨吸烟对肺癌发生的影响、机制及莱菔硫烷干预作用的研究几无报道。我们前期研究发现慢性吸烟暴露能诱导人正常肺支气管上皮HBE细胞恶性转化且具有肺癌干细胞特性，此表型与上调ΔNp63α、激活Notch通路有关；莱菔硫烷可抑制慢性吸烟诱导的肺癌干细胞转化。然ΔNp63α/Notch是否真正介导慢性吸烟暴露诱导的肺癌干细胞及莱菔硫烷的干预效应尚属未知。本课题采用体外细胞模型和动物模型相结合的方法，创新性地探讨ΔNp63α/Notch通路在慢性吸烟暴露诱导肺癌干细胞中的调控作用及机制，并在此基础上研究莱菔硫烷对慢性吸烟暴露诱导肺癌干细胞的干预作用。旨在自肺癌干细胞视角探索吸烟诱发肺癌的分子机制并为通过靶向作用于肺癌干细胞关键分子而干预肺癌提供新的科学依据和研究策略。

吸烟是引起肺癌的最重要因素。肿瘤干细胞对肿瘤的发生、发展起决定性作用。我们研究发现，慢性吸烟暴露诱导人支气管上皮细胞获得肺癌干细胞特性，并上调IL-6的表达；IL-6通过上调ΔNp63α表达，转录激活Notch信号通路进而调节肺癌干细胞特性；莱菔硫烷能抑制慢性吸烟暴露诱导的肺癌干细胞特性，IL-6/ΔNp63α/Notch在其中发挥重要的调控作用。拓展研究显示，THBE肺癌干细胞中Wnt/β-catenin信号通路被激活；大蒜素抑制THBE肺癌干细胞活性，并下调Wnt/β-catenin通路活性；激活Wnt/β-catenin信号通路能逆转大蒜素对THBE肺癌干细胞活性的抑制作用。体内外实验显示，慢性吸烟暴露能诱导肝组织具有肝癌干细胞特性，并上调IL-33的表达；IL-33激活p38/AP-1活性；抑制p38/AP-1活性逆转慢性吸烟暴露诱导的肝癌干细胞特性。