IL-6/JAK/STAT3通路调控脂肪酸β-氧化促进溃疡性结肠炎相关结肠癌肿瘤生成中的机制研究

IBD associated colorectal cancer (CAC) is characterized as chronic intestinal inflammatory to tumor, while the molecular pathogenesis remains unclear, and the diagnosis and treatment challenge clinical physicians. IL-6/JAK/STAT3 signaling pathway play a vital role in this procedure, but the detailed mechanism is not fully understood. Recent studies demonstrated this pathway regulates energy metabolism, including fatty acids regulation. Previous bioinformatics results revealed CPT1A/B，which lay in FAO are increased in CRC and correlated with worse prognosis. Meanwhile, STAT3 knockdown in intestinal epithelial cells (IEC) results in decreased CTP1B expression and increased apoptosis markers，while overexpressed STAT3 reverses these results. .This subject aims to explore:1) expression of key molecules in IL-6/JAK/STAT3 and FAO pathway in intestinal mucosal of UC patients; 2) knocking out by CRISPR-cas9, overexpression of IL-6R、STAT3 and treatment of JAK inhibitor in IECs, then detecting profiles in FAO, CPT1A/B transcriptional and translational, NADPH, and apoptosis and proliferation level to figure out the detailed mechanism of IL-6/JAK/STAT3 pathway regulates FAO to determine cell fate. 3) by using STAT3 gene knockout mice, JAK inhibitor treatment and control CAC models, to further explore the mechanism of IL-6/JAK/STAT3 pathway regulates FAO in CAC tumorigenesis in vivo, and provides theoretical evidence of JAK inhibitor in application of IBD and CAC.

IBD相关结肠癌是慢性炎症进展至肿瘤的一种疾病，分子机制尚不明确，诊疗困难。IL-6/JAK/STAT3 通路在IBD结肠癌肿瘤生成中发挥重要作用，机制尚不完全明确。研究证实此通路可调控能量代谢，包括脂肪酸代谢。.生物信息学及预实验得知：1）脂肪酸氧化（FAO）中CPT1A/B在结肠癌升高，与不良预后相关；2）肠上皮细胞系中，STAT3干扰后CPT1B表达降低，凋亡增加。.本项目拟首先探讨UC患者肠粘膜、低/高级别上皮瘤变组织中IL-6/JAK/STAT3 通路分子及CPT1A/B表达水平。其次将在细胞层面通过CRISPR-cas9敲除、过表达IL-6R、STAT3，及JAK抑制剂处理后检测FAO代谢变化、CPT1A/B调控机制及凋亡、增殖变化。再次，通过基因敲除鼠、JAK抑制剂处理小鼠及对照小鼠CAC模型，研究体内水平IL-6/JAK/STAT3 对FAO调控在CAC中的作用。

项目背景：.IBD相关结肠癌是慢性炎症进展至肿瘤的一种疾病，分子机制尚不明确。IL-6/JAK/STAT3 通路在IBD结肠癌肿瘤生成中发挥重要作用。研究证实此通路可调控能量代谢，包括脂肪酸代谢。前期结果证实：1、脂肪酸氧化（FAO）中CPT1A/B在结肠癌升高，与不良预后相关；2、肠上皮细胞系中，STAT3干扰后CPT1B表达降低，凋亡增加。因此本项目探讨IL-6/JAK/STAT3 通路调控脂肪酸代谢对UC相关结肠癌的发生机制的影响。.主要研究内容：.1、 UC及癌变患者组织中 IL-6、JAK3、STAT3、CPT1A/B 等水平变化 ；.2、IL-6/JAK/STAT3 通路调控肠粘膜上皮细胞及结肠癌肿瘤细胞中 FAO对细胞凋亡、增殖及氧化应激的影响。.3、小鼠模型体内实验检测 IL-6/JAK/STAT3 通路调控 FAO 通路在 CAC 中的作用。 .重要结果：.1、患者肠粘膜组织中，从正常对照、高级别瘤变的结肠组织中，CPT1B水平均呈上升水平；.2、在结肠癌细胞系中对STAT3 敲低后或加入JAK抑制剂，尤其是JAK3的抑制剂可造成CPT1A/B水平降低；.3、对ROS 进行检测可得知，在H2O2处理后，过表达CPT1B均可以降低ROS 造成的凋亡。.关键数据及科学意义：.1、CPT1B在UC进展至结肠癌中表达水平发生变化，细胞实验证实STAT3对CT1B具有调控作用，而JAK抑制剂可对CT1B造成抑制作用；.2、JAK-STAT3调控UC相关结肠癌的脂肪酸代谢对肿瘤的影响的机制很可能是通过ROS 的变化造成的。