靶向共调控血管和淋巴管新生相关microRNAs对实验性原发肺癌发生与发展的影响及机制研究

The formations of new blood vessels and lymphatic vessels are crucial for tumour cells to remove metabolic waste and provide oxygen and nutrients, a critical process that allows tumour cells to enter a state of uncontrolled proliferation, invision and metastasis.Recently, What should be paid more attention is the new advancement in the functional research of vascular endothelial growth factor family. Our previus studies had shown for the first time that tumour cell proliferation, invasion and lymphatic metastasis involve VEGF-C-mediated autocrine stimulation mechanisms on the regulation of the expression of other factors of VEGF family and their receptors, and that VEGF-C may act in multiple ways to promote tumour progression. Simutanously, our studies showed for the first time that microRNA-128 showed significantly lower expression in human non-small cell lung cancer than nomal human fetal lung fibroblast cell line, and suggested that microRNA-128 could decrese expression of VEGF-C through direct 3′UTR interactions. Those results have not been reported worldwide. Simultaneously, some reports showed that the expression of VEGF-A was regulated by miR-126. Those results suggest that the angiogenesis and lymphangiogenesis mediated by VEGF family were regulated by the key factor-microRNAs. This study was desigend on the basis of our previous works. We would like to adopt many experimental technologies, such as immunological technique, pathology tecnique, molecular biology and transgenic mice, to investigate the role and mechanism of regulation the expression of microRNA-128/microRNA-126 on the occuring and developing of experimental lung cancer.The study will not only put forward a new concept and new mechanism on the occuring and developing of NSCLC,but also provide new scientific foundation and new approach for cancer therapeutics which take microRNA-128 as the potential therapeutic targets designed to target pathological angiogenic and lymphangiogenic signalings.

血管、淋巴管新生是肿瘤细胞获得氧和养分的关键步骤，亦是肿瘤增殖、复发和转移的始作俑者。值得关注的是，近年VEGF家族介导的肿瘤血管和淋巴管新生研究取得了新进展。2011年我们首次报道VEGF-C 除参与淋巴管、血管生成外，还影响VEGF 家族其他因子及受体的表达，是肿瘤增殖、侵袭和转移的关键因子；亦首次证实miR-128调控VEGF-C介导的肿瘤血管和淋巴管新生，国内外未见相关报道。同时亦有报道证实miR-126调控VEGF-A介导的肿瘤血管新生，提示VEGF家族因子介导的肿瘤血管和淋巴管新生服从于关键因素microRNAs的调控。本课题以前期工作为基础，以转基因小鼠诱发的原发性肺癌为研究对象，采用慢病毒载体介导的基因转染技术，调控肿瘤血管和淋巴管新生相关microRNAs表达，探讨对肺癌的作用及机制。新机制和新概念的提出，将丰富肿瘤血管和淋巴管新生的理论，也将为肺癌靶向治疗提供科学依据。

研究的重要发现：.1.本研究首次证实miR-128在非小细胞肺癌组织表达下调，而且miR-128的表达水平与非小细胞肺癌患者的肿瘤分化、病理分期和淋巴结转移密切相关。此外，miR-128在非小细胞肺癌细胞株的表达亦显著降低。提示miR-128可能是评估非小细胞肺癌患者肿瘤分级和分期的有用标志物。.2.研究结果明确证实miR-128可显著抑制非小细胞肺癌细胞的体外增殖、克隆形成、迁移和侵袭能力，并且阻滞细胞周期于G1期和促发细胞凋亡的发生。而且，本研究的体外实验结果亦证实miR-128过表达可抑制非小细胞肺癌裸鼠移植瘤模型的肿瘤增长。提示，miR-128可以作为非小细胞肺癌发生发展的抑制因子。miR-128不仅仅可以作为非小细胞肺癌诊断的关键标记物，而且可以作为非小细胞肺癌治疗的理想靶点。.3.miR-128的过表达在癌细胞和血管内皮细胞导致血管和淋巴管生成相关的VEGF-A、VEGFR-2和VEGFR-3因子的表达下调，及下游信号通路因子ERK、AKT和p38的磷酸化水平下调。体内恢复miR-128的表达水平可显著抑制A549细胞的裸鼠移植瘤模型的肿瘤发生和发展及血管和淋巴管生成。证实miR-128可能是非小细胞肺癌潜在的肿瘤发生发展的抑制基因，可以直接靶向调控肿瘤血管和淋巴管生成相关的VEGF-C基因的表达。.4.本研究显示，通过靶向调控VEGF-C基因的表达，miR-128可同时抑制VEGF-C和VEGF-A基因的表达，而且同时阻断了ERK、AKT和p38信号通路的活性，这提示miR-128在非小细胞肺癌的血管和淋巴管生成方面起着关键作用。.总之，本研究提示，在癌细胞和血管内皮细胞恢复miR-128的表达水平可以同时抑制多个与肿瘤发生发展、血管淋巴管生成相关的因子和信号通路。因此，本研究提示针对miR-128/VEGF-C相互作用的靶向治疗可能是非小细胞肺癌的新治疗策略之一。.取得的成果：.1.发表SCI收录论文3篇，最高影响因子为5.617（European Journal of Cancer），3篇SCI收录论文累计影响因子为9.568，其中2篇论文分别发表于European Journal of Cancer（IF5.617）和Oncology Reports（IF2.191），均标注国家自然科学基金资助。.2.发表国内核心期刊论文3篇，均标国自然资助。