基于单细胞转录组学及表观遗传组学分析的肺癌进化分子机制研究

The evolution of lung cancer underwent multistage of gene mutation, abnormal molecular expression, atypical adenomatous hyperplasia, adenocarcinoma in situ, minimally invasive adenocarcinoma and invasive adenocarcinoma. It has been found that some important signaling pathways play an important role in the progression of lung adenoma to lung adenocarcinoma, while there was still lack of comprehensive study on the evolution of lung cancer. Based on the recent research progress and the results of our previous studies, we propose the hypotheses that some key molecular targets and signaling pathways activated when lung cancer evolving from benign to malignant, so find the key epigenetic targets will be significant to the precise diagnosis and intervention of lung cancer. This study will establish lung cancer patient cohort with different evolution stage, and base on single cell RNA-seq and single cell ATAC-seq performed on the nuclei of different pathological types of patients, we could find the key driver gene of lung cancer evolution, the relationship between the specific regulatory regions and gene expression, then reveal the molecular characteristics of cell subgroups at different stages. Combined with bioinformatic analysis, we would map the molecular profiling, and discover all cellular subpopulations and key molecular targets in the evolution of lung cancer. The results could explore a new way to blocking the cancer progress, and provide a scientific basis for precise intervention of lung cancer.

肺癌进化历经基因突变、分子表达异常、非典型增生、原位癌、微浸润癌及浸润癌的多阶段发展过程。研究发现一些关键信号通路在小鼠早期肺腺瘤进化为肺腺癌的过程中被激活，但是目前仍缺乏对肺癌进化的系统性研究。基于近期国内外研究进展和我们前期研究结果，我们提出假设：在肺癌的早期进化过程中，由于关键分子靶点及调控位点出现异常，导致肺癌进化发展，而发现这些特异性靶点,将对肺癌早期精准诊断及干预有着重要的意义。本课题将建立肺癌进化患者队列，拟采用单细胞测序技术，通过对不同病理阶段肺癌组织的细胞核进行scRNA-seq和scATAC-seq测序，寻找肺癌进化的关键驱动基因、及特异性开放调控区域与基因表达的关联，揭示不同阶段肿瘤细胞亚群的分子特征变化。结合生物信息分析，描绘肺癌进化的分子图谱，发现肺癌进化过程关键的分子靶点，探寻阻断肺癌由早期向晚期进展的有效方法，为肺癌的早期精准干预提供科学依据。

肺癌是全球头号癌症杀手，其中肺腺癌是肺癌最常见的病理类型。肺腺癌演进历经基因突变、分子表达异常、非典型增生（AAH）、原位癌（AIS）、微浸润癌（MIA）及浸润癌（IA）的多阶段发展过程。本研究纳入AAH，AIS，MIA及IA四个阶段的25例患者的肿瘤及正常样本样本进行了单细胞RNA测序，总共获得 268,471 cells个细胞。研究发现在非典型腺瘤增生中一类与肺泡2型细胞(AT2)非常相似的细胞（AT2-like cells）。随着LUAD的进展，该亚群细胞转录谱开始出现去分化，具有干细胞样细胞的特征。同时，发现了与能量代谢和核糖体合成相关的基因，这些基因在LUAD的早期阶段上调，并可能促进其进展。进一步证实MDK和TIMP1基因随着肺腺癌进展表达逐渐升高，是 LUAD 演进的关键分子。对肿瘤微环境分析发现，肿瘤相关成纤维细胞在AAH和AIS阶段便开始出现，产生影响肿瘤血管生成、免疫和代谢的分泌因子；随着肿瘤进展NK细胞的比例逐渐减小，耗竭性T淋巴细胞逐渐增加，免疫细胞逐渐由免疫激活状态转变为免疫抑制状态，从而参与肺腺癌的演进。该研究阐明了LUAD演进肿瘤细胞的转录特征，为肺癌早期诊断和早期治疗提供了新的策略。