Kin17在非小细胞肺癌中的表达、作用及分子机制研究

Recently lung cancer is the leading cause of cancer-related death in the world. Non-small cell lung cancer (NSCLC), a highly lethal disease, accounts for 80-85% of all lung cancers, with less than 15% of patients surviving beyond 5 years, because NSCLC is typically diagnosed at an advanced stage. The effective treatments to cure this disease are urgently needed. The molecular mechanisms should be explored, so as to find new effective targets for lung cancer therapy. Kin17 has been determined to participate in DNA replication and DNA damage repair. Our previous works，which has been publised，showed that up-regulation of Kin17 in breast cancer played important roles in rapid proliferation of cancer cells. Silence of Kin17 expression resulted in rudeced DNA replicaiton, more induced DNA damage and blocked DNA cycle in cancer cells. Moreover,knockdown of Kin17 expression inhibited cell growth, cell differentiation, colony formation and increased sensitivity to chemotherapy in breast cancer cells. Our recent studies showed that Kin17 was strongly increased in several lung cancer tissues and A549 cell line of NSCLC; knockdown of Kin17 expression slowed down the cell growth of A549 cells. Thus Kin17 is expected to be associated with the tumorigenesis and development of lung cancer,which hasn't been reported now. Moreover, the association of Kin17 expression and prognosis of patients with tumors are still unknown. The effect of Kin17 on tumorigenic ability in cancer cells is undetermined. These issues are related to the use of Kin17 targeting in tumor treatment.It costs short time to performed follow-up study and analyse of influencing factor related to prognosis of lung cancer, because of high mortality rate in lung cancer. Thus Kin17 expression in the tissues and the cell lines of NSCLC and the controls will be detected in this subject, the association of Kin17 expression and prognosis or clinicopathologic characteristics of patients with NSCLC will also be investigated. We will assess the influence of Kin17 in the biological property，such as DNA replicaiton, cell cycle, cell proliferation, colony fomation ability, cell differentiation, tumorigenic ability, the sensitivity to chemotherapy, etc. The underlying molecular mechanisms of Kin17 in NSCLC cells will be explored. We believe that these studies will lay the solid foundation for the early differential diagnosis and molecularly targeted therapies in lung cancer.

肺癌是全球头号肿瘤杀手，致死率极高，迫切需要深入的研究与有效的诊治措施。申请者已经发表的前期成果表明，Kin17在肿瘤细胞的DNA复制与修复、细胞增殖与分化中发挥重要作用。本研究初步检测到Kin17在肺癌组织中高表达，并影响着肺癌细胞的增殖活性，其很可能与肺癌的发生发展有关，但Kin17在肺癌中的相关研究尚未见报道。而且Kin17与肿瘤患者的预后的关系及Kin17是否制约着肿瘤细胞的致瘤性等涉及到Kin17在肿瘤治疗中运用的重要问题，在国内外尚未阐明。本项目拟通过研究Kin17在肺癌的主要类型(非小细胞肺癌，NSCLC）的组织和细胞系中的表达，探讨Kin17的表达与NSCLC患者的预后生存、病理参数的关系，分析其对NSCLC细胞的细胞周期、增殖、生长分化、致瘤能力和对化疗药物敏感性等生物学行为的影响，进一步探索其分子作用机制，为NSCLC的早期鉴别诊断与分子靶向治疗提供坚实的理论依据。

肺癌是全球头号肿瘤杀手，致死率极高。非小细胞肺癌（non-small cell lung cancer, NSCLC）是肺癌的主要类型，约占80-85%，5年生存率低于15%。现有相关肿瘤标志物的灵敏度还不够理想，而且在临床治疗过程中常出现治疗后复发、对常用化疗药物耐受及肿瘤转移等棘手问题，迫切需要深入的研究与有效的诊治措施。NSCLC的分子机制尚有待进一步阐明，以期找到更有效的治疗靶标。Kin17是一个在物种进化中高度保守的基因，在人机体各组织器官中普遍低表达，已被证实与细胞的DNA复制与DNA损伤修复有关。申请者已发表的前期成果表明，Kin17在肿瘤细胞的细胞增殖、克隆形成、细胞分化中发挥重要作用，但其在肺癌中的相关研究尚未见报道。因此，本项目探讨了Kin17在NSCLC中的表达、功能及分子机制，以便评估其在NSCLC中的应用前景。本研究国内外首次发现，Kin17在NSCLC患者临床标本组织中表达比正常对照标本明显升高，很可能为一个潜在的NSCLC早期鉴别诊断新指标，并可用于肺癌诊断试剂盒的开发。而且，高表达Kin17与NSCLC患者的淋巴结转移与高肿瘤级别密切相关。通过运用携带Kin17特异性siRNA序列的病毒重组载体，显著下调了NSCLC细胞A549中Kin17 mRNA与蛋白表达水平，而且明显抑制了A549细胞的细胞周期进展、迁移能力及侵袭性能，还促进了肿瘤细胞的凋亡，其很可能是一个潜在的抑制肺癌转移新策略。基因芯片分析使我们初步了解Kin17在NSCLC细胞中的信号传导途径。Western blot 结果提示，Kin17很可能通过EGFR、MMP-7和Myc等重要信号因子，调控NSCLC细胞的生长与转移等生物学行为。本项目研究成果荣获国家发明专利1项与奖励2项，发表成果论文7篇，其中SCI收录期刊论文3篇，北大中文核心期刊论文2篇。通过本项目研究，锻炼了研究生的科研思维与实验技术，提升了负责人的个人科研能力与综合素质。Kin17在NSCLC的分子调控机制尚有待更深入进行探索，以期为NSCLC的诊治提供坚实的理论依据。我们积极与大型医院及企业加强交流与合作，将致力于将本项目研究成果应用于NSCLC的诊断试剂盒及靶向药物的研发。