B-Myb在肺癌发生发展中的作用机制与临床意义研究

A surprising results are found that B-Myb were highly expressed in lung cancer tissues and closely associated with the lung cancer progression and prognosis, when exploring the transcriptional regulation of new tumor associated gene PRR11. Further research found that overexpression of B-Myb could up-regulate the expression of CCNA1 and MMP1, promote the process of cell cycle and cell proliferation, and enhance the ability of lung cancer cell invasion and metastasis. Those results suggest that, through mediating abundant targeted genes, B-Myb may play an important role in the lung carcinogenesis. In the present study, we will utilize various techniques such as gene overexpression and RNA interference to analyze the biological behavior of lung cancer caused by B-Myb, such as cell cycle procession, cell proliferation, cell invasion and cell metastasis. Further conducting ChIP-on-chip and Microarray, we screen and identify B-Myb targeted genes and the pathway networks in lung cancer cells. Then, by using the methods of quantitative PCR and IHC, we measure the expression of B-Myb in massive lung cancer tissues and analyze the clinical significance. This study will not only clarify the molecular mechanisms of B-Myb in the lung cancer development and its clinical values, but also provide novel insights into the diagnosis and treatment of cancer.

我们在肿瘤相关新基因PRR11的转录调控研究中，意外发现：Myb家族新成员B-Myb在肺癌组织中高表达，且其表达与肺癌分期预后等高度相关；外源过表达B-Myb能够上调CCNA1和MMP1等基因表达，显著促进肺癌细胞周期进程、细胞增殖以及肺癌细胞的侵袭转移能力。该数据强烈提示，B-Myb可通过调控大量靶基因的表达而在肺癌发生发展过程中扮演重要促进作用。本项目拟在此基础上，进一步采用基因过表达和RNA干扰等技术分析B-Myb对肺癌细胞周期进程、细胞增殖和侵袭转移等生物学行为的调节作用；采用ChIP-on-chip和Microarray技术大规模分析鉴定其作为转录因子在肺癌细胞中调控的下游靶基因及其网络通路；采用定量PCR和IHC技术大样本分析其在肺癌中的表达水平及其临床意义。由此阐明B-Myb促进肺癌发生发展的作用机制与临床意义，并初步评价其作为新靶点在肺癌分子诊断和靶向治疗中的潜在应用价值。

转录因子B-Myb是一个癌基因，在一些人类肿瘤中表达增多。然而，B-Myb在人肺癌发生发展中的作用仍然不清楚。本课题中，我们首次检测B-Myb在肺癌中的表达以及功能作用。首先，采用定量qRT-PCR和免疫组化的方法对组织芯片样本进行了检测，发现B-Myb在非小细胞肺癌中表达增高，且其表达与肺癌的分期和分级呈正相关。其次，“基因获得实验”发现，B-Myb过表达后能够显著增强肺癌的细胞生长、克隆生成、细胞迁移和侵袭能力。相应的，“细胞丧失实验”发现，B-Myb被敲出后，降低了细胞的增长能力以及细胞迁移和侵袭能力。B-Myb过表达能够促进裸鼠中非小细胞肺癌的肿瘤细胞生长能力。最后，RNA测序结果显示B-Myb过表达能够引起下游靶基因（COL11A1, COL6A1, FN1, MMP2, NID1, FLT4, INSR, 和CCNA1）的表达上调，并激活一些信号通路如ERK-AKT信号通路。总之，我们的实验结果显示B-Myb在非小细胞肺癌中起到促进肿瘤生长的作用，同时也提示我们B-Myb可作为非小细胞肺癌诊断和治疗的候选标志物。