MOLECULAR CLONING OF A T(15;19) IN LUNG CANCER CELL LINE

这是一份申请K 08奖给Thao Dang，M.D.旨在支持五年的实验室培训，以进一步发展她在分子遗传学方面的技能，并探索一种新的致癌机制。恶性转化是遗传异常累积的结果。 特异性染色体易位是造血系统恶性肿瘤中癌基因激活的主要机制，但在更常见的上皮肿瘤中尚未描述。 我们已经建立了一个细胞系，HCC 2429，从一个积极的，转移性肺癌，具有正常的核型，除了染色体15 q和19 p之间的一个单一的易位。 使用定位克隆，我们证明了19号染色体上的断裂点位于Notch 3起始位点上游约40 kb处，Notch 3是Notch原癌基因家族的成员。 这种易位与Notch 3的大量过表达相关，支持t（15;19）易位导致这种推定的细胞原癌基因失调的假设。 此外，我们还证明了Notch 3在一组肺癌细胞系中的过表达，并表明它与涉及19 p的易位高度相关。 因此，我们已经确定了一种新的复发机制，癌基因激活肺癌以及一个假定的癌基因，以前不知道参与人类癌症。在大卫Carbone博士的指导下，Dang博士将完成已鉴定的t（15;19）易位的分子表征，确定Notch 3受体和配体在肺癌和正常组织中的表达谱，并进行研究以表征Notch 3的转化性质及其对肺癌下游信号通路的影响。 在范德比尔特英格拉姆癌症中心的研究环境是特殊的口径，并将提供博士党与经验丰富的分子生物学家以及遗传学家互动的机会。 K 08奖给予的支持将使Dang博士能够建立在她现有的知识基础上，并促进她在竞争激烈的环境中向独立研究者过渡。

This is an application for a K08 award for Thao Dang, M.D. designed to support five-years of laboratory training to further develop her skills in molecular genetics and to explore a novel mechanism of carcinogenesis. Malignant transformation is the result of an accumulation of genetic abnormalities. Specific chromosomal translocations are a major mechanism for oncogene activation in hematopoietic malignancies, but have not been described in the much more common epithelial tumors. We have established a cell line, HCC2429, from an aggressive, metastatic lung cancer that has a normal karyotype except for a single translocation between chromosomes 15q and 19p. Using positional cloning we demonstrated that the breakpoint on chromosome 19 lies approximately 40 kb upstream from the start site of Notch3, a member of the Notch proto- oncogene family. This translocation is associated with massive overexpression of Notch3, supporting the hypothesis that the t(15;19) translocation results in the deregulation of this putative cellular proto-oncogene. Furthermore, we have also demonstrated Notch3 over-expression in a panel of lung cancer cell lines and shown that it is highly correlated with translocations involving 19p. We have therefore identified a novel recurring mechanism for oncogene activation in lung cancer as well as a putative oncogene not previously known to be involved in human cancer. Under the mentorship of Dr. David Carbone, Dr. Dang will complete the molecular characterization of the identified t(15;19) translocation, determine the spectrum of the Notch3 receptor and ligand expression in lung cancer and normal tissues, and perform studies to characterize the transforming nature of Notch3 and its effects on downstream signaling pathways in lung cancer. The research environment at the Vanderbilt Ingram Cancer Center is of exceptional caliber and will provide Dr. Dang with the opportunity to interact with experienced molecular biologists as well as geneticists. The support given by this K08 award will allow Dr. Dang to build on her existing knowledge and promote her transition to an independent investigator in a highly competitive environment.