DIFFERENTIALLY EXPRESSED GENE PRODUCTS IN HUMAN GLIOMAS

人类神经胶质瘤的肿瘤发生已经被描述为通过 遗传损伤的积累最终导致 原癌基因和/或肿瘤抑制基因的功能丧失。 这一假设是基于先前的研究， 表皮生长因子受体基因扩增和缺失 与神经胶质瘤中的9、10和17号染色体相关的序列。 这 该项目是针对本地化和确定一个假定的 位于染色体上的胶质母细胞瘤相关肿瘤抑制基因（GTS） 10. 一些研究表明，染色体缺失 10个等位基因是在10个等位基因中观察到的最常见的遗传变异。 胶质母细胞瘤（GBM）。 为了进一步研究这一发现，我们重新- 利用微细胞技术将人10号染色体插入两株胶质母细胞瘤细胞系中， 介导的染色体转移，并已证明了戏剧性的损失， 杂交细胞的致瘤表型。 杂交细胞表现出 他们的能力，生长在软琼脂糖，饱和密度下降， 在裸鼠体内不能形成肿瘤。 利用 这种功能性方法证明了GTS基因的存在， 10号染色体。 我们分离GTS基因的长期目标包括使用 两种非相互排斥的方法：片段10号染色体， 将各种定义的片段重新插入GBM细胞中， GTS基因的功能性肿瘤抑制试验。 我们的努力 将特别指向区域10 q22到10 qter，其中 初步证据表明GTS基因可能存在于 此外，本发明还 将对cDNA表达文库进行消减杂交 以鉴定作为重新表达的结果的差异表达的基因， 10号染色体插入GBM细胞。 差异表达 然后将基因产物的基因结构表征， 表达模式、序列和基因结构，以便最终 检查他们的职能作用。 此外，这两种方法可以 结合起来，以确定基因映射到特定的染色体区域， 兴趣和差异表达。 这些结果应该会增加 我们对神经胶质细胞中特定基因改变的理解 肿瘤发生，然后可能为我们提供新的诊断标志物或特异性 用于人类神经胶质瘤的治疗干预的靶点。

The oncogenesis of human gliomas has been described to occur through the accumulation of genetic damage that eventually leads to the activation of proto-oncogenes and/or the loss of function of tumor suppressor genes. This hypothesis is based on previous studies that have described amplification of epidermal growth factor receptor gene and losses of sequences associated with chromosomes 9, 10, and 17 in gliomas. This project is directed at the localization and identification of a putative glioblastoma-associated tumor suppressor (GTS) gene located on chromosome 10. Several investigations have demonstrated that deletion of chromosome 10 alleles are the most frequent genetic alteration observed in glioblastomas (GBMs). To further examine this observation, we have re- inserted human chromosome 10 into two glioblastoma cell lines by micro-cell mediated chromosomal transfer and have demonstrated a dramatic loss of the tumorigenic phenotype of the hybrid cells. The hybrid cells exhibit a loss of their ability to grow in soft agarose, a decreased saturation density in monolayer, and failure to form tumor in nude animals. The utilization of this functional method demonstrates the presence of a GTS gene on chromosome 10. Our long-term goal to isolate the GTS gene involves the use of two non-mutually exclusive approaches: to fragment chromosome 10, and to re-insert the various defined pieces into GBM cells to regionally locate the GTS gene by assaying for functional tumor suppression. Our efforts will particularly be directed towards the region 10q22 to 10qter, where preliminary evidence suggests the GTS gene may reside. Additionally, subtractive hybridizations will be performed on cDNA expression libraries to identify genes which are differentially expressed as a result of re- insertion of chromosome 10 into GBM cells. The differentially expressed gene products will then be characterized for their gene structure, expression patterns, sequence, and gene structure, in order to eventually examine their functional roles. Furthermore, these two approaches can be combined to identify genes which map to specific chromosomal regions of interest and are differentially expressed. These results should increase our understanding of the specific genetic alterations involved in glial oncogenesis and may then provide us with new diagnostic markers or specific targets for therapeutic intervention in human gliomas.