COMPARISON OF THE PROTEOMES OF PROLIFERATING AND DIFFERENTIATING NEUROBLASTOMA C

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 周围神经发育过程中正常分化过程的扰动导致神经母细胞瘤，这是一种儿童周围神经系统癌症。超过50%的儿童神经母细胞瘤有转移性或侵袭性疾病，总体预后较差。因此，寻找与神经母细胞瘤发生发展相关的新分子靶点具有重要的临床意义。我们的研究表明，与正常神经脊源性细胞相比，神经母细胞瘤细胞中一种名为二肽基肽酶IV(DPPIV)的细胞表面蛋白的表达显著减少。此外，恢复神经母细胞瘤细胞中DPPIV的表达会导致其分化、凋亡，并抑制其致瘤潜能。分泌的蛋白质/多肽在调节这些过程中起着关键作用，这是公认的事实。有趣的是，DPPIV存在于细胞质膜上，也以分泌的形式存在，并且DPPIV被证明调节一些分泌的有丝分裂原肽的活性和水平。因此，DPPIV可能通过调节肿瘤细胞分泌的蛋白质谱来发挥肿瘤抑制基因的作用，使其微环境对肿瘤细胞的生存和扩散的支持程度降低。因此，鉴定神经母细胞瘤细胞中受DPPIV调控的分泌蛋白具有重要意义。基于这些数据，我们假设DPPIV对具有生长抑制和刺激功能的蛋白质或多肽的表达具有不同的调节作用。我们目前的建议旨在利用蛋白质组学技术来鉴定差异表达的分泌肽。我们将采用细胞培养中氨基酸稳定同位素标记(SILAC)技术来鉴定和定量一对未分化和分化的NB细胞系在细胞外介质中差异表达或释放的蛋白质。这些研究将与VGN蛋白质组核心设施的教职员工合作进行。我们提出的研究有望确定具有预后、诊断和/或治疗价值的新多肽。此外，拟议研究的结果可能有助于更好地了解神经母细胞瘤的生物学。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Perturbation in the normal differentiation process during peripheral neural development leads to neuroblastoma, a childhood cancer of peripheral nervous system. More than 50% of children with neuroblastoma have metastatic or aggressive disease with poor overall prognosis. Thus, identification of novel molecular targets involved in the development of neuroblastoma is of clinical importance. Our studies have shown that expression of a cell surface protease called dipeptidyl peptidase IV (DPPIV) is significantly decreased in neuroblastoma cells as compared to normal neural crest derived cells. Furthermore, restoration of DPPIV expression in neuroblastoma cells leads to their differentiation, apoptosis, and suppression of their tumoigenic potential. It is well established that secreted proteins/peptides play a pivotal role in regulatingthese processes. Interestingly, DPPIV is present on cell plasma membrane as well as in secreted form and DPPIV is shown to regulate the activities and levels of some of the secreted mitogenic peptides. Thus, it is likely that DPPIV functions as tumor suppressor gene by modulating the spectrum of proteins secreted by tumor cells, rendering their microenvironment less supportive of the survival and spread of tumor cells. Thus identification of secreted proteins that are regulated by DPPIV in neuroblastoma cells is of importance. Based on these data, we hypothesize that DPPIV differentially regulates the expression of proteins or peptides with growth inhibitory and stimulatory functions. Our current proposal is aimed at identifying the differentially expressed secreted peptides by employing proteomic technologies. We will adapt stable isotopic labeling with amino acids in cell culture (SILAC) technology to identify and quantify proteins differentially expressed or released into the extracellular media by a pair of undifferentiated and differentiated NB cell lines. These studies will be carried out in collaboration with faculty members of VGN proteomic core facility. Our proposed studies are expected to identify the novel peptides with prognostic, diagnostic and/or therapeutic value. Also, results from the proposed studies may contribute significantly to better understanding of biology of neuroblastoma.