神经母细胞瘤是最常见的儿童颅外实体恶性肿瘤，迄今为止其发生发展分子机制不清。本课题在文献报道以及前期工作的基础之上，提出RRS1在NB细胞中表达增高，并通过参与调节NB细胞pre-rRNA转录、加工，影响60S核糖体亚基的装配，从而调节NB细胞周期，导致神经母细胞瘤增殖加快并抑制分化，最终致使NB迅速进展分子机制的假说。本课题将以人神经母细胞瘤细胞系和儿童神经母细胞瘤临床样本为研究对象，建立裸鼠成瘤模型，验证RRS1可调节神经母细胞瘤进展的科学假说；同时采用蛋白质亲和层析联合质谱、Co-IP、GST Pull-Down、Northern blotting、RNA EMSA等手段揭示RRS1在神经母细胞瘤中影响核糖体装配的分子机制；为神经母细胞瘤临床诊疗提供线索和理论依据。

Neuroblastoma(NB) is the most common extracranial solid tumor of childhood, which characters difficult diagnosis, rapid progression and poor prognosis resulting in survival rates of less than 50%. The precise mechanism of development and progression of NB is still unclear. RRS1 (ribosome biogenesis regulator homolog) homolog has been discovered in the nucleoli protostome of HeLa cells in last decade. Although yeast Rrs1 has been widely studied in S. cerevisiae, the role of RRS1 in the progression of neuroblastoma has not been discovered yet. Moreover, the function of RRS1 homolog is not well understood. Relying on our initial results, it has demonstrated that lentiviral knock-down of RRS1 in SH-SY5Y inhibits cell proliferation and promotes apoptosis. Besides, our study show that RRS1 involving in neuronal differentiation by using microarray analysis by IPA. While Rrs1 is involved in yeast ribosome assembly, the mechanism of RRS1 in regulation of neuroblastoma progression and its role in control of ribosomal assembly remains to be resolved, hence the study will demonstrate the importance of RRS1 involving in neuroblastoma progression. It has been shown that yeast Rrs1 participates in 60S ribosome assembling by recruiting rpL5 and rpL11 with 5S rRNA to regulate the proliferation of yeast. Therefore, it seems reasonable that RRS1 homolog implies in neuroblastoma progression via regulation of ribosome assembling. To investigate the hypothesis above, human neuroblastoma cell lines and nude mice will be used for the study the role of RRS1 in neuroblastoma proliferation and differentiation. Realtime-PCR and IHF will be performed to explore the relationship between expression level of RRS1 and tumor status, which also includes sex, age, INSS stages and Shimada classification. Furthermore, affinity chromatography combined LC-MS/MS, GST Pull-Down, Co-IP, Northern blotting and RNA EMSA will be applied to investigate the molecular mechanism for regulation of RRS1 in human ribosome biogenesis. In summary, the results from this study will provide evidence to discover a novel biomarker for prognosis of neuroblastoma.