CircSHPRH通过编码多肽抑制FOXC2介导的儿童神经母细胞瘤淋巴管新生的作用及机制研究

13-顺式维甲酸(13-cis-RA)可促进细胞分化,发挥治疗肿瘤的作用。但13-cis-RA维持治疗方案对高度侵袭性神经母细胞瘤(NB)收效甚微,这可能与13-cis-RA能够促进淋巴管新生相关。CircRNA结构稳定、半衰期长,是理想的抗肿瘤药物原型。我们前期筛选出能够抑制NB淋巴管新生的circSHPRH,提示该circRNA有潜力克服13-cis-RA治疗瓶颈。我们还发现,circSHPRH可编码多肽,并抑制FOXC2表达最终影响淋巴管新生重要因子VEGFC表达。课题组将综合运用分子生物学方法,结合细胞、动物模型和临床样本分析,阐明circSHPRH及其编码多肽抑制FOXC2介导的NB淋巴管新生的机制;明确circSHPRH与13-cis-RA联合应用抗NB的协同作用。通过本项目,可明确circSHPRH与13-cis-RA联合抑制恶性NB进展的分子基础,以期优化13-cis-RA治疗NB方案。

13-cis retinoic acid (13-cis-RA) plays a pivotal role in anti-tumor therapeutic regimen by promoting the differentiation of tumor cells. The 13-cis-RA regimen is a maintenance therapy for high-risk neuroblastoma, but it has little effect on progressive disease of neuroblastoma, possibly because of its ability of promoting lymphangiogenesis. With stable structure and longer half-life, circRNAs are regarded as promising anti-tumor drug prototypes. In order to find certain circRNAs associated with lymphangiogenesis, we conducted circRNA sequencing on 94 neuroblastoma samples. With lymphangiogenesis experiment, we identified circSHPRH, a circRNA capable of inhibiting lymphangiogenesis in neuroblastoma, which has the potential to overcome the bottleneck of 13-cis-RA treatment. Subsequently, high resolution LC-MS/MS was performed to identify proteins from the neuroblastoma samples, and the circSHPRH was found to encode a 146 amino acid polypeptide SHPRH-146aa. Besides, bioinformatics analysis showed that SHPRH-146aa shares DNA binding domain with SHPRH, indicating that SHPRH-146a may functionate by a dominant negative mechanism. In addition, FOXC2, an important factor involved in lymphangiogenesis, was significantly downregulated by overexpression of circSHPRH in SH-SY5Y cells, further indicating that circSHPRH had the inhibiting effect on lymphangiogenesis. The aim of this study is to comprehensively elucidate the mechanism that circSHPRH and its encoded polypeptide SHPRH-146aa inhibit FOXC2-mediated lymphangiogenesis, and clarify the synergistic effect of circSHPRH and 13-cis-RA in the function of anti-neuroblastoma. The implementation of this project could uncover the molecular mechanism of the joint inhibiting effect of circSHPRH and 13-cis-RA on neuroblastoma, and provide molecular basis for optimizing the regimen of 13-cis-RA for neuroblastoma.