ISL1 promoted tumorigenesis and EMT via Aurora kinase A-induced activation of PI3K/AKT signaling pathway in neuroblastoma

Yizhuo Zhang,Juan Wang,Feifei Sun,Yi Que,Mengzhen Li,Suying Lu,Lian Zhang,Junting Huang,Xiaoyun Bu,Chengtao Sun,Jia Zhu,Li Zhang,Yu Zhang

doi:10.1038/s41419-021-03894-3

Abstract

Neuroblastoma (NB) is the most common extracranial solid malignancy in children and its mortality rate is relatively high. However, driver genes of NB are not clearly identified. Using bioinformatics analysis, we determined the top 8 differentially expressed genes (DEGs) in NB, including GFAP, PAX6, FOXG1, GAD1, PTPRC, ISL1, GRM5, and GATA3. Insulin gene enhancer binding protein 1 (ISL1) is a LIM homeodomain transcription factor which has been found to be highly expressed in a variety of malignant tumors, but the function of ISL1 in NB has not been fully elucidated. We identified ISL1 as an oncogene in NB. ISL1 is preferentially upregulated in NB tissues compared with normal tissues. High ISL1 expression is significantly associated with poor outcome of NB patients. Knockdown of ISL1 markedly represses proliferation and induces cell apoptosis in vitro, and suppresses tumorigenicity in vivo, while overexpression of ISL1 has the opposite effects. Mechanistically, we demonstrate that ISL1 promotes cell proliferation and EMT transformation through PI3K/AKT signaling pathway by upregulating Aurora kinase A (AURKA), a serine-threonine kinase that is essential for the survival of NB cells. The blockade of AURKA attenuates the function of ISL1 overexpression in the regulation of cell proliferation and migration, Conclusively, this study showed that ISL1 targeted AURKA to facilitate the development of NB, which provided new insights into the tumorigenesis of NB. Thus, ISL1 may be a promising therapeutic target in the future.

Highlights

Neuroblastoma (NB) is the most common extracranial solid malignancy in children and accounts for 12% of pediatric cancer deaths [1]
As shown in the Venn diagram (Fig. 1C), a total of 22 upregulated and 28 downregulated genes were found to be significantly differentially expressed significantly different from that in normal tissues, and both Insulin gene enhancer binding protein 1 (ISL1) and GATA3 were significantly higher in NB tissues than in normal tissues (Supplementary Fig. 2). quantitative real-time PCR (qRT-PCR) analysis demonstrated mRNA expression levels of 8 hub genes, in which ISL1 and GATA3 were highly expressed in 5 NB cell lines compared with that in HEK293T (Fig. 2A–H)
We performed western blot (WB) analysis, and our results showed that compared with si-NC NB cells, si-ISL1 NB cells had lower phosphorylated AKT (p-AKT) expression level; while expression level of AKT had no significant difference between these two groups (Fig. 7C, D)

Summary

Introduction

Neuroblastoma (NB) is the most common extracranial solid malignancy in children and accounts for 12% of pediatric cancer deaths [1]. Multimodality treatment for patients with high-risk NB includes chemotherapy, surgery, external beam radiation, and immunotherapy [4]. AntiGD2-specific mAb immunotherapy has shown significant improvement in the outcome for high-risk NB patients [5, 6], the understanding of the molecular and genetic properties related to NB is still necessary for designing promising treatments for NB patients. The Gene Expression Omnibus (GEO) database has evolved rapidly in recent years and was gradually used for the bioinformatics mining of gene expression profiles in cancers [7, 8]. We performed a series of interactive analyses on the GEO datasets, and extracted the top 8 hub genes. To further explore the relationship between the selected hub genes and the pathogenesis of NB, ISL1 was identified as the key research element for further study

Methods

Results

Conclusion