LncRNA RP11-1100L3.8 Involves in the Pathogenesis of Multiple Myeloma by Regulating NR4A1.

Abstract

Although numerous studies have revealed that various long-non coding RNA (lncRNA) are implicated in multiple myeloma (MM) regulation, MM lncRNA profile and novel functional lncRNAs in MM need to be elucidated. Herein, lncRNAs and mRNAs (messenger ribonucleic acids) patterns in MM were evaluated using RNA-sequencing (RNAseq). Differentially expressed (DE) genes were defined and a complex regulatory network based on validation and predication was shaped. LncRNA-seq data analysis identified 539 DE lncRNAs and RP11-1100L3.8 was the most up-regulated known lncRNA. Subsequently, the upregulation and clinical RP11-1100L3.8 utilization value was verified in an expanded cohort. Based on the results of Cis nearby-targets and co-expression analysis, 1 correlation pair RP11-1100L3.8-nuclear receptor subfamily 4 group A member 1 (NR4A1) was defined. It is worth noting that NR4A1 is one of the top 5 significantly up-regulated DE mRNAs in MM patients. Moreover, it was found that NR4A1 overexpression is associated with poor prognosis in MM patients, making it suitable as biomarker. Additionally, spearman correlation analysis revealed the positive association between RP11-1100L3.8 and NR4A1 in MM patients. Furthermore, the dominant NR4A1 interacted genes were predicated and it was found that the genes containing NR4A1 were remarkably enriched in phosphatidylinositol 3-kinase (PI3K)-AKT (protein kinase B) signaling pathway. In addition, in vitro experiment suggested that RP11-1100L3.8 downregulation decreased NR4A1 expression in U266 and RPMI 8226 MM cells. RP11-1100L3.8 inhibition declined proliferation and promoted apoptosis in MM cells, which were rescued by NR4A1 overexpression. Moreover, it was found that RP11-1100L3.8 inhibition impeded PI3K and AKT phosphorylation and rapamycin mammalian target in MM cells, which was rescued by NR4A1 overexpression. This study identifies RP11-1100L3.8 as a potential MM biomarker, and it may be involved in MM pathophysiology by regulating NR4A1-mediated PI3K-AKT signaling pathway. This study provides a novel biomarker candidate for MM therapy.