MYC-Activated LncRNA MNX1-AS1 Promotes the Progression of Colorectal Cancer by Stabilizing YB1

Cancer Res. 2021 May 15;81(10):2636-2650. doi: 10.1158/0008-5472.CAN-20-3747. Epub 2021 Mar 29.

Abstract

Long noncoding RNAs (lncRNA) are involved in tumorigenesis and drug resistance. However, the roles and underlying mechanisms of lncRNAs in colorectal cancer are still unknown. In this work, through transcriptomic profiling analysis of 21 paired tumor and normal samples, we identified a novel colorectal cancer-related lncRNA, MNX1-AS1. MNX1-AS1 expression was significantly upregulated in colorectal cancer and associated with poor prognosis. In vitro and in vivo gain- and loss-of-function experiments showed that MNX1-AS1 promotes the proliferation of colorectal cancer cells. MNX1-AS1 bound to and activated Y-box-binding protein 1 (YB1), a multifunctional RNA/DNA-binding protein, and prevented its ubiquitination and degradation. A marked overlap between genes that are differentially expressed in MNX1-AS1 knockdown cells and transcriptional targets of YB1 was observed. YB1 knockdown mimicked the loss of viability phenotype observed upon depletion of MNX1-AS1. In addition, MYC bound the promoter of the MNX1-AS1 locus and activated its transcription. In vivo experiments showed that ASO inhibited MNX1-AS1, which suppressed the proliferation of colorectal cancer cells in both cell-based and patient-derived xenograft models. Collectively, these findings suggest that the MYC-MNX1-AS1-YB1 axis might serve as a potential biomarker and therapeutic target in colorectal cancer. SIGNIFICANCE: This study highlights the discovery of a novel colorectal cancer biomarker and therapeutic target, MNX1-AS1, a long noncoding RNA that drives proliferation via a MYC/MNX1-AS1/YB1 signaling pathway. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/10/2636/F1.large.jpg.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Cell Proliferation
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology*
  • Disease Progression
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Homeodomain Proteins / genetics*
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Prognosis
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism*
  • RNA, Antisense / genetics*
  • RNA, Long Noncoding / genetics*
  • Survival Rate
  • Transcription Factors / genetics*
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays
  • Y-Box-Binding Protein 1 / chemistry*
  • Y-Box-Binding Protein 1 / genetics
  • Y-Box-Binding Protein 1 / metabolism

Substances

  • Homeodomain Proteins
  • MNX1 protein, human
  • MYC protein, human
  • Proto-Oncogene Proteins c-myc
  • RNA, Antisense
  • RNA, Long Noncoding
  • Transcription Factors
  • Y-Box-Binding Protein 1
  • YBX1 protein, human