LncRNA-SLC16A1-AS1 induces metabolic reprogramming during Bladder Cancer progression as target and co-activator of E2F1

Theranostics. 2020 Jul 29;10(21):9620-9643. doi: 10.7150/thno.44176. eCollection 2020.

Abstract

Long non-coding RNAs (lncRNAs) have emerged as integral components of E2F1-regulated gene regulatory networks (GRNs), but their implication in advanced or treatment-refractory malignancy is unknown. Methods: We combined high-throughput transcriptomic approaches with bioinformatics and structure modeling to search for lncRNAs that participate in E2F1-activated prometastatic GRNs and their phenotypic targets in the highly-relevant case of E2F1-driven aggressive bladder cancer (BC). RNA immunoprecipitation was performed to verify RNA-protein interactions. Functional analyses including qRT-PCR, immunoblotting, luciferase assays and measurement of extracellular fluxes were conducted to validate expression and target gene regulation. Results: We identified E2F1-responsive lncRNA-SLC16A1-AS1 and its associated neighboring protein-coding gene, SLC16A1/MCT1, which both promote cancer invasiveness. Mechanistically, upon E2F1-mediated co-transactivation of the gene pair, SLC16A1-AS1 associates with E2F1 in a structure-dependent manner and forms an RNA-protein complex that enhances SLC16A1/MCT1 expression through binding to a composite SLC16A1-AS1:E2F1-responsive promoter element. Moreover, SLC16A1-AS1 increases aerobic glycolysis and mitochondrial respiration and fuels ATP production by fatty acid β-oxidation. These metabolic changes are accompanied by alterations in the expression of the SLC16A1-AS1:E2F1-responsive gene PPARA, a key mediator of fatty acid β-oxidation. Conclusions: Our results unveil a new gene regulatory program by which E2F1-induced lncRNA-SLC16A1-AS1 forms a complex with its transcription factor that promotes cancer metabolic reprogramming towards the acquisition of a hybrid oxidative phosphorylation/glycolysis cell phenotype favoring BC invasiveness.

Keywords: E2F1; RNA-protein complex; SLC16A1-AS1; bladder cancer; metabolic reprogramming.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / genetics
  • Cell Line, Tumor
  • Cellular Reprogramming / physiology*
  • Disease Progression
  • E2F1 Transcription Factor / genetics*
  • Gene Expression Regulation, Neoplastic / genetics
  • Glycolysis / genetics
  • Humans
  • Mitochondria / genetics
  • Monocarboxylic Acid Transporters / genetics*
  • Oxidation-Reduction
  • Promoter Regions, Genetic / genetics
  • RNA, Long Noncoding / genetics*
  • Symporters / genetics*
  • Transcriptional Activation / genetics
  • Urinary Bladder Neoplasms / genetics*
  • Urinary Bladder Neoplasms / pathology

Substances

  • E2F1 Transcription Factor
  • E2F1 protein, human
  • Monocarboxylic Acid Transporters
  • RNA, Long Noncoding
  • Symporters
  • monocarboxylate transport protein 1
  • Adenosine Triphosphate