Hsa_circ_0007590/PTBP1 complex reprograms glucose metabolism by reducing the stability of m6A-modified PTEN mRNA in pancreatic ductal adenocarcinoma

Cancer Gene Ther. 2024 Jul;31(7):1090-1102. doi: 10.1038/s41417-024-00786-4. Epub 2024 May 27.

Abstract

The role of circular RNAs (circRNAs) in glucose metabolism in pancreatic duct adenocarcinoma (PDAC) remains elusive. Through RNA sequencing of cells cultured under conditions of glucose deprivation, we identified hsa_circ_0007590. Sanger sequencing and RNase R and Act D treatments were performed to confirm the circular RNA features of hsa_circ_0007590. RNA in situ hybridization (RNA-ISH) and quantitative reverse transcription PCR (qRT-PCR) were used to estimate hsa_circ_0007590 expression in PDAC clinical specimens and cell lines. hsa_circ_0007590 expression was higher in PDAC patients and closely related to the clinicopathological characteristics of the disease. Cytoplasm‒nuclear fractionation and FISH assays demonstrated that hsa_circ_0007590 was located in the nucleus. Gain-of-function and loss-of-function assays were performed to assess the biological behaviors of PDAC cells. Seahorse XF assays were performed to validate the Warburg effect. hsa_circ_0007590 facilitated the proliferation, migration, and invasion of PDAC cells and promoted the Warburg effect. Mass spectrometry, RNA pulldown, RNA immunoprecipitation (RIP), RNA m6A quantification, m6A dot blot, MeRIP, and Western blotting were conducted to investigate the detailed mechanism through which hsa_circ_0007590 produces these effects. Mechanistically, hsa_circ_0007590 targeted PTBP1 and increased the expression of the m6A reader protein YTHDF2, leading to PTEN mRNA degradation and PI3K/AKT/mTOR pathway activation. Overall, hsa_circ_0007590, which targets PTBP1, reprograms glucose metabolism by attenuating the stability of m6A-modified PTEN mRNA and holds potential promise as a therapeutic target for PDAC.

MeSH terms

  • Animals
  • Carcinoma, Pancreatic Ductal* / genetics
  • Carcinoma, Pancreatic Ductal* / metabolism
  • Carcinoma, Pancreatic Ductal* / pathology
  • Cell Line, Tumor
  • Female
  • Glucose* / metabolism
  • Heterogeneous-Nuclear Ribonucleoproteins* / genetics
  • Heterogeneous-Nuclear Ribonucleoproteins* / metabolism
  • Humans
  • Male
  • Mice
  • Middle Aged
  • PTEN Phosphohydrolase* / genetics
  • PTEN Phosphohydrolase* / metabolism
  • Pancreatic Neoplasms* / genetics
  • Pancreatic Neoplasms* / metabolism
  • Pancreatic Neoplasms* / pathology
  • Polypyrimidine Tract-Binding Protein* / genetics
  • Polypyrimidine Tract-Binding Protein* / metabolism
  • RNA Stability
  • RNA, Circular* / genetics
  • RNA, Circular* / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism

Substances

  • PTEN Phosphohydrolase
  • PTEN protein, human
  • RNA, Circular
  • Glucose
  • Heterogeneous-Nuclear Ribonucleoproteins
  • Polypyrimidine Tract-Binding Protein
  • PTBP1 protein, human
  • RNA, Messenger