N6-methyladenosine-modified circ_104797 sustains cisplatin resistance in bladder cancer through acting as RNA sponges

Cell Mol Biol Lett. 2024 Feb 23;29(1):28. doi: 10.1186/s11658-024-00543-3.

Abstract

Background: Bladder cancer (BCa) ranks among the predominant malignancies affecting the urinary system. Cisplatin (CDDP) remains a cornerstone therapeutic agent for BCa management. Recent insights suggest pivotal roles of circular RNA (circRNA) and N6-methyladenosine (m6A) in modulating CDDP resistance in BCa, emphasizing the importance of elucidating these pathways to optimize cisplatin-based treatments.

Methods: Comprehensive bioinformatics assessments were undertaken to discern circ_104797 expression patterns, its specific interaction domains, and m6A motifs. These findings were subsequently corroborated through experimental validations. To ascertain the functional implications of circ_104797 in BCa metastasis, in vivo assays employing CRISPR/dCas13b-ALKBH5 were conducted. Techniques, such as RNA immunoprecipitation, biotin pull-down, RNA pull-down, luciferase reporter assays, and western blotting, were employed to delineate the underlying molecular intricacies.

Results: Our investigations revealed an elevated expression of circ_104797 in CDDP-resistant BCa cells, underscoring its pivotal role in sustaining cisplatin resistance. Remarkably, demethylation of circ_104797 markedly augmented the potency of cisplatin-mediated apoptosis. The amplification of circ_104797 in CDDP-resistant cells was attributed to enhanced RNA stability, stemming from an augmented m6A level at a distinct adenosine within circ_104797. Delving deeper, we discerned that circ_104797 functioned as a microRNA reservoir, specifically sequestering miR-103a and miR-660-3p, thereby potentiating cisplatin resistance.

Conclusions: Our findings unveil a previously uncharted mechanism underpinning cisplatin resistance and advocate the potential therapeutic targeting of circ_104797 in cisplatin-administered patients with BCa, offering a promising avenue for advanced BCa management.

Keywords: Bladder cancer; Cisplatin resistance; N6-methyladenosine; circ_104797; miR-103a.

MeSH terms

  • Adenosine / analogs & derivatives*
  • Cell Line, Tumor
  • Cell Proliferation
  • Cisplatin / pharmacology
  • Cisplatin / therapeutic use
  • Drug Resistance, Neoplasm / genetics
  • Humans
  • MicroRNAs* / genetics
  • MicroRNAs* / metabolism
  • Urinary Bladder Neoplasms* / drug therapy
  • Urinary Bladder Neoplasms* / genetics
  • Urinary Bladder Neoplasms* / metabolism

Substances

  • Cisplatin
  • N-methyladenosine
  • MicroRNAs
  • MIRN660 microRNA, human
  • Adenosine