Mechanism of methyltransferase like 3 in epithelial-mesenchymal transition process, invasion, and metastasis in esophageal cancer

Bioengineered. 2021 Dec;12(2):10023-10036. doi: 10.1080/21655979.2021.1994721.

Abstract

Methyltransferase like 3 (METTL3) has been identified to serve as a definitive inducer in cancer progression. This study sought to analyze the regulatory mechanism of METTL3 in epithelial-mesenchymal transition (EMT), invasion, and metastasis in esophageal cancer (ESCA). The METTL3 expressions in cancer tissues and cells were detected with extensive analysis of its correlation with clinical baseline data. The cells were transfected with sh-RNA-METTL3 and microRNA (miR)-20a-5p mimic, followed by evaluation of invasion, migration, and EMT. The N6-methyladenosine (m6A) level and enrichment of DiGeorge Critical Region 8 (DGCR8) and m6A were observed. The binding relationship between miR-20a-5p and Nuclear Factor I-C (NFIC) was verified, followed by Pearson correlation analysis. A subcutaneous tumor formation assay was conducted prior to observation of lung metastases. Our results revealed that METTL3 was highly expressed in ESCA patients and associated with severe lymph node involvement and distant metastasis. METTL3 downregulation radically inhibited the invasiveness, migration, and EMT. METTL3 elevated the miR-20a-5p expression via improving m6A modification. METTL3 inhibition downregulated the miR-20a-5p expression. Moreover, miR-20a-5p upregulation facilitated ESCA cell invasiveness and migration by targeting NFIC transcription. METTL3 inhibition suppressed tumor growth and lung metastasis in vivo. Overall, METTL3 promoted m6A modification and the binding of DGCR8 to miR-20a-5p to further elevate the miR-20a-5p expression and inhibit NFIC transcription, thus promoting EMT, invasion and migration.

Keywords: DGCR8; Esophageal cancer; METTL3; NFIC; epithelial-mesenchymal transition; m6A modification; miR-20a-5p; pri-miR-20a-5p.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / analogs & derivatives
  • Adenosine / metabolism
  • Animals
  • Base Sequence
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation / genetics
  • DNA Methylation / genetics
  • Down-Regulation / genetics
  • Epithelial-Mesenchymal Transition / genetics*
  • Esophageal Neoplasms / genetics*
  • Esophageal Neoplasms / pathology*
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Male
  • Methyltransferases / genetics
  • Methyltransferases / metabolism*
  • Mice
  • Mice, Nude
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Middle Aged
  • Models, Biological
  • NFI Transcription Factors / genetics
  • NFI Transcription Factors / metabolism
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Transcription, Genetic
  • Up-Regulation / genetics

Substances

  • MIRN20a microRNA, human
  • MicroRNAs
  • NFI Transcription Factors
  • N-methyladenosine
  • Methyltransferases
  • METTL3 protein, human
  • Adenosine

Grants and funding

The study was sponsored by Lianyungang High-tech Zone Science and Technology Plan Project [ZD201929]. The funding organisations had no role in the concept, design, analysis or writing of the manuscript.