SAMD1 suppresses epithelial-mesenchymal transition pathways in pancreatic ductal adenocarcinoma

PLoS Biol. 2024 Aug 13;22(8):e3002739. doi: 10.1371/journal.pbio.3002739. eCollection 2024 Aug.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) poses a significant threat due to its tendency to evade early detection, frequent metastasis, and the subsequent challenges in devising effective treatments. Processes that govern epithelial-mesenchymal transition (EMT) in PDAC hold promise for advancing novel therapeutic strategies. SAMD1 (SAM domain-containing protein 1) is a CpG island-binding protein that plays a pivotal role in the repression of its target genes. Here, we revealed that SAMD1 acts as a repressor of genes associated with EMT. Upon deletion of SAMD1 in PDAC cells, we observed significantly increased migration rates. SAMD1 exerts its effects by binding to specific genomic targets, including CDH2, encoding N-cadherin, which emerged as a driver of enhanced migration upon SAMD1 knockout. Furthermore, we discovered the FBXO11-containing E3 ubiquitin ligase complex as an interactor and negative regulator of SAMD1, which inhibits SAMD1 chromatin-binding genome-wide. High FBXO11 expression in PDAC is associated with poor prognosis and increased expression of EMT-related genes, underlining an antagonistic relationship between SAMD1 and FBXO11. In summary, our findings provide insights into the regulation of EMT-related genes in PDAC, shedding light on the intricate role of SAMD1 and its interplay with FBXO11 in this cancer type.

MeSH terms

  • Animals
  • Cadherins / genetics
  • Cadherins / metabolism
  • Carcinoma, Pancreatic Ductal* / genetics
  • Carcinoma, Pancreatic Ductal* / metabolism
  • Carcinoma, Pancreatic Ductal* / pathology
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Epithelial-Mesenchymal Transition* / genetics
  • F-Box Proteins* / genetics
  • F-Box Proteins* / metabolism
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Pancreatic Neoplasms* / genetics
  • Pancreatic Neoplasms* / metabolism
  • Pancreatic Neoplasms* / pathology
  • Prognosis
  • Receptors, LDL* / genetics
  • Receptors, LDL* / metabolism

Substances

  • Cadherins
  • F-Box Proteins
  • Intracellular Signaling Peptides and Proteins
  • SAMD1 protein, human
  • Receptors, LDL

Grants and funding

This project was supported by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG, 109546710, 416910386, 516068166), the Fritz Thyssen Foundation (Fritz Thyssen Stiftung, 10.20.1.005MN) and the German José Carreras Leukemia Foundation (José Carreras Leukämie-Stiftung, DJCLS 06 R/2022) to R.L. Open access funding is provided by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG, 416910386) and the Open Access Publishing Fund of Philipps-Universität Marburg. The funders played no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.