EACR26-1706

Epithelial NAPE-PLD loss promotes stemness and tumor progression in obesity-associated colorectal cancer

M. Rinaldi1, M. Nanì1,2, P. De Cicco1, F. Piscitelli3, P. Canì4, F. Borrelli1, A. Izzo1, B. Romano1
1Department of Pharmacy, School of Medicine and Surgery, University of Naples Federico II, Naples, Italy
2Inflammatory Bowel Disease Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clinic of Barcelona,, Barcelona, Spain
3Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche,, Pozzuoli, Italy
4Institute of Experimental and Clinical Research (IREC), UCLouvain, Université catholique de Louvain, Brussels, Belgium
Introduction:

Obesity is a major risk factor for colorectal cancer (CRC) and is associated with increased tumor aggressiveness and poor prognosis. Obesity-related metabolic dysfunction alters lipid signaling pathways, including N-acylethanolamines (NAEs), bioactive lipids regulating epithelial homeostasis and inflammation. NAEs are synthesized by N-acyl-phosphatidylethanolamine phospholipase D (NAPE-PLD), an enzyme genetically and functionally linked to obesity. However, its epithelial-intrinsic role in obesity-associated CRC remains unclear.

Material and method:

NAPE-PLD expression and transcriptomic profiles were analyzed in colonic biopsies from CRC patients stratified by body mass index. NAE levels were quantified by liquid chromatography–mass spectrometry. In vivo CRC was induced using azoxymethane in obese db/db mice treated with the selective NAPE-PLD inhibitor lei-401. An inducible intestinal epithelial-specific NAPE-PLD knockout model (NAPE-PLDΔIEC) was used to dissect epithelial-intrinsic mechanisms. RNA sequencing, flow cytometry, quantitative PCR and colonic organoid cultures were performed to evaluate transcriptional reprogramming, immune modulation and epithelial plasticity.

Result and discussion:

NAPE-PLD expression was significantly reduced in tumors from obese CRC patients compared with normal-weight counterparts. Obesity-associated CRC displayed activation of WNT signaling and suppression of tight junction pathways, consistent with barrier dysfunction and proliferative rewiring. In obese db/db mice, pharmacological inhibition of NAPE-PLD reduced survival, increased tumor burden and promoted a pro-inflammatory immune shift. Consistently, epithelial-specific deletion of NAPE-PLD altered colonic NAE levels and induced transcriptional reprogramming toward proliferative and stemness-associated programs. NAPE-PLD-deficient organoids exhibited hyperproliferative growth and structural enlargement, with dysregulation of stem cell markers (LGR5, ASCL2, BMI1, CD133, SOX9) and differentiation markers (VIL1, CDX2, MUC2, KLF4, KRT20), indicating enhanced epithelial plasticity.

Conclusion:

Epithelial NAPE-PLD functions as a metabolic checkpoint preserving intestinal homeostasis in obesity-associated CRC. Its loss disrupts NAE signaling, promotes stemness-driven reprogramming and enhances tumor progression. Targeting the NAPE-PLD/NAE axis may represent a therapeutic opportunity in metabolically driven CRC.