Gene Expression Defines a Claudinlow Subtype in Stomach Adenocarcinomas

Overview

A distinct Claudinlow subtype of stomach adenocarcinoma (STAD) characterized by reduced Claudin expression and a high NF-YAl/NF-YAs ratio has been identified. This subtype shows a unique 158-gene signature linked to poor clinical outcomes and EMT features.

Background

Stomach adenocarcinoma (STAD) is a heterogeneous cancer with poor survival rates, traditionally classified by histology and molecular features into subtypes such as EBV, MSI, GS, and CIN. Claudins are epithelial cell proteins involved in cell–cell adhesion, and their reduced expression is associated with aggressive epithelial cancers including STAD. The NF-Y transcription factor, particularly the ratio of its NF-YA long to short splice variants, plays a role in regulating EMT and tumor aggressiveness. Previous studies in breast cancer have linked NF-YA isoform ratios to EMT phenotypes, suggesting a similar mechanism in STAD.

Data Highlights

Key Findings

• A Claudinlow STAD subtype was identified by comparing a 158-gene NF-YA isoform signature with a 24-gene EMT-related signature.
• This subtype exhibits reduced expression of Claudin-3, Claudin-4, and Claudin-7, proteins critical for epithelial cell adhesion.
• High NF-YAl/NF-YAs splice variant ratio correlates with EMT features and poor prognosis in STAD.
• STAD cell lines were reclassified based on gene expression profiles, improving subtype characterization.
• Findings parallel observations in breast cancer, where NF-YA isoform ratios influence EMT and metastatic potential.

Clinical Implications

Recognition of the Claudinlow STAD subtype with elevated NF-YAl/NF-YAs ratio may refine prognostic stratification and guide therapeutic decisions. Targeting pathways regulating NF-YA splicing or Claudin expression could represent novel treatment strategies. Molecular classification beyond histology is essential for personalized management of STAD patients.

Conclusion

This study identifies a distinct Claudinlow molecular subtype of stomach adenocarcinoma characterized by reduced Claudin expression and an elevated NF-YAl/NF-YAs ratio, associated with EMT features and poor clinical outcomes. These insights enhance the molecular taxonomy of STAD and may inform future therapeutic approaches.

References

1. Nishijima et al. 2018 -- Identification of Claudinlow Subtype in STAD
2. TCGA Research Network 2014 -- Comprehensive Molecular Characterization of Gastric Adenocarcinoma
3. Chaligne et al. 2020 -- NF-YA Isoforms and EMT in Breast Cancer
4. Harbin Medical University Cancer Hospital Dataset 2021