SCIN: A Key Driver in Chronic Atrophic Gastritis-Gastric Cancer Cascade with Implications for Immunity and Prognosis

Gastric cancer (GC) is a major global health burden, and chronic atrophic gastritis (CAG), a key precancerous lesion in the Correa cascade, is critical in its pathogenesis. As a Ca²⁺-dependent actin-regulating protein, scinderin (SCIN) has been implicated in tumor progression across multiple malignancies, including gastric cancer. This study investigated SCIN expression dynamics during CAG-to-GC progression, its association with the tumor immune microenvironment (TIME) and clinical prognosis, and validated its role via integrated bioinformatics and experiments.

Transcriptomic data from TCGA and GEO were analyzed using R. WGCNA and ceRNA networks identified SCIN as the core RNA and its interacting miRNAs/lncRNAs. GSVA, GSEA, immune infiltration, and checkpoint analyses explored SCIN's immunological relevance. Prognostic value was assessed via Cox models and ROC curves. SCIN expression was validated in 28 human gastric tissues by RT-qPCR and Western blotting. Functional assays (CCK-8, Transwell, flow cytometry) investigated its role in GC cells.

SCIN expression significantly increased along normal mucosa→CAG→GC, with high diagnostic performance (AUC). Elevated SCIN correlated with poor survival and served as an independent prognostic factor. It was involved in immune-related pathways, modulated the TIME, and correlated with immune checkpoint markers. SCIN knockdown inhibited GC cell migration, enhanced apoptosis, and altered cell cycle.

This study is the first to identify SCIN as a key molecular driver in the CAG-to-GC transition. SCIN represents a robust prognostic biomarker and a potential target for immunotherapeutic intervention in GC.