Serum STARD4-AS1 as a Novel Marker for Gastric Cancer Diagnosis and Promotes Gastric Cancer Progression.

[INTRODUCTION] Gastric cancer (GC) is a lethal malignant tumor necessitating high-sensitivity detection to improve diagnostic accuracy and the prognosis of patients. Alterations in long noncoding RNAs can influence cancer progression through various mechanisms. Our study tried to explore the potential of STARD4 antisense RNA 1 (STARD4-AS1) as a GC biomarker and its mechanism of action in GC development.

[METHODS] Pan-cancer analysis using The Cancer Genome Atlas database identified STARD4-AS1. Serum STARD4-AS1 levels in patients with GC were measured by quantitative real-time PCR, and diagnostic efficiency was assessed using receiver operating characteristic curves. Functional inactivation experiments and western blotting evaluated the biological role of STARD4-AS1 in GC cells. Bioinformatics analysis explored its potential role in GC immunotherapy and underlying mechanisms.

[RESULTS] Pan-cancer analysis revealed lower overall survival in GC patients with higher STARD4-AS1 expression. Quantitative real-time PCR confirmed the reproducibility and stability of STARD4-AS1 as a marker. Serum STARD4-AS1 levels in patients with GC were significantly higher than those in healthy subjects and gastritis patients. Receiver operating characteristic analysis demonstrated that STARD4-AS1 outperformed carcinoembryonic antigen, carbohydrate antigen 199 , and carbohydrate antigen 724 in differentiating GC from gastritis, with optimal diagnostic power when combined with these markers. Knockdown of STARD4-AS1 inhibited GC cell proliferation and metastasis and inhibited the epithelial-mesenchymal transition process. Biosignature prediction indicated that higher STARD4-AS1 expression could evaluate prognosis, as well as regulate GC progression through phosphatidylinositol-mediated signaling, and transmembrane receptor protein tyrosine phosphatase signaling pathway.

[DISCUSSION] Serum STARD4-AS1 may serve as a diagnostic biomarker and oncogene function for GC for improving diagnosis, monitoring progression, and evaluating prognosis of GC.