Screening Biomarkers Related to Circadian Rhythm of Gastric Cancer Through Bioinformatics.

Circadian rhythm (CR) dysregulation is increasingly recognized as a contributor to gastric cancer (GC) development, yet the biological and immunological consequences of CR-related alterations remain unclear. In this study, integrative transcriptomic analyses identified 147 CR-related differentially expressed genes in GC. Functional enrichment revealed significant involvement in circadian processes, cytokine activity, and immune-related signaling pathways. By applying three complementary machine learning algorithms, five robust hub genes (INHBA, DEPTOR, PDCD4, SELENBP1, and SIRT4) were identified. Among them, INHBA and SELENBP1 showed significant prognostic value, and SELENBP1 expression was strongly associated with immune infiltration patterns. Experimental validation confirmed that SELENBP1 overexpression suppressed GC cell proliferation, migration, and inflammatory cytokine secretion, and displayed a clear 24-h circadian oscillation. Collectively, these findings highlight key CR-related molecular alterations in GC and identify SELENBP1 as a promising diagnostic biomarker with potential immunoregulatory and circadian-dependent functional relevance.