GPR17 Suppresses Triple-Negative Breast Cancer Progression and Serves as an Independent Prognostic Biomarke

G protein-coupled receptor 17 (GPR17), a Gi protein-coupled receptor, has been defined poorly about its roles and clinical significance in triple-negative breast cancer (TNBC). The biological expression profile, prognostic value and functional roles of GPR17 in TNBC were elucidated in the present study. Differentially expressed genes were screened through comprehensive bioinformatics analyses of the GSE233242 dataset. GPR17 expression patterns and their prognostic significance in TNBC were evaluated based on the UALCAN, bc-GenExMiner v4.8 and KM-Plotter databases. Prognostic correlations of GPR17 were further validated in a retrospective cohort comprising 163 TNBC patients. In vitro functional assays for cell proliferation, migration and invasion were conducted in MDA-MB-231 and MDA-MB-453 cells after GPR17 overexpression. GPR17 was significantly downregulated in TNBC tumor tissues ( p < 0.001), and reduced GPR17 expression was associated with more aggressive tumor phenotypes in TNBC patients. GPR17 expression was closely correlated with clinical T stage and lymph node metastasis, and was identified as an independent prognostic factor for the disease. Ectopic GPR17 overexpression significantly suppressed the proliferative, migratory and invasive capacities of MDA-MB-231 and MDA-MB-453 TNBC cell lines. GPR17 holds potential as a novel prognostic biomarker for TNBC, with its expression levels closely associated with tumor progression and able to predict clinical outcomes in TNBC patients. GPR17 was identified as a DEG from GSE233242. In 163 TNBC patients, low GPR17 expression correlated with poor OS and RFS. In vitro, GPR17 overexpression suppressed TNBC cell proliferation, migration, and invasion. Low GPR17 predicts poor prognosis and its overexpression suppresses malignant phenotypes.