Proline- and Serine-Rich Coiled-Coil 1 Predicts an Unfavorable Prognosis and Exhibits Oncogenic Activities in Breast Cancer

Proline- and serine-rich coiled-coil 1 (PSRC1) has been implicated in various cancers, yet its role in breast cancer (BRCA) remains incompletely understood. Here, we employed the UALCAN database to explore PSRC1 expression in BRCA and obtained survival prognosis data from the Kaplan–Meier Plotter database. Additionally, PSRC1 expression was analyzed in 81 pairs of BRCA tissues and their corresponding adjacent noncancerous tissues through quantitative real-time PCR, western blotting, and immunohistochemistry. We observed PSRC1 was overexpressed in BRCA tissues, especially in triple negative breast cancer (TNBC). Higher PSRC1 levels correlated with poorer outcomes for BRCA patients. In 81 BRCA tumor tissues, PSRC1 protein levels were significantly associated with positive vessel tumor embolus. Subsequently, the clinical relevance of PSRC1 in BRCA was assessed using the chi-square test, the Kaplan–Meier model with a Log-rank test, as well as univariate and multivariate analyses. Patients with high PSRC1 had worse prognoses. Elevated PSRC1 expression served as an independent predictor of prognosis. Moreover, we investigated the effects of PSRC1 on BRCA cell phenotypes in MCF-7 and BT549 cells and used a mouse xenograft model with BT549 cells to determine its in vivo effect. Both in vitro and in vivo experiments demonstrated that silencing PSRC1 inhibited cell proliferation, migration, and tumor development. In summary, our results indicate that high PSRC1 expression is closely linked to BRCA patient survival and could be a valuable prognostic biomarker for this disease.