SMURF1 Downregulation Highlights Its Potential Role in Breast Cancer

This study aimed to evaluate the mRNA and protein levels of SMURF1 and SMURF2 in breast cancer and to elucidate their potential biological roles through in silico analyses. Tumor and adjacent normal tissue samples were collected from 30 newly diagnosed breast cancer patients who underwent mastectomy. The mRNA expression levels of SMURF1 and SMURF2 were analyzed by quantitative PCR (qPCR), and their protein expression patterns were evaluated using immunohistochemistry (IHC). In addition, protein–protein interaction (PPI) and functional enrichment analyses were performed via the STRING database to identify potential molecular interactions and biological pathways associated with these genes. The mRNA expression level of SMURF1 was significantly downregulated in tumor tissues compared to normal breast tissues (p = 0.002), whereas no significant difference was observed in SMURF2 mRNA expression (p = 0.981). IHC results revealed that SMURF1 and SMURF2 protein levels did not differ significantly between tumor and normal samples. The in silico analysis demonstrated that SMURF1 and SMURF2 interact with multiple proteins involved in key signaling pathways, particularly the TGF-β/BMP and Wnt/β-catenin pathways. The findings suggest that the downregulation of SMURF1 in breast cancer may contribute to tumor progression by enhancing Wnt/β-catenin signaling activity. The interactions of SMURF1 and SMURF2 with TGF-β/BMP pathway regulators indicate that these genes may play dual roles in both tumor-suppressive and oncogenic mechanisms, depending on the cellular context.