SCD5 Expression Correlates with Prognosis and Response to Neoadjuvant Chemotherapy in Breast Cancer

Neoadjuvant chemotherapy (NACT) represents a standard option for breast cancer. Unfortunately, about 55% to 80% of breast cancer patients do not have a favorable response to chemotherapy. Highly specific tumor biomarker that can predict the pathological response to neoadjuvant chemotherapy is lacking. Stearoyl-CoA desaturase 5 (SCD5) is an integral membrane protein of the endoplasmic reticulum that participates in lipid metabolism. However, the role of SCD5 in breast cancer remains unclear. Our study aims to understand its expression signature, prognosis value and correlation with pathological response to NACT in breast cancer using public databases. Analysis of samples from public databases showed that SCD5 expression was down-regulated across human cancers and associated with more aggressive breast cancer phenotypes. Survival analysis revealed that SCD5 expression was related to prognosis in breast cancer, especially triple-negative breast cancer (TNBC). Integrated analysis of multiple public datasets indicated that SCD5 expression signature was associated with response to NACT, particularly in TNBC. Based on functional enrichment analysis, SCD5 was implicated in pathways involved in metabolism and cell cycle. SCD5-related biological functions included negative regulation of cell cycle, cell division and DNA repair. Moreover, a significantly negative correlation between SCD5 expression and several cell cycle regulators was noted. Taken together, SCD5 was involved in the development and progression of breast cancer and might be a predictive biomarker for response to NACT. These results provided information for us to better understand SCD5 from the perspective of bioinformatics and highlighted the clinical importance of SCD5 in breast cancer, especially TNBC.