Knowledge Bank

Cancer-associated fibroblasts (CAF) are stromal cells that have been shown to regulate invasion and metastasis in various cancers including breast cancer. However, the molecular mechanism in breast cancer is not known. This project aims to analyze the role of tumor suppressor SLIT2 in regulating CAF differentiation in breast cancer. The level of SLIT2 mRNA was analyzed in human normal epithelial and breast adenocarcinoma cells by RT-PCR. SLIT2 protein expression in normal breast epithelial cells versus fibroblasts was compared by Western Blot technique. Results showed that SLIT2 mRNA is downregulated in breast adenocarcinoma cells compared to normal breast epithelial cells. Similarly, SLIT2 is overexpressed in normal fibroblasts versus normal epithelial cells. In addition, fibroblast cells were treated with conditioned media obtained from breast adenocarcinoma cells to induce myofibroblasts differentiation. SLIT2 and α-SMA (myofibroblasts marker) mRNA expression in myofibroblasts and fibroblasts was analyzed by RT-PCR. Results showed that the breast adenocarcinoma cell conditioned media enhanced α-SMA and downregulated SLIT2 in myofibroblasts. SLIT2 expression in patient samples was extracted from publicly available datasets (Oncomine and CBioportal). SLIT2 is significantly downregulated among invasive cancers. SLIT2 alterations were also investigated and compared to survival outcomes. Alteration(s) in SLIT2 gene and transcription correlates to lower survival compared to breast cancer patients without SLIT2 alterations. This study suggests use of CAF-secreted factors as a tool to develop novel strategy for targeting breast cancer cells. Complete understanding of the cell signaling mechanism between breast adenocarcinoma cells and cancer-associated fibroblasts could be utilized to develop therapeutic agents against breast cancer.