Discoidin domain receptor 1 (DDR1), a promising biomarker, induces epithelial to mesenchymal transition in renal cancer cells

Discoidin domain receptor I (DDR1) is confirmed as a receptor tyrosine kinase (RTK), which plays a consequential role in a variety of cancers. Nevertheless, the influence of DDR1 expression and development in renal clear cell carcinoma (RCCC) are still not well corroborated. In our research, we firstly discovered that the expression level of DDR1 was remarkable related to TNM stage (p = 0.032), depth of tumor invasion (p = 0.047), and lymph node metastasis (p = 0.034) in 119 RCCC tissue samples using tissue microarray. The function of DDR1 was then evaluated in vitro using collagen I and DDR1 small interfering RNA (siRNA) to regulate the expression of DDR1 in OS-RC-2 and ACHN renal cancer cells (RCC). DDR1 expression correlated with increased RCC cell migration, invasion, and angiogenesis. Further study revealed that high expression of DDR1 can result in epithelial to mesenchymal transition (EMT) activation. Western blot assay showed that the N-cadherin protein and vimentin were induced while E-cadherin was reduced after DDR1 over expression. Our results suggest that DDR1 is both a prognostic marker for RCCC and a potential functional target for therapy.