Overexpression of Discoidin Domain Receptor 1 Is Associated with Tumor Size in Esophageal Squamous Cell Carcinoma

Background. Discoidin domain receptor 1 (DDR1) is confirmed as a member of the transmembrane receptor tyrosine kinase (RTK) superfamily, which plays an influential role in various cancers. Increasing evidence has suggested that DDR1 is plays role in cancer progression and metastasis. However, DDR1 function and the underlying mechanism of DDR1 receptor signaling pathways is largely unknown, especially in esophageal squamous cell carcinoma (ESCC). Methods and results. We obtained 42 paired samples of ESCC tumors (N = 21) and adjacent normal tissues (N = 21) from newly diagnosed ESCC patients. In this study, the expression of DDR1 in esophageal cancer was retrieved based on the GENT2, OncoDB databases. AlsoqRT-PCR experiments was used to measure DDR1 expression experimentally in ESCC tissues compared to adjacent non-tumor tissues (NTs). Moreover, the correlation between the expression of DDR1 and clinic pathologic factors was analyzed. The diagnostic significance of the results was subsequently evaluated utilizing the receiver operating characteristic (ROC) curve. The result showed that mRNA expression of DDR1 was up-regulated in ESCC tissues compared with NTs (p = 0.0001). Statistical analysis revealed that DDR1 expression was significantly higher in samples with a tumor size of more than five centimeters (p = 0.02). The ROC curve analysis indicated that DDR1 expression level in tissue potentially have high accuracy for diagnosing ESCC compared with adjacent non-tumor tissues NTs (AUC = 0.92, Specificity = 84%, sensitivity = 96%). Conclusions. Our findings suggest that overexpression of the DDR1 might play a function in promoting cancer and tumor size. Moreover, DDR1 can potentially act as a novel biomarker for identifying ESCC patients, indicating the potential of this receptor for ESCC-targeted therapeutics.