Determining the effects of Ephrin Type B Receptor 6 and Type A Receptor 3 on facilitating colorectal epithelial cell malignant transformation.

Ephrin Type-A Receptor 3 (EphA3) and Ephrin Type-B Receptor 6 (EphB6) belong to the ephrin receptor group consisting of the largest subset of receptor tyrosine kinases (RTKs) and are essential for neurogenesis and embryogenesis. The current study aimed to evaluate their functional roles in transforming colorectal epithelial cells and dissect the underlying molecular mechanisms. We observed altered EphA3 and EphB6 expression in tumor tissues as compared to normal tissues in a tissue microarray study. Enforced EphB6 expression promoted IMCE cell proliferation, migration, and invasion in vitro and tumor formation in nude mice, with a stronger oncogenic activity than EphA3. Pathway analysis of differentially expressed genes from a gene microarray study provided important insight into potential mechanisms through which EphB6 may regulate the malignant transformation of colorectal epithelial cells. This study represents the first demonstration of EphB6 in enhancing colorectal epithelial cell transformation, suggesting its stipulative role in the early-stage of colorectal tumorigenesis. Our findings primarily uncover novel biomarkers and therapeutic targets of colorectal cancer.