NDRG3 facilitates colorectal cancer metastasis through activating Src phosphorylation

Ting Li, Ruochuan Sun, Mingdian Lu, Jiacong Chang, Xiangling Meng,* Huo Wu* Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, He Fei, 230222, China *These authors contributed equally to this work Background: NDRG3 is an N-myc downregulated gene (NDRG). The aim of this article was to identify the role of NDRG3 in colorectal cancer (CRC) and to determine the mechanism underlying its function. Methods: Using immunohistochemical staining, expression and clinicopathological variables of NDRG3 were analyzed in 170 CRC samples. Overexpression of NDRG3 was employed in SW1116 cells, downregulation of NDRG3 was achieved in RKO cells, then migration and invasion assays were performed in vitro, and a mouse model was constructed in vivo. Results: Increased expression of NDRG3 was observed in primary CRC tissues, and this expression was correlated with distant metastasis. Consistently, ectopic expression of NDRG3 in SW1116 cells enhanced cell migration and invasion, while knockdown of NDRG3 in RKO cells significantly suppressed CRC cell metastasis. The portal vein injection models suggested that NDRG3 overexpression facilitates liver metastasis. These events were associated with the phosphorylation of Src (c-Src) at Tyr 419 site. Conclusion: Our results showed that NDRG3 facilitates CRC migration and invasion by activating Src phosphorylation, suggesting the role of NDRG3 as a candidate oncogene. Keywords: NDRG3, colorectal cancer, metastasis, Sr