Overexpression of DIXDC1 correlates with enhanced cell growth and poor prognosis in human pancreatic ductal adenocarcinoma.

ABSTRACT

Disheveled-axin (DIX) domain containing 1 (DIXDC1), a protein containing a coiled-coil domain and a DIX domain, is involved in the progression of multiple cancers. However, the role of DIXDC1 in human pancreatic ductal adenocarcinoma (PDAC) remains unclear. In this study, we investigated the role and prognostic value of DIXDC1 in the development of human PDAC. Western blot analysis revealed that DIXDC1 was highly expressed in PDAC tissues and cell lines. Immunohistochemistry on 165 paraffin-embedded sections showed that high expression of DIXDC1 was significantly correlated with tumor size (P = .002), histological differentiation (P = .001), tumor node metastasis (TNM) stage (P = .001), and the proliferation marker Ki-67 (P = .000). Importantly, Kaplan-Meier analysis revealed that high expression of DIXDC1 was obviously correlated with worsened overall survival (P < .001). In vitro, using serum starvation-refeeding experiments, our results suggested that DIXDC1 was up-regulated in proliferating PDAC cells, together with the percentage of cells at the S phase, and was correlated with the expression of cyclin D1. In addition, depletion of DIXDC1 decreased PCNA and cyclin D1 levels. Accordingly, CCK-8, colony formation, and flow cytometry analyses revealed that knocking down DIXDC1 induced growth impairment and G1/S cell cycle arrest in PDAC cells, while overexpression of DIXDC1 led to accelerated cell proliferation and cell cycle progression. On the basis of these results, we propose that DIXDC1 could play an important role in the tumorigenesis of PDAC and serve as a potential therapeutical target to prevent PDAC progression.