Overexpression of NUAK1 is associated with disease-free survival and overall survival in patients with gastric cancer.

Novel (nua) kinase family 1 (NUAK1) is a member of the human adenosine monophosphate-activated protein kinases family, which is overexpressed in multiple human malignancies and thought to be involved in tumor invasion and metastasis ability. Our study is to investigate the association of NUAK1 expression with clinicopathological parameters and prognostic significance of patients with gastric cancer. The expression patterns of the NUAK1 protein in 117 primary archival gastric cancer specimens and 46 adjacent normal epithelial tissues from patients were detected by immunohistochemistry assay. Staining evaluation results were analyzed statistically in relation to various clinicopathological characters, recurrence-free survival and overall survival. High level of NUAK1 expression was detected in gastric cancer, significantly more than in adjacent normal epithelial cells. In gastric cancer, NUAK1 was positively correlated with depth of invasion, lymph node metastasis, pathological stage, surgical resection and histological differentiation. However, no correlations between NUAK1 expression and patients' age, sex, tumor size, location, CA19-9 or CEA were detected. The recurrence-free survival and overall survival were significantly shorter for patients with NUAK1 higher scores than those with NUAK1 lower scores. Multivariate analysis identified NUAK1 was an independent prognostic factor for both recurrence-free survival and overall survival. Our findings provided convincing evidence for NUAK1 overexpression, which was tightly associated with more aggressive tumor behavior and a poor prognosis, indicating that NUAK1 is a valuable molecular biomarker for gastric cancer progression. It might also act as a promising target for both prognostic prediction and therapeutics.