Y-box binding protein 1 is correlated with lymph node metastasis in intestinal-type gastric cancer

Aims Y‐box binding protein‐1 (YB‐1) is known to modulate gene transcription and protein translation, as well as cellular response to drug treatment. The aim of this study is to correlate YB‐1 protein expression levels with clinicopathological parameters in intestinal‐type gastric cancer tissue samples (as categorized by the Lauren classification) and substantiate the findings with in vitro experimentation. Methods and results Paraffin‐embedded samples from 167 patients with intestinal‐type gastric cancer were used for the construction of tissue microarrays (TMAs). TMA slides were immunostained and YB‐1 immunoreactivity score was based on the weighted average intensity score. Univariate analysis revealed that YB‐1 immunohistochemical expression was correlated significantly with lymph node status (P = 0.054, borderline significance) and perforation (P = 0.043). YB‐1 expression was also found to be an independent predictor of lymph node spread by multivariate analysis. Furthermore, siRNA‐mediated YB‐1 gene knockdown in MKN7 gastric cancer cells (which is known to originate from an intestinal‐type gastric cancer tissue) inhibited cell migration (P = 0.0002) and invasion in vitro (P = 0.0129) significantly. Conclusion YB‐1 expression is associated with lymph node spread in intestinal‐type gastric cancer and is a potential prognostic biomarker in this subtype of gastric cancer.