ABSTRACT
In addition to regulating apoptosis via its interaction with the death domain of Fas receptor, death domain associated protein 6 (Daxx) is also known to be involved in transcriptional regulation, suggesting that the function of Daxx depends on its subcellular localization. In this study, we aimed to explore Daxx subcellular localization in gastric cancer (GC) cells and correlate the findings with clinical data in GC patients. Seventy pairs of tissue samples (GC and adjacent normal tissue) were analyzed immunohistochemically for Daxx expression and localization (nuclear and cytoplasmic). The Daxx Nuclear/Cytoplasmic ratio (Daxx NCR) values in tissue microarray data with 522 tumor samples were further analyzed. The defined Prior cohort (n = 277, treatment between 2006 and 2009) and Recent cohort (n = 245, treatment between 2010 and 2011) were then used to examine the relationship between Daxx NCR and clinical data. The Daxx NCR was found to be clinically informative and significantly higher in GC tissue. Using Daxx NCR (risk ratio = 2.0), both the Prior and Recent cohorts were divided into high- and low-risk groups. Relative to the low-risk group, the high-risk patients had a shorter disease free survival (DFS) and overall survival (OS) in both cohorts. Importantly, postoperative chemotherapy was found having differential effect on high- and low-risk patients. Such chemotherapy brought no survival benefit, (and could potentially be detrimental,) to high-risk patients after surgery. Daxx NCR could be used as a prognosis factor in GC patients, and may help select the appropriate population to benefit from chemotherapy after surgery.
