Rsf-1/HBXAP overexpression is associated with disease-specific survival of patients with gallbladder carcinoma

Dysregulated chromatin remodeling often leads to abnormal gene expression or silencing in cells, thereby implicating tumor development and progression. As a subunit of remodeling and spacing factor (RSF) complex, Rsf-1, a novel nuclear protein with histone chaperon function, mediates ATPase-dependent chromatin remodeling and confer tumor aggressiveness in common carcinomas. We aimed, for the first time, to evaluate the Rsf-1 expression status and its associations with clinicopathological features and patient survival in a well characterized cohort of gallbladder carcinomas. Using tissue microarray-based immunohistochemistry, we assessed Rsf-1 expression in gallbladder carcinomas, yielding 88 cases undergoing surgical intervention with interpretable results. The Rsf-1 overexpression, present in 61 cases (69.3%), was significantly associated with higher histological grades (p = 0.002) and vascular invasion (p = 0.037) and marginally with non-papillary histotypes (p = 0.058). In univariate log-rank analysis, Rsf-1 overexpression was significantly predictive of disease-specific survival (p = 0.0015), which remained prognostically independent [p = 0.0191, risk ratio (RR) = 2.683], along with American Joint Committee on Cancer stages II-IV (p = 0.0265, RR = 2.102). Our findings indicate that Rsf-1 overexpression is common and associated with adverse prognosticators in gallbladder carcinomas. It may confer tumor aggressiveness through chromatin remodeling and represents a potential prognostic biomarker of gallbladder carcinomas.