Elevated HBXIP expression is associated with aggressive phenotype and poor prognosis in esophageal squamous cell carcinoma.

The oncoprotein hepatitis B virus X-interacting protein (HBXIP) has been suggested to play an essential role in several malignancies. However, the clinicopathological significance and prognostic value of HBXIP expression in esophageal squamous cell carcinoma (ESCC) is still unknown. Therefore the aim of this study was to characterize HBXIP expression and its prognostic value in ESCC. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to assess the mRNA and protein expression of HBXIP in ESCC tissues and cell lines. Immunohistochemistry (IHC) was conducted to characterize the expression pattern of HBXIP in 152 archived paraffin-embedded ESCC and matched nontumorous tissues. The mRNA and protein expression of HBXIP in ESCC tissues was significantly higher than those in adjacent nontumorous tissues. High HBXIP expression was associated with histological grade ( P =0.016), depth of tumor invasion ( P =0.012), lymph node metastasis ( P <0.001) and TNM stage ( P =0.002). Kaplan-Meier analysis indicated that ESCC patients with high HBXIP expression had poor disease-free survival (DFS) and overall survival (OS). Furthermore, multivariate Cox regression analyses demonstrated that HBXIP expression remained an independent prognostic factor for DFS and OS. Collectively, our present study demonstrated that HBXIP may be a candidate molecular prognostic marker for ESCC.