Background: Epithelium-specific ETS 3 (ESE3) is down-regulated frequently in several malignancies and involved in carcinogenesis and progression. However, ESE3 expression pattern and its relationship with clinical features and prognosis in hepatocellular carcinoma (HCC) are still largely unknown.
Methods: ESE3 expression was analyzed by quantitative real-time PCR and western blotting in HCC cell lines, and then, it was analyzed by immunohistochemistry in HCC tissues and peritumoral normal tissues from total 94 HCC patients. The relationship between ESE3 expression and clinical features was investigated to illustrate the potential prognostic value in HCC. ESE3 roles on HCC progression were evaluated in vitro and vivo by MTT assay and mice tumor model, respectively.
Results: ESE3, mainly located in the cytoplasm, was remarkably down-regulated in HCC tissues and cell lines. Low ESE3 expression was positively associated with tumor progression and metastasis features. Kaplan-Meier analysis demonstrated that low ESE3 expression contributed to poor recurrence-free survival (RFS) and overall survival (OS) (both p < 0.01) of patients, and maintained its prognostic value in predicting poor RFS and OS of "Early-stage" HCC patients regardless of clinical features being studied. Multivariate survival analysis was also identified ESE3 as an independent prognostic factor for RFS (p = 0.05 for marginal significance) and OS (p = 0.031). ESE3 expression restoration in cells led to a significant inhibition in HepG2 cell proliferation in vitro and vivo (both p < 0.001).
Conclusions: Down-regulated ESE3 expression in HCC tissues could serve as a potential therapeutic target against HCC and appears to be as a poor prognostic indicator for prognosis, especially in "Early-stage" HCC patients.
Keywords: Epithelium-specific ETS 3; Hepatocellular carcinoma; Prognostic indicator; Therapeutic target; Tissue microarray.