Poly (C)-binding protein 2 (PCBP2) promotes the progression of esophageal squamous cell carcinoma (ESCC) through regulating cellular proliferation and apoptosis

Abstract

PCBP2 (Poly(C)-binding protein 2) is a member of PCBP family, which has many functions including mRNA stabilization, translational silence and translational enhancement performed by their poly(C)-binding ability. The abnormal expression of PCBP2 was correlated with various carcinomas. However, the significance and mechanism of PCBP2 in esophageal squamous cell carcinoma (ESCC) progression remain unclear. In this study, Western Blot and immunohistochemistry (IHC) analysis revealed that PCBP2 was overexpressed in ESCC tissues and cell lines. Statistical results also indicated that PCBP2 expression level was significantly positively correlated with ESCC clinicopathological parameters such as tumor grade and tumor size. Furthermore, PCBP2 expression level could also be recognized as an independent prognostic factor for ESCC patients' overall survival. Serum starvation and refeeding assay along with PCBP2-shRNA transfection demonstrated that PCBP2 expression promoted proliferation of ESCC cells. The results above are partly due to growth arrest of cell cycle at G1/S phase. We also found that reduced PCBP2 expression might induce ESCC cell apoptosis with increased cleaved caspase3 expression. Overall, our findings indicated that PCBP2 might be involved in the ESCC progression and be considered as a new treatment target in ESCC.

Keywords: Apoptosis; Esophageal squamous cell carcinoma (ESCC); PCBP2; Proliferation.