Overexpression of SCAMP3 is an indicator of poor prognosis in hepatocellular carcinoma

SCAMP3, an isoform of the secretory carrier membrane proteins (SCAMPs) family, is a membrane-trafficking protein involved in endosome transport. Previous microarray data showed that SCAMP3 mRNA is highly expressed in hepatocellular carcinoma (HCC). In this study, the expression and clinical significance of SCAMP3 in 100 pairs of HCC and adjacent normal tissue were investigated. siRNA transfection was performed to silence SCAMP3 expression in HCC cells. The MTS assay and flow cytometry were used to detect the proliferation, cell cycle progression of HCC cells. Compared with adjacent normal tissues, SCAMP3 expression was dramatically increased in HCC tissues demonstrated by Western blotting (P < 0.05). In immunohistochemistry, compared with the adjacent normal tissues, SCAMP3 was detected in 96% of the HCC samples with a significant increase in intensity and number of stained cells (P < 0.05). Also, high SCAMP3 expression was found in 86% of the HCC samples (P < 0.05). The increased SCAMP3 expression was significantly correlated with vascular invasion (P = 0.004) and tumor stage (P = 0.001). Univariate and multivariate survival analyses showed that the expression of SCAMP3 was an independent prognostic factor of overall survival of HCC patients. Knockdown of SCAMP3 expression led to suppression of cell proliferation and blockage of cell cycle of HCC cells. In conclusion, our present study suggested that SCAMP3 may serve as a promising prognostic biomarker and molecular target of HCC and further investigation is warranted.