Overexpression of non-SMC condensin I complex subunit G serves as a promising prognostic marker and therapeutic target for hepatocellular carcinoma

The non-SMC condensin I complex subunit G (NCAPG) that organizes the coiling topology of individual chromatids, represents an overexpressed antigen in various types of cancer, and also contributes to restructuring chromatin into rod-shaped mitotic chromosomes and ensuring the segregation of sister chromatid during cell division. In this study, we investigated the association between NCAPG expression and the biological behavior of hepatocellular carcinoma (HCC) to further explore the potential of NCAPG as a therapeutic target. The expression of NCAPG was detected in human HCC cell lines and tumor samples. The effects of NCAPG on the cell cycle, apoptosis and metastasis were investigated by various assays. NCAPG was found to be overexpressed in HCC compared with the adjacent normal tissue (P<0.001), and high levels of NCAPG expression were found to significantly correlate with recurrence, the time of recurrence, metastasis, differentiation and TNM stage. Furthermore, an elevated expression of NCAPG was associated with a poor overall survival (P<0.05). In addition, in vitro experiments further confirmed the ex vivo data; i.e., the knockdown of NCAPG expression reduced HCC cell viability, but induced apoptosis and arrested the cells at the S phase of the cell cycle. The knockdown of NCAPG expression also inhibited tumor cell migration and the cell invasive capacity in vitro. At the protein level, the knockdown of NCAPG expression upregulated Bax, cleaved caspase-3 and E-cadherin, but downregulated cyclin A1, CDK2, Bcl-2, N-cadherin and HOXB9 expression, suggesting that the knockdown of NCAPG expression suppressed tumor cell epithelial-mesenchymal transition. On the whole, this study demonstrates that NCAPG plays an important role in the development and progression of HCC, and that it may be a novel therapeutic target for patients with HCC.