Clinical significance and in vitro biological function of GALNS protein in hepatocellular carcinoma

To investigate the clinical significance and in vitro biological function of N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in hepatocellular carcinoma (HCC).

A retrospective cohort study was conducted on 72 HCC patients in our hospital from January 2008 to December 2014. Their HCC tissues and para-cancerous tissues were collected and detected for GALNS expression with immunohistochemical staining. The clinical significance of GALNS in HCC was analyzed based on the results to immunohistochemical staining and clinicopathological data. The biological function of GALNS in HCC cell lines Huh7 and LM3 was detected by cell migration and proliferation assay after GALNS knockdown.

①In the 72 HCC tissues, there were 32 samples with high and 40 with low expression of GALNS. Its high level was associated with tumor length, TNM stage and intrahepatic metastasis (Chi-square=20.649, 14.849, 5.667, P<0.05); ②The 1-, 3- and 5-year survival rates of the 72 patients after surgical treatment were 87.50%, 42.50% and 40.00%, respectively for those with low GALNS level, and 37.50%, 12.50% and 3.13%, for those high expression level. The survival rate was significantly better in the low expression patients than those of high level (Chi-square=9.268, P<0.05); ③GALNS expression (HR=2.502, 95%CI=1.369-4.572, P=0.003), distant metastasis (HR=1.908, 95%CI=1.018-3.573, P=0.044), vascular invasion (HR=2.361, 95%CI=1.267-4.398, P=0.044) P=0.007) and pathological stage (HR=2.223, 95%CI=1.185-4.171, P=0.013) were independent risk factors for HCC. ④Down-regulation of GALNS significantly inhibited the proliferation and metastasis of HCC cells (P<0.05).

GALNS is highly expressed in liver cancer tissues and an independent risk factor for the prognosis of HCC patients. Downregulation of GALNS can inhibit the proliferation and migration of liver cancer cells.