Down-regulation of β-1,3-N-acetylglucosaminyltransferase-8 by siRNA inhibits the growth of human gastric cancer.

β-1,3-N-acetylglucosaminyltransferase-8 (β3Gn-T8) is the most recently identified enzyme in the β3Gn-T family, but its biological function is poorly understood. To elucidate the effects of β3Gn-T8 on gastric cancer behavior, β3Gn-T8 was down-regulated in AGS cells using small interfering RNA (siRNA). The mRNA and protein expression levels of β3Gn-T8 were detected using RT-PCR and Western blotting, respectively, and sequence-specific inhibition using siRNA was also measured using RT-PCR in human SPCA-1 and SGC-7901 cells. The cell proliferation rate was determined using MTT and the percentage of apoptotic cells was measured using flow cytometry. AGS cells transfected with β3Gn-T8 siRNA were subcutaneously transplanted into nude mice and tumorigenicity was assessed. The siRNA efficiently suppressed β3Gn-T8 expression in AGS cells, and the down-regulation of β3Gn-T8 caused significant inhibition of tumor cell growth in vitro. The apoptotic rate of AGS cells increased to 10.13% 48 h after siRNA transfection, which was five times that of the control cells. Furthermore, the knockdown of β3Gn-T8 expression reduced the tumorigenicity of gastric cancer cells in nude mice, suggesting that β3Gn-T8 has potential as a gastric cancer therapeutic target.