Fig. 4.

Overexpression of ST6GAL1 enhanced the invasive ability and chemoresistance of MHCC97L cells both in vitro and in vivo. After full-length sequence transfection, ST6GAL1 mRNA (A) and protein (B) were increased notably in MHCC97L cells as shown by real-time PCR and Western blot. C, flow cytometry analysis showed that the α-2,6 sialylation level detected by FITC-SNA on the cell surface was also increased in MHCC97L/ST6GAL1 cells. D, in vitro ECMatrix gel analysis was performed. The average number of cells that invaded through the filter was counted. MHCC97L/ST6GAL1 cells were significantly more invasive (*p < 0.05) than the MHCC97L and MHCC97L/mock cells. The chemoresistance of MHCC97L cells increased with the ST6GAL1 expression vector transfection in vitro (E) and in vivo (F). G, up-regulation of ST6GALI was also shown by IHC staining in xenograft tumors derived from MHCC97L/ST6GAL1 cells (400×). The data are means ± S.D. of three independent assays (*p < 0.05).