Fig. 6.

Overexpression of ST8SIA2 gene inhibits the invasive ability and chemoresistance of MHCC97H cells both in vitro and in vivo. After full-length sequence transfection, ST8SIA2 mRNA (A) and ST8SIAII protein (B) were increased notably in MHCC97H cells as shown by real-time PCR and Western blot. C, flow cytometry analysis showed that the α-2,8 sialylation level detected by FITC-Siglec7 on the cell surface was also increased in MHCC97H/ST8SIA2 cells. D, in vitro ECMatrix gel analysis was performed. The average number of cells that invaded through the filter was counted. MHCC97H/ST8SIA2 cells were significantly less invasive (*p < 0.05) than the MHCC97H and MHCC97H/ST8SIA2 cells. The chemosensitivity of MHCC97H cells was increased with ST8SIA2 expression vector transfection in vitro (E) and in vivo (F). G, up-regulation of ST8SIAII was also shown by IHC staining in xenograft tumors derived from MHCC97H/ST8SIA2 cells (400×). The data are means ± S.D. of three independent assays (*p < 0.05).