Fig. 5

EGFR phosphorylation is enhanced in SKOV3 ovarian cancer cells with ST6Gal-I overexpression, but decreased in cells with ST6Gal-I knockdown. a. SKOV3 cells were stably transduced with lentivirus encoding human ST6Gal-I, or alternatively, shRNA for ST6Gal-I. ST6Gal-I overexpression (OE) and knockdown (KD) were confirmed by immunoblotting. EV, OE or KD cell lysates were precipitated by SNA-agarose and immunoblotted for EGFR to detect levels of α2-6 sialylated EGFR. Total cell lysates were immunoblotted for activated EGFR (p-EGFR, pY1068) or total EGFR. b. Densitometric analysis of three independent blots of basal p-EGFR in SKOV3 cells (normalized to β-tubulin). c. Representative p-EGFR immunoblot of EV, OE or KD cells treated with EGF for 5, 15 and 30 min. d. Densitometric analysis of three independent blots of p-EGFR in EGF-treated SKOV3 cells. *, p < 0.05