FIG 5.

LMP1 regulates IGF1R activation via ligand IGF1. (A) qRT-PCR was used to assess the expression of IGF1R, IGF1, and IGF2. (B) ELISAs measured the secretion of IGF1. In panels A and B, the ratio of LMP1-positive cells relative to LMP1-negative cells is depicted. (C) LMP1-expressing 293T cell lysates were immunoprecipitated with anti-pTyr and probed with anti-IGF1R to detect pIGF1R after treatment with control goat IgG (CTL IgG) or with neutralizing anti-IGF1R (Ab) for 24 h. In parallel, total cell lysates (TCLs) were probed for IGF1R, LMP1, and GAPDH. (D) Proliferation of 293T or MCF10a (MCF) cells when treated with neutralizing anti-IGF1R (Ab) or IgG control for 48 h. The fraction of treated cells relative to cells without treatment was calculated, and proliferation of LMP1-positive cells was taken relative to that of LMP1-negative cells. All antibody concentrations are μg/ml. *, the value for LMP1-positive cells is significantly different than that for pBabe control cells (P < 0.05).