Figure 5
From: Roles of the PI-3K and MEK pathways in Ras-mediated chemoresistance in breast cancer cells
Effects of dn PI-3K (Δp85) and dn MEK (K97 M) on Ras-induced drug resistance. MCF7RasG12V cells were transfected with plasmid containing HA-tagged MEK (K97 M) or HA-tagged PI-3K (Δp85) for 16 h for transient expression, followed by a 8-h exposure to doxorubicin, paclitaxel, or 5-fluorauracil, and a 16-h postdrug period in a medium containing 10% CS FBS. The cells were then harvested for detection of the expressions of the dn forms of PI-3K (A, gel a) or MEK (A, gel b) by Western blot analyses with an anti-HA antibody, and for determination of apoptosis by ELISA (B) and by TUNEL (C). The statistical differences between the cells expressing dn PI-3K (Δp85) and dn MEK (K97 M) in enhancing the cytotoxicity of drugs (doxorubicin, paclitaxel, or 5-fluorouracil) were calculated by Student's t-test. dn: dominant negative; NS*=nonspecific signals.
