Skip to main content
. 2000 Oct 30;151(3):483–494. doi: 10.1083/jcb.151.3.483

Figure 1.

Figure 1

Inhibition of PI 3-kinase signaling but not MAPK signaling induces apoptosis of HMN1 cells. (A) PD 98059 inhibits MAPK signaling (ERK phosphorylation at threonine-202/tyrosine-204) and LY 294002 inhibits PI 3-kinase signaling (Akt phosphorylation at serine-473). HMN1 cells were grown in serum-free medium for 16 h, followed by stimulation with 10 μg/ml insulin or 20% fetal bovine serum in the absence or presence of 30 μM PD 98059 or LY 294002. Samples were blotted with antibodies against phospho-ERK or phospho-Akt. (B) LY 204002, but not PD98059, induces cell death. HMN1 cells were treated with 30 μM LY 294002 (dissolved in ethanol) or 30 μM PD 98059 (dissolved in DMSO), and cell viability was determined after 18 h. 1, DMSO; 2, PD 98059; 3, ethanol; 4, LY 294002. LY 294002 causes a significant decrease in viability. Data represent mean ± SEM of three independent experiments. (C) HMN1 cells were treated as described above, and after 18 h soluble DNA was extracted for DNA fragmentation assay. 1, DMSO; 2, PD 98059; 3, ethanol; 4, LY 294002. Note prominent DNA laddering after treatment with LY 294002. Data are from a representative experiment performed three times.