Figure 1
FTS inhibits AML cell proliferation and the Rheb/mTOR pathway, similarly to rapamycin. (a) The 621.102 (TSC2-deficient) and 621.103 (TSC2-re-expressing) AML cells were seeded and grown for 6 days in the absence and in the presence of the indicated concentrations of FTS, or with 0.1% Me2SO4 (control). Cells were directly counted and a typical inhibition curve is shown (means±S.E.M., n=3). (b) The 621.102 and 621.103 cells were seeded and grown for 6 days in the absence and in the presence of the indicated concentrations of rapamycin. Cells were directly counted and a typical inhibition curve is shown (means±S.E.M., n=3). (c) The 621.102 cells were seeded and grown for 2 days in the absence and in the presence of 75 μM FTS or 10 nM rapamycin or 0.1% Me2SO4 (control). Cells then were fixed, PI stained and subjected to FACS for cell cycle analysis (see Materials and methods section). Typical histograms are shown in the upper panel. The quantification of the different cell cycle phases is shown in the lower panel. No significant difference was observed after FTS or rapamycin treatment. (d) The 621.102 cells were seeded and grown for 6 days in the absence and in the presence of the indicated concentration of both FTS and rapamycin, or with 0.1% Me2SO4 (control). Cells were directly counted and the percentages of live cells are presented. (e) TSC2-deficient 621.102 and TSC2-re-expressing 621.103 cells were treated for 2 days with 75 μM FTS or 10 nM rapamycin or 0.1% Me2SO4 (control). Rheb, p-389 S6K, total S6K, Ras-GTP, Ras, β-tubulin and TSC2 were assayed by immunoblotting, as described in Materials and methods section. Statistical analyses of immunoblots from three experiments are shown in the lower panel (n=3, *P<0.05, ** P<0.01, *** P<0.001)
