FIGURE 6.

Regulation of cell proliferation by the mTOR-S6K2-hnRNP F complex. A, rapamycin blocks hnRNP F-dependent cell proliferation. Myc-hnRNP F and pcDNA control cells were plated at equal cell numbers and allowed to grow exponentially in 10% FBS-supplemented DMEM for 48 h. Rapamycin was added at a final concentration of 25 nm, and the cells were further allowed to proliferate for another 72 h. Total cell numbers were analyzed by Casy cell counter. The error margins represent the standard errors of the mean. *, p < 0.05; ***, = p < 0.05. B, overexpression of S6K2 drives cell proliferation. Hek293 cells were transfected with a mammalian expression vector encoding either S6K1 or S6K2 or left untransfected (Untr). C, siRNA down-regulation of hnRNP F blocks S6K2-driven cell proliferation. Hek293 cells were co-transfected with plasmid DNA encoding S6K2 or the corresponding empty vector (VO), and either scramble oligonucleotides (Sc) or siRNA targeting hnRNP F or H. B and C, 48 h later, the resulting cells were pulsed in the presence of BrdUrd and analyzed by flow cytometry. The results shown are representative of at least three independent experiments where 10,000 cells were analyzed. The error margins represent the standard errors of the mean. ***, p < 0.05.