TIAM2 is required for cell growth and survival in ATL cells. (A) The ChIP-seq gene tracks represent H3K27Ac signals at the TIAM2 gene loci. See legend to Figure 1D for details. (B) TIAM2 mRNA expression in various samples was measured by qRT-PCR. See the legend to Figure 2B for details. (C) TIAM2 mRNA expression in 2 THZ1-sensitive (TL-Om1 and ATL-55T[–]) and 2 THZ1-resistant (MT-2 and ATL-43b[−]) cell lines was analyzed by qRT-PCR. See the legend to Figure 4G for details. *P < .05, **P < .01 by 2-sample, 2-tailed Student t test compared with the DMSO-treated control. ^#Expression level was below cutoff. (D) The cell viability of the ATL (TL-Om1 and ATL-55T[–]) and T-ALL cell line (Jurkat) at days 5 and 7 after transduction with control shRNA (short hairpin green fluorescent protein [shGFP]) or shRNAs targeting TIAM2 (shTIAM2-1 and 2). The data are presented as a percentage of the shGFP control and shown as the mean ± standard deviation of triplicate experiments. **P < .01, ***P < .001 by 2-sample, 2-tailed Student t test compared with the shGFP control. (E) Cell deaths were determined on day 5 after TIAM2 knockdown. Cells were stained with Annexin V and propidium iodide (PI) and analyzed by flow cytometry. Live, Annexin V-negative, PI-negative; Apoptotic, Annexin V–positive, PI-negative; Necrotic, Annexin V-negative, PI-positive. The results are shown as a percentage of total cells for each cell line. (F) Relative cell growth rates of Jurkat single clones transduced with MSCV-puro (empty vector [EV] control) or MSCV-puro-TIAM2 (2 clones: TIAM1 and TIAM2) were determined over 5 days in 5% FBS RPMI 1640 media. The data are presented as the mean ± standard deviation of triplicate experiments.