Figure 3.

dG Induces the Death of Cancer Cell Lines

(A) HeLa cells were infected with VLPs containing Vpx (VLP_vpx) or not (VLP_ctrl). After 24 h, cells were treated with 0.5 mM of each dN for an additional 24 h. Cell viability was assessed as in Figure 1A.

(B and C) HeLa (B) and MDA-MB231 (C) cells were left uninfected (NI) or were infected with VLPs containing Vpx (VLP_vpx) or not (VLP_ctrl). After 24 h, cells were treated with 0.5 mM dG, and brightfield images were acquired after an additional 10–12 h. Scale bars represent 300 μm.

(D) MDA-MB231 cells were treated as in (C), and confluency was monitored after dG addition using a live-cell imaging system in the incubator (Incucyte). The mean of 9 measurements ± SD is shown.

(E–G) Wild-type and Samhd1^−/− B16F10 cells were treated with dG as indicated for 20 h.

(E and F) Cells were then stained with Annexin V and 7AAD and analyzed by flow cytometry. Representative fluorescence-activated cell sorting (FACS) plots are shown in (E), and Annexin V⁺ 7AAD⁻ and Annexin V⁺ 7AAD⁺ cells were quantified in (F).

(G) Confluency was determined as in (D).

(H) Jurkat cells were treated for 20 h with dG as indicated or with 25 μM etoposide. Cell viability was determined as in Figure 1A.

(I) Jurkat cells were treated with dG as indicated for 20 h and then seeded in semi-solid medium containing dG. After 13 days, cell colonies were counted, and the number colonies per field of view are shown.

(J and K) Jurkat cells were reconstituted with hemagglutinin (HA)-tagged wild-type or K11A mutant SAMHD1 using a lentivector. Uninfected cells (NI) served as control.

(J) Cells were then treated with dG for 48 h. Cell viability was determined as in Figure 1A.

(K) SAMHD1 levels in total cell extracts were determined by western blot. β-Actin served as a loading control.

(A), (D)–(H), and (J)–(K) are representative of three independent experiments and (B) and (C) of two experiments. In (A), (F)–(H), and (J), dots represent technical triplicates and means ± SD are shown. In (I), data from two independent experiments were pooled, and dots represent the mean of technical duplicates per experiment. The p values determined with two-way ANOVA are indicated. ^∗p < 0.05; ^∗∗p < 0.01; ^∗∗∗p < 0.001; ^∗∗∗∗p < 0.0001.

See also Figures S2 and 3.