Fig. 3: Zinc mediates tumour susceptibility to TNF-mediated cell death.

Lysis of ⁵¹Cr-labelled MC38 tumour cells (A) and E0771 tumour cells (B) in 2-fold increasing concentrations of indicated metals in the presence of 10 ng/mL TNF over 16 h, using only non-toxic metal concentration determined in Supplementary Fig. S2 (i.e., metal concentrations causing <10% tumour lysis), Ordinary one-way ANOVA, pooled data n = 2. C Lysis of ⁵¹Cr-labelled MC38 tumour cells in increasing concentrations of TNF over 16 h in standard media or media supplemented with 100 µM ZnSO₄. Right plot shows normalized percent tumour lysis at 50 ng/mL TNF, Mann–Whitney test, pooled data n = 4. D MC38 tumour cell death measured by PI uptake following 16 h of treatment with 10 ng/mL TNF in standard media or media supplemented with 100 µM zinc sulfate, 2way ANOVA, n = 3. E Lysis of ⁵¹Cr-labelled MC38 tumour cells in increasing concentrations of TNF over 16 h in media treated with 7 µM TPEN or the corresponding vehicle. Right plot shows normalized percent tumour lysis at 50 ng/mL TNF, Mann–Whitney test, pooled data n = 2. F MC38 tumour cell death measured by PI uptake following 7 h of treatment with 10 ng/mL TNF and 7 uM TPEN or the corresponding vehicle, 2way ANOVA, n = 3. G Immunoblot analysis of MC38 tumour cells following treatment with 10 ng/mL TNF with/without 7 µM TPEN or 70 µM ZnSO₄ for the indicated time. All error bars show +/−SEM, *P < 0.05, **P < 0.01, ****P < 0.0001.