Fig. 4: OSW-1 induces OSBP and ORP4 protein degradation and promotes ER stress to induce p53 K120 acetylation and necroptosis. | Cell Death & Differentiation

Fig. 4: OSW-1 induces OSBP and ORP4 protein degradation and promotes ER stress to induce p53 K120 acetylation and necroptosis.

From: Depletion of oxysterol-binding proteins by OSW-1 triggers RIP1/RIP3-independent necroptosis and sensitization to cancer immunotherapy

Fig. 4

A Western blotting of indicated proteins in HCT116 cells treated with OSW-1 (0.5 nM) at indicated time points. B–D HCT116 cells transfected with empty vector, OSBP, ORP4, or both OSBP and ORP4 were treated with OSW-1 (0.5 nM) for 24 h. B Crystal violet staining of viable cells. Western blotting of indicated proteins in whole cell lysates (WCL) and HMGB1 in 20-μl cell culture medium (M) from cells transfected with C OSBP or D ORP4. E Western blotting of indicated proteins in HCT116 cells transfected with control (Ctr), OSBP, ORP4, or both OSBP and ORP4 siRNAs for 48 h. F TEM analysis of HCT116 cells treated with OSW-1 as in (B). Upper, representative TEM pictures with arrowheads indicating ERs (Scale bars, 1 μm); lower, quantification of dilated, fragmented, and normal ERs. Results were expressed as means ± s.d. from counting ERs in six randomly selected fields. G, H HCT116 cells were treated for 24 h with OSW-1 (0.5 nM) alone or in combination with Salubrinal (5 μM). G Crystal violet staining of viable cells. H Western blotting of indicated proteins. ** P < 0.01; *** P < 0.001.

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