Journal: Neoplasia (New York, N.Y.)
Article Title: PRAS40 activates the IRE1α-XBP-1-mediated unfolded protein response to exacerbate colorectal cancer by enhancing ST6Gal1-dependent α-2, 6 sialylation of GRP78
doi: 10.1016/j.neo.2026.101297
Figure Lengend Snippet: Effects of β-sitosterol on ST6Gal1 function and PRAS40-induced cell proliferation. (A) Flow chart for discovery of ST6Gal1 inhibitors. (B) Molecular docking of the interaction of ST6Gal1 protein and β-sitosterol was shown in stick model. ST6Gal1 was shown in blue, β-sitosterol was shown in yellow, and the binding sites of ST6Gal1 were shown in purple. Hydrogen bonds were indicated by yellow dashed lines, and the numbers represented the lengths of hydrogen bonds. (C) Chemical structure of β-sitosterol. (D) SPR assays for the binding affinity of β-sitosterol and ST6Gal1. (E) The ST6Gal1 enzyme activity in the cells treated with or without β-sitosterol. (F-I) The HCT116 cells were transfected with empty vector or ST6Gal1 expression vector followed with or without β-sitosterol treatment (50 μM). SNA-pull down assays (F), representative images (G), cell viability analyses (H), and flow cytometry analyses (I). (J-N) The CRC allografts were established in C57 mice by control or PRAS40-depleted MC38 cells, followed with intraperitoneal injection of β-sitosterol (200 mg/kg), CDDP (3 mg/kg) or combination of both. Experiment flow chart (J), body weight (K), tumor volume (L), tumor weight (M), tumor images (N). Data represent the mean ± SD. Scale bar, 400 μm. * P < 0.05; ** P < 0.01; *** P < 0.001.
Article Snippet: Antibodies were purchased for detection of PRAS40 (Cell Signaling); GRP78, XBP-1, PARP, IRE1, Flag, GST, ST6Gal1, α-tubulin, β-actin (Proteintech); and SNA (Vector Laboratories).
Techniques: Binding Assay, Activity Assay, Transfection, Plasmid Preparation, Expressing, Flow Cytometry, Control, Injection