The tumor tissues were homogenized by bead beating in RIPA buffer containing with 1%
proteinase inhibitor cocktail (200 μL/20 mg tissue, ThermoFisher, #78429) within 10 min at 4 °C. The lysates were then centrifuged at 15,000 r.p.m. for 20 min at 4 °C, the supernatants were collected and quantified by BCA assay. Samples were dissolved in SDS-PAGE protein loading buffer (5X, Boster, AR1112) and boiled for 10 min, and equal amounts of each sample were applied to 12% Tris-glycine gel (
Novex gel, Invitrogen) and subjected to electrophoresis, which was subsequently transferred to a PDVF (polyvinylidene difluoride) membrane and blocked in 5% non-fat milk blocking buffer for 1 h at room temperature. The membranes were incubation with the primary antibody overnight at 4 °C (STING (D1V5L) mAb, #50494, dilution 1/1000; Phospho-STING (Ser365) (D8F4W) mAb, #72971, dilution 1/1000; IRF-3 (D83B9) mAb, #4302, dilution 1/1000; Phospho-IRF-3 (Ser396) (D6O1M) mAb, #29047, dilution 1/1000, Cell Signaling;
β-Actin, ab179467, dilution 1/1000, Abcam), and then horseradish peroxidase (HRP)-conjugated secondary antibodies (anti-rabbit IgG, HRP-linked antibody, #7074, dilution 1/3000; Cell Signaling). Finally, the membranes were soaked in
ECL substrate (Thermo Scientific) and imaged under Azure Biosystems software (v. 1.5.0.0518).
Wang Z., Li W., Park J., Gonzalez K.M., Scott A.J, & Lu J. (2022). Camptothesome Elicits Immunogenic Cell Death to Boost Colorectal Cancer Immune Checkpoint Blockade. Journal of controlled release : official journal of the Controlled Release Society, 349, 929-939.