Journal: Journal of the American Chemical Society
Article Title: Hijacking Extracellular Targeted Protein Degrader–Drug Conjugates for Enhanced Drug Delivery
doi: 10.1021/jacs.5c15047
Figure Lengend Snippet: Generation of LIPTACs for degradation of EGFR. (a) Schematic illustration of LDLR-Ctx LIPTAC bispecific constructs. (b) Western blot showing degradation of total EGFR on HeLa cells following 24 h of treatment with Ctx-LIPTAC or 50 nM control antibodies. Data represents three biological replicates. Percent EGFR levels were quantified by ImageJ relative to PBS control. (c) Changes in surface EGFR based on flow cytometry analysis on MDA-MB-231 cells following 24 h of 50 nM 142F1 isotype IgG, Ctx IgG, Ctx-LIPTAC, or Ctx-KineTAC treatment. Percent EGFR was determined by median fluorescence intensity (MFI) of the PE fluorescence channel of live cells. Each sample was tested in biological triplicate and error bars represented standard deviation. Statistics were calculated by unpaired two-tailed student t test. *** P < 0.001. **** P < 0.0001. (d) Western blot showing degradation of total EGFR on MDA-MB-231 cells after 24 h treatment of 50 nM Ctx, KineTAC, monomeric LDLR isotype, or varying concetrations of LIPTACs. Data represented three biological replicates. (e) EGFR degradation in A431 cells following 24 h of Ctx-LIPTAC1 treatment. Data represents three biological replicates. (f) Flow cytometry analysis showing degradation of surface EGFR on A431 cells following 24 h of Ctx-LIPTACs, 50 nM Ctx IgG, and 50 nM Ctx-KineTAC treatment. Each sample was tested in biological triplicate and error bars represent standard deviations. Statistics were calculated by unpaired two-tailed student t test. *** P < 0.001. **** P < 0.0001. (g) Western blot analysis of EGFR and LDLR in LDLR knockout and control HCC1143 cells after 24 h of 5 nM LIPTAC treatment. Data represent two biological replicates. (h) Fold-change in surface protein abundance in MDA-MB-231 cells following 48 h of treatment with or without 50 nM Ctx-LIPTAC1, as measured by quantitative proteomics analysis. N-Linked cell surface glycoproteins were captured by the cell-surface capture technology and enriched by biocytin hydrazide. Surface proteins were annotated using the SURFY database. (i) Confocal microscopy images of HeLa cells treated with 50 nM of indicated bispecific antibodies or isotype controls for 24 h. Scale bar, 10 μm.
Article Snippet: Antibodies used included rabbit anti-human EGFR (Cell Signaling Technology, catalog no. 4267S, 1:1000), rabbit anti-human PD-L1 (Cell Signaling Technology, catalog no. 13684S, 1:1000), rabbit anti-human CXCR4 (Cell Signaling Technology, catalog no. 64837S, 1:1000), rabbit anti-human ERBB2 (Cell Signaling Technology, catalog no. 4290S, 1:1000), rabbit anti-human CDCP1 (Cell Signaling Technology, catalog no. 13794S, 1:1000), mouse anti-human α-tubulin (Cell Signaling Technology, 3873S, 1:3000), goat anti-human LDLR (R&D Systems, catalog no. AF2148, 1:1000), IRDye 800CW goat anti-rabbit IgG (LI-COR Biosciences, catalog no. 926-32211), IRDye 680RD goat anti-mouse IgG (LI-COR Biosciences, catalog no. 926-68070, 1:5000), IRDye 800CW donkey anti-goat IgG (LI-COR Biosciences, catalog no. 926-32214, 1:5000), and peroxidase goat anti-rabbit IgG (H+L) (Jackson ImmunoResearch, catalog no. 111-035-144, 1:5000).
Techniques: Construct, Western Blot, Control, Flow Cytometry, Fluorescence, Standard Deviation, Two Tailed Test, Knock-Out, Quantitative Proteomics, Confocal Microscopy