Fig. 4: BQ modulates levels of BCL-2 family proteins and enhances sensitivity to BCL-XL PROTAC-based degradation in PDAC.
From: De novo pyrimidine biosynthesis inhibition synergizes with BCL-XL targeting in pancreatic cancer
a, b Flow cytometry-based BH3 profiling of PaTu-8902 and PaTu-8988T cells treated with BQ for 7 days shows priming (a) and specificity of BCL-2 protein family apoptotic dependency (b). Apoptosis is measured by Cytochrome c release (y-axis). Alamethicin (AlaM) and DMSO were used as positive and negative control for apoptosis induction, respectively. Experimental data sets (a, b) were derived from the same experiments and analyzed using same ALaM and DMSO controls. Conditions: BIM, BID and PUMA BH3 peptides inhibit all anti-apoptotic BCL-2 family proteins (BIM and BID also directly activate BAX and BAK), BAD BH3 peptide inhibits BCL2, BCL-W and BCL-XL, HRK and MS1 peptides inhibit BCL-XL and MCL1, respectively. Data are presented as mean relative Cytochrome c release of two biologically independent experiments each with technical duplicate measurements, n = 4 (3 measurements for PaTu-8902 BQ 5 μΜ include two duplicates from one experiment and one measurement from the second experiment). Error bars represent s.d. of all measurements. c, d Immunoblot analysis of BCL-2 family proteins in lysates from PaTu-8902 and PaTu-8988T cells treated with 5 µM BQ for 24 and 48 hours (c) or the indicated concentrations of DT2216 for 16 hours (d). e Immunoblot analysis of BCL-2 family proteins in lysates from PaTu-8902 and PaTu-8988T cells treated with 5 µM BQ or 5 µM DT2216 alone or BQ in combination with DT2216 for 24 hours. f Apoptosis regulatory gene expression assessed by qRT-PCR in PaTu-8902 and PaTu-8988T cells treated with 5 μM BQ, 24 hours. Expression levels normalized to GAPDH and presented as mean ± s.d. of 3 independent replicates (representative of three independent experiments). Significance was determined by t-test, **** p < 0.0001 (BCL2L1 encodes BCL-XL; BCL2L11 encodes BIM). g Immunoblot analysis of p65 (RelA subunit of NF-κB) and p105 (precursor of the NF-κB p50 subunit) activation in lysates from PaTu-8902 and PaTu-8988T cells treated for 24 and 48 hours with BQ (5 µM). Source data are provided as a Source Data file.
