Journal: bioRxiv

Article Title: Quinolinic acid phosphoribosyl transferase moonlights as an apoptosis regulator to empower lung cancer progression

doi: 10.64898/2026.04.01.715697

Figure Lengend Snippet: (A–B) Annexin V, CF450 staining (0.25 µg/ml) in NSCLC cells with QPRT knockdown cultured in 2D (A) and 3D conditions with representative spheroid images (B) (n = 4). (C) Quantification of cell viability using PI staining for PC9, H2009 and H2030, and SYTOX Green for H1581 cells with QPRT silencing upon Z-VAD-FMK (50 µM for PC9, H2009 and H2030, and 100 µM for H1581) treatment (n = 4). (D) Immunoblots for co-IP experiments of V5-QPRT and its interaction with pro-caspase 3 in PC9, H2009 and H2030 cells. (E) Caspase-3/7 activity level in NSCLC cells with QPRT knockdown (n = 4). (F) Ribbon representation of QPRT (PDB: 5AYY) in complex with quinolinic acid with active site residues shown as sticks. Residues are colored according to ConSurf conservation scores . (G) Measurement of QPRT enzymatic activity over time of wild-type and catalytically inactive QPRT mutants purified form bacterial cells (n = 3). (H) Immunoblots for caspase-3 co-immunoprecipitated with catalytically inactive QPRT K139A versus wild-type QPRT. Data are represented as the mean ± SEM with statistical significance measured by one-way ANOVA followed by Dunnett’s post hoc test for panels A, B, and E, and followed by Tukey’s post hoc test for panel E. For the graph in panel G statistical significance was measured by two-way repeated measures ANOVA followed by Dunnett’s post hoc test and p value for the last time point is shown on the graphs. Scale bars in B indicate 400 µm.

Article Snippet: For anti-Caspase-3 rabbit polyclonal Ab (Cell Signaling Technology, 9662S) 5% BSA in TBST was used to block the membranes instead of milk.

Techniques: Staining, Knockdown, Cell Culture, Western Blot, Co-Immunoprecipitation Assay, Activity Assay, Purification, Immunoprecipitation

Journal: bioRxiv

Article Title: Quinolinic acid phosphoribosyl transferase moonlights as an apoptosis regulator to empower lung cancer progression

doi: 10.64898/2026.04.01.715697

Figure Lengend Snippet: In NSCLC cells as diagrammed in de novo NAD + biosynthesis is inactive, and NAD + pools are fueled by the salvage pathways and by the Preiss-Handler pathway. Instead, QPRT functions as an apoptosis inhibitor by interacting with caspase 3 and preventing its activation thereby conferring NSCLC resistance to apoptosis and enabling them to thrive through the stresses of tumor progression (2) .

Article Snippet: For anti-Caspase-3 rabbit polyclonal Ab (Cell Signaling Technology, 9662S) 5% BSA in TBST was used to block the membranes instead of milk.

Techniques: Activation Assay