A, Schematic representing experimental constructs utilized to overexpress TP53WT or TP53R175H in isogenic hPNE-KRASWT or hPNE-KRASG12D pancreatic epithelial cells (top). Histogram showing Cxcl1 secretion from each hPNE cell system annotated by respective KRAS and/or TP53 mutational status (bottom); B, Bubble plot representing the top 10 transcription factors hyperphosphorylated in hPNE-KRASG12DTP53R175H compared with hPNE-KRASG12DTP53WT cells, with relative ratio of expression indicated on y-axis; C, Histograms representing relative fold change in CXCL1 gene expression (left) and secretion (in pg/mL; right) from hPNE-KRASG12DTP53WT and hPNE-KRASG12DTP53R175H in absence or presence of Creb inhibitor 666-15 (CREBi 0.5 μM for 24h, n=3); D, Chromatin immunoprecipitation and sequencing (ChIP-seq) peak signals and heat maps of CREB regions in CREB and RNApol-II ChIP material (n=2 biologic replicates each) in Kras-Trp53 cooperative KPC 6694c2 cells; E, ChIP-seq heatmaps showing co-occupied CREB and RNApol-II peaks (N=9488), CREB-unique peaks (N=6799), RNApol-II unique peaks (N=59032), with adjacent callout box showing curated gene module implicated in inflammatory signaling and innate immune regulation; F, Integrative Genome Viewer (IGV) plot visualizing co-occupancy of peaks in CREB and RNApol-II ChIP-seq data at the transcriptional start site of Cxcl1 promoter; G, ChIP-qPCR of Cxcl1 and Cdh8 (negative control) from CREB and RNApol-II immunoprecipitated purified DNA in KPC 6694c2 cells; H-I,
CXCL1 gene expression (left) and secretion (right) each in human MiaPaCa-2 cells (H) and human PDM-168 patient-derived organoids (I) in absence or presence of CREBi 666-15 (0.5 μM for 24h) or absence or presence of Creb siRNA (n=3 each); J, Schematic of Creb inhibitor treatment of KPC orthotopic mice in vivo (top). Bar plots showing Cxcl1 gene expression via qPCR and protein levels via ELISA (in pg/mL) in whole tumor lysates from vehicle-treated vs. Crebi-treated mice (n=4–7 mice); K, Cxcl1 immunostaining with corresponding H&E staining in representative tumor sections from vehicle- vs. CREBi-treated mice (n=4–5/group; scale bar=50μm).