Angiogenesis blockade overcomes acquired KRAS G12D inhibitor resistance driven by KRAS-PI3K? interaction
The KRAS G12D mutation is a key oncogenic driver in many solid tumors, including pancreatic, gastric, and colorectal cancers. While recent preclinical studies have characterized features associated with innate and acquired KRAS G12D inhibitor resistance, strategies to overcome resistance, especially in the gastrointestinal cancer context, remain underexplored. Here, we generated nine gastrointestinal cancer models of acquired resistance to the KRAS G12D-selective inhibitor MRTX1133. We identified the enrichment of angiogenesis, hypoxia, and epithelial-to-mesenchymal transition (EMT) in an isogenic patient-derived organoid model of acquired resistance by single-cell RNA sequencing. In the nine resistant models, VEGFA expression and VEGFR2 phosphorylation were unanimously increased. Subsequent mechanistic studies revealed that an autocrine VEGFA signaling loop, initiated by an increased interaction between KRAS and PI3K?, drives both EMT and RAS independence. Elevated mitochondrial oxidative stress in resistant cells led to CCT2-mediated KRAS stabilization, thereby enhancing PI3K? activity. Moreover, we observed that cancer-vascular paracrine signaling both amplified angiogenesis and EMT signatures in cancer cells and promoted endothelial cell proliferation. Significantly, disruption of VEGFA signaling reversed EMT induction and restored sensitivity to MRTX1133. Concordantly, in mouse xenograft models, the combination of anti-VEGFR2 therapy and MRTX1133 rechallenge significantly reduced tumor growth, angiogenesis, and proliferation markers without adverse effects on body weight. These findings identify a critical role for VEGFA signaling in resistance to KRAS G12D inhibition and provide a rationale for combination therapies targeting angiogenesis in gastrointestinal cancers. Overall design: RNA-seq profiling the interactions between patient derived organoids and endothelial cells