Spatial single‑cell maps of pancreatic premalignancy reveal niche states and rapid dismantling by KRAS inhibitor in preclinical tissue

Dr. Jose Reyes presented spatial single‑cell characterization of premalignant pancreatic tissue in genetically engineered mouse models and described how epithelial phenotypic diversification goes hand‑in‑hand with reorganization of stroma and immune cells. He defined a continuum from gastric‑like premalignant epithelial states to progenitor‑like states and showed that these epithelial programs are spatially associated with distinct fibroblast and myeloid cell signatures.

Using spatial ordering and niche analysis, the presenter identified a progenitor‑associated niche rich in myofibroblastic fibroblasts (expressing genes such as tenascin and periostin) and immunosuppressive myeloid markers. These niche states closely resembled the microenvironments later found in frank PDAC, suggesting that niche remodeling is an early and possibly deterministic step in progression.

To test whether niche states are reversible, the group used a selective small‑molecule inhibitor of oncogenic KRAS (MRTX‑1133) in very early premalignant mice. A brief, two‑day treatment produced a striking depletion of progenitor‑like epithelial cells (HGD2‑marked in presenter’s images) and a collapse of the associated fibroblast and immune niche—changes that the speaker said occurred without complete epithelial ablation, implying selective sensitivity of progenitor‑like cells to KRAS blockade at an early stage.

The presenter framed these results as evidence that early niche assembly can be both necessary for and vulnerable to targeted interruption; he proposed that understanding the dynamics and tipping points of such niche transitions (how many cells or what duration of signal creates a self‑sustaining niche) is a key challenge for early interception strategies.