3D genomic mapping reveals multifocality of human pancreatic precancers

作者：Braxton AM, Kiemen AL, Grahn MP, Forjaz A, Parksong J, Mahesh Babu J, Lai J, Zheng L, Niknafs N, Jiang L, Cheng H, Song Q, Reichel R, Graham S, Damanakis AI, Fischer CG, Mou S, Metz C, Granger J, Liu XD, Bachmann N, Zhu Y, Liu Y, Almagro-Pérez C, Jiang AC, Yoo J, Kim B, Du S, Foster E, Hsu JY, Rivera PA, Chu LC, Liu F, Fishman EK, Yuille A, Roberts NJ, Thompson ED, Scharpf RB, Cornish TC, Jiao Y, Karchin R, Hruban RH, Wu PH, Wirtz D, Wood LD · 发表于：Nature · 年份：2024 · DOI：10.1038/s41586-024-07359-3

Pancreatic intraepithelial neoplasias (PanINs) are the most common precursors of pancreatic cancer, but their small size and inaccessibility in humans make them challenging to study1. Critically, the number, dimensions and connectivity of human PanINs remain largely unknown, precluding important insights into early cancer development. Here, we provide a microanatomical survey of human PanINs by analysing 46 large samples of grossly normal human pancreas with a machine-learning pipeline for quantitative 3D histological reconstruction at single-cell resolution. To elucidate genetic relationships between and within PanINs, we developed a workflow in which 3D modelling guides multi-region microdissection and targeted and whole-exome sequencing. From these samples, we calculated a mean burden of 13 PanINs per cm3 and extrapolated that the normal intact adult pancreas harbours hundreds of PanINs, almost all with oncogenic KRAS hotspot mutations. We found that most PanINs originate as independent clones with distinct somatic mutation profiles. Some spatially continuous PanINs were found to contain multiple KRAS mutations; computational and in situ analyses demonstrated that different KRAS mutations localize to distinct cell subpopulations within these neoplasms, indicating their polyclonal origins. The extensive multifocality and genetic heterogeneity of PanINs raises important questions about mechanisms that drive precancer initiation and confer differential progression risk in the...