Spatial Molecular Plasticity Underpins Lethal Morphologies in Lung Adenocarcinoma.

Abstract

Adenocarcinoma of the lung (LUAD) is common and highly lethal. Clinical grading of LUAD strongly predicts recurrence and survival after surgery and is determined by morphological assessment of histological growth patterns in resected tumors. In particular, the 2 archetypally lethal morphologies, solid, and micropapillary growth patterns, are highly distinct from each other, but little is known about their defining molecular features or how their appearances are related to their biology and mechanisms of lethality. Pure epithelial growth patterns and subregions were identified within 7 distinct LUAD growth patterns across 51 resected tumors and characterized using NanoString GeoMx digital spatial profiler in 160 epithelially pure regions of interest. Results were validated in 27 cases at the protein level using Akoya PhenoImager multiplex immunofluorescence, in 432 cases at the RNA level with TempO-Seq, and in 30 cases with an independent GeoMx digital spatial profiler. Analyses of gene expression reveal fundamental divergent evolutionary trajectories leading to solid and micropapillary growth. Additionally, we identify recurrent localized intratumoral plasticity in both growth patterns. These states can explain the origins of growth patterns and their mechanisms of virulence. Our work highlights dramatic divergence in gene expression programs between highly lethal modes of LUAD tumor growth. We go on to show how microscopically localized hypoxia in the primary tumor helps to establish and maintain cellular survival strategies and tumor architecture, suggesting morphology-specific mechanisms of LUAD tumor metastasis and suggesting new therapeutic vulnerabilities.