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Human cells tightly control their dimensions, but in some cancers, normal cell size control is lost. In this study we measure cell volumes of epithelial cells from human lung adenocarcinoma progression in situ. By leveraging artificial intelligence (AI), we reconstruct tumor cell shapes in three dimensions (3D) and find airway type 2 cells display up to 10-fold increases in volume. Surprisingly, cell size increase is not caused by altered ploidy, and up to 80% of near-euploid tumor cells show abnormal sizes. Size dysregulation is not explained by cell swelling or senescence because cells maintain cytoplasmic density and proper organelle size scaling, but is correlated with changes in tissue organization and loss of a novel network of processes that appear to connect alveolar type 2 cells. To validate size dysregulation in near-euploid cells, we sorted cells from tumor single-cell suspensions on the basis of size. Our study provides data of unprecedented detail for cell volume dysregulation in a human cancer. Broadly, loss of size control may be a common feature of lung adenocarcinomas in humans and mice that is relevant to disease and identification of these cells provides a useful model for investigating cell size control and consequences of cell size dysregulation. [ABSTRACT FROM AUTHOR]

Zona Pellucida domain (ZP) proteins are critical components of the body's external-most protective layers, apical extracellular matrices (aECMs). Although their loss or dysfunction is associated with many diseases, it remains unclear how ZP proteins assemble in aECMs. Current models suggest that ZP proteins polymerize via their ZPn subdomains, while ZPc subdomains modulate ZPn behavior. Using the model organism C. elegans, we investigated the aECM assembly of one ZP protein, LET-653, which shapes several tubes. Contrary to prevailing models, we find that LET-653 localizes and functions via its ZPc domain. Furthermore, we show that ZPc domain function requires cleavage at the LET-653 C-terminus, likely in part to relieve inhibition of the ZPc by the ZPn domain, but also to promote some other aspect of ZPc domain function. In vitro, the ZPc, but not ZPn, domain bound crystalline aggregates. These data offer a new model for ZP function whereby the ZPc domain is primarily responsible for matrix incorporation and tissue shaping. Author summary: Apical extracellular matrices line and shape external body surfaces and the insides of biological tubes. Common components of apical matrices are Zona Pellucida domain (ZP) proteins. These proteins are typically thought to form fibrillar polymers via their N-terminal ZPn subdomains, but how they do so in vivo, and whether other assembly mechanisms occur, is not well understood. Here we use the model organism C. elegans to investigate how one ZP protein, LET-653, assembles into a matrix layer. We visualized the matrix assembly of the LET-653 ZP domain in vivo and demonstrated that, unlike previously described ZP proteins, LET-653 functions and incorporates into matrix via its C-terminal ZPc subdomain. This study identifies new mechanisms by which ZP proteins can assemble into matrices. [ABSTRACT FROM AUTHOR]