Biology subjects

Nyga, A.

Publications and source records attributed to Nyga, A..

3 recordsLinked to original sources

bioRxiv2023

Quantification of extracellular matrix components in immunolabeled tissue samples

In recent years, the interaction between cells and the extracellular matrix (ECM) has become a new focus in understanding tissue morphogenesis, regeneration, and disease. However, the lack of specific techniques to study the ECM composition in preserved tissue structures remains a major obstacle to explaining ECM changes in response to extrinsic stimuli. To overcome this, we propose a novel strategy that uses multidimensional fluorescence microscopy and computational tools to quantify ECM composition in immunolabeled tissues and/or cell-derived matrices (CDM). This approach includes a detailed protocol for densitometric fluorescence calibration and procedures for image acquisition, processing, and automated quantification. Using this method, we present new data comparing collagen types I, III, and IV, and fibronectin contents in various tissues. These results emphasize the importance of studying ECM composition in situ under both normal homeostatic and disease conditions. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=135 SRC="FIGDIR/small/535641v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@1203e08org.highwire.dtl.DTLVardef@1c88c1borg.highwire.dtl.DTLVardef@1664ac2org.highwire.dtl.DTLVardef@b63154_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2021

Oncogenic RAS instructs morphological transformation of human epithelia via differential tissue mechanics.

The RAS proto-oncogene is a critical regulator of cell state, morphology and mechanics, and plays a key role in cancer progression. Here, by using a human epithelial model in vitro, we ask how morpho-mechanical changes driven by oncogenic RAS activation at the level of individual cells are collectively integrated to drive changes in tissue behaviour. We found that the uniform oncogenic expression of HRAS.V12 in confined epithelial monolayers causes reproducible changes in the structure and organization of the tissue, which acquires a transitory bilayered morphology. RAS-driven bilayering associates with reproducible layer-specific differences in cell-cell contractility and cell-matrix forces. These drive the initially flat tissues to form three-dimensional structures mimicking some of the behaviours seen in human cancers. Our findings establish a physical mechanism of cellular collectives through which uniform expression of RAS can be interpreted differently in different places of the same tissue to regulate its physiological and pathological morphology.

cancer biology↗

bioRxiv2019

Cancer Associated Fibroblasts Mediate Cancer Progression and Remodel the Tumouroid Stroma

ObjectiveCancer associated fibroblasts (CAFs) are highly differentiated and heterogenous cancer stromal cells that promote tumour growth, angiogenesis and matrix remodelling. DesignWe utilised a novel 3D in vitro model of colorectal cancer, composed of a cancer mass and surrounding stromal compartment. We compared cancer invasion with an acellular stromal surround, a healthy or normal cellular stroma and a cancerous stroma. For the cancerous stroma we incorporated six patient-derived CAF samples to study their differential effects on cancer growth, vascular network formation, and remodelling. ResultsCAFs enhanced the distance and surface area of the invasive cancer mass whilst inhibiting vascular-like network formation. These processes were driven by the upregulation of hepatocyte growth factor (HFG), metallopeptidase inhibitor 1 (TIMP1) and fibulin 5 (FBLN5). Remodelling appeared to occur through the process of disruption of complex networks and was associated with the up upregulation of vascular endothelial growth factor (VEGFA) and down-regulation in vascular endothelial cadherin (VE-Cadherin). ConclusionThese results support, within a biomimetic 3D, in vitro framework, the direct role of CAFs in promoting cancer invasion and that CAFs are also key components in driving vasculogenesis and angiogenesis.

cancer biology↗