Investigating the role of tissue fluidity in cell extrusion and wound healing in colorectal cancer organoids
Lead Research Organisation:
University College London
Department Name: Lab for Molecular Cell Bio MRC-UCL
Abstract
The movement of cells relative to each other, termed tissue fluidity, is an important property of dynamic tissues. Its significance is well characterized in morphogenesis and development, and there is emerging evidence that tissue fluidity plays a key role repair and maintenance of epithelial tissue integrity. There has also been increasing interest in the role tissue fluidity plays in the onset and progression of cancer, with a particular focus on exploring this behaviour in 3D systems. A recent publication from the Mao group showed that upon wounding by laser ablation of the Drosophila imaginal wing disc, cellular intercalations at the wound site play an important role in facilitating fast and effective wound closure. A computational vertex model of epithelial tissue was used to predict and confirm the experimental findings, and it was shown that disabling cellular intercalations prevented the wounds from closing fully. In contrast, when intercalations were enabled in the model, the wound was able to close, and cells showed a decrease in cellular elongation over time as they were able to intercalate from the wound edge.
Extrusion is a well characterised process by which dead, dying or crowded cells are squeezed out of the epithelium by surrounding cells. Dysregulation of the molecular machinery responsible for facilitating extrusion has also been seen in many cancers. An adapted version of the wound healing vertex model has been used to explore the role of tissue fluidity in cellular extrusion, and preliminary evidence suggests that solid tissues are able to extrude cells more effectively than fluid tissues. The colon represents an ideal tissue to explore the behaviours of extrusion. Epithelial cells in the colon are constantly migrating from the base of the crypt to the villi in order to be extruded into the luminal space of the colon. The colon is also prone to damage during digestion and in common inflammatory bowel conditions, and as a result undergoes regular wound healing of microlesions. The aim of my PhD is therefore to use colorectal cancer organoids to investigate the role of tissue fluidity in cell extrusions and wound healing in one physiological disease model, as well as develop computational simulations using the vertex model described earlier, to predict and confirm experimental findings.
We will use multiple state-of-the-art biophysical and imaging techniques to achieve the above aims. 3D traction force microscopy will be used understand of the significance of traction forces at play between the organoids and their surrounding substrate, and microcavity organoid culture arrays will be used to strengthen the reproducibility of the system, a common shortfall of organoid research. Further in the project, the molecular and signalling pathways involved in tissue fluidity will be explored in more detail using Thiol-reactive organoid barcoding in situ (TOBis) in combination with mass cytometry (with Dr. Chris Tape, UCL CI). To achieve high throughput analysis, we will investigate the impact of molecular and mechanical modulation on the colorectal cancer organoids using the Opera Phenix HTP system. These technologies and model systems should provide insights into the importance of tissue fluidity in extrusion and wound healing, and a deeper understanding in how abrogation of these behaviours could have implications for therapeutic intervention for colorectal cancer.
Extrusion is a well characterised process by which dead, dying or crowded cells are squeezed out of the epithelium by surrounding cells. Dysregulation of the molecular machinery responsible for facilitating extrusion has also been seen in many cancers. An adapted version of the wound healing vertex model has been used to explore the role of tissue fluidity in cellular extrusion, and preliminary evidence suggests that solid tissues are able to extrude cells more effectively than fluid tissues. The colon represents an ideal tissue to explore the behaviours of extrusion. Epithelial cells in the colon are constantly migrating from the base of the crypt to the villi in order to be extruded into the luminal space of the colon. The colon is also prone to damage during digestion and in common inflammatory bowel conditions, and as a result undergoes regular wound healing of microlesions. The aim of my PhD is therefore to use colorectal cancer organoids to investigate the role of tissue fluidity in cell extrusions and wound healing in one physiological disease model, as well as develop computational simulations using the vertex model described earlier, to predict and confirm experimental findings.
We will use multiple state-of-the-art biophysical and imaging techniques to achieve the above aims. 3D traction force microscopy will be used understand of the significance of traction forces at play between the organoids and their surrounding substrate, and microcavity organoid culture arrays will be used to strengthen the reproducibility of the system, a common shortfall of organoid research. Further in the project, the molecular and signalling pathways involved in tissue fluidity will be explored in more detail using Thiol-reactive organoid barcoding in situ (TOBis) in combination with mass cytometry (with Dr. Chris Tape, UCL CI). To achieve high throughput analysis, we will investigate the impact of molecular and mechanical modulation on the colorectal cancer organoids using the Opera Phenix HTP system. These technologies and model systems should provide insights into the importance of tissue fluidity in extrusion and wound healing, and a deeper understanding in how abrogation of these behaviours could have implications for therapeutic intervention for colorectal cancer.
