Abstract
This research focusses on the roles of CAIX and V-ATPase in hypoxic conditions, their influence upon macrophages, and how macrophages subsequently influence colorectal cancer cells in vitro, and addresses gaps in understanding the relationships between the tumour microenvironment (TME) and macrophages. Such enquiries are vital due to the fundamental role tumour-associated immunity plays in cancer progression. The research methodology included co-culturing HT29 cells with THP-1-derived macrophages in hypoxic 2D and 3D models, the inhibition of CAIX and V-ATPase by U-104 and omeprazole, and measuring cell proliferation, adhesion, and migration patterns.The project involved developing a model of HT29 colorectal adenocarcinoma with macrophage infiltration, identifying a 2:1 HT29 to THP-1 macrophages ratio as optimal to preserving HT29 viability. The approach has successfully provided a model of “hot” macrophage infiltration in in vivo tumour scenarios, crucial for investigating tumour-macrophage interactions within the natural hypoxic gradient of a tumour.
Co-culture with macrophages heightened HT29 cancer cell invasiveness, which was attenuated upon CAIX inhibition by U-104. Combining CAIX inhibition with V-ATPase inhibitor omeprazole enhanced cytotoxic effects against hypoxic HT29 cells. This highlights the influence of acidity and CAIX on macrophage behaviour, and macrophage-mediated cancer progression.
The key findings elucidated that hypoxia and CAIX play a role in inhibiting THP-1 monocyte proliferation, while CAIX contributes to adhesion between THP-1 monocytes and HT29 cells. Inhibition of CAIX alters macrophage migration patterns within the TME, identifying a potential impact of pH regulation on macrophage behaviour.
The findings underscore the significance of our developed HT29-macrophage model in simulating tumour scenarios, vital for understanding hypoxia-linked tumorigenesis. They reveal the impact of CAIX inhibition on HT29 invasiveness and the synergistic cytotoxicity of CAIX and acidity targeting. They illuminate the role of CAIX in macrophage interactions, contributing insights into tumour-macrophage dynamics in in vitro cancer progression.
Date of Award | 23 May 2024 |
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Original language | English |
Awarding Institution |
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Supervisor | Roben Gieling (Supervisor) & Stephen Todryk (Supervisor) |
Keywords
- hypoxia
- spheroids
- HT29 cells
- HCT116 cells
- THP-1-derived macrophages