Why the study?
Endothelial cells in the inflammatory tumour microenvironment are crucial in inflammation and angiogenesis, making them potential targets of radiation therapy whose effects under inflammatory conditions warranted investigation.
Ionizing radiation alters endothelial cell chemokine release and tumour cell interactions, suggesting endothelial cells in the inflammatory tumour microenvironment regulate radiation response.
May modulate endothelial-tumor interactions in inflamed microenvironments; leaves open whether this alters radiotherapy responses in vivo.
Purpose. Most tumours are characterized by an inflammatory microenvironment, and correlations between inflammation and cancer progression have been shown. Endothelial cells (ECs), as part of the tumour microenvironment, play a crucial role in inflammatory processes as well as in angiogenesis and could be critical targets of cancer therapy like irradiation. Therefore, in the present study we investigated the effect of ionizing radiation on endothelial cells under inflammatory conditions and their interactions with tumour cells. Methods. Nonactivated and TNF-α treatment-activated human EC EA.hy926 were irradiated with doses between 0.1 Gy and 6 Gy with a linear accelerator. Using a multiplex assay, the accumulation of various chemokines (IL-8, MCP-1, E-selectin, and P-selectin) and soluble adhesion molecules (sICAM-1 and VCAM-1) as well as protein values of the vascular endothelial growth factor (VEGF) was measured in the supernatant at different time points. The adhesion capability of irradiated and nonirradiated A549 tumour cells to EA.hy926 cells was measured using flow cytometry, and the migration of tumour cells was investigated with a scratch motility assay. Results. In contrast to unirradiated cells, IR of ECs resulted in a modified release of chemokines IL-8 and MCP-1 as well as the adhesion molecules sICAM-1 and VCAM-1 in the EC, whereas concentrations of E-selectin and P-selectin as well as VEGF were not influenced. IR always affected the adhesion capability of tumour cells to ECs with the effect dependent on the IR-treated cell type. TNF-α treatment generally increased adhesion ability of the tumour cells. Tumour cell migration was clearly inhibited after IR. This inhibitory effect was eliminated for radiation doses from 0.5 to 2 Gy when, additionally, an inflammatory environment was predominant. Conclusions. Our results support past findings suggesting that ECs, as part of the inflammatory microenvironment of tumours, are important regulators of the actual tumour response to radiation therapy.
No takes yet. Share an insight, caveat, or question.
Schröder et al. (2019) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: