Extracellular matrix stiffness mediates radiosensitivity in a 3D nasopharyngeal carcinoma model

Abstract

Purpose Radiotherapy is one of the essential treatment modalities for nasopharyngeal carcinoma (NPC), however, radioresistance still poses challenges. Three-dimensional (3D) tumor culture models mimic the in vivo growth conditions of cells more accurately than 2D models. This study is to compare the tumor biological behaviors of NPC cells in 2D, On-Surface 3D and Embedded 3D systems, and to investigate the correlation between radioresistance and extracellular matrix (ECM) stiffness. Methods The morphology and radioresistance of the human NPC cell line CNE-1 were observed in 2D and 3D systems. The CCK-8 assay, wounding healing assays, flow cytometry, soft agar assays, and western blot analysis were used to evaluate differences in biological behaviors such as proliferation, migration, cell cycle distribution, and stem cell activity. Different ECM stiffness systems were established by co-blending collagen and alginate in varying proportions. ECM stiffness was evaluated by compressive elastic moduli measurement and colony formation assay was used to assess radioresistance of NPC cells in systems with different ECM stiffness after irradiation. Results Compared to 2D models, the morphology of NPC cells in 3D culture microenvironments has more in common with in vivo tumor cells and 3D cultured NPC cells exhibit stronger radioresistance. Integrin β1 but not the epithelial-to-mesenchymal transition pathway in 3D models boost migration ability. Cell proliferation was enhanced, the proportion of tumor stem cells was increased, and G1/S phase arrest occurred in 3D models. NPC cells cultured in softer ECM systems (with low alginate proportions) exhibit striking resistance to ionizing radiation. Conclusion The tumor biological behaviors of NPC cells in 3D groups were obviously different from that of 2D. Radioresistance of NPC cells increased with the stiffness of ECM decreasing.

Interaction between intratumoral microbiota and tumor mediates the response of neoadjuvant therapy for rectal cancer

“…Previously, the correlation between CAFs and ECM was established in a study that observed the signature of CAF in the TME and defined the function of CAF based on gene expression and immunostaining ( Lee et al, 2020 ). Moreover, ECM remodeling has also been linked to tumor treatment resistance in several studies ( Drain et al, 2021 ; Pietilä et al, 2021 ; Fang et al, 2022 ). In our work, we explored five clusters of CAF subpopulations that presented potential interactions with important microbes, in which clusters 7 and 10 were found to be responsible for ECM formation, similar to another study reporting that microbiota inside CRC was co-localized with CAFs, activated the TLR2/NF-κB pathway in the CRC microenvironment ( Xu et al, 2022 ).…”

3D Cell Models in Radiobiology: Improving the Predictive Value of In Vitro Research

“…Much evidence has accumulated in recent years indicating a difference in radiosensitivity between cells growing in a 2D or 3D environment, and the majority of these studies have shown an increase in radioresistance in 3D cultures [ 15 , 24 , 33 , 34 ]. This is reflected in differences, which can be very significant, between survival curves obtained from 2D or 3D models [ 35 , 36 ]. For this reason, the exclusive use of 2D cellular models for the definition of survival curves and the application of the LQ model to radiotherapy plans could lead to an underestimation of the radiation dose necessary to eradicate the tumor and to an incorrect assessment of the risk–benefit ratio.…”

“…Stiffness increase in tumors has been shown to be fundamental in the regulation of many biological effects [ 9 , 29 , 36 , 70 , 77 , 81 ]. In particular, it has been reported that ECM stiffness can modulate the DNA damage response to radiation due to the ability of integrins to detect mechanical stimuli.…”