SP6.6 - Examining the Immunomodulatory Effects of Fibrosis Induced by Radiation Using Adipose-derived Stem Cells

Abstract Background and Introduction Radiation-induced fibrosis (RIF) is a complication of radiotherapy in the treatment of head and neck cancer. RIF is characterised by the formation of fibrous tissue and is associated with significant morbidity. Autologous fat grafting (AFG) is a promising approach for treating RIF, and adipose-derived stem cells (ADSC) have been identified as key contributors to this therapeutic effect. Method The experimental group included subjecting human-derived fibroblasts (iHDF) to radiation, whereas the control group remained radiation-free. Both groups were then treated with ADSC-controlled medium and co-cultured with ADSC. The amounts of important immunomodulators produced by iHDF cells were then collected and evaluated using enzyme-linked immunosorbent assays (ELISA) and real-time reverse transcription-polymerase chain reaction (RT-PCR). Results Co-cultured iHDF samples demonstrated a slight reduction in CCL2 concentrations compared to untreated iHDF samples (p = 0.0006). The iHDF co-culture samples exhibit a marginal elevation in CCL3 levels compared to the untreated iHDF samples (p = 0.0247). The co-culture samples of iHDF demonstrate a substantial and measurable elevation in IL-8 levels compared to the untreated iHDF samples (p = 0.027). The expression of Col1A1 is decreased in iHDF samples in comparison to control groups. Discussion CCL2 is implicated in the recruitment of ADSCs to specific locations. The elevated production of IL-8 in ADSC samples is associated with the pro-angiogenic characteristics of ADSC secretions, which promote healing in fibrotic tissue. Conclusion ADSCs were shown to possess anti-fibrotic properties via stimulating pro-angiogenic factors. However, experimental data indicates a concomitant elevation in pro-inflammatory factors. Further research is needed to explore the in-vivo effects of ADSC.