Effect And Mechanism Of Ionizing Radiation Combined EGFR Inhibitor Enhances NK Cell-mediated Killing Of Oral Squamous Cell Carcinoma

Objective In this study,we investigated the effects of ionizing radiation and EGFR inhibitor cetuximab on the expression of NKG2 D ligand on the surface of SCC25 cells in oral squamous cell carcinoma,and provide experimental support for oral squamous cell carcinoma radiotherapy combined with cetuximab enhanced NK cell immunity.Methods 1.The changes of peripheral lymphocytes and subtypes were detected before and after radiotherapy for clinical patients.The CCK8 kit was then used to detect the relationship between NK cell lethality and NK cell proportions.2.PCR technique was used to detect the expression of NKG2 D ligand m RNA 24 hours before and after exposure to ionizing radiation.The changes of NKG2 D ligand on the surface of tumor cells treated with EGFR inhibitor were detected by flow cytometry.3.CCK8 kit and LDH lactate dehydrogenase release test to detect the NK cells' ability to kill SCC25 after ionizing radiation and EGFR inhibitor treatment.Results 1.The proportion of peripheral blood NK cells in patients with clinical oral tumor after radiotherapy was increased in peripheral blood after radiotherapy.CCK8 experiments show that NK cells can kill SCC25 significantly,and the higher the proportion of NK cells,the stronger the killing effect on SCC25.2.After SCG25 received 2Gy ionizing radiation,the expression of NKG2 D ligand m RNA increased to some extent,in which MICB expression increased significantly,and reached a peak in a certain period of time.3.Both NK cells and the EGFR inhibitor cetuximab can significantly kill SCC25.As the three factors,ionizing radiation,EGFR inhibitor cetuximab and NK cells,exist simultaneously,the killing effect on SCC25 is the most significant.Conclusion 1.After radiotherapy,the number of peripheral blood CD4+T cells and CD8+T cells decreased and the proportion decreased,but the proportion of NK cells in peripheral blood was increased after radiotherapy.The higher the proportion of NK cells,the stronger the ability to kill tumor cells.2.Both ionizing radiation and EGFR inhibitor can increase the expression of NKG2 D ligand in the SCC25 surface.3.Both NK cells and the EGFR inhibitor cetuximab can significantly kill SCC25.As the three factors,ionizing radiation,EGFR inhibitor cetuximab and NK cells,exist simultaneously,the killing effect on SCC25 is the most significant.4.Ionizing radiation combined with EGFR inhibitors may enhance NK cells' killing effect on oral squamous cell carcinoma by improving the expression of NKG2 D ligands on the surface of tumor cells.