Evaluation of Molecular-level Changes of Programmed Cell Death Ligand-1 after Radiation Therapy in a BALB/c CT26 Colorectal Mouse Tumor Model

In this study, female BALB/c mice inoculated with CT26 tumor cells were irradiated with 3 different RT regimens using the same BED of 40 gray (Gy). These included ablative RT (1*15 Gy), hypo-fractionated RT (2*10 Gy), and conventional (Hyper-fractionated) RT (10*3 Gy). PD-L1 expression was analyzed with immunohistochemical staining on days 2 and 20 and when the size of tumors had reached 2 cm2 after RT. All treated groups expressed PD-L1, but the group receiving single ablative high-dose RT showed higher expression compared to the other groups. No significant differences in PD-L1 expression were observed at different times in the same group. These findings showed that different regimens of RT have different effects on the TME, so a combination of RT and immune checkpoint blockade could be clinically used in cancer patients.PMID:37496409 | DOI:10.18502/ijaai.v22i2.12677
Source: Iranian Journal of Allergy, Asthma and Immunology - Category: Allergy & Immunology Authors: Source Type: research