COMPARATIVE GENE EXPRESSION PROFILING BETWEEN EX VIVO AND IN VIVO IRRADIATION AT 4 HOURS

LEBERLE, J.; BIOLATTI, V.; NEGRIN, L.; CASCÓN, A.; BREZÁN, R.; IRAZOQUI, J.; ALVAREZ, A; VENTIMIGLIA, R.; PERONA, M.; IBAÑEZ, I. L.; BELLORA, N.

Congreso; Reunión Anual de Sociedades de Biociencias 2022; 2022

SAIC, SAI, FAIC, SAFIS

Introduction and objectives: The molecular study of the radioinduced response by the massive analysis of the radiomodulated transcriptome has gained great relevance in recent years, both in the field of radioprotection and radiotherapy (RT). The aim of this work was to evaluate the transcriptome of irradiated human leukocytes at 4 hours post-exposure ex vivo and in vivo in order to identify a trend in the gene expression profile between conditions. Materials and methods: Leukocytes from healthy individuals were X-ray irradiated ex vivo at 25, 100 and 200 cGy. Leukocytes were also collected from patients with different tumors which received an in vivo irradiation corresponding to a single RT fraction, equivalent to a 1.6 cGy blood dose. Control samples were non-irradiated ex vivo or collected prior to the RT session. Then, leukocytes were cultured for 4 hours at 37°C and 5% CO2 for RNA extraction. The transcriptome was sequenced by RNA-seq (Illumina Platform, 150 bp paired-end). Sequencing reads were mapped to the human genome hg38 (STAR software). A comparative analysis of the transcriptomes was performed between irradiated vs. control samples by applying different bioinformatic pipelines, DESeq2 and limma:voom tools. Results: First, we identified 15737 differentially expressed genes (DEGs) associated with biological variability which were then removed to highlight the DEGs modulated by ionizing radiation in every dose vs. controls (0 Gy). The most significant radioinduced DEGs ex vivo were SEMA7A, CD70, PCNA, CDKN1A, DDB2, AEN and FDXR and a long non-coding RNA, LINC02846. Finally, transcripts per million (TPMs) were analyzed, showing consistent gene expression levels between conditions. Conclusion: A similar trend was observed in the expression profile of the most significant radioinduced DEGs between ex vivo and in vivo, showing that these DEGs have a similar behavior after irradiation.