Divergent evolutionary response to multiple fractions of radiation (MF2) therapy in cervical cancer cell lines (CCCL)

Introduction: Treatment for locally-advanced cervical cancer is not currently tailored based on genomic markers of treatment response. We aim to explore the potential for differential evolutionary trajectories of radiation (RT) resistance throughout treatment using two in vitro models. Methods: Sixteen cervical cancer cell lines ( CCCL) were exposed to 1.8 Gy fractions of RT radiation for five sequential days and the surviving fraction (MF2) calculated. Differential gene expression (DGE) was performed on pre and post - treatment samples. Partial least squares (PLS) regression was completed with MF2 as the endpoint . Protein-protein interaction (PPI) network and overrepresentation analysis of genes was also performed. Four CCCL (BOKU, SKG II SF, ME180, and HeLa) were serially exposed to 50 Gy of gamma radiation RT given in 2Gy fractions. Five evolutionary replicates and three passage-controls were maintained. The mean integral survival as a function of dose (AUC) was calculated and ANOVA analysis performed. Results: MF2 as the phenotypic endpoint identified 19 DE genes. PLS identified histones (H4C8, H2BC18, H2BC4) as positively associated and transcriptional regulators (NR2F1, KALRN) as negatively associated with MF2 (Figure 1AB). PPI and Reactome Pathways also highlighted histone deacetylase pathways, nucleosome assembly and regulation of membrane potentials (Figure 1BC). Longitudinal treatment RT identified differential evolutionary trajectories between CCCL replicates. Two BOKU (p = 0.005 and 0.0090), one SKG II SF (p = 0.0146), and one ME180 (p = 0.0384) replicates became resistant. Four SKG II SF (p < 0.0001), and two HeLa (p = 0.0005 and p = 0.0068) became more sensitive to radiationRT (1C). Conclusion: Divergent evolutionary trajectories under therapeutic stress can be elicited using in vitro evolutionary experimentation with cervical cancer cell linesCCCL. Genomic correlation with divergent evolutionary trajectories may allow for the identification of real-time markers of resistance or sensitivity and allow for true RT radiotherapy personalization. Citation Format: Johanna Kelley, Arda Durmaz, Michelle Kuznicki, Aaron Petty, Jacob Scott, Roberto Vargas. Divergent evolutionary response to multiple fractions of radiation (MF2) therapy in cervical cancer cell lines (CCCL) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2403.