Luka Bojic*, Jovana Kostic, Aleksandra Medić, Milena Milivojevic, Jelena Pejic, Mina Peric, Isidora Petrovic and Danijela Stanisavljevic
Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Serbia
luka.bojic [at] imgge.bg.ac.rs
Abstract
Osteosarcoma is an aggressivetumor, and therapeutic approaches for its treatment have n’t significantly changed over the past several decades, resulting in persistently poor clinical outcomes for affected patients. Although transcriptomic analyses have contributed to a better understanding of osteosarcoma biology, many studies have been conducted on cohorts that included metastatic samples and samples obtained after chemotherapy treatment. Analyses of such heterogeneous samples may obscure transcriptional patterns associated with the intrinsic aggressiveness of the tumor. To achieve a clearer understanding of these transcriptional programs, we analyzed transcriptomic profiles of osteosarcoma samples that hadn’t been previously exposed to therapy and with no metastases. By focusing on these samples, we aimed to obtain a more accurate insight into the biological characteristics associated with aggressive osteosarcoma behavior. Our analysis identified the transcription factor CTCF as one of the key regulators in osteosarcoma. CTCF was strongly associated with transcription programs linked to unfavorable clinical outcomes. The CTCF regulon identified in our analysis was enriched for transcriptional programs associated with proliferation and metabolic reprogramming, indicating a potentially important role for CTCF in regulating these processes. In addition, CTCF regulon activity showed a strong association with patient survival. Given the role of CTCF in chromatin organization and transcriptional regulation, alterations in its regulatory activity may contribute to gene expression changes associated with tumor aggressiveness. To investigate the possibility of pharmacological modulation of this regulatory network, we analyzed the interaction between the natural compound hesperidin and the DNA-binding domain of CTCF using molecular docking and molecular dynamics simulations. Our results of indicated a potentially stable interaction between hesperidin and CTCF. Furthermore, transcriptomic analysis of osteosarcoma cells treated with hesperidin demonstrated changes in the composition of the CTCF regulon, reduced CTCF activity, and enrichment of pathways related to apoptosis and negative regulation of various metabolic processes. Additional analyses confirmed that hesperidin treatment led to a statistically significant increase in the proportion of SAOS-2 cells undergoing early and late apoptosis. Our findings highlight the CTCF regulatory network as a potential driver of aggressive osteosarcoma biology. Moreover, this approach may contribute to the identification of novel prognostic biomarkers and therapeutic opportunities.
Keywords: Osteosarcoma, CTCF regulon, Hesperidin, Transcriptomics
Acknowledgement: Ministry of Science, Technological Development and Innovation of the Republic of Serbia, institutional funding – 200042 (University of Belgrade, Institute of Molecular Genetics and Genetic Engineering) (RS-MESTD-inst-2020-200042) and the Science Fund of the Republic of Serbia, (grant no. 7503).