Publication
Developing targeted chronotherapy protocols in T-cell acute lymphoblastic leukemia
| Summary: | Circadian rhythms are an essential mechanism to the proper adaptation of organisms to their environment and to the periodical changes which occur inherent to life on Earth. The disruption of circadian rhythms contributes to oncogenesis by promoting the onset of all can- cer hallmarks. Furthermore, a link exists between the Circadian Molecular Clock, which regu- lates circadian oscillations in humans, and the PI3K/AKT/mTOR pathway, which is hyperac- tivated in T-ALL patients. This link resides in the activity of CK2, a kinase that contributes towards the activation of PI3K signaling by inhibiting PTEN, and towards the establishment of rhythmicity by phosphorylating BMAL1, allowing its nuclear localization. There are a lot of unknowns regarding the persistence of circadian rhythms in T-ALL, and thus, in this work, we set out to characterize circadian rhythms in leukemic cells and to compare them to healthy counterparts. First, we found a distinct lack of BMAL1 in most leukemic samples we analyzed. However, some rhythmicity was still present in T-ALL cells, even if slightly less pronounced than that displayed by healthy thymocytes. Out of all the genes analyzed, IL7R appeared as the most consistently rhythmic. The data presented considerable heterogeneity. Thus, syn- chronization was employed to improve consistency. To truly assess the effect of BMAL1 ab- sence, we performed qPCRs on CMC genes and checked for survival differences in mice with different levels of BMAL expression. The results suggested that absence of BMAL1 expression correlates negatively with rhythmicity and survival. Finally, we successfully tested a lucifer- ase-based PI3K signaling activity readout reporter, that should facilitate the analysis of PI3K pathway oscillations. Coupled with the knowledge we are acquiring about circadian oscilla- tions, this novel tool will be of key importance in defining the best points for the development of targeted chronotherapeutic protocols for T-ALL in the future. |
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| Main Authors: | Marques, Tomás Francisco da Silva |
| Subject: | BMAL1 Circadian Rhythms Circadian Molecular Clock Luciferase based reporter PI3K/AKT/mTOR Pathway T-ALL |
| Year: | 2025 |
| Country: | Portugal |
| Document type: | master thesis |
| Access type: | open access |
| Associated institution: | Universidade Nova de Lisboa |
| Language: | English |
| Origin: | Repositório Institucional da UNL |
| Summary: | Circadian rhythms are an essential mechanism to the proper adaptation of organisms to their environment and to the periodical changes which occur inherent to life on Earth. The disruption of circadian rhythms contributes to oncogenesis by promoting the onset of all can- cer hallmarks. Furthermore, a link exists between the Circadian Molecular Clock, which regu- lates circadian oscillations in humans, and the PI3K/AKT/mTOR pathway, which is hyperac- tivated in T-ALL patients. This link resides in the activity of CK2, a kinase that contributes towards the activation of PI3K signaling by inhibiting PTEN, and towards the establishment of rhythmicity by phosphorylating BMAL1, allowing its nuclear localization. There are a lot of unknowns regarding the persistence of circadian rhythms in T-ALL, and thus, in this work, we set out to characterize circadian rhythms in leukemic cells and to compare them to healthy counterparts. First, we found a distinct lack of BMAL1 in most leukemic samples we analyzed. However, some rhythmicity was still present in T-ALL cells, even if slightly less pronounced than that displayed by healthy thymocytes. Out of all the genes analyzed, IL7R appeared as the most consistently rhythmic. The data presented considerable heterogeneity. Thus, syn- chronization was employed to improve consistency. To truly assess the effect of BMAL1 ab- sence, we performed qPCRs on CMC genes and checked for survival differences in mice with different levels of BMAL expression. The results suggested that absence of BMAL1 expression correlates negatively with rhythmicity and survival. Finally, we successfully tested a lucifer- ase-based PI3K signaling activity readout reporter, that should facilitate the analysis of PI3K pathway oscillations. Coupled with the knowledge we are acquiring about circadian oscilla- tions, this novel tool will be of key importance in defining the best points for the development of targeted chronotherapeutic protocols for T-ALL in the future. |
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