Abstract 24P
Background
A promising direction in the field of developing new drugs is the synthesis of molecules that combine the structural features of two or more biologically active substances in one compound, based on the assumption that a new molecule can “inherit” the desired pharmacological properties of active fragments or lead to the emergence of new properties. Camptothecin, a specific irreversible inhibitor of topoisomerase I, is poorly soluble in biological fluids, which is the main limitation of its use in clinical practice. The goal of our work was to create molecules based on camptothecin and pentacyclic steroids that exhibit high selectivity towards biotargets, have acceptable water solubility and the ability to pass through cell membranes, and create the basis for the development and introduction these compounds into clinical practice.
Methods
When studying new molecules, a complex of in vitro, in vivo and in silico methods was used, including modern methods of flow cytometry, fluorescence microscopy, multiparametric analysis and immunoblotting.
Results
It was shown that the hybrid molecules showed significantly greater inhibitory activity against human topoisomerase I than the original camptothecin. The level of apoptosis, cell cycle dynamics and DNA damage in tumor cells was assessed using flow cytometry. It was also found that some synthesized compounds have their own fluorescence, preferentially accumulating in dead cells. The total protein or phosphorylated protein levels of various biological analytes, such as kinases or signaling proteins (CREB, ERK/MAP, p70 S6, p21, p38, PI3K/AKT/mTOR, JNK(A), p53, MDM2, Bcl-2/Bax, STAT3 and STAT5, Nf-kB, Caspase 3-8-9, JNK, ATM, Chk1, Chk2, and H2AX) in cell lysates after treated novel compounds were determined. Hybrid molecules cause the accumulation of phosphorylated histone H2A.X in all cell lines studied, and also effectively inhibit the PI3K/Akt/mTOR signaling pathway in human leukemia cells.
Conclusions
A line of effective biologically oriented targeted antitumor compounds based on camptothecin and pentacyclic triterpenoids has been created, which has a unique mechanism of action on cell DNA, blocks growth and proliferation, and has a pronounced genotoxic effect.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
N. D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences, Moscow, Russian Federation.
Funding
Grant Russian Science Foundation (Project No. 22-13-00160).
Disclosure
All authors have declared no conflicts of interest.