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MYC deregulation, a cardinal event in Burkitt lymphoma (BL) pathogenesis, necessitates the elucidation of the molecular mechanisms governing MYC activation to devise innovative and effective therapeutic strategies. The t(8;14)(q24;q32) chromosomal translocation commonly observed in hematological malignancies results in MYC deregulation, endowing cancer cells with a competitive edge through heightened cell proliferation, cell cycle progression, apoptosis evasion, and metabolic reprogramming. Recent discoveries of recurrent MYC mutations in BL underscore the potential of precision medicine, employing tailored therapeutics to specifically inhibit MYC activity. However, the intricate genetic landscape of BL, featuring additional alterations, such as mutations in TP53, TCF3, and ID3, may necessitate a combinatorial approach targeting multiple oncogenic pathways for effective intervention. Despite significant strides in hematological malignancy treatment, a comprehensive understanding of the molecular mechanisms underpinning MYC's oncogenic properties remains crucial for the potential development of highly potent and selective MYC-directed cancer therapies. This review offers an in-depth analysis of MYC translocation and its implications in Burkitt lymphoma, with a spotlight on cutting-edge advances in research and emerging therapeutic paradigms. [ABSTRACT FROM AUTHOR]

Etoposide is an anticancer drug that acts by inducing topoisomerase II-mediated DNA cleavage. Despite its wide use, etoposide is associated with some very serious side-effects including the development of treatment-related acute myelogenous leukemias. Etoposide targets both human topoisomerase IIα and IIβ. However, the contributions of the two enzyme isoforms to the therapeutic vs. leukemogenic properties of the drug are unclear. In order to develop an etoposide-based drug with specificity for cancer cells that express an active polyamine transport system, the sugar moiety of the drug has been replaced with a polyamine tail. To analyze the effects of this substitution on the specificity of hybrid molecules toward the two enzyme isoforms, we analyzed the activity of a series of etoposide-polyamine hybrids toward human topoisomerase IIα and IIβ. All of the compounds displayed an ability to induce enzyme-mediated DNA cleavage that was comparable to or higher than that of etoposide. Relative to the parent drug, the hybrid compounds displayed substantially higher activity toward topoisomerase IIβ than IIα. Modeling studies suggest that the enhanced specificity may result from interactions with Gln778 in topoisomerase IIβ. The corresponding residue in the α isoform is a methionine. [ABSTRACT FROM AUTHOR]

Adaptive QM/MM (quantum mechanical/molecular mechanical) methods repartition molecules on-the-fly into the QM and MM regions based on a partitioning criterion. A density-based partitioning scheme offers a unique way of carrying out QM and MM assignments on the presence/absence of (non) covalent interactions between non-QM core molecules and the QM core. Here, we present two improvements to promote our density-based adaptive partitioning strategy for adaptive QM/MM calculations. First, bond formation/breaking processes between non-QM core molecules and the QM core are monitored using a density-based descriptor, to define an adaptive QM core region on the fly. Second, the density-based adaptive QM/MM partitioning scheme is made efficient enough for large systems by utilizating an adaptive search region and a Voronoi style-partitioning scheme. The adaptive search region is used to preselect the subset of molecules that may interact strongly enough with the QM core region, and then a density-based interaction calculation is only carried out on this subset. A Voronoi style-partitioning scheme achieves an efficient assignment of the density-based interactions. [ABSTRACT FROM AUTHOR]

An artificial nucleoside surrogate with 1H-imidazo[ 4,5-f][1,10]phenanthroline (P) acting as an aglycone has been introduced into DNA oligonucleotide duplexes. This nucleoside surrogate can act as a bidentate ligand, and so is useful in the context of metal-mediated base pairs. Several duplexes involving a hetero base pair with an imidazole nucleoside have been investigated. The stability of DNA duplexes incorporating the respective AgI-mediated base pairs strongly depends on the sequence context. Quantum mechanical/ molecular mechanical (QM/MM) calculations have been performed in order to gain insight into the factors determining this sequence dependence. The results indicated that, in addition to the stabilizing effect that results from the formation of coordinative bonds, destabilizing effects may occur when the artificial base pair does not fit optimally into the surrounding B-DNA duplex. [ABSTRACT FROM AUTHOR]