RNA Targeting in Acute Myeloid Leukemia

Abstract

Nucleosides and their analogues constitute an essential family of anticancer drugs. DNA has been the presumptive target of the front-line prodrug for acute myeloid leukemia (AML), cytarabine (ara-C), since the 1980s. Here, the biomolecular targeting of ara-C was evaluated in primary white blood cells using the ara-C mimic “AzC” and azide–alkyne “click” reactions. Fluorescent staining and microscopy revealed that metabolic incorporation of AzC into primary white blood cells was unexpectedly enhanced by the DNA polymerase inhibitor aphidicholine. According to RNaseH digestion and pull-down-and-release experiments, AzC was incorporated into short RNA fragments bound to DNA in peripheral blood monocytes (PBMCs) collected from all six healthy human donors tested. Samples from 22 AML patients (French–American–British classes M4 and M5) exhibited much more heterogeneity, with 27% incorporating AzC into RNA and 55% into DNA. The overall survival of AML patients whose samples incorporated AzC into RNA was approximately 3-fold higher as compared to that of the DNA cohort (p ≤ 0.056, χ2 = 3.65). These results suggest that the RNA primers of DNA synthesis are clinically favorable targets of ara-C, and that variable incorporation of nucleoside drugs into DNA versus RNA may enable future patient stratification into treatment-specific subgroups.

A Kinetic and Fluorogenic Enhancement Strategy for Labeling of Nucleic Acids

“…[20,30,31,54,55] The new capability of reacting bioorthogonal functional groups in native DNA and RNA will open up new opportunities in biological and translational research such as the real-time study of chromosome segregation in animals, [56] and predicting nucleoside drug responses of cancer patients. [14]…”

“…Chemoselective modification reactions of biomolecules provide indispensable tools for biological and biomedical research [1–4] . In particular, bioorthogonal labeling reactions for chemical biology have been successfully developed for sequence recognition, [5–7] detection of viral infection, [8–10] protein crosslinking, [11] elucidation of metabolic pathways [12] and probing drug resistance and sensitivity mechanisms [13, 14] . Such bioorthogonal methodologies were originally designed for proteins or carbohydrates and subsequently applied to nucleic acids [15–18] .…”

“…Previous studies involving the chemical modification of cellular vinyl‐modified DNA by bioorthogonal methods have depended on cell fixation and denaturation to facilitate tetrazine‐alkene reactions [20, 30, 31, 54, 55] . The new capability of reacting bioorthogonal functional groups in native DNA and RNA will open up new opportunities in biological and translational research such as the real‐time study of chromosome segregation in animals, [56] and predicting nucleoside drug responses of cancer patients [14] …”

“…[1][2][3][4] In particular, bioorthogonal labeling reactions for chemical biology have been successfully developed for sequence recognition, [5][6][7] detection of viral infection, [8][9][10] protein crosslinking, [11] elucidation of metabolic pathways [12] and probing drug resistance and sensitivity mechanisms. [13,14] Such bioorthogonal methodologies were originally designed for proteins or carbohydrates and subsequently applied to nucleic acids. [15][16][17][18] These include copper-catalyzed or strainpromoted azide-alkyne cycloadditions (CuAAC/SPAAC), inverse electron-demand Diels-Alder (IEDDA) reactions between alkenes and tetrazines, and 1,3-dipolar "photoclick" reactions of tetrazoles.…”

Cancer Prognosis According to Parthanatos Features

“…Previous studies have focused on metabolic incorporation of ara-C into DNA and downstream apoptosis (Cassier et al, 2017;Deng et al, 2017;Harrison et al, 2016;Schneider et al, 2017;Vincelette and Yun, 2014). However, recent reports suggest that ara-C incorporation into primer RNA is responsible for its therapeutic efficacy (Messikommer et al, 2020;Triemer et al, 2018), and active killing of AML primary isolates by ara-C can be a caspase-independent process (Carter et al, 2003).…”