Comparison of Pyrrolobenzodiazepine Dimer Bis-imine versus Mono-imine: DNA Interstrand Cross-linking, Cytotoxicity, Antibody-Drug Conjugate Efficacy and Toxicity.

Antibody-drug conjugates (ADC) delivering pyrrolobenzodiazepine (PBD) DNA cross-linkers are currently being evaluated in clinical trials, with encouraging results in Hodgkin and non-Hodgkin lymphomas. The first example of an ADC delivering a PBD DNA cross-linker (loncastuximab tesirine) has been recently approved by the FDA for the treatment of relapsed and refractory diffuse large B-cell lymphoma. There has also been considerable interest in mono-alkylating PBD analogs.

Simultaneous monitoring of multiple attributes of pyrrolobenzodiazepine antibody-drug conjugates by size exclusion chromatography - high resolution mass spectrometry.

Antibody-drug conjugates (ADCs) are an emerging class of oncology treatments combining the unique specificity of monoclonal antibodies with the highly cytotoxic properties of small molecule compounds. Pyrrolobenzodiazepines (PBDs) are highly potent agents capable of inhibiting cellular DNA replication which leads to apoptosis. To ensure efficacy and patient safety upon administration of such toxic and heterogeneous molecules, their structure and quality attributes must be closely monitored.

Quantifying CDK inhibitor selectivity in live cells.

Concerted multidisciplinary efforts have led to the development of Cyclin-Dependent Kinase inhibitors (CDKi's) as small molecule drugs and chemical probes of intracellular CDK function. However, conflicting data has been reported on the inhibitory potency of CDKi's and a systematic characterization of affinity and selectivity against intracellular CDKs is lacking. We have developed a panel of cell-permeable energy transfer probes to quantify target occupancy for all 21 human CDKs in live cells, and present a comprehensive evaluation of intracellular isozyme potency and selectivity for a collection of 46 clinically-advanced CDKi's and tool molecules.

An Activity-Based Probe Targeting Non-Catalytic, Highly Conserved Amino Acid Residues within Bromodomains.

Bromodomain-containing proteins are epigenetic modulators involved in a wide range of cellular processes, from recruitment of transcription factors to pathological disruption of gene regulation and cancer development. Since the druggability of these acetyl-lysine reader domains was established, efforts were made to develop potent and selective inhibitors across the entire family. Here we report the development of a small molecule-based approach to covalently modify recombinant and endogenous bromodomain-containing proteins by targeting a conserved lysine and a tyrosine residue in the variable ZA or BC loops.

CDA directs metabolism of epigenetic nucleosides revealing a therapeutic window in cancer.

Cells require nucleotides to support DNA replication and repair damaged DNA. In addition to de novo synthesis, cells recycle nucleotides from the DNA of dying cells or from cellular material ingested through the diet. Salvaged nucleosides come with the complication that they can contain epigenetic modifications.