Disulfiram (DSF), a derivative of thiuram, has been used in humans to treat alcoholism for more than 60 years. Over the past decade, however, increasing evidence indicates that DSF possesses a great potential for the treatment of human cancers. DSF's anticancer activity has been demonstrated in both in vitro and in vivo model systems, and has been tested in human clinical trials for various cancer types. It is also evident that DSF can sensitize tumor cells to radiotherapy and enhance the cytotoxicity of anticancer drugs, thus DSF may serve as an adjuvant therapy. The key to DSF's anticancer action relates to its ability to suppress cancer stem cells by targeting aldehyde dehydrogenase (ALDH), a marker of cancer stem cells, and inhibit proteasome activity in cancer cells by forming complexes with metal ions. In addition, DSF targets epigenetic mechanisms and modulates cellular signaling pathways to slow down tumor progression. DSF also induces apoptosis, inhibits cancer cell proliferation, and suppresses cancer cell metastasis. Considering that the pharmacokinetics of DSF are well-established and a safety profile has been recorded, this compound is an attractive "old" drug that has great potential for rapid development into a new cancer therapeutic. This article provides a brief review of the history of DSF use in humans, evidence for its anticancer activities, the molecular mechanisms of DSF action that have been illustrated by recent studies, and the potential for repurposing DSF as a new chemotherapeutic drug in the near future.

Our results suggested that cucurbitacin E may be an effective regimen for the chemotherapy of pancreatic cancer.

Site-specific antibody-drug conjugates (ADCs) are designed to overcome the heterogeneity observed with first-generation ADCs that use random conjugation to surface-exposed lysine residues or conjugation to interchain disulfide bonds. Despite significantly enhanced homogeneity, however, the production of site-specific ADCs yields some process-related species heterogeneity, including stereoisomers, unconjugated antibody, underconjugated species, and overconjugated species. An elevated level of size variants, such as heavy chain-light chain species (half ADC), heavy chain-heavy chain-light chain species, and light chain species, is also observed with the final site-specific ADC product. To understand the root cause of heterogeneity generated during the ADC conjugation process, we designed time-course studies for each conjugation step, including reduction, oxidation, conjugation, and quenching. We developed both non-reduced peptide map and LabChip-based capillary electrophoresis sodium dodecyl sulfate methods for time-course sample analysis. On the basis of our time-course data, the half ADC and unconjugated antibody were generated during oxidation as a result of alternative disulfide bond arrangements. During oxidation, two hinge cysteines formed an intra-chain disulfide bond in the half ADC, and three inter-chain hinge disulfide bonds were formed in the unconjugated antibody. Time-course data also showed that the elevated level of size variants, especially heavy chain-heavy chain-light chain species and light chain species, resulted from the quenching step, where the quenching reagent engaged in a disulfide bond exchange reaction with the ADC and broke the disulfide bonds connecting the heavy chain and light chain. Underconjugated and overconjugated species arose from the equilibrium established during the conjugation reaction.

Cucurbitacin B has a potential value for suppressing metastasis of human hepatoma cells through suppressing the expression of MMP-9.

Tryptic digestion of proteins followed by liquid chromatography with tandem mass spectrometry analysis is an extensively used approach in proteomics research and biopharmaceutical product characterization, owing to the high level of cleavage fidelity produced with this technique. However, nonspecific trypsin cleavages have been frequently reported and shown to be related to a number of digestion conditions and predigestion sample treatments. In this work, we reveal that, for a number of commercial trypsins, reconstitution and storage conditions can have a significant impact on the occurrence of trypsin nonspecific cleavages. We analyzed the tryptic digestion of a variety of biotherapeutics, using trypsins reconstituted under different conditions. The results indicate that, for many commercial trypsins, commonly recommended reconstitution/storage conditions (mildly acidic, e.g., 50 mM acetic acid, 1 mM HCl) can actually promote nonspecific trypsin activities, which are time dependent and can be as high as 20% in total relative abundance. In contrast, using water for reconstitution and storage can effectively limit nonspecific cleavages to 1%. Interestingly, the performances of different commercial trypsins were found to be quite distinct in their levels of nonspecific cleavages and responses to the two reconstitution conditions. Our findings demonstrate the importance of choosing the appropriate trypsin for tryptic digestion and the necessity of assessing the impact of trypsin reconstitution and storage on nonspecific cleavages. We advocate for manufacturers of commercial trypsins to reevaluate manufacturing processes and reconstitution/storage conditions to provide good cleavage specificity.