The Use of Social Media in Orphan Drug Development.

Social media has transformed how people interact with one another through the Internet, and it has the potential to do the same for orphan drug development. Currently, social media influences the orphan drug development process in the following three ways: assisting the study of orphan diseases, increasing the awareness of orphan disease, and playing a vital role in clinical trials. However, there are some caveats to the utilization of social media, such as the need to protect patient privacy by adequately de-identifying personal health information, assuring consistent quality and representativeness of the data, and preventing the unblinding of patient group assignments. Social media has both potential for improving orphan drug development and pitfalls, but with proper oversight on the part of companies, support and participation of patients and their advocacy groups, and timely guidance from regulatory authorities, the positives outweigh the negatives for this powerful and patient-centric tool.

Human Cerberus prevents nodal-receptor binding, inhibits nodal signaling, and suppresses nodal-mediated phenotypes.

The Transforming Growth Factor-ß (TGFß) family ligand Nodal is an essential embryonic morphogen that is associated with progression of breast and other cancers. It has therefore been suggested that Nodal inhibitors could be used to treat breast cancers where Nodal plays a defined role. As secreted antagonists, such as Cerberus, tightly regulate Nodal signaling during embryonic development, we undertook to produce human Cerberus, characterize its biochemical activities, and determine its effect on human breast cancer cells. Using quantitative methods, we investigated the mechanism of Nodal signaling, we evaluated binding of human Cerberus to Nodal and other TGFß family ligands, and we characterized the mechanism of Nodal inhibition by Cerberus. Using cancer cell assays, we examined the ability of Cerberus to suppress aggressive breast cancer cell phenotypes. We found that human Cerberus binds Nodal with high affinity and specificity, blocks binding of Nodal to its signaling partners, and inhibits Nodal signaling. Moreover, we showed that Cerberus profoundly suppresses migration, invasion, and colony forming ability of Nodal expressing and Nodal supplemented breast cancer cells. Taken together, our studies provide mechanistic insights into Nodal signaling and Nodal inhibition with Cerberus and highlight the potential value of Cerberus as anti-Nodal therapeutic.

Inhibition of CDC25B phosphatase through disruption of protein-protein interaction.

CDC25 phosphatases are key cell cycle regulators and represent very attractive but challenging targets for anticancer drug discovery. Here, we explored whether fragment-based screening represents a valid approach to identify inhibitors of CDC25B. This resulted in identification of 2-fluoro-4-hydroxybenzonitrile, which directly binds to the catalytic domain of CDC25B. Interestingly, NMR data and the crystal structure demonstrate that this compound binds to the pocket distant from the active site and adjacent to the protein-protein interaction interface with CDK2/Cyclin A substrate. Furthermore, we developed a more potent analogue that disrupts CDC25B interaction with CDK2/Cyclin A and inhibits dephosphorylation of CDK2. Based on these studies, we provide a proof of concept that targeting CDC25 phosphatases by inhibiting their protein-protein interactions with CDK2/Cyclin A substrate represents a novel, viable opportunity to target this important class of enzymes.