A hypothalamic pathway for Augmentor α-controlled body weight regulation.

Augmentor α and ß (Augα and Augß) are newly discovered ligands of the receptor tyrosine kinases Alk and Ltk. Augα functions as a dimeric ligand that binds with high affinity and specificity to Alk and Ltk. However, a monomeric Augα fragment and monomeric Augß also bind to Alk and potently stimulate cellular responses. While previous studies demonstrated that oncogenic Alk mutants function as important drivers of a variety of human cancers, the physiological roles of Augα and Augß are poorly understood. Here, we investigate the physiological roles of Augα and Augß by exploring mice deficient in each or both Aug ligands. Analysis of mutant mice showed that both Augα single knockout and double knockout of Augα and Augß exhibit a similar thinness phenotype and resistance to diet-induced obesity. In the Augα-knockout mice, the leanness phenotype is coupled to increased physical activity. By contrast, Augß-knockout mice showed similar weight curves as the littermate controls. Experiments are presented demonstrating that Augα is robustly expressed and metabolically regulated in agouti-related peptide (AgRP) neurons, cells that control whole-body energy homeostasis in part via their projections to the paraventricular nucleus (PVN). Moreover, both Alk and melanocortin receptor-4 are expressed in discrete neuronal populations in the PVN and are regulated by projections containing Augα and AgRP, respectively, demonstrating that two distinct mechanisms that regulate pigmentation operate in the hypothalamus to control body weight. These experiments show that Alk-driven cancers were co-opted from a neuronal pathway in control of body weight, offering therapeutic opportunities for metabolic diseases and cancer.

Discovery of anaplastic lymphoma kinase inhibitors from natural product library: A holistic in silico approach.

Over the years, phytochemical compounds have shown compelling evidences in exhibiting powerful antitumor properties. Moreover, due to the lack of safety and high cost of cancer therapies, opportunities are being sought out in these compounds as an alternative treatment modality. Therefore, in the present study, 1,574 compounds from NPACT library were examined to excavate potent and nontoxic anaplastic lymphoma kinase (ALK) inhibitors. Notably, two pharmacophore hypotheses (AAAHP and DDRRR) were generated using ligand-based and energy-based techniques, respectively, to eliminate false-positive prediction in database screening. Furthermore, molecular docking and Prime MM/GBSA analysis were performed on the screened compounds to examine inhibitory activity against ALK. The analysis revealed that the two hits, namely, NPACT00018 and NPACT01077, exhibited better docking scores, binding energies, and also ensured excellent drug-likeness properties than the reference compound, crizotinib. Finally, the results were subjected to molecular dynamics studies to gain insight into the stability of these compounds in the binding pocket of ALK protein. Indeed, the useful predictions generated by the present computational models are of immense importance and could further speed up the anticancer drug development in the near future.

N-[18F]-Fluoroacetylcrizotinib: A potentially potent and selective PET tracer for molecular imaging of non-small cell lung cancer.

N-[18F]fluoroacetylcrizotinib, a fluorine-18 labeled derivative of the first FDA approved tyrosine kinase inhibitor (TKI) for the treatment of Anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC), crizotinib, was successfully synthesized for use in positron emission tomography (PET). Sequential in vitro biological evaluation of fluoracetylcrizotinib and in vivo biodistribution studies of [18F]fluoroacetylcrizotinib demonstrated that the biological activity of the parent compound remained unchanged, with potent ALK kinase inhibition and effective tumor growth inhibition. These results show that [18F]fluoroacetylcrizotinib has the potential to be a promising PET ligand for use in NSCLC imaging. The utility of PET in this context provides a non-invasive, quantifiable method to inform on the pharmacokinetics of an ALK-inhibitor such as crizotinib prior to a clinical trial, as well as during a trial in the event of acquired drug resistance.