First Results from a Screening of 300 Naturally Occurring Compounds: 4,6-dibromo-2-(2',4'-dibromophenoxy)phenol, 4,5,6-tribromo-2-(2',4'-dibromophenoxy)phenol, and 5-epi-nakijinone Q as Substances with the Potential for Anticancer Therapy.

There is a variety of antineoplastic drugs that are based on natural compounds from ecological niches with high evolutionary pressure. We used two cell lines (Jurkat J16 and Ramos) in a screening to assess 300 different naturally occurring compounds with regard to their antineoplastic activity. The results of the compounds 4,6-dibromo-2-(2',4'-dibromophenoxy)phenol (P01F03), 4,5,6-tribromo-2-(2',4'-dibromophenoxy)phenol (P01F08), and 5-epi-nakijinone Q (P03F03) prompted us to perform further research.

Important scaffold function of the Janus kinase 2 uncovered by a novel mouse model harboring a Jak2 activation-loop mutation.

Janus kinases (Jak) play essential roles in cytokine and growth factor signaling. Conventional gene targeting of Jak2, creating a null allele, leads to a block in definitive erythropoiesis as a result of failing signal transduction at the homomeric erythropoietin receptor (EpoR) and at the heteromeric interferon γ receptor (IFNGR). To investigate the in vivo relevance of the activation loop of Jak2, a Jak2-YY1007/1008FF knockin mutation was introduced into the germline of mice.