Differential selectivity of JAK2 inhibitors in enzymatic and cellular settings
| Autor: | Bee-Chun Sun, Renee Emkey, Ivonne Archibeque, Laurie B. Schenkel, Liqin Liu, Josie Han Lee, Violeta Yu, Stephanie D. Geuns-Meyer, Jeanne Pistillo |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Cancer Research
Oncogene Proteins Fusion Cell Biology Cell Line hemic and lymphatic diseases Genetics medicine STAT5 Transcription Factor Animals Humans Phosphorylation Molecular Biology Protein Kinase Inhibitors Cells Cultured Cell Proliferation chemistry.chemical_classification Dose-Response Relationship Drug Cell growth Precursor Cells B-Lymphoid Reproducibility of Results Cell Biology Hematology Janus Kinase 2 Molecular biology Small molecule Enzyme assay High-Throughput Screening Assays Enzyme medicine.anatomical_structure chemistry Biochemistry Cell culture Tyrosine kinase 2 biology.protein Leukocytes Mononuclear Janus kinase |
| Zdroj: | Experimental hematology. 41(5) |
| ISSN: | 1873-2399 |
| Popis: | Small molecule inhibitors of Janus kinase (JAK) family members (JAK1, JAK2, JAK3, and Tyk2) are currently being pursued as potential new modes of therapy for a variety of diseases, including the inhibition of JAK2 for the treatment of myeloproliferative disorders. Selective inhibition within the JAK family can be beneficial in avoiding undesirable side effects (e.g., immunosuppression) caused by parallel inhibition of other JAK members. In an effort to design an assay paradigm for the development of JAK2 selective inhibitors, we investigated whether compound selectivity differed between cellular and purified enzyme environments. A set of JAK2 inhibitors was tested in a high-throughput JAK family cell assay suite and in corresponding purified enzyme assays. The high-throughput JAK cell assay suite comprises Ba/F3 cells individually expressing translocated ETS leukemia (TEL) fusions of each JAK family member (TEL-JAK Ba/F3) and an AlphaScreen phosphorylated-STAT5 (pSTAT5) immunoassay. Compound potencies from the TEL-JAK Ba/F3 pSTAT5 assays were similar to those determined in downstream cell proliferation measurements and more physiologically relevant cytokine-induced pSTAT5 PBMC assays. However, compound selectivity data between cell and purified enzyme assays were discrepant because of different potency shifts between cell and purified enzyme values for each JAK family member. For any JAK small molecule development program, our results suggest that relying solely on enzyme potency and selectivity data may be misleading. Adopting the high-throughput TEL-JAK Ba/F3 pSTAT5 cell assay suite in lead development paradigms should provide a more meaningful understanding of selectivity and facilitate the development of more selective JAK inhibitors. |
| Databáze: | OpenAIRE |
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