Discover the most talked about and latest scientific content & concepts.

Concept: Protein kinase inhibitor


A library of 367 protein kinase inhibitors, the GSK Published Kinase Inhibitor Set (PKIS), which has been annotated for protein kinase family activity and is available for public screening efforts, was assayed against the commonly used luciferase reporter enzymes from the firefly, Photinus pyralis (FLuc) and marine sea pansy, Renilla reniformis (RLuc). A total of 22 compounds (∼6% of the library) were found to inhibit FLuc with 10 compounds showing potencies ≤1 µM. Only two compounds were found to inhibit RLuc, and these showed relatively weak potency values (∼10 µM). An inhibitor series of the VEGFR2/TIE2 protein kinase family containing either an aryl oxazole or benzimidazole-urea core illustrate the different structure activity relationship profiles FLuc inhibitors can display for kinase inhibitor chemotypes. Several FLuc inhibitors were broadly active toward the tyrosine kinase and CDK families. These data should aid in interpreting the results derived from screens employing the GSK PKIS in cell-based assays using the FLuc reporter. The study also underscores the general need for strategies such as the use of orthogonal reporters to identify kinase or non-kinase mediated cellular responses.

Concepts: Signal transduction, Enzyme, Protein kinase, Enzyme inhibitor, Inhibitor, Protein kinase inhibitor, Luciferase, Sea pansy


There have been few reports of a response to dasatinib or nilotinib after failure of two prior sequential tyrosine kinase inhibitors. We report the outcome of 82 chronic phase patients who received nilotinib or dasatinib as third-line alternative tyrosine kinase inhibitor therapy. Thirty-four patients failed to respond to nilotinib and were started on dasatinib as third-line tyrosine kinase inhibitor therapy while 48 patients were switched to nilotinib after dasatinib failure. Overall, we obtained a cytogenetic response in 32 of 82 patients and major molecular response in 13 patients; disease progression occurred in 12 patients. At last follow up, 70 patients (85.4%) were alive with a median overall survival of 46 months. Our results show that third-line tyrosine kinase inhibitor therapy in chronic myeloid leukemia patients after failure of two prior sequential tyrosine kinase inhibitors may induce a response that, in some instances, could prolong overall survival and affect event-free survival.

Concepts: Signal transduction, Protein kinase, Leukemia, Chronic myelogenous leukemia, Protein kinase inhibitor, Tyrosine kinase inhibitors, Pell number, Lapatinib


The aim of this study was to assess the role of skin rash in predicting the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and the prognosis of patients with non-small cell lung cancer (NSCLC).

Concepts: Immune system, Cancer, Signal transduction, Lung cancer, Non-small cell lung carcinoma, Epidermal growth factor receptor, Epidermal growth factor, Protein kinase inhibitor


Drug discovery programs frequently target members of the human kinome and try to identify small molecule protein kinase inhibitors, primarily for cancer treatment, additional indications being increasingly investigated. One of the challenges is controlling the inhibitors degree of selectivity, assessed by in vitro profiling against panels of protein kinases. We manually extracted, compiled and standardized such profiles published in the literature: we collected 356,908 data points corresponding to 482 protein kinases, 2,106 inhibitors and 661 patents. We then analyzed this dataset in terms of kinome coverage, results reproducibility, popularity and degree of selectivity of both kinases and inhibitors. We used the dataset to create robust proteochemometric models capable of predicting kinase activity (the ligand-target space was modeled with an externally validated RMSE of 0.41 ± 0.02 log units and R02 0.74 ± 0.03), in order to account for missing or unreliable measurements. The influence on the prediction quality of parameters such as number of measurements, Murcko scaffold frequency or inhibitor type was assessed. Interpretation of the models enabled to highlight inhibitors and kinases properties correlated with higher affinities, and an analysis in the context of kinases crystal structures was performed. Overall, the models quality allows the accurate prediction of kinase-inhibitor activities and their structural interpretation, thus paving the way for the rational design of compounds with a targeted selectivity profile.

Concepts: Scientific method, Signal transduction, Adenosine triphosphate, Enzyme, Kinase, Protein kinase, Enzyme inhibitor, Protein kinase inhibitor


Despite the efficacy of standard-of-care EGFR tyrosine kinase inhibitors (TKIs), erlotinib, gefitinib and afatinib, in EGFR mutation-positive non-small-cell lung cancer, resistance develops, most commonly due to the T790M mutation. Osimertinib showed clinical activity in the treatment of T790M-positive disease following progression on a first-line TKI, and is approved in this setting. Recently, osimertinib improved efficacy versus first-generation TKIs (erlotinib and gefitinib) in the first-line setting. Multiple factors can influence first-line treatment decisions, including subsequent therapy options, presence of brain metastases and tolerability, all of which should be considered in the long-term treatment plan. Further research into treatment sequencing is also needed, to optimize outcomes in EGFR mutation-positive non-small-cell lung cancer.

Concepts: Cancer, Metastasis, Lung cancer, Non-small cell lung carcinoma, Epidermal growth factor receptor, Adenocarcinoma, Protein kinase inhibitor, Erlotinib


Resistance to tyrosine kinase inhibitors in patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) is frequently caused by mutations in the BCR-ABL kinase domain. Ponatinib (AP24534) is a potent oral tyrosine kinase inhibitor that blocks native and mutated BCR-ABL, including the gatekeeper mutant T315I, which is uniformly resistant to tyrosine kinase inhibitors.

Concepts: Cancer, Protein kinase, Leukemia, Blood disorders, Acute lymphoblastic leukemia, Chronic myelogenous leukemia, Imatinib, Protein kinase inhibitor


The introduction of imatinib, a tyrosine kinase inhibitor (TKI), has greatly increased survival for patients with chronic myeloid leukemia (CML). Conversely, nonadherence to imatinib and other TKIs undoubtedly results in disease progression and treatment resistance. We examined trends in imatinib expenditures from 2002 to 2011 and assessed the association between copayment requirements for imatinib and TKI adherence.

Concepts: Cancer, Signal transduction, Protein kinase, Tyrosine kinase, Leukemia, Chronic myelogenous leukemia, Imatinib, Protein kinase inhibitor


Coactivation of tyrosine kinase limits the efficacy of tyrosine kinase inhibitors. We hypothesized that a strategic combination therapy could overcome tyrosine kinase coactivation and compensatory oncogenic signaling in patients with adrenocortical carcinoma (ACC).

Concepts: Cancer, Signal transduction, Receptor tyrosine kinase, Protein kinase, Protein kinase inhibitor, Adrenocortical carcinoma


Activating epidermal growth factor receptor (EGFR) gene mutations can be successfully treated by EGFR tyrosine kinase inhibitors (EGFR-TKIs), but nearly 50% of all patients' exhibit progression of the disease until treatment because of T790M mutations. It is proposed that this is mostly caused by therapy-resistant tumor clones harboring a T790M mutation. Until now no cost-effective routine-diagnostic method for EGFR-resistance mutation status analysis is available leaving long-time response to TKI treatment to chance. Unambiguous identification of T790M EGFR mutations is mandatory to optimize initial treatment strategies.

Concepts: Immune system, Cancer, Signal transduction, Lung cancer, Non-small cell lung carcinoma, Epidermal growth factor receptor, Epidermal growth factor, Protein kinase inhibitor