pha-848125 and Lung-Neoplasms

Elevated glucose consumption is fundamental to cancer, but selectively targeting this pathway is challenging. We develop a high-throughput assay for measuring glucose consumption and use it to screen non-small-cell lung cancer cell lines against bioactive small molecules. We identify Milciclib that blocks glucose consumption in H460 and H1975, but not in HCC827 or A549 cells, by decreasing SLC2A1 (GLUT1) mRNA and protein levels and by inhibiting glucose transport. Milciclib blocks glucose consumption by targeting cyclin-dependent kinase 7 (CDK7) similar to other CDK7 inhibitors including THZ1 and LDC4297. Enhanced PIK3CA signaling leads to CDK7 phosphorylation, which promotes RNA Polymerase II phosphorylation and transcription. Milciclib, THZ1, and LDC4297 lead to a reduction in RNA Polymerase II phosphorylation on the SLC2A1 promoter. These data indicate that our high-throughput assay can identify compounds that regulate glucose consumption and that CDK7 is a key regulator of glucose consumption in cells with an activated PI3K pathway.

Topics: A549 Cells; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Class I Phosphatidylinositol 3-Kinases; Cyclin-Dependent Kinase-Activating Kinase; Cyclin-Dependent Kinases; Glucose; Glucose Transporter Type 1; High-Throughput Screening Assays; Humans; Lung Neoplasms; Phenylenediamines; Phosphorylation; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines; Quinazolines; RNA Polymerase II; RNA, Messenger; Signal Transduction; Triazines

Kinase inhibitors are important cancer therapeutics. Polypharmacology is commonly observed, requiring thorough target deconvolution to understand drug mechanism of action. Using chemical proteomics, we analyzed the target spectrum of 243 clinically evaluated kinase drugs. The data revealed previously unknown targets for established drugs, offered a perspective on the "druggable" kinome, highlighted (non)kinase off-targets, and suggested potential therapeutic applications. Integration of phosphoproteomic data refined drug-affected pathways, identified response markers, and strengthened rationale for combination treatments. We exemplify translational value by discovering SIK2 (salt-inducible kinase 2) inhibitors that modulate cytokine production in primary cells, by identifying drugs against the lung cancer survival marker MELK (maternal embryonic leucine zipper kinase), and by repurposing cabozantinib to treat FLT3-ITD-positive acute myeloid leukemia. This resource, available via the ProteomicsDB database, should facilitate basic, clinical, and drug discovery research and aid clinical decision-making.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cytokines; Drug Discovery; fms-Like Tyrosine Kinase 3; Humans; Leukemia, Myeloid, Acute; Lung Neoplasms; Mice; Molecular Targeted Therapy; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proteomics; Xenograft Model Antitumor Assays

K-ras is the most frequently mutated oncogene in non-small cell lung cancer (NSCLC), the most common form of lung cancer. Recent studies indicate that NSCLC patients with mutant K-ras do not respond to epidermal growth factor receptor inhibitors. In the attempt to find alternative therapeutic regimes for such patients, we tested PHA-848125, an oral pan cyclin-dependent kinase inhibitor currently under evaluation in phase II clinical trial, on a transgenic mouse model, K-Ras(G12D)LA2, which develops pulmonary cancerous lesions reminiscent of human lung adenocarcinomas. We used magnetic resonance imaging and positron emission tomography to follow longitudinally disease progression and evaluate therapeutic efficacy in this model. Treatment of K-Ras(G12D)LA2 mice with 40 mg/kg twice daily for 10 days with PHA-848125 induced a significant tumor growth inhibition at the end of treatment (P < 0.005) and this was accompanied by a reduction in the cell membrane turnover, as seen by 11C-Choline-positron emission tomography (P < 0.05). Magnetic resonance imaging data were validated versus histology and the mechanism of action of the compound was verified by immunohistochemistry, using cyclin-dependent kinase-related biomarkers phospho-Retinoblastoma and cyclin A. In this study, multimodality imaging was successfully used for the preclinical assessment of PHA-848125 therapeutic efficacy on a lung adenocarcinoma mouse model. This compound induced a volumetric and metabolic anticancer effect and could represent a valid therapeutic approach for NSCLC patients with mutant K-ras.

Topics: Adenocarcinoma; Amino Acid Substitution; Animals; Antineoplastic Agents; Aspartic Acid; Cyclin-Dependent Kinases; Diagnostic Imaging; Disease Models, Animal; Drug Evaluation, Preclinical; Genes, ras; Glycine; Humans; Lung Neoplasms; Mice; Mice, Transgenic; Mutant Proteins; Pyrazoles; Quinazolines; Treatment Outcome