Bifunctional Inhibitor Reveals NEK2 as a Therapeutic Target and Regulator of Oncogenic Pathways in Lymphoma.

Expression of the serine/threonine kinase never in mitosis gene A (NIMA)-related kinase 2 (NEK2) is essential for entry into mitosis via its role in facilitating centrosome separation. Its overactivity can lead to tumorigenesis and drug resistance through the activation of several oncogenic pathways, including AKT. Although the cancer-enabling activities of NEK2 are documented in many malignancies, including correlations with poor survival in myeloma, breast, and non-small cell lung cancer, little is known about the role of NEK2 in lymphoma. Here, in tumors from patients with diffuse large B-cell lymphoma (DLBCL), the most common, aggressive non-Hodgkin lymphoma, we found a high abundance of NEK2 mRNA and protein associated with an inferior overall survival. Using our recently developed NEK2 inhibitor, NBI-961, we discovered that DLBCL cell lines and patient-derived cells exhibit a dependency on NEK2 for their viability. This compromised cell fitness was directly attributable to efficient NEK2 inhibition and proteasomal degradation by NBI-961. In a subset of particularly sensitive DLBCL cells, NBI-961 induced G2/mitosis arrest and apoptosis. In contrast, an existing indirect NEK2 inhibitor, INH154, did not prevent NEK2 autophosphorylation, induce NEK2 proteasomal degradation, or affect cell viability. Global proteomics and phospho-proteomics revealed that NEK2 orchestrates cell-cycle and apoptotic pathways through regulation of both known and new signaling molecules. We show the loss of NEK2-sensitized DLBCL to the chemotherapy agents, doxorubicin and vincristine, and effectively suppressed tumor growth in mice. These studies establish the oncogenic activity of NEK2 in DLBCL and set the foundation for development of anti-NEK2 therapeutic strategies in this frequently refractory and relapse-prone cancer.

ProteoViz: a tool for the analysis and interactive visualization of phosphoproteomics data.

Quantitative proteomics generates large datasets with increasing depth and quantitative information. With the advance of mass spectrometry and increasingly larger data sets, streamlined methodologies and tools for analysis and visualization of phosphoproteomics are needed both at the protein and modified peptide levels. To assist in addressing this need, we developed ProteoViz, which includes a set of R scripts that perform normalization and differential expression analysis of both the proteins and enriched phosphorylated peptides, and identify sequence motifs, kinases, and gene set enrichment pathways. The tool generates interactive visualization plots that allow users to interact with the phosphoproteomics results and quickly identify proteins and phosphorylated peptides of interest for their biological study. The tool also links significant phosphosites with sequence motifs and pathways that will help explain the experimental conditions and guide future experiments. Here, we present the workflow and demonstrate its functionality by analyzing a phosphoproteomic data set from two lymphoma cell lines treated with kinase inhibitors. The scripts and data are freely available at and via the ProteomeXchange with identifier PXD015606.

Parasitic infections represent a significant health threat among recent immigrants in Chicago.

Parasitic infections are likely under-recognized among immigrant populations in the USA. We conducted a cross-sectional study to evaluate if such infections have health impacts among recent immigrants in Chicago and to identify predictive factors for parasitic infections. A total of 133 recent immigrants were enrolled, filling out a standardized medical questionnaire and providing blood and stool samples. Appriximately 12% of subjects (15/125) who provided a blood or stool sample for testing were found to have evidence of current or prior infection with a pathogenic parasite, of which Toxocara spp. (8 subjects, 6.4%) and Strongyloides stercoralis (5 subjects, 4%) were most commonly identified. Parasitic infection was more likely among subjects who had immigrated within the previous 2 years and those with a self-reported history of worms in the stool. The most useful surrogate markers identified for parasitic infections were an elevated immunoglobulin E level (seen in 46.7% (7/15) of subjects with parasitic infections and 20% (22/110) of uninfected individuals, p = 0.04) and the presence of Blastocystis hominis cysts on Ova & Parasite exam (detected in 38.5% (5/13) of subjects with parasitic infections who provided a stool sample and 5.1% (5/98) of uninfected subjects, p = 0.002). Our study found that parasitic infections may be common in recent US immigrants, which highlights an important health disparity among a vulnerable population that merits further study. Additionally, clinical risk factors, symptoms, and laboratory findings traditionally thought to be associated with parasites were commonly found but not predictive of infection in this study population.