Glioblastoma multiforme (GBM) is a high-grade brain tumor of which the survival patients remain poor.
Tousled-like kinase 1 (TLK1), a serine-threonine kinase, was identified to be overexpressed in cancers such
as GBM. TLK1 plays an important role in controlling survival pathways. To date, there is no structure
available for TLK1 as well as its inhibitors. We aimed to create a homology model of TLK1 and to identify
suitable molecular inhibitors that are likely to bind and inhibit TLK1 activity via in silico high-throughput
virtual screening (HTVS) protein-ligand docking. The 3D homology models of TLK1 were derived from
various servers. All models were evaluated using Swiss Model QMEAN server. Validation was performed
using multiple tools. Energy minimization was performed using YASARA. Subsequently, HTVS was
performed using Molegro Virtual Docker 6.0 and ligands derived from ligand.info database. Drug-like
molecules were filtered using ADME-Tox filtering program. Best homology model was obtained from the
Aurora B kinase (PDB ID:4B8M) derived from Xenopus levias structure that share sequence similarity with
human TLK1. Two compounds were identified from HTVS to be the potential inhibitors as it did not violate
the Lipinski rule of five and the CNS-based filter as a potential drug-like molecule for GBM
Helicobacter pylori at multiplicity of infection (MOI ≥ 50) have been shown to cause apoptosis in RAW264.7 monocytic macrophage cells. Because chronic gastric infection by H. pylori results in the persistence of macrophages in the host's gut, it is likely that H. pylori is present at low to moderate, rather than high numbers in the infected host. At present, the effect of low-MOI H. pylori infection on macrophage has not been fully elucidated. In this study, we investigated the genome-wide transcriptional regulation of H. pylori-infected RAW264.7 cells at MOI 1, 5 and 10 in the absence of cellular apoptosis. Microarray data revealed up- and down-regulation of 1341 and 1591 genes, respectively. The expression of genes encoding for DNA replication and cell cycle-associated molecules, including Aurora-B kinase (AurkB) were down-regulated. Immunoblot analysis verified the decreased expression of AurkB and downstream phosphorylation of Cdk1 caused by H. pylori infection. Consistently, we observed that H. pylori infection inhibited cell proliferation and progression through the G1/S and G2/M checkpoints. In summary, we suggest that H. pylori disrupts expression of cell cycle-associated genes, thereby impeding proliferation of RAW264.7 cells, and such disruption may be an immunoevasive strategy utilized by H. pylori.