Cell-based screen identifies a new potent and highly selective CK2 inhibitor for modulation of circadian rhythms and cancer cell growth.

Compounds targeting the circadian clock have been identified as potential treatments for clock-related diseases, including cancer. Our cell-based phenotypic screen revealed uncharacterized clock-modulating compounds. Through affinity-based target deconvolution, we identified GO289, which strongly lengthened circadian period, as a potent and selective inhibitor of CK2. Phosphoproteomics identified multiple phosphorylation sites inhibited by GO289 on clock proteins, including PER2 S693. Furthermore, GO289 exhibited cell type-dependent inhibition of cancer cell growth that correlated with cellular clock function. The x-ray crystal structure of the CK2α-GO289 complex revealed critical interactions between GO289 and CK2-specific residues and no direct interaction of GO289 with the hinge region that is highly conserved among kinases. The discovery of GO289 provides a direct link between the circadian clock and cancer regulation and reveals unique design principles underlying kinase selectivity.

Rigosertib induces cell death of a myelodysplastic syndrome-derived cell line by DNA damage-induced G2/M arrest.

A multi-kinase inhibitor, rigosertib (ON 01910.Na) has recently been highlighted as a novel type of anti-cancer agent for the treatment of the myelodysplastic syndromes (MDS), but its action mechanisms remain to be clarified. We investigated the in vitro effects of rigosertib on an MDS-derived cell line MDS-L and a myeloid leukemia cell line HL-60. Rigosertib suppressed the proliferation of both HL-60 and MDS-L cells and induced apoptosis by inhibition of the PI3 kinase/Akt pathway. As the effects on cell cycle, rigosertib treatment promoted the phosphorylation of histone H2AX and led to the DNA damage-induced G2/M arrest. In addition, an immunofluorescence staining study demonstrated the abnormal localization of aurora A kinase, suggesting that rigosertib causes perturbation of spindle assembly and deregulated mitotic patterns towards cell cycle arrest and apoptosis. We also found that rigosertib exerted growth inhibitory effects on two lymphoid cell lines, Jurkat and Ramos. We further examined the molecular pathways influenced by rigosertib from the gene expression profiling data of MDS-L cells and found a possible involvement of rigosertib treatment in the upregulation of the genes related to microtubule kinetics and the downregulation of the mRNA degradation system. The gene set enrichment analysis showed the suppression of "nonsense-mediated mRNA decay (NMD)" as the most significantly affected gene set. These data provide a new aspect and a potential utility of rigosertib for the treatment of refractory hematopoietic malignancies.

Lavender essential oil inhalation suppresses allergic airway inflammation and mucous cell hyperplasia in a murine model of asthma.

AIMS: Lavender essential oil (Lvn) has been reported to have anti-inflammatory effects. Bronchial asthma is characterized by bronchial allergic inflammation with airway remodeling. Therefore, we evaluated the anti-inflammatory effect of Lvn on experimentally induced bronchial asthma in a murine model. MAIN METHODS: BALB/c mice were sensitized by an intraperitoneal injection of ovalbumin (OVA) at days 0 and 14, and subsequently challenged with nebulized OVA on days 28-30 (Control-Asthma group). Mice in the treatment group inhaled Lvn on days 14-31 (Lvn-Asthma group). The allergic inflammatory response was determined on days 32 and 33. KEY FINDINGS: An increase in airway resistance was inhibited in the Lvn-Asthma group than in the Control-Asthma group. The Lvn-Asthma group showed lower total cell numbers and eosinophils in bronchoalveolar lavage (BAL) fluids and peribronchial and perivascular tissues when compared with the Control-Asthma group. The Lvn-Asthma group also had less mucin hyperplasia than the Control-Asthma group. Furthermore, the Lvn-Asthma group showed lower interleukin (IL)-5 and IL-13 cytokine levels in BAL fluids, as well as reduced IL-4 and IL-5 mRNA expression in lung tissue, compared with the Control-Asthma group and determined by FlowCytomix and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. In addition, Lvn inhalation reduced Muc5b mRNA expression in the lungs without significantly changing the expression of Muc5ac mRNA. SIGNIFICANCE: Lvn inhibits allergic inflammation and mucous cell hyperplasia with suppression of T-helper-2 cell cytokines and Muc5b expression in a murine model of asthma. Consequently, Lvn may be useful as an alternative medicine for bronchial asthma.