The optimization of aminooxadiazoles as orally active inhibitors of Cdc7.

A series of aminooxadiazoles was optimized for inhibition of Cdc7. Early lead isoquinoline 1 suffered from modest cell potency (cellular IC50=0.71 µM measuring pMCM2), low selectivity against structurally related kinases, and high IV clearance in rats (CL=18 L/h/kg). Extensive optimization resulted in azaindole 26 (Cdc7 IC50=1.1 nM, pMCM2 IC50=32 nM) that demonstrated robust lowering of pMCM2 in a mouse pharmacodynamic (PD) model when dosed orally. Modifications to improve the pharmacokinetic profile of this series were guided by trapping experiments with glutathione in rat hepatocytes.

AMG 900, a small-molecule inhibitor of aurora kinases, potentiates the activity of microtubule-targeting agents in human metastatic breast cancer models.

Breast cancer is the most prevalent malignancy affecting women and ranks second in cancer-related deaths, in which death occurs primarily from metastatic disease. Triple-negative breast cancer (TNBC) is a more aggressive and metastatic subtype of breast cancer that is initially responsive to treatment of microtubule-targeting agents (MTA) such as taxanes. Recently, we reported the characterization of AMG 900, an orally bioavailable, potent, and highly selective pan-Aurora kinase inhibitor that is active in multidrug-resistant cell lines. In this report, we investigate the activity of AMG 900 alone and in combination with two distinct classes of MTAs (taxanes and epothilones) in multidrug-resistant TNBC cell lines and xenografts. In TNBC cells, AMG 900 inhibited phosphorylation of histone H3 on Ser(10), a proximal substrate of Aurora-B, and induced polyploidy and apoptosis. Furthermore, AMG 900 potentiated the antiproliferative effects of paclitaxel and ixabepilone at low nanomolar concentrations. In mice, AMG 900 significantly inhibited the growth of MDA-MB-231 (F(11); parental), MDA-MB-231 (F(11)) PTX-r (paclitaxel-resistant variant), and DU4475 xenografts. The combination of AMG 900 with docetaxel enhanced tumor inhibition in MDA-MB-231 (F(11)) xenografts compared with either monotherapy. Notably, combining AMG 900 with ixabepilone resulted in regressions of MDA-MB-231 (F(11)) PTX-r xenografts, in which more than 50% of the tumors failed to regrow 75 days after the cessation of drug treatment. These findings suggest that AMG 900, alone and in combination with MTAs, may be an effective intervention strategy for the treatment of metastatic breast cancer and provide potential therapeutic options for patients with multidrug-resistant tumors.

Gastrostomy tube placement by endoscopy versus radiologic methods in patients with ALS: a retrospective study of complications and outcome.

Gastrostomy tube placement for malnutrition and weight loss stabilization occurs in many patients with ALS. We sought to compare the outcome and complications of gastrostomy tube placement by endoscopic (PEG) and multiple radiologic (RIG) methods in ALS patients. A retrospective analysis was conducted on all ALS patients evaluated at Northwestern University who received gastrostomy tubes between January 2009 and March 2012. One hundred and eight gastrostomy tube attempts were made on a total of 100 different patients. Failed gastrostomy tube placement occurred in 15.7% of PEGs and 1.9% of RIGs. Post-procedure aspiration was recognized after 10.5% PEG and 0 RIG attempts. Multivariate analysis revealed a linear increase in risk of post-procedure aspiration for every increase in ALSFRS swallow score. No statistically significant differences in failure or complications were observed when comparing two different methods of RIG (push-type vs. pull-type). Our findings support gastrostomy tube placement by radiographic methods in ALS patients. Gastrostomy tube placement by RIG was more often successful and less often associated with aspiration. Our findings add to the growing body of literature that argues for early gastrostomy tube placement in young patients with prominent bulbar involvement.

FUS-immunoreactive inclusions are a common feature in sporadic and non-SOD1 familial amyotrophic lateral sclerosis.

OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is a fatal disorder of motor neuron degeneration. Most cases of ALS are sporadic (SALS), but about 5 to 10% of ALS cases are familial (FALS). Recent studies have shown that mutations in FUS are causal in approximately 4 to 5% of FALS and some apparent SALS cases. The pathogenic mechanism of the mutant FUS-mediated ALS and potential roles of FUS in non-FUS ALS remain to be investigated. METHODS: Immunostaining was performed on postmortem spinal cords from 78 ALS cases, including SALS (n = 52), ALS with dementia (ALS/dementia, n = 10), and FALS (n = 16). In addition, postmortem brains or spinal cords from 22 cases with or without frontotemporal lobar degeneration were also studied. In total, 100 cases were studied. RESULTS: FUS-immunoreactive inclusions were observed in spinal anterior horn neurons in all SALS and FALS cases, except for those with SOD1 mutations. The FUS-containing inclusions were also immunoreactive with antibodies to TDP43, p62, and ubiquitin. A fraction of tested FUS antibodies recognized FUS inclusions, and specific antigen retrieval protocol appeared to be important for detection of the skein-like FUS inclusions. INTERPRETATION: Although mutations in FUS account for only a small fraction of FALS and SALS, our data suggest that FUS protein may be a common component of the cellular inclusions in non-SOD1 ALS and some other neurodegenerative conditions, implying a shared pathogenic pathway underlying SALS, non-SOD1 FALS, ALS/dementia, and related disorders. Our data also indicate that SOD1-linked ALS may have a pathogenic pathway distinct from SALS and other types of FALS.