Guanidino quinazolines and pyrimidines promote readthrough of premature termination codons in cells with native nonsense mutations.

Using small molecules to induce readthrough of premature termination codons is a promising therapeutic approach to treating genetic diseases and cancers caused by nonsense mutations, as evidenced by the widespread use of ataluren to treat nonsense mutation Duchene muscular dystrophy. Herein we describe a series of novel guanidino quinazoline and pyrimidine scaffolds that induce readthrough in both HDQ-P1 mammary carcinoma cells and mdx myotubes. Linkage of basic, tertiary amines with aliphatic, hydrophobic substituents to the terminal guanidine nitrogen of these scaffolds led to significant potency increases. Further potency gains were achieved by flanking the pyrimidine ring with hydrophobic substituents, inducing readthrough at concentrations as low as 120 nM and demonstrating the potential of these compounds to be used either in combination with ataluren or as stand-alone therapeutics.

Geometric-phase intraocular lenses with multifocality.

We demonstrate a new type of multifocal and extended depth of focus (EDOF) intraocular lenses (IOLs) embedding µm-thin geometric phase (GP) lens layers. As an emerging approach for lens phase design, the GP modulated IOLs outperform conventional diffractive IOLs in multifocality while completely avoiding the clinically undesirable demand for additional surface patterns to standard monofocal IOL designs. The number of foci and light splitting ratio of the GP IOLs are adjusted by changing the number of stacked GP layers and the thickness of each layer. Bifocal and trifocal GP IOLs are fabricated by radial alignment of anisotropic orientation in UV-curable liquid crystal polymers. After characterizing the defocus image and modulation transfer function of the GP IOLs, it is expected that GP IOLs will alleviate the most common problems associated with multifocal and EDOF IOLs, blurred vision and photic phenomena caused by light scattering and posterior capsule opacification.

BMI1 is a therapeutic target in recurrent medulloblastoma.

Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor, representing 20% of newly diagnosed childhood central nervous system malignancies. Although advances in multimodal therapy yielded a 5-year survivorship of 80%, MB still accounts for the leading cause of childhood cancer mortality. In this work, we describe the epigenetic regulator BMI1 as a novel therapeutic target for the treatment of recurrent human Group 3 MB, a childhood brain tumor for which there is virtually no treatment option beyond palliation. Current clinical trials for recurrent MB patients based on genomic profiles of primary, treatment-naive tumors will provide limited clinical benefit since recurrent metastatic MBs are highly genetically divergent from their primary tumor. Using a small molecule inhibitor against BMI1, PTC-028, we were able to demonstrate complete ablation of self-renewal of MB stem cells in vitro. When administered to mice xenografted with patient tumors, we observed significant reduction in tumor burden in both local and metastatic compartments and subsequent increased survival, without neurotoxicity. Strikingly, serial in vivo re-transplantation assays demonstrated a marked reduction in tumor initiation ability of recurrent MB cells upon re-transplantation of PTC-028-treated cells into secondary recipient mouse brains. As Group 3 MB is often metastatic and uniformly fatal at recurrence, with no current or planned trials of targeted therapy, an efficacious targeted agent would be rapidly transitioned to clinical trials.

Discovery and Optimization of Small Molecule Splicing Modifiers of Survival Motor Neuron 2 as a Treatment for Spinal Muscular Atrophy.

The underlying cause of spinal muscular atrophy (SMA) is a deficiency of the survival motor neuron (SMN) protein. Starting from hits identified in a high-throughput screening campaign and through structure-activity relationship investigations, we have developed small molecules that potently shift the alternative splicing of the SMN2 exon 7, resulting in increased production of the full-length SMN mRNA and protein. Three novel chemical series, represented by compounds 9, 14, and 20, have been optimized to increase the level of SMN protein by >50% in SMA patient-derived fibroblasts at concentrations of <160 nM. Daily administration of these compounds to severe SMA Δ7 mice results in an increased production of SMN protein in disease-relevant tissues and a significant increase in median survival time in a dose-dependent manner. Our work supports the development of an orally administered small molecule for the treatment of patients with SMA.

Total synthesis of (+)-kalkitoxin.

The neurotoxic lipopeptide (+)-kalkitoxin was synthesized by a route which employed asymmetric organocopper conjugate addition followed by in situ enolate alkylation to install the anti,anti-1,2,4-trimethyl relationship of the toxin; the synthesis of kalkitoxin required sixteen steps and proceeded in 3% overall yield.

Motor neuron disease. SMN2 splicing modifiers improve motor function and longevity in mice with spinal muscular atrophy.

Spinal muscular atrophy (SMA) is a genetic disease caused by mutation or deletion of the survival of motor neuron 1 (SMN1) gene. A paralogous gene in humans, SMN2, produces low, insufficient levels of functional SMN protein due to alternative splicing that truncates the transcript. The decreased levels of SMN protein lead to progressive neuromuscular degeneration and high rates of mortality. Through chemical screening and optimization, we identified orally available small molecules that shift the balance of SMN2 splicing toward the production of full-length SMN2 messenger RNA with high selectivity. Administration of these compounds to Δ7 mice, a model of severe SMA, led to an increase in SMN protein levels, improvement of motor function, and protection of the neuromuscular circuit. These compounds also extended the life span of the mice. Selective SMN2 splicing modifiers may have therapeutic potential for patients with SMA.

The clinical characteristics and treatment outcomes of patients with ruptured middle cerebral artery aneurysms associated with intracerebral hematoma.

OBJECTIVE: The objective of this study is to evaluate the clinical presentation and outcomes of patients with an intracerebral hematoma (ICH) associated with a ruptured middle cerebral artery (MCA) aneurysm, and the correlation factors associated with the aneurysm and characteristics of the hematoma. METHODS: A retrospective evaluation of clinical and radiologic characteristics and outcomes was conducted for 24 patients (11 men and 13 women; mean age, 53 years) with ruptured MCA aneurysms associated with ICH between September 2008 and December 2011. RESULTS: Thirteen (54%) of the 24 patients had a favorable outcome, four (17%) suffered from severe disability, and seven (29%) died. Based on Hunt and Hess grade, one patient was classified as Grade II, three as Grade III, 12 as Grade IV, and eight as Grade V. Patients with an unfavorable outcome had significantly larger aneurysms (p = 0.047) and ICH volumes (p = 0.002), compared with patients in the group with a favorable outcome. The most frequent rupture point of aneurysms was the lateral aspect of the aneurysm (54.2%). When the rupture point is toward the lateral direction, the distribution of ICH tended to be located at the temporal lobe and intrasylvian. CONCLUSION: Results of the present study suggest an association of the initial clinical state, the size of the aneurysm, and ICH volume with outcome. Although no difference was observed between the location of the rupture point and patient outcomes, an accurate assessment of ICH patterns and the rupture point in angiography may help to ensure surgical exposure and a safe aneurysm clipping.

The complete surgical resection without the radiotherapy for a recurred anaplastic ependymoma at the cervicomedullary junction.

The intramedullary anaplastic ependymoma rarely occurs in the cervicomedullary junction. A 45-year-old woman had a history of right arm pain for several months. Magnetic resonance imaging (MRI) of the cervical spine demonstrated an intramedullary tumor with syrinx at the cervicomedullary junction. The patient underwent a partial resection at another institute. Neurologic deficit worsened after the first surgery. The follow up MRI showed that the enlarged enhancing tumor and syrinx still existed with the same size and configuration. Complete surgical resection was achieved in the revision surgery. Final histologic examination confirmed the diagnosis of an anaplastic ependymoma, and since complete surgical resection was achieved the patient did not receive adjuvant radiation or chemotherapy. The patient was followed-up periodically at the outpatient department, and at the 7 months follow-up the muscle tone of the right hand was normal but with mild sensory deficit, and the MRI demonstrated no evidence of recurrent disease. Intramedullary anaplastic ependymoma that occur in the cervicomedullary junction which are completely resected may be followed-up without adjuvant radiation or chemotherapy to attain good clinical outcome.

Design of novel, potent, and selective human beta-tryptase inhibitors based on alpha-keto-[1,2,4]-oxadiazoles.

A series of novel alpha-keto-[1,2,4]-oxadiazoles has been synthesized as human tryptase inhibitors for evaluation as a new class of anti-asthmatic agent. The inhibitor design is focused on using a prime-side hydrophobic pocket and the S2 pocket of beta-tryptase to achieve inhibition potency and selectivity over other serine proteases.

Structure-guided design of peptide-based tryptase inhibitors.

Improved peptide-based inhibitors of human beta tryptase were discovered using information gleaned from tripeptide library screening and structure-guided design methods, including fragment screening. Our efforts sought to improve this class of inhibitors by replacing the traditional Lys or Arg P1 element. The optimized compounds display low nanomolar potency against the mast cell target and several hundred-fold selectivity with respect to serine protease off targets. Thus, replacement of Lys/Arg at P1 in a peptide-like scaffold does not need to be accompanied by a loss in target affinity.

Novel, potent, selective, and orally bioavailable human betaII-tryptase inhibitors.

The synthesis of novel [1,2,4]oxadiazoles and their structure-activity relationship (SAR) for the inhibition of tryptase and related serine proteases is presented. Elaboration of the P'-side afforded potent, selective, and orally bioavailable tryptase inhibitors.

Total synthesis and biological evaluation of +-kalkitoxin, a cytotoxic metabolite of the cyanobacterium Lyngbya majuscula.

+-Kalkitoxin, a metabolite of the marine cyanobacterium Lyngbya majuscula, was synthesized from (R)-2-methylbutyric acid, (R)-cysteine, and (3S, 4S, 6S)-3,4,6-trimethyl-8-(methylamino)octanoic acid. A key step in the synthesis was installation of the anti,anti methyl stereotriad by means of a tandem asymmetric conjugate addition of an organocopper species to an alpha,beta-unsaturated N-acyl oxazolidin-2-one followed in situ by alpha-methylation of the resultant enolate. The thiazoline portion of kalkitoxin was assembled by titanium tetrachloride catalyzed cyclization of a vinyl substituted amido thiol.