PABPN1 gene therapy for oculopharyngeal muscular dystrophy

Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant, late-onset muscle disorder characterized by ptosis, swallowing difficulties, proximal limb weakness and nuclear aggregates in skeletal muscles. OPMD is caused by a trinucleotide repeat expansion in the PABPN1 gene that results in an N-terminal expanded polyalanine tract in polyA-binding protein nuclear 1 (PABPN1). Here we show that the treatment of a mouse model of OPMD with an adeno-associated virus-based gene therapy combining complete knockdown of endogenous PABPN1 and its replacement by a wild-type PABPN1 substantially reduces the amount of insoluble aggregates, decreases muscle fibrosis, reverts muscle strength to the level of healthy muscles and normalizes the muscle transcriptome. The efficacy of the combined treatment is further confirmed in cells derived from OPMD patients. These results pave the way towards a gene replacement approach for OPMD treatment.

Oculopharyngeal muscular dystrophy is caused by trinucleotide repeat expansions in the PABPN1 gene. Here the authors use AAV-based gene therapy to knockdown the mutant gene and replace it with a wild-type allele, and show effectiveness in mice and in patient cells.

Abstract OT3-04-01: BRE12-158: A phase II randomized controlled trial of genomically directed therapy after preoperative chemotherapy in patients with triple negative breast cancer (TNBC)

Background: About 1/3 of patients with TNBC who receive preoperative therapy will experience a pathological complete response (pCR). Patients with residual disease have a markedly inferior overall survival (OS) compared to those who experience pCR. Recently, the CREATE-X trial demonstrated an improvement in disease free survival (DFS) and OS for post-neoadjuvant capecitebine; although the addition of capecitebine to standard therapy has not previously improved outcome across other non-selected adjuvant or neo-adjuvant trials. Prior data have also demonstrated that the residual tumors are genomically diverse and that these genetic changes are reflected at time of relapse.

Trial Design: This trial is a randomized phase II trial to determine whether a genomically guided therapy in the setting of incomplete response to standard neoadjuvant therapy will improve outcomes compared to standard of care. DNA from archived tumor samples collected at the time of surgery will be extracted and sequenced. The sequencing data will be interrogated for known genomic drivers of sensitivity or resistance to existing FDA approved agents. A cancer genomic tumor board (CGTB) will consider the genomic data along with the patient's prior treatment history, toxicities, and comorbidities and select the optimal therapy. Participants with a CGTB recommendation will be randomized to Experimental Arm A (genomically directed monotherapy) or Control Arm B (standard of care). Participants may have no CGTB recommendation either because sequencing did not identify a matched drug or because the drug was contraindicated and will be assigned to Control Arm B.

Eligibility criteria: Patients must have histologically confirmed TNBC with completion of all definitive local therapy and no evidence of metastatic disease. There must be significant residual disease characterized by >2cm primary tumor, or lymph node positivity or RCB classification II or III. An FFPE tumor block with tumor cellularity >20% is required. All patients must have completed preoperative chemotherapy including a taxane or anthracycline or both.

Specific aims: The Primary Aim is to compare 2-year DFS with a genomically directed therapy vs. standard of care. Secondary Aims include 1-year DFS, 5-year OS, collection of archival specimens for correlative studies, and to describe toxicities. Exploratory Aims are to describe the evolution of genomically directed therapies during the course of the study and to evaluate the drug specific effect on efficacy and toxicity.

Statistical methods: In order to detect an improvement in the fraction of patients free from disease at 2-year from 40% in the control Arm B to 63.2% in the genomically directed Experimental Arm A (corresponding to an HR=0.5), 136 participants will have 80% power to detect a difference in DFS using a two-side log-rank test with 0.05 level of significance.

Present accrual/target accrual: 38 accrued of 136 to be randomized.

Citation Format: Schneider B, Miller KD, Badve S, O'Neil B, Helft P, Chitambar C, Falkson C, Nanda R, McCormick M, Danso M, Blaya M, Langdon R, Lippman M, Paplomata E, Walling R, Thompson M, Robin E, Aggarwal L, Shalaby I, Canfield V, Adesunloye B, Lee T, Daily K, Ma C, Erban J, Radhakrishnan N, Bruetman D, Graham M, Reddy NA, Lynce FC, Radovich M. BRE12-158: A phase II randomized controlled trial of genomically directed therapy after preoperative chemotherapy in patients with triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT3-04-01.

The prediction of postoperative stroke or death in patients with preoperative atrial fibrillation undergoing non-cardiac surgery: a VISION sub-study

BACKGROUND

The optimal means of pre-operative risk stratification in patients with atrial fibrillation (AF) is uncertain.

OBJECTIVE

To examine the accuracy of AF thromboembolic risk models (the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores) for predicting 30-day stroke and/or all-cause mortality after non-cardiac surgery in patients with preoperative AF, and to compare these risk scores with the Revised Cardiac Risk Index (RCRI).

PATIENTS/METHODS

A multicentre (8 countries, 2007-2011) prospective cohort study of patients ≥ 45 years of age undergoing inpatient non-cardiac surgery, who were followed until 30 days after surgery. We calculated c-statistics for each risk prediction model and net reclassification improvements (NRIs) compared with the RCRI.

RESULTS

The 961 patients with preoperative AF were at higher risk of any cardiovascular event in the 30 days postoperatively compared with the 13 001 patients without AF: 26.6% vs. 9.0%; adjusted odds ratio, 1.58; 95% confidence interval [CI], 1.33-1.88. All thromboembolic risk scores predicted postoperative death just as well as the RCRI (with c-indices between 0.67 and 0.72). Compared with the RCRI (which had a c-index of 0.64 for 30-day stroke/death), the CHADS2 (c-index, 0.67; NRI, 0.31; 95% CI, 0.02-0.61) significantly improved postoperative stroke/mortality risk prediction, largely due to improved discrimination of patients who did not subsequently have an event.

CONCLUSIONS

In AF patients, the three thromboembolic risk scores performed similarly to the RCRI in predicting death within 30 days and the CHADS2 score was the best predictor of postoperative stroke/death regardless of type of surgery.

In vitro self-assembly of human pericyte-supported endothelial microvessels in three-dimensional coculture: a simple model for interrogating endothelial-pericyte interactions

We describe a method for coculture of macro- or microvascular human endothelial cells (ECs) and pericytes (PCs) within a 3-dimensional (3-D) protein matrix resulting in lumenized EC cords invested by PCs. To prevent apoptotic cell death of ECs in 3-D culture, human umbilical vein or dermal microvascular ECs were transduced to express the antiapoptotic protein Bcl-2. To prevent PC-mediated gel contraction, the collagen-fibronectin gel was polymerized within a polyglycolic acid nonwoven matrix. Over the first 24-48 h, EC-only gels spontaneously formed cords that developed lumens via vacuolization; such vascular networks were maintained for up to 7 days. In EC-PC cocultures, PCs were recruited to the EC networks. PC investment of EC cords both limited the lumen diameter and increased the degree of vascular network arborization. Peg and socket junctions formed between ECs and PCs in this system, but dye transfer, indicative of gap junction formation, was not observed. This simple system can be used to analyze bidirectional signals between ECs and PCs in a 3-D geometry.

Public health genomics and the new molecular epidemiology of bacterial pathogens

Laboratory methods that can unambiguously fingerprint pathogenic microbes are needed to investigate the transmission of human infectious diseases from diverse sources, such as from the community, from the environment, within hospitals, or from contaminated food or water sources. Public health investigations currently rely on laboratory subtyping methods that ultimately provide only a fraction of the total genetic information of a pathogen, and although there is widespread success using existing subtyping methods, they do not always provide sufficient evidence to link disease cases together into outbreaks or to link these human cases to the culprit source. Alternatively, whole-genome sequencing of bacterial pathogens provides an unabridged examination of the genetic content of individual pathogen isolates, enabling public health laboratories to benefit from comparative analyses of total genetic content. In this context, whole-genome sequencing represents the ultimate epidemiological typing method - a universally applicable, highly detailed typing platform capable of providing the entire genetic blueprint of a pathogen and distinguishing strains to the single nucleotide level. These new genomic methods, if implemented within existing public health laboratory response programs, promise to revolutionize the ability of the laboratory to provide information and evidence on the evolution, transmission and virulence for bacterial pathogens - and this revolution is launching the new field of 'genomicepidemiology'.

The isolation and identification of cis-diamminedichloroplatinum (ii)-DNA adducts by anion-exchange HPLC and inductively coupled plasma mass-spectrometry

The adducts produced by the reaction of cis-diamminedichloroplatinum(II) with DNA have previously been isolated and characterised. These adducts may be measured at the cellular level by immunochemical detection but the accuracy of this assay is dependent on the number of adducts per nucleotide. We have developed a novel assay for cisplatin-DNA adducts, utilising an established method in which platinated DNA is digested to form a mixture of nucleotides and adducts; these are then separated by anion exchange HPLC. The number of cisplatin-DNA adducts is determined by measurement of the platinum content of the HPLC fractions by inductively coupled plasma mass spectrometry. The assay has been validated by cochromatography of purified drug-DNA adducts whose identity has been confirmed by NMR. We describe an application of the assay, namely the measurement of in vitro removal of cisplatin-DNA adducts from calf thymus DNA by cell free extracts derived from tumour cell lines. Adduct removal is dependent on both the amount of extract protein and the duration of the reaction. Almost 70% of adducts are removed from 5mug of DNA (drug:nucleotide ratio 0.08) by 80mug of extract. Other potential applications of the assay are discussed.

Search for a new gauge boson in electron-nucleus fixed-target scattering by the APEX experiment

We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'→ e+ e- reaction, and set an upper limit of α'/α ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.