Successful knock-in of Hypertrophic Cardiomyopathy-mutation R723G into the MYH7 gene mimics HCM pathology in pigs

Familial Hypertrophic Cardiomyopathy (HCM) is the most common inherited cardiac disease. About 30% of the patients are heterozygous for mutations in the MYH7 gene encoding the ß-myosin heavy chain (MyHC). Hallmarks of HCM are cardiomyocyte disarray and hypertrophy of the left ventricle, the symptoms range from slight arrhythmias to sudden cardiac death or heart failure. To gain insight into the underlying mechanisms of the diseases' etiology we aimed to generate genome edited pigs with an HCM-mutation. We used TALEN-mediated genome editing and successfully introduced the HCM-point mutation R723G into the MYH7 gene of porcine fibroblasts and subsequently cloned pigs that were heterozygous for the HCM-mutation R723G. No off-target effects were determined in the R723G-pigs. Surprisingly, the animals died within 24 h post partem, probably due to heart failure as indicated by a shift in the a/ß-MyHC ratio in the left ventricle. Most interestingly, the neonatal pigs displayed features of HCM, including mild myocyte disarray, malformed nuclei, and MYH7-overexpression. The finding of HCM-specific pathology in neonatal R723G-piglets suggests a very early onset of the disease and highlights the importance of novel large animal models for studying causative mechanisms and long-term progression of human cardiac diseases.

Thrombophilic Polymorphisms Are Common in Women with Fetal Loss without Apparent Cause

An association between fetal loss and thrombophilia has recently been described but has not been yet fully elucidated. We have evaluated prospectively the prevalence of the three common thrombophilic polymorphisms (TP) factor V G1691A (Leiden), thermolabile-methyl-enetetrahydrofolate reductase (TL-MTHFR) C677T and factor II G20210A mutations, in 76 women with fetal loss (≥3 in first, ≥2 in second, ≥1 in third trimester) without apparent cause and 106 controls without fetal loss. Thirty seven out of 76 (49%) of the women in the fetal loss group had at least one TP compared to only 23/106 (22%) in the control group (p = 0.0001). Factor V-Leiden was more common in the fetal loss group 24/76 (32%) compared to the control group 11/106 (10%) (OR = 4.0, 95% CI: 1.8-8.8, p <0.001). Five of the 76 patients (7%) were homozygous for factor V-Leiden compared to none of the controls (p = 0.012). A trend, albeit no statistically significant difference was found between women with fetal loss and control groups regarding factor II G20210A (8% vs. 4% respectively, OR = 2.2, 95% CI: 0.6-8.0, p = 0.23) and MTHFR C677T (18% vs. 10% respectively, OR = 1.95, 95% CI: 0.83-4.6, p = 0.12). Combined TP were documented in 6/76 (8%) patients compared to 1/106 (1%) in controls (OR = 9.0, 95% CI: 1.1-76, p = 0.02). Second or third trimester fetal loss were more common cause of pregnancy termination in 37 patients with TP compared to 39 patients without TP (57/158 (36%) vs. 23/135 (17%) respectively, (p = 0.0004). Thrombophilic polymorphisms are common in women with fetal loss without apparent cause and are associated with late pregnancy wastage. Combinations of TP increase the risk for fetal loss.

Gestational Outcome in Thrombophilic Women with Recurrent Pregnancy Loss Treated by Enoxaparin

Inherited and acquired thrombophilia are associated with recurrent pregnancy loss (RPL). We have evaluated the efficacy and safety of the low molecular weight heparin enoxaparin in 50 women, (mean age 26 ± 3 years) with RPL (>3 losses in 1st, >2 losses in 2nd and >1 loss in 3rd trimester) who were found to harbor thrombophilia. Twentyseven had a solitary thrombophilic defect, and twenty-three women had combined thrombophilic defects: 17 – two defects and 6 – three defects. Following diagnosis of thrombophilia, sixty-one subsequent pregnancies were treated with the low molecular weight heparin enoxaparin throughout gestation until 4 weeks after delivery. Dosage was 40 mg/day in women with solitary defect and 80 mg/day in combined defects. Aspirin, 75 mg daily was given in addition to enoxaparin to women with antiphospholipid syndrome. Forty-six out of 61 (75%) gestations treated by enoxaparin resulted in live birth compared to only 38/193 (20%) of the untreated pregnancies in these 50 women prior to diagnosis of thrombophilia (p <0.00001). In 23 women without a single living child following 82 untreated gestations, antithrombotic therapy resulted in 26/31 (84%) successful deliveries (p <0.0001). In 20 women with a prior living child, antithrombotic therapy improved successful delivery from 33/86 (38%) to 20/21 (95%) (p <0.0001). Enoxaparin dose of 40 mg/day resulted in live birth in 24/35 (69%) of gestations, compared to 19/23 (83%) gestations in women treated with 80 mg/day (p = 0.37). Only one thrombotic episode and one mildbleeding episode were noticed during enoxaparin therapy. Enoxaparin is safe and effective in prevention of pregnancy loss in women with inherited and acquired thrombophilia.

Purification of Zika virus RNA-dependent RNA polymerase and its use to identify small-molecule Zika inhibitors

Background

The viral RNA-dependent RNA polymerase (RdRp) enzymes of the Flaviviridae family are essential for viral replication and are logically important targets for development of antiviral therapeutic agents. Zika virus (ZIKV) is a rapidly re-emerging human pathogen for which no vaccine or antiviral agent is currently available.

Methods

To facilitate development of ZIKV RdRp inhibitors, we have established an RdRp assay using purified recombinant ZIKV NS5 polymerase.

Results

We have shown that both the hepatitis C virus (HCV) nucleoside inhibitor sofosbuvir triphosphate and a pyridoxine-derived non-nucleoside small-molecule inhibitor, DMB213, can act against ZIKV RdRp activity at IC 50 s of 7.3 and 5.2 μM, respectively, in RNA synthesis reactions catalysed by recombinant ZIKV NS5 polymerase. Cell-based assays confirmed the anti-ZIKV activity of sofosbuvir and DMB213 with 50% effective concentrations (EC 50 s) of 8.3 and 4.6 μM, respectively. Control studies showed that DMB213 did not inhibit recombinant HIV-1 reverse transcriptase and showed only very weak inhibition of HIV-1 integrase strand-transfer activity. The S604T substitution in motif B of the ZIKV RdRp, which corresponds to the S282T substitution in motif B of HCV RdRp, which confers resistance to nucleotide inhibitors, also conferred resistance to sofosbuvir triphosphate, but not to DMB213. Enzyme assays showed that DMB213 appears to be competitive with natural nucleoside triphosphate (NTP) substrates.

Conclusions

Recombinant ZIKV RdRp assays can be useful tools for the screening of both nucleos(t)ide compounds and non-nucleotide metal ion-chelating agents that interfere with ZIKV replication.

Involvement of the heparanase procoagulant domain in bleeding and wound healing

Essentials Heparanase forms a complex with tissue factor and enhances the generation of factor Xa. The present study was aimed to identify the procoagulant domain of heparanase. Procoagulant peptides significantly shortened bleeding time and enhanced wound healing. Tissue factor pathway inhibitor (TFPI)-2 derived peptides inhibited the procoagulant peptides.

SUMMARY

Background Heparanase, which is known to be involved in angiogenesis and metastasis, was shown to form a complex with tissue factor (TF) and to enhance the generation of activated factor X (FXa). Our study demonstrated that peptides derived from TF pathway inhibitor (TFPI)-2 impeded the procoagulant effect of heparanase, and attenuated inflammation, tumor growth, and vascularization. Aims To identify the procoagulant domain in the heparanase molecule, and to evaluate its effects in a model of wound healing that involves inflammation and angiogenesis. Methods Twenty-four potential peptides derived from heparanase were generated, and their effect was studied in an assay of FXa generation. Peptides 14 and 16, which showed the best procoagulant effect, were studied in a bleeding mouse model and in a wound-healing mouse model. Results Peptides 14 and 16 increased FXa levels by two-fold to three-fold, and, at high levels, caused consumption coagulopathy. The TFPI-2-derived peptides explored in our previous study were found to inhibit the procoagulant effect induced by peptides 14 and 16. In the bleeding model, time to clot formation was shortened by 50% when peptide 14 or peptide 16 was topically applied or injected subcutaneously. In the wound-healing model, the wound became more vascular, and its size was reduced to one-fifth as compared with controls, upon 1 week of exposure to peptide 14 or peptide 16 applied topically or injected subcutaneously. Conclusions The putative heparanase procoagulant domain was identified. Peptides derived from this domain significantly shortened bleeding time and enhanced wound healing.

Correcting covariate-dependent measurement error with non-zero mean

There are many settings in which the distribution of error in a mismeasured covariate varies with the value of another covariate. Take, for example, the case of HIV phylogenetic cluster size, large values of which are an indication of rapid HIV transmission. Researchers wish to find behavioral correlates of HIV phylogenetic cluster size; however, the distribution of its measurement error depends on the correctly measured variable, HIV status, and does not have a mean of zero. Further, it is not feasible to obtain validation data or repeated measurements. We propose an extension of simulation-extrapolation, an estimation technique for bias reduction in the presence of measurement error that does not require validation data and can accommodate errors whose distribution depends on other, error-free covariates. The proposed extension performs well in simulation, typically exhibiting less bias and variability than either regression calibration or multiple imputation for measurement error. We apply the proposed method to data from the province of Quebec in Canada to examine the association between HIV phylogenetic cluster size and the number of reported sex partners. Copyright © 2017 John Wiley & Sons, Ltd.

Outcome of Patients with Venous Thromboembolism and Factor V Leiden or Prothrombin 20210 Carrier Mutations During the Course of Anticoagulation

BACKGROUND

Individuals with factor V Leiden or prothrombin G20210A mutations are at a higher risk to develop venous thromboembolism. However, the influence of these polymorphisms on patient outcome during anticoagulant therapy has not been consistently explored.

METHODS

We used the Registro Informatizado de Enfermedad TromboEmbólica database to compare rates of venous thromboembolism recurrence and bleeding events occurring during the anticoagulation course in factor V Leiden carriers, prothrombin mutation carriers, and noncarriers.

RESULTS

Between March 2001 and December 2015, 10,139 patients underwent thrombophilia testing. Of these, 1384 were factor V Leiden carriers, 1115 were prothrombin mutation carriers, and 7640 were noncarriers. During the anticoagulation course, 160 patients developed recurrent deep vein thrombosis and 94 patients developed pulmonary embolism (16 died); 154 patients had major bleeding (10 died), and 291 patients had nonmajor bleeding. On multivariable analysis, factor V Leiden carriers had a similar rate of venous thromboembolism recurrence (adjusted hazard ratio [HR], 1.16; 95% confidence interval [CI], 0.82-1.64), half the rate of major bleeding (adjusted HR, 0.50; 95% CI, 0.25-0.99) and a nonsignificantly lower rate of nonmajor bleeding (adjusted HR, 0.66; 95% CI, 0.43-1.01) than noncarriers. Prothrombin mutation carriers and noncarriers had a comparable rate of venous thromboembolism recurrence (adjusted HR, 1.00; 95% CI, 0.68-1.48), major bleeding (adjusted HR, 0.75; 95% CI, 0.42-1.34), and nonmajor bleeding events (adjusted HR, 1.10; 95% CI, 0.77-1.57).

CONCLUSIONS

During the anticoagulation course, factor V Leiden carriers had a similar risk for venous thromboembolism recurrence and half the risk for major bleeding compared with noncarriers. This finding may contribute to decision-making regarding anticoagulation duration in selected factor V Leiden carriers with venous thromboembolism.

The Clinical Course of Venous Thromboembolism May Differ According to Cancer Site

BACKGROUND

We hypothesized that the clinical course of venous thromboembolism in patients with active cancer may differ according to the specificities of primary tumor site.

AIM AND METHODS

We used data from RIETE (international registry of patients with venous thromboembolism) to compare the clinical venous thromboembolism-related outcomes during the course of anticoagulation in patients with one of the 4 more frequent cancers (breast, prostate, colorectal, or lung cancer).

RESULTS

As of September 2014, 3947 cancer patients were recruited, of whom 938 had breast, 629 prostate, 1189 colorectal, and 1191 lung cancer. Overall, 55% had metastatic disease (42%, 36%, 53%, and 72%, respectively). During the course of anticoagulant therapy (mean duration, 139 days), the rate of thromboembolic recurrences was similar to the rate of major bleeding in patients with breast (5.6 [95% confidence interval (CI), 3.8-8.1] vs 4.1 [95% CI, 2.7-5.9] events per 100 patient-years) or colorectal cancer (10 [95% CI, 7.6-13] vs 12 [95% CI, 9.4-15] per 100 patient-years). In contrast, in patients with prostate cancer, the rate of venous thromboembolic recurrences was half the rate of major bleeding (6.9 [95% CI, 4.4-10] vs 13 [95% CI, 9.2-17] events per 100 patient-years), whereas in those with lung cancer, the rate of thromboembolic recurrences was twofold higher than the rate of major bleeding (27 [95% CI, 22-23] vs 11 [95% CI, 8.6-15] per 100 patient-years).

CONCLUSIONS

Significant differences in the clinical profile of venous thromboembolic-related outcomes were observed according to the site of cancer. These findings suggest the development of cancer-specific anticoagulant strategies as an area for further research.

Abstract P2-07-11: The association between angiotensin receptor blockers usage and breast cancer characteristics

Background: Data regarding the impact of angiotensin receptor blockers (ARB) on breast cancer are inconsistent. We evaluate the association between ARB usage and breast cancer characteristics and outcomes.

Methods: All patients who were treated in our institute for estrogen receptor positive, human epidermal growth factor receptor 2 negative early breast cancer between 4/2005 and 3/2012 and whose tumors were sent for Oncotype-DX analysis were included. Medical records were retrospectively reviewed for clinical-pathological parameters, related comorbidities, treatment and outcomes. Data regarding ARB usage was retrieved. Usage of several pre-specified medications for hypertension including angiotensin converting enzyme inhibitors (ACEI), mineralocorticoid receptor antagonists (MRA), and β-blockers (BB) was also evaluated. Each medication group was compared to the rest of the study population.

Results:671 patients were included in the study cohort. Forty six (7%) were treated with ARB, 93 (14.2%) with ACEI, 14 (2.1%) with MRA, and 115 (17.5%) with BB. ARB usage was associated with different histological subtype distribution (P=0.009), higher incidence of macroscopic nodal involvement (P&lt;0.001) and more advanced stage at diagnosis (p&lt;0.001). These findings remained significant on multivariate analysis. Patients treated with ARB had worse 5-year breast cancer specific survival (94.7% vs. 98.8%, P=0.024) and worse 5-year overall survival (94.6% vs. 98.8%, p=0.015), but these differences were not demonstrated on multivariate analysis (p=0.251 and p=0.441. respectively).

Conclusions: Patients treated with ARB presented with more advanced breast cancer disease and some distinct histological features. Further research is required to elucidate the effect of ARB treatment on breast cancer.

Tumor burdenPopulation (no.)Tumor size, cm (SD)Macroscopic node posotive1Stage Mean, cm (SD)P, univariate analysis%P, univariate analysisI, %II, %P, univariate analysisAll (671)1.68 (0.8)-9-71.228.3-ARB (46)1.89 (0.81)0.05423.9&lt;0.0013763&lt;0.001ACEI (93)1.93 (0.93)0.0048.50.86363.835.10.355MRA (14)1.88 (0.67)0.32914.30.36357.142.90.907BB (115)1.77 (0.95)0.21613.20.08766.731.60.0911Macroscopic nodes: lymph node metastases&gt; 2 millimeter

Histological characteristicsPopulation (no.)Ki67 (%)Estrogen recepator stain intensityHistology subtype Mean, (SD)P, univariate analysisMean, (SD)P, univariate analysisIDC (%)ILC (%)P, univariate analysisAll (671)15.91 (13.58)-2.47 (0.57)-80.912.2-ARB (46)12.27 (7.19)0.0052.57 (0.59)0.24665.226.10.009ACEI (93)17.1 (14.24)0.4032.44 (0.55)0.51575.5160.358MRA (14)21.4 (11.2)0.1972.63 (0.42)0.30385.87.10.841BB (115)15.93 (12.93)0.992.51 (0.58)0.49675.713.90.186IDC- invasive ductal carcinoma, ILC- invasive lobular carcinoma

Citation Format: Goldvaser H, Rizel S, Hendler D, Neiman V, Shepshelovich D, Shochat T, Sulkes A, Brenner B, Yerushalmi R. The association between angiotensin receptor blockers usage and breast cancer characteristics [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 P2-07-11.

Abstract P5-08-25: The association between smoking and breast cancer characteristics and outcome

Background: Smoking is associated with an increased incidence of hormone receptor positive breast cancer. Data regarding worse breast cancer outcome in smokers are accumulating. Current literature regarding the impact of smoking on breast cancer characteristics is limited. The aim of this study was to evaluate the impact of smoking on the characteristics and outcome of estrogen receptor positive, human epidermal growth factor receptor 2 (HER2) negative early breast cancer.

Methods: This was a retrospective single center study. All patients diagnosed from 4/2005 through 3/2012 and treated in our institute for early, estrogen receptor positive, HER2 negative breast cancer, whose tumors were sent for Oncotype DX analysis were included. Medical records were reviewed for demographics, clinico-pathological parameters, treatment and outcome. Patients were grouped and compared according to smoking history (present or past smokers vs. never smokers) and status (current vs. former and never smokers). Heavy smokers (pack years ≥30) were analyzed separately.

Results: A total of 671 patients were included. 28.7% had a history of smoking, 17% were current smokers and 11.5% were heavy smokers. Smoking had no impact on tumor size, nodal involvement and Oncotype DX recurrence score. Angiolymphatic and perineural invasion rates were higher in current smokers than in the rest of the cohort (11% vs. 5.1%, p=0.023, 9% vs. 3.45%, p=0.013, respectively). Smoking had no other impact regarding histological characteristics. Five-year disease free survival and overall survival rates were 95.7% and 98.5%, respectively. Smoking had no impact on outcome.

Conclusions: In patients with estrogen receptor positive, HER2 negative, early breast cancer, smoking had no clinically significant influence on tumor characteristics and outcome. As the study was limited to a specific subgroup of the breast cancer population in this heterogeneous disease and since smoking is a modifiable risk factor for the disease, further research is required to clarify the possible impact of smoking on breast cancer.

Breast cancer characteristics according to history of smoking, smoking status and pack yearsPopulation (no.)Mean tumor size, cm (SD)Macroscopic N + (%)Oncotype Dx RS, mean (SD)Histology, IDC (%)Angiolymphatic invasion (%)Perniural invasion (%)Ki67 (%), mean (SD)Hx smoking (178)1.66 (0.9)10.718.9 (9.4)817.75.915.8 (13.5)No Hx of smoking (443)1.7 (0.8)8.419.33 (10.8)805.43.816 (14.1)Active smokers (104)1.76 (1)9.619.7 (9)8211916.5 (14.6)Never/former smokers (513)1.68 (0.8)919.1 (10.5)805.13.515.8 (13.7)PY 0-29 (523)1.69 (0.8)9.419.2 (10.7)806416.2 (14.2)PY≥30 (67)1.67 (1)918.3 (8.8)859913.8 (12.1)

Citation Format: Goldvaser H, Gal O, Rizel S, Hendler D, Neiman V, Shochat T, Sulkes A, Brenner B, Yerushalmi R. The association between smoking and breast cancer characteristics and outcome [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 P5-08-25.

Does antiretroviral treatment change HIV-1 codon usage patterns in its genes: a preliminary bioinformatics study

BACKGROUND

Codon usage bias has been described for various organisms and is thought to contribute to the regulation of numerous biological processes including viral infections. HIV-1 codon usage has been previously shown to be different from that of other viruses and man. It is evident that the antiretroviral drugs used to restrict HIV-1 replication also select for resistance variants. We wanted to test whether codon frequencies in HIV-1 sequences from treatment-experienced patients differ from those of treatment-naive individuals due to drug pressure affecting codon usage bias.

RESULTS

We developed a JavaScript to determine the codon frequencies of aligned nucleotide sequences. Irrespective of subtypes, using HIV-1 pol sequences from 532 treatment-naive and 52 treatment-experienced individuals, we found that pol sequences from treatment-experienced patients had significantly increased AGA (arginine; p = 0.0002***) and GGU (glycine; p = 0.0001***), and decreased AGG (arginine; p = 0.0001***) codon frequencies. The same pattern was not observed when subtypes B and C sequences were analyzed separately. Additionally, irrespective of subtypes, using HIV-1 gag sequences from 524 treatment-naive and 54 treatment-experienced individuals, gag sequences from treatment-experienced patients had significantly increased CUA (leucine; p < 0.0001***), CAG (glutamine; p = 0.0006***), AUC (isoleucine; p < 0.0001***) and UCU (serine; p = 0.0005***), and decreased AUA (isoleucine; p = 0.0003***) and CAA (glutamine; p = 0.0006***) codon frequencies.

CONCLUSION

Using pol and gag genes derived from the same HIV-1 genome, we show that antiretroviral therapy changed certain HIV-1 codon frequencies in a subtype specific way.

Beyond Condoms: Risk Reduction Strategies Among Gay, Bisexual, and Other Men Who Have Sex With Men Receiving Rapid HIV Testing in Montreal, Canada

Gay, bisexual, and other men who have sex with men (MSM) have adapted their sexual practices over the course of the HIV/AIDS epidemic based on available data and knowledge about HIV. This study sought to identify and compare patterns in condom use among gay, bisexual, and other MSM who were tested for HIV at a community-based testing site in Montreal, Canada. Results showed that while study participants use condoms to a certain extent with HIV-positive partners and partners of unknown HIV status, they also make use of various other strategies such as adjusting to a partner's presumed or known HIV status and viral load, avoiding certain types of partners, taking PEP, and getting tested for HIV. These findings suggest that MSM who use condoms less systematically are not necessarily taking fewer precautions but may instead be combining or replacing condom use with other approaches to risk reduction.