Performance of Risk Assessment Models for Peripartum Thromboprophylaxis.

OBJECTIVE: There is no consensus on which risk stratification approach to use for thromboprophylaxis in pregnancy, and most available risk assessment models (RAMs) for venous thromboembolism (VTE) events have not been validated in pregnancy. Our objective was to compare the performance of some of the most commonly used VTEs RAMs in our patient population in the peripartum period. STUDY DESIGN: This is a retrospective cohort of women who delivered at our institution in 2015 and 2016. We excluded patients with history of prior or current VTEs or those already receiving anticoagulants. Antepartum, intrapartum, and postpartum records were reviewed. Data were collected on known risk factors for VTEs in order to calculate scores for 3 RAMs on admission for delivery: Padua, Caprini, and Royal College of Obstetricians and Gynaecologists (RCOG). The primary objective was to the estimate the performance of the various RAMs in preventing postpartum VTEs. We calculated the proportion of women who would have been high risk, determined the number of VTEs cases within high- and low-risk categories, as well as calculated the number needed to treat (NNT) for each RAM. We performed analyses using different RAM scores cutoffs, VTEs outcome rates, and effectiveness of anticoagulation to prevent VTEs. The P value <.05 was considered statistically significant. RESULTS: A total of 6094 women were included. Three women had VTEs for an overall rate of 0.04% (N = 3; 95% confidence interval [CI]: 0.01-0.15). The proportion of women categorized as high risk for VTEs were 62% (95% CI: 61-64) for RCOG, 0.8% (95% CI: 0.6-1.0) for Padua, and 94% (95% CI: 94-95) for Caprini. Of the 3 VTEs, the RCOG model classified 1 woman as high risk and Padua model classified 3 women as high risk; whereas the Caprini did not identify any women as high risk. Assuming 100% effectiveness of thromboprophylaxis, the observed NNT was 3838 using RCOG, not able to calculate using Padua (no VTEs cases occurred in the high-risk group, thus none were prevented), and 1927 using Caprini. CONCLUSION: The rates of VTEs in pregnancy are very low and the available RAMs do not identify most of them. The RCOG and Caprini RAMs would categorize a large proportion of women as high risk and are associated with high NNTs. The Padua RAM appears to have the lowest NNT but missed all the VTEs in our cohort.

Loss of Glis2/NPHP7 causes kidney epithelial cell senescence and suppresses cyst growth in the Kif3a mouse model of cystic kidney disease.

Enlargement of kidney tubules is a common feature of multiple cystic kidney diseases in humans and mice. However, while some of these pathologies are characterized by cyst expansion and organ enlargement, in others, progressive interstitial fibrosis and kidney atrophy prevail. The Kif3a knockout mouse is an established non-orthologous mouse model of cystic kidney disease. Conditional inactivation of Kif3a in kidney tubular cells results in loss of primary cilia and rapid cyst growth. Conversely, loss of function of the gene GLIS2/NPHP7 causes progressive kidney atrophy, interstitial inflammatory infiltration, and fibrosis. Kif3a null tubular cells have unrestrained proliferation and reduced stabilization of p53 resulting in a loss of cell cycle arrest in the presence of DNA damage. In contrast, loss of Glis2 is associated with activation of checkpoint kinase 1, stabilization of p53, and induction of cell senescence. Interestingly, the cystic phenotype of Kif3a knockout mice is partially rescued by genetic ablation of Glis2 and pharmacological stabilization of p53. Thus, Kif3a is required for cell cycle regulation and the DNA damage response, whereas cell senescence is significantly enhanced in Glis2 null cells. Hence, cell senescence is a central feature in nephronophthisis type 7 and Kif3a is unexpectedly required for efficient DNA damage response and cell cycle arrest.

Hedgehog signaling indirectly affects tubular cell survival after obstructive kidney injury.

Hedgehog (Hh) is an evolutionary conserved signaling pathway that has important functions in kidney morphogenesis and adult organ maintenance. Recent work has shown that Hh signaling is reactivated in the kidney after injury and is an important mediator of progressive fibrosis. Pericytes and fibroblasts have been proposed to be the principal cells that respond to Hh ligands, and pharmacological attenuation of Hh signaling has been considered as a possible treatment for fibrosis, but the effect of Hh inhibition on tubular epithelial cells after kidney injury has not been reported. Using genetically modified mice in which tubule-derived hedgehog signaling is increased and mice in which this pathway is conditionally suppressed in pericytes that express the proteoglycan neuron glial protein 2 (NG2), we found that suppression of Hh signaling is associated with decreased macrophage infiltration and tubular proliferation but also increased tubular apoptosis, an effect that correlated with the reduction of tubular ß-catenin activity. Collectively, our data suggest a complex function of hedgehog signaling after kidney injury in initiating both reparative and proproliferative, prosurvival processes.

miR-124 inhibits STAT3 signaling to enhance T cell-mediated immune clearance of glioma.

miRNAs (miR) have been shown to modulate critical gene transcripts involved in tumorigenesis, but their role in tumor-mediated immunosuppression is largely unknown. On the basis of miRNA gene expression in gliomas using tissue microarrays, in situ hybridization, and molecular modeling, miR-124 was identified as a lead candidate for modulating STAT3 signaling, a key pathway mediating immunosuppression in the tumor microenvironment. miR-124 is absent in all grades and pathologic types of gliomas. Upon upregulating miR-124 in glioma cancer stem cells (gCSC), the STAT3 pathway was inhibited, and miR-124 reversed gCSC-mediated immunosuppression of T-cell proliferation and induction of forkhead box P3 (Foxp3)(+) regulatory T cells (Treg). Treatment of T cells from immunosuppressed glioblastoma patients with miR-124 induced marked effector response including upregulation of interleukin (IL)-2, IFN-γ, and TNF-α. Both systemic administration of miR-124 or adoptive miR-124-transfected T-cell transfers exerted potent anti-glioma therapeutic effects in clonotypic and genetically engineered murine models of glioblastoma and enhanced effector responses in the local tumor microenvironment. These therapeutic effects were ablated in both CD4(+)- and CD8(+)-depleted mice and nude mouse systems, indicating that the therapeutic effect of miR-124 depends on the presence of a T-cell-mediated antitumor immune response. Our findings highlight the potential application of miR-124 as a novel immunotherapeutic agent for neoplasms and serve as a model for identifying miRNAs that can be exploited as immunotherapeutics.

A systematic analysis of cell cycle regulators in yeast reveals that most factors act independently of cell size to control initiation of division.

Upstream events that trigger initiation of cell division, at a point called START in yeast, determine the overall rates of cell proliferation. The identity and complete sequence of those events remain unknown. Previous studies relied mainly on cell size changes to identify systematically genes required for the timely completion of START. Here, we evaluated panels of non-essential single gene deletion strains for altered DNA content by flow cytometry. This analysis revealed that most gene deletions that altered cell cycle progression did not change cell size. Our results highlight a strong requirement for ribosomal biogenesis and protein synthesis for initiation of cell division. We also identified numerous factors that have not been previously implicated in cell cycle control mechanisms. We found that CBS, which catalyzes the synthesis of cystathionine from serine and homocysteine, advances START in two ways: by promoting cell growth, which requires CBS's catalytic activity, and by a separate function, which does not require CBS's catalytic activity. CBS defects cause disease in humans, and in animals CBS has vital, non-catalytic, unknown roles. Hence, our results may be relevant for human biology. Taken together, these findings significantly expand the range of factors required for the timely initiation of cell division. The systematic identification of non-essential regulators of cell division we describe will be a valuable resource for analysis of cell cycle progression in yeast and other organisms.

The tumor microenvironment expression of p-STAT3 influences the efficacy of cyclophosphamide with WP1066 in murine melanoma models.

Melanoma is a common and deadly tumor that upon metastasis to the central nervous system (CNS) has median survival duration of less than 5 months. Activation of the signal transducer and activator of transcription 3 (STAT3) has been identified as a key mediator that drives the fundamental components of melanoma. We hypothesized that WP1066, a novel inhibitor of STAT3 signaling, would enhance the antitumor activity of cyclophosphamide (CTX) against melanoma, including disease within the CNS. The mechanisms of efficacy were investigated by tumor- and immune-mediated cytotoxic assays, in vivo evaluation of the reduction of regulatory T cells (Tregs) and by determining intratumoral p-STAT3 expression by immunohistochemistry. Combinational therapy of WP1066, with both metronomic and cytotoxic dosing of CTX, was investigated in a model system of systemic and intracerebral melanoma in syngeneic mice. Inhibition of p-STAT3 by WP1066 was enhanced with CTX in a dose-dependent manner. However, in mice with intracerebral melanoma, the greatest therapeutic benefit was seen in animals treated with cytotoxic CTX dosing and WP1066, whose median survival time was 120 days, an increase of 375%, with 57% long-term survivors. This treatment efficacy correlated with p-STAT3 expression levels within the tumor microenvironment. The efficacy of the combination of cytotoxic dosing of CTX with WP1066 is attributed to the direct tumor cytotoxic effects of the agents and has the greatest therapeutic potential for the treatment of CNS melanoma.

miRNA-mediated immune regulation and immunotherapeutic potential in glioblastoma.

Glioblastoma (GB), the most common primary neoplasm of the CNS, remains universally fatal with standard therapies and has a mean overall survival time of only 14.6 months. Even in the most favorable situations most patients do not survive longer than 2 years. Another hallmark of GBs, apart from the poor control of proliferation, is an immune suppressed tumor microenvironment. miRNAs usually bind the 3' untranslated region of target mRNAs and direct their post-transcriptional repression. Certain miRNAs are known to have altered expression levels in GB tumors, and in many immune cell subtypes. miRNAs have been found to serve important roles in gene regulation and are implicated in many processes in oncogenesis and immune deregulation. In this article we focus on the miRNAs involved in gliomagenesis and in the regulation of the immune response. We also present current challenges and miRNA immunotherapeutic strategies that should be investigated further.