Single-cell atlas of human liver development reveals pathways directing hepatic cell fates

The liver has been studied extensively due to the broad number of diseases affecting its vital functions. However, therapeutic advances have been hampered by the lack of knowledge concerning human hepatic development. Here, we addressed this limitation by describing the developmental trajectories of different cell types that make up the human liver at single-cell resolution. These transcriptomic analyses revealed that sequential cell-to-cell interactions direct functional maturation of hepatocytes, with non-parenchymal cells playing essential roles during organogenesis. We utilized this information to derive bipotential hepatoblast organoids and then exploited this model system to validate the importance of signalling pathways in hepatocyte and cholangiocyte specification. Further insights into hepatic maturation also enabled the identification of stage-specific transcription factors to improve the functionality of hepatocyte-like cells generated from human pluripotent stem cells. Thus, our study establishes a platform to investigate the basic mechanisms directing human liver development and to produce cell types for clinical applications.

The reactome pathway knowledgebase 2022

The Reactome Knowledgebase (https://reactome.org), an Elixir core resource, provides manually curated molecular details across a broad range of physiological and pathological biological processes in humans, including both hereditary and acquired disease processes. The processes are annotated as an ordered network of molecular transformations in a single consistent data model. Reactome thus functions both as a digital archive of manually curated human biological processes and as a tool for discovering functional relationships in data such as gene expression profiles or somatic mutation catalogs from tumor cells. Recent curation work has expanded our annotations of normal and disease-associated signaling processes and of the drugs that target them, in particular infections caused by the SARS-CoV-1 and SARS-CoV-2 coronaviruses and the host response to infection. New tools support better simultaneous analysis of high-throughput data from multiple sources and the placement of understudied ('dark') proteins from analyzed datasets in the context of Reactome's manually curated pathways.

Long-term outcomes of primary cystocele repair by transvaginal mesh surgery versus laparoscopic mesh sacropexy: extended follow up of the PROSPERE multicentre randomised trial

OBJECTIVE

To compare the effectiveness and safety of laparoscopic sacropexy (LS) and transvaginal mesh (TVM) at 4 years.

DESIGN

Extended follow up of a randomised trial.

SETTING

Eleven centres.

POPULATION

Women with cystocele stage ≥2 (pelvic organ prolapse quantification [POP-Q], aged 45-75 years without previous prolapse surgery.

METHODS

Synthetic non-absorbable mesh placed in the vesicovaginal space and sutured to the promontory (LS) or maintained by arms through pelvic ligaments and/or muscles (TVM).

MAIN OUTCOME MEASURES

Functional outcomes (pelvic floor distress inventory [PFDI-20] as primary outcome); anatomical assessment (POP-Q), composite outcome of success; re-interventions for complications.

RESULTS

A total of 220 out of 262 randomised patients have been followed at 4 years. PFDI-20 significantly improved in both groups and was better (but below the minimal clinically important difference) after LS (mean difference -7.2 points; 95% CI -14.0 to -0.05; P = 0.029). The improvement in quality of life and the success rate (LS 70%, 61-81% versus TVM 71%, 62-81%; hazard ratio 0.92, 95% CI 0.55-1.54; P = 0.75) were similar. POP-Q measurements did not differ, except for point C (LS -57 mm versus TVM -48 mm, P = 0.0093). The grade III or higher complication rate was lower after LS (2%, 0-4.7%) than after TVM (8.7%, 3.4-13.7%; hazard ratio 4.6, 95% CI 1.007-21.0, P = 0.049)).

CONCLUSIONS

Both techniques provided improvement and similar success rates. LS had a better benefit-harm balance with fewer re-interventions due to complications. TVM remains an option when LS is not feasible.

TWEETABLE ABSTRACT

At 4 years, Laparoscopic Sacropexy (LS) had a better benefit-harm balance with fewer re-interventions due to complications than Trans-Vaginal Mesh (TVM).

Medulloblastoma Arises from the Persistence of a Rare and Transient Sox2+ Granule Neuron Precursor

Medulloblastoma (MB) is a neoplasm linked to dysregulated cerebellar development. Previously, we demonstrated that the Sonic Hedgehog (SHH) subgroup grows hierarchically, with Sox2⁺ cells at the apex of tumor progression and relapse. To test whether this mechanism is rooted in a normal developmental process, we studied the role of Sox2 in cerebellar development. We find that the external germinal layer (EGL) is derived from embryonic Sox2⁺ precursors and that the EGL maintains a rare fraction of Sox2⁺ cells during the first postnatal week. Through lineage tracing and single-cell analysis, we demonstrate that these Sox2⁺ cells are within the Atoh1⁺ lineage, contribute extensively to adult granule neurons, and resemble Sox2⁺ tumor cells. Critically, constitutive activation of the SHH pathway leads to their aberrant persistence in the EGL and rapid tumor onset. We propose that failure to eliminate this rare but potent developmental population is the tumor initiation mechanism in SHH-subgroup MB.

Functional genomic landscape of cancer-intrinsic evasion of killing by T cells

The genetic circuits that allow cancer cells to evade destruction by the host immune system remain poorly understood^1-3. Here, to identify a phenotypically robust core set of genes and pathways that enable cancer cells to evade killing mediated by cytotoxic T lymphocytes (CTLs), we performed genome-wide CRISPR screens across a panel of genetically diverse mouse cancer cell lines that were cultured in the presence of CTLs. We identify a core set of 182 genes across these mouse cancer models, the individual perturbation of which increases either the sensitivity or the resistance of cancer cells to CTL-mediated toxicity. Systematic exploration of our dataset using genetic co-similarity reveals the hierarchical and coordinated manner in which genes and pathways act in cancer cells to orchestrate their evasion of CTLs, and shows that discrete functional modules that control the interferon response and tumour necrosis factor (TNF)-induced cytotoxicity are dominant sub-phenotypes. Our data establish a central role for genes that were previously identified as negative regulators of the type-II interferon response (for example, Ptpn2, Socs1 and Adar1) in mediating CTL evasion, and show that the lipid-droplet-related gene Fitm2 is required for maintaining cell fitness after exposure to interferon-γ (IFNγ). In addition, we identify the autophagy pathway as a conserved mediator of the evasion of CTLs by cancer cells, and show that this pathway is required to resist cytotoxicity induced by the cytokines IFNγ and TNF. Through the mapping of cytokine- and CTL-based genetic interactions, together with in vivo CRISPR screens, we show how the pleiotropic effects of autophagy control cancer-cell-intrinsic evasion of killing by CTLs and we highlight the importance of these effects within the tumour microenvironment. Collectively, these data expand our knowledge of the genetic circuits that are involved in the evasion of the immune system by cancer cells, and highlight genetic interactions that contribute to phenotypes associated with escape from killing by CTLs.

Abstract 5724: Revelation of shared transcriptional gradients in glioblastoma tumors and cultured glioma stem cells

The brain tumor Glioblastoma (GBM) is a virtual death sentence for anyone who is diagnosed, with a median survival time of 12-15 months with standard treatments1 and a 5 year survival rate of under 10% 2. There is a strong body of evidence supporting the existence of stem like cells, termed glioma stem cells (GSCs), that can repopulate the tumor after removal and therapy application3-6. Thus, GSCs present a tantalizing target for potential therapies against GBM. However, studies of GSCs have shown heterogeneity at the level of the transcriptome and drug response5,7, suggesting that there is significant biological variation that translates into differential sensitivity to various drugs. A full characterization of biological heterogeneity may aid in the search for targeted therapies.

Here, we profile the transcriptomes of 72 patient derived GSC cultures, and obtain scRNA-seq on 29 cultures from 26 patients (> 69,000 cells) plus 5 GBM tumors (> 14,000 cells). With this data, we find two anticorrelated transcriptional programs in the GSC cultures, one associated with immune or injury response related pathways and the other with neural developmental pathways. We then compare the GSC cultures to patient tumors in the scRNA-seq data, and find that a portion of GBM tumor cells are similar to GSC cultures. We find that a gradient between GSC and astrocyte programs separates cells with stemness properties from those that are not stem-like, and that within stem-like tumor cells and non stem-like tumor cells a gradient between the neural developmental and immune related programs exists as was seen for the cultured GSCs. In GSCs, we also find epigenetic variation in DNA methylation associated with the developmental and immune related programs. Overall these data suggest variation between two biological programs manifests at the level of gene expression and epigenetic regulation in GSCs in tumors.

1. Stupp, R. et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. N. Engl. J. Med. 352, 987-996 (2005).

2. Brennan, C. W. et al. The somatic genomic landscape of glioblastoma. Cell 155, 462-477 (2013).

3. Singh, S. K. et al. Identification of human brain tumour initiating cells. Nature 432, 396-401 (2004).

4. Chen, J. et al. A restricted cell population propagates glioblastoma growth after chemotherapy. Nature 488, 522-526 (2012).

5. Lan, X. et al. Fate mapping of human glioblastoma reveals an invariant stem cell hierarchy. Nature 549, 227-232 (2017).

6. Patel, A. P. et al. Single-cell RNA-seq highlights intratumoral heterogeneity in primary glioblastoma. Science 344, 1396-1401 (2014).

7. Meyer, M. et al. Single cell-derived clonal analysis of human glioblastoma links functional and genomic heterogeneity. Proc. Natl. Acad. Sci. U. S. A. 112, 851-856 (2015).

Citation Format: Owen K. Whitley, Laura M. Richards, Florence Cavalli, Paul Guilhamon, Fiona Coutinho, Michelle Kushida, H. Artee Luchman, Samuel Weiss, Mathieu Lupien, Peter Dirks, Trevor Pugh, Gary Bader. Revelation of shared transcriptional gradients in glioblastoma tumors and cultured glioma stem cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5724.

Relapse-Fated Latent Diagnosis Subclones in Acute B Lineage Leukemia Are Drug Tolerant and Possess Distinct Metabolic Programs

Disease recurrence causes significant mortality in B-progenitor acute lymphoblastic leukemia (B-ALL). Genomic analysis of matched diagnosis and relapse samples shows relapse often arising from minor diagnosis subclones. However, why therapy eradicates some subclones while others survive and progress to relapse remains obscure. Elucidation of mechanisms underlying these differing fates requires functional analysis of isolated subclones. Here, large-scale limiting dilution xenografting of diagnosis and relapse samples, combined with targeted sequencing, identified and isolated minor diagnosis subclones that initiate an evolutionary trajectory toward relapse [termed diagnosis Relapse Initiating clones (dRI)]. Compared with other diagnosis subclones, dRIs were drug-tolerant with distinct engraftment and metabolic properties. Transcriptionally, dRIs displayed enrichment for chromatin remodeling, mitochondrial metabolism, proteostasis programs, and an increase in stemness pathways. The isolation and characterization of dRI subclones reveals new avenues for eradicating dRI cells by targeting their distinct metabolic and transcriptional pathways before further evolution renders them fully therapy-resistant. SIGNIFICANCE: Isolation and characterization of subclones from diagnosis samples of patients with B-ALL who relapsed showed that relapse-fated subclones had increased drug tolerance and distinct metabolic and survival transcriptional programs compared with other diagnosis subclones. This study provides strategies to identify and target clinically relevant subclones before further evolution toward relapse.

Abstract AP17: MOLECULAR AND FUNCTIONAL HETEROGENEITY OF CANCER ASSOCIATED FIBROBLASTS IN HIGH-GRADE SEROUS OVARIAN CANCER

High grade serous ovarian cancer (HGSC) is typically diagnosed at an advanced stage and the vast majority of patients relapse and die within 5 years of diagnosis. Significant clinical problems in HGSC include wide-spread abdominal dissemination of disease and chemotherapy resistance. Cancer-associated fibroblasts (CAFs) have been shown to play a role in promotion of cancer cell proliferation and invasion, and mediation of chemotherapy resistance. To interrogate the molecular properties of CAFs in HGSC we used fluorescence activated cell sorting to isolate CAFs directly from primary tumor samples and performed gene expression profiling. We found that patients stratify into two classes based on their CAF gene signatures: One with high expression of Fibroblast Activation Protein (FAP-High; FH) and one with low expression of FAP (FAP-Low; FL). FH CAFs express classical CAF genes whereas FL CAFs possesses a preadipocyte-like molecular signature. The FL phenotype has remained largely unnoticed as it is generally out-competed in vitro by FH cells when grown under classical CAF culture conditions. Patients from The Cancer Genome Atlas (TCGA), as well as from our own institute, can be stratified into FH and FL subtypes; in both cohorts patients with FH CAFs have a significantly shorter disease-free and overall survival. In vitro and in vivo functional assays performed with isolated CAFs of both types indicate that FH CAFs aggressively promote proliferation, invasion and therapy resistance of cancer cells, whereas FL CAFs do not. Finally, we identified TCF21, a transcriptional repressor, as a FL-specific transcription factor. Analysis of published TCF21 ChIP-Seq data indicates that TCF21 targets a large number of genes specific to FH CAFs. Overexpression of TCF21 in FH CAFs partially reversed their ability to promote cancer cell invasion and tumor growth. Our discovery of CAF heterogeneity in HGSC highlights the need to personalize patient treatment with respect to both cancer and stromal phenotypes. FH patients may benefit from inhibition of cancer-stroma interactions or from epigenetic modulators that reprogram cancer-promoting FH CAFs into the non-supportive FL state.

Citation Format: Ali Hussain, Veronique Voisin, Stephanie Poon, Jalna Meens, Julia Dmytryshyn, Josh Paterson, Marcus Bernardini3, Gary Bader, Benjamin G Neel, Laurie E Ailles. MOLECULAR AND FUNCTIONAL HETEROGENEITY OF CANCER ASSOCIATED FIBROBLASTS IN HIGH-GRADE SEROUS OVARIAN CANCER [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr AP17.

[Assessment of pelvic floor muscle training programs and urinary incontinence in women: A literature Review]

OBJECTIVES

Pelvic floor rehabilitation is efficient for the first line treatment of urinary incontinence in women. However, several questions remain as regards the best pelvic floor muscle training program to recommend. The objective was perform a literature review regarding the muscular strengthening program to recommend to treat stress or mixed urinary incontinence in women.

METHODS

We performed a systematic review of studies on the topic using Medline's database covering the 10 last years. Among the 1130 articles that were identified, we retained 6 for our analysis.

RESULTS

Given the heterogeneity of the exercise programs, it was impossible to exhaustively and comparatively analyze their efficacies. However, a significant improvement is noted when the exercises are based on the muscular training principles of the American College of Sports Medicine. They combine long and short contractions with the practice of the knack in situations of pressure exertion and are part of a self-rehabilitation program based on the needs of the patient and the individual's progression.

CONCLUSION

Current knowledge does not allow us to recommend an optimal muscle training program to treat female urinary incontinence. Research must be conducted to evaluate different muscular training regimens but also their integration into a program based on personal needs as well as factors of adherence to the treatment of patients.

Abstract 140: A novel signature of mesenchymal stromal cells in high-grade serous ovarian carcinoma

High grade serous ovarian cancer (HGSOC) is the most common and lethal subtype of ovarian cancer. Many cancers, including HGSOC, contain a “stromal” component comprised of cancer-associated fibroblasts (CAFs), immune cells, and blood vessels, as well as their secreted factors and extracellular matrix. This complex microenvironment plays a significant role in promoting tumor growth, therapy resistance, and invasion. The majority of studies of CAFs utilize cells cultured and passaged in vitro under crude conditions to maintain their viability. Such conditions alter the original phenotype of the cells and may select for specific subpopulations to grow out. To facilitate direct isolation of CAFs from primary tumor tissues, we screened a panel of antibodies to identify cell surface proteins that are uniquely expressed on CAFs. We discovered CD49e as a mesenchymal marker and then validated its specificity to CAFs through immunohistochemistry on tissue sections obtained from HGSOC patients. The discovery of CD49e as a CAF-specific cell surface marker facilitated fluorescence-activated cells sorting (FACS) to isolate CAFs directly from primary tumors, allowing us to avoid in vitro manipulation and to characterize their transcriptional and functional profiles in the primary setting. We next performed transcriptional profiling of primary CAFs isolated from 12 HGSOC patients and found that CAFs fall into two subgroups with unique gene expression signatures. A cell surface protein, fibroblast activation protein (FAP) is the defining marker for separating the two subgroups (FAP-Hi and FAP-Lo). The FAP-Hi subgroup possesses the classical gene signature of CAFs that is reported in the literature. When we isolated FAP-Hi and FAP-Lo cells and placed them into classical CAF growth conditions in vitro, both cell types had mesenchymal features, but FAP-Hi cells grow faster. Thus under the classical conditions for growing CAFs, FAP-Hi cells have a growth advantage, outcompeting FAP-Lo cells and becoming the dominant cells used for experimentation. Flow cytometry for FAP indicates that both CAF subtypes co-exist in every tumor, but their ratio varies from one patient to another. Patients whose tumors are dominated by FAP-Hi CAFs have worse clinical outcome than patients whose tumors are dominated by FAP-Lo CAFs. Thus, we have functionally characterized the role of FAP-Hi and FAP-Lo fibroblasts in the context of HGSOC. We have shown that FAP-Hi fibroblasts support tumor proliferation and invasion of ovarian cancer cells in vitro and in vivo. On the other hand, FAP-Lo cells suppress cancer cell proliferation and invasion in vitro and in vivo.

Citation Format: Ali Hussain, Veronique Voisin, Stephanie Poon, Jalna Meens, Julia Dmytryshyn, Gary Bader, Benjamin Neel, Laurie Ailles. A novel signature of mesenchymal stromal cells in high-grade serous ovarian carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 140.

Abstract 2271: Pathway analysis suggests biological processes driven by germline genetic associations with breast cancer prognosis

Finding the impact of germline variants on breast cancer survival could provide novel insights in its etiology and help identify new therapeutic targets. While genome-wide association studies (GWAS) have made considerable progress in identifying germline variants associated with diverse risk phenotypes, survival analysis has been hampered by a lack of power. To overcome this limitation, we aimed to assess whether biological networks operating in breast cancer prognosis can be inferred by integrating patient genotypes and the associated survival data in a pathway analysis.

We analyzed ~7.3 million genotyped and imputed variants from 84,457 breast cancer patients in all, estrogen receptor (ER) positive and negative breast cancers and validated the results in 12,381 independent samples. First, a Cox model was fitted to obtain summary statistics for each variant. We then integrated the summary statistics into gene scores using the Pascal algorithm. Finally, we constructed pathways based on the gene scores and a protein-protein interaction network with the HotNet2 tool. To assess the validity of the significant networks (P<0.01) found by Hotnet2, we tested the association of the germline variants forming the subnetworks with prognosis. We selected genetic variants that best represented the genetic association of each subnetwork with survival by using a Lasso-penalized Cox model. Then we computed a polygenic hazard score (PHS) on the independent validation set and used it to run a univariate Cox model that allowed selecting the networks significantly associated with prognosis (P<0.05).

We found significant subnetworks in the ER-specific analyses, but not in those including all breast cancers. We then clustered the networks into functional pathways to identify significant (Padj<0.05) functional groups. The enriched processes included growth factor signalling, DNA repair and cell cycle functions. These pathways overlapped with similar biological processes obtained in a downstream characterization analysis based on the genotypes and mRNA expression data of the TCGA breast cancer study and were complemented by key enriched transcription factors (Padj<0.01).

The approach developed is novel in studying germline variants and breast cancer-specific mortality and shows an alternative method to handle underpowered datasets. The networks and the posterior functional characterization suggest that there is some genetic regulation of biological processes associated with breast cancer prognosis specifically for each ER-status subgroup.

Citation Format: Maria Escala Garcia, Qi Guo, Lodewyk Wessels, Gary Bader, Paul Pharoah, Georgia Chenevix-Trench, Douglas Easton, Sander Canisius, Marjanka Schmidt. Pathway analysis suggests biological processes driven by germline genetic associations with breast cancer prognosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2271.

Mammary molecular portraits reveal lineage-specific features and progenitor cell vulnerabilities

Casey et al. integrate epigenomic, transcriptomic, and proteomic profiling of primary basal and luminal mammary cells to identify master epigenetic regulators of the mammary epithelium and uncover stem and progenitor cell vulnerabilities. They develop a pipeline to identify drugs that abrogate progenitor cell activity in normal and high-risk breast cancer patient samples in vitro and in vivo.

The mammary epithelium depends on specific lineages and their stem and progenitor function to accommodate hormone-triggered physiological demands in the adult female. Perturbations of these lineages underpin breast cancer risk, yet our understanding of normal mammary cell composition is incomplete. Here, we build a multimodal resource for the adult gland through comprehensive profiling of primary cell epigenomes, transcriptomes, and proteomes. We define systems-level relationships between chromatin–DNA–RNA–protein states, identify lineage-specific DNA methylation of transcription factor binding sites, and pinpoint proteins underlying progesterone responsiveness. Comparative proteomics of estrogen and progesterone receptor–positive and –negative cell populations, extensive target validation, and drug testing lead to discovery of stem and progenitor cell vulnerabilities. Top epigenetic drugs exert cytostatic effects; prevent adult mammary cell expansion, clonogenicity, and mammopoiesis; and deplete stem cell frequency. Select drugs also abrogate human breast progenitor cell activity in normal and high-risk patient samples. This integrative computational and functional study provides fundamental insight into mammary lineage and stem cell biology.

Automated Computational Inference of Multi-protein Assemblies from Biochemical Co-purification Data

Biology has amassed a wealth of information about the function of a multitude of protein-coding genes across species. The challenge now is to understand how all these proteins work together to form a living organism, and a crucial step for gaining this knowledge is a complete description of the molecular "wiring circuits" that underlie cellular processes. In this chapter, we describe a general computational framework for predicting multi-protein assemblies from biochemical co-fractionation data.

ASCL1 Reorganizes Chromatin to Direct Neuronal Fate and Suppress Tumorigenicity of Glioblastoma Stem Cells

Glioblastomas exhibit a hierarchical cellular organization, suggesting that they are driven by neoplastic stem cells that retain partial yet abnormal differentiation potential. Here, we show that a large subset of patient-derived glioblastoma stem cells (GSCs) express high levels of Achaete-scute homolog 1 (ASCL1), a proneural transcription factor involved in normal neurogenesis. ASCL1^hi GSCs exhibit a latent capacity for terminal neuronal differentiation in response to inhibition of Notch signaling, whereas ASCL1^lo GSCs do not. Increasing ASCL1 levels in ASCL1^lo GSCs restores neuronal lineage potential, promotes terminal differentiation, and attenuates tumorigenicity. ASCL1 mediates these effects by functioning as a pioneer factor at closed chromatin, opening new sites to activate a neurogenic gene expression program. Directing GSCs toward terminal differentiation may provide therapeutic applications for a subset of GBM patients and strongly supports efforts to restore differentiation potential in GBM and other cancers.

The health care and life sciences community profile for dataset descriptions

Access to consistent, high-quality metadata is critical to finding, understanding, and reusing scientific data. However, while there are many relevant vocabularies for the annotation of a dataset, none sufficiently captures all the necessary metadata. This prevents uniform indexing and querying of dataset repositories. Towards providing a practical guide for producing a high quality description of biomedical datasets, the W3C Semantic Web for Health Care and the Life Sciences Interest Group (HCLSIG) identified Resource Description Framework (RDF) vocabularies that could be used to specify common metadata elements and their value sets. The resulting guideline covers elements of description, identification, attribution, versioning, provenance, and content summarization. This guideline reuses existing vocabularies, and is intended to meet key functional requirements including indexing, discovery, exchange, query, and retrieval of datasets, thereby enabling the publication of FAIR data. The resulting metadata profile is generic and could be used by other domains with an interest in providing machine readable descriptions of versioned datasets.

Differences in glycemic control across world regions: a post-hoc analysis in patients with type 2 diabetes mellitus on dual antidiabetes drug therapy

Objective:

This post-hoc analysis of the EDGE (Effectiveness of Diabetes control with vildaGliptin and vildagliptin/mEtformin) study assessed inter-regional differences in baseline characteristics and response to treatment intensification with dual oral antidiabetes drugs (OADs) in patients with type 2 diabetes mellitus (T2DM).

Methods:

Patients with T2DM inadequately controlled with first-line monotherapy were assigned to receive a dipeptidyl peptidase-4 (DPP-4) inhibitor, vildagliptin, or comparator OADs as add-on dual therapy. The primary effectiveness end point (PEP) was achieving glycated hemoglobin (HbA1c) reduction >0.3% without hypoglycemia, peripheral edema, discontinuation owing to gastrointestinal events or weight gain ⩾5% at 12 months. The secondary effectiveness end point (SEP) was achieving HbA1c of <7% without hypoglycemia or weight gain ⩾3% at 12 months.

Results:

Baseline characteristics of patients (N=43 791), including mean HbA1c (8.2%), varied across regions. Baseline age (62.3 years) and T2DM duration (6.3 years) were greater in patients from Europe than those from India and the Middle East (age: 51.8 and 52.1 years; T2DM duration: 4.3 and 4.2 years, respectively). The probability of achieving PEP with dual therapy was higher in India (odds ratio (OR): 1.5), Latin America (OR: 1.2) and Middle East (OR: 2.0) than in Europe (OR: 0.8) and East Asia (OR: 0.3). Achievement of SEP in patients receiving dual therapy was greater in Latin America (OR: 1.7) and Middle East (OR: 1.7). Vildagliptin add-on therapy allowed more patients to achieve SEP across regions. Women aged ⩾45 years less often attained glycemic target (HbA1c<7%) without significant weight gain ⩾5% compared with women aged <45 years (OR: 0.876, 95% confidence interval: 0.774, 0.992; P=0.037).

Conclusions:

Baseline HbA1c and T2DM duration differed considerably across all regions. Treatment intensification with second OAD, particularly with a DPP-4 inhibitor vildagliptin, resulted in good treatment response without tolerability issues despite delayed intensification of failing monotherapy across regions.

Automated brain volumetrics in multiple sclerosis: a step closer to clinical application

BACKGROUND

Whole brain volume (WBV) estimates in patients with multiple sclerosis (MS) correlate more robustly with clinical disability than traditional, lesion-based metrics. Numerous algorithms to measure WBV have been developed over the past two decades. We compare Structural Image Evaluation using Normalisation of Atrophy-Cross-sectional (SIENAX) to NeuroQuant and MSmetrix, for assessment of cross-sectional WBV in patients with MS.

METHODS

MRIs from 61 patients with relapsing-remitting MS and 2 patients with clinically isolated syndrome were analysed. WBV measurements were calculated using SIENAX, NeuroQuant and MSmetrix. Statistical agreement between the methods was evaluated using linear regression and Bland-Altman plots. Precision and accuracy of WBV measurement was calculated for (1) NeuroQuant versus SIENAX and (2) MSmetrix versus SIENAX.

RESULTS

Precision (Pearson's r) of WBV estimation for NeuroQuant and MSmetrix versus SIENAX was 0.983 and 0.992, respectively. Accuracy (Cb) was 0.871 and 0.994, respectively. NeuroQuant and MSmetrix showed a 5.5% and 1.0% volume difference compared with SIENAX, respectively, that was consistent across low and high values.

CONCLUSIONS

In the analysed population, NeuroQuant and MSmetrix both quantified cross-sectional WBV with comparable statistical agreement to SIENAX, a well-validated cross-sectional tool that has been used extensively in MS clinical studies.

Inhibition of Dopamine Receptor D4 Impedes Autophagic Flux, Proliferation, and Survival of Glioblastoma Stem Cells

Glioblastomas (GBM) grow in a rich neurochemical milieu, but the impact of neurochemicals on GBM growth is largely unexplored. We interrogated 680 neurochemical compounds in patient-derived GBM neural stem cells (GNS) to determine the effects on proliferation and survival. Compounds that modulate dopaminergic, serotonergic, and cholinergic signaling pathways selectively affected GNS growth. In particular, dopamine receptor D4 (DRD4) antagonists selectively inhibited GNS growth and promoted differentiation of normal neural stem cells. DRD4 antagonists inhibited the downstream effectors PDGFRβ, ERK1/2, and mTOR and disrupted the autophagy-lysosomal pathway, leading to accumulation of autophagic vacuoles followed by G0/G1 arrest and apoptosis. These results demonstrate a role for neurochemical pathways in governing GBM stem cell proliferation and suggest therapeutic approaches for GBM.

[Study of the factors motivating refusal of women to participate to a randomized clinical trial in gynecological surgery. Retrospective observational bicentric study]

INTRODUCTION

Randomized controlled trials (RCT) in surgery are often subject to difficulties inherent in the study design and recruitment of patients. Women's participation rate to RCTs in surgery is relatively low and varies from 30 to 70%. These recruitment problems might induce a weak scientific value and even stop the study. Thus, optimizing recruitment is a challenge for surgical research. In contemporary literature, we lack data on motivations and profile of women who refuse to participate in a RCT in surgery.

OBJECTIVE

To explore the potentially influential factors affecting women's decision to decline participation in PROSPERE trial, comparing laparoscopic sacrocolpopexy (LSCP) to vaginal mesh for cystocele repair.

PATIENT AND METHOD

Retrospective, observational, qualitative, bicentric study conducted in the department of gynecology of Poissy and Lille hospitals. Patients included were those who refused to participate to PROSPERE trial in both centers. Factors of non-participation in the trial were recorded at the time of the first visit. A control group consisted of women who agreed to participate in the trial was also analyzed.

RESULTS

In both centers, 139 were eligible to participate in the trial but 35 of them (25%) refused. Thirty-two women agreed to declare their refusal motivations. Vaginal mesh was finally performed in 18 (56,2%) patients and LSCP in 14 patients (43,8%). The control group consisted of 20 women, including 9 operated by vaginal mesh and 11 by LSCP. Patient's characteristics were similar in the both groups. Most influencing factor in refusal for participation was "previous choice of technique" in 50% cases (16/32), followed by "geographical remoteness and difficulties for additional visits" in 40.6% cases (13/32), and finally by "do not accept the concept of randomization" in 21.8% cases (7/32). The most influencing factor in women's acceptance was interest in helping others by "supporting medical research" in 100% cases (20/20), followed by "potential personal benefits and close follow-up" in 60% (12/20).

CONCLUSION

Our study identified the most influential factors relevant to women decision-making whether or not to participate in RCT in surgery. A number of factors leading to refusal of participation are potentially correctable leading to better recruitment rates in future RCTs. Optimization of information on the principle of randomization, limiting the number of additional visits could help researchers improve participation rates.

Dynamic interplay between locus-specific DNA methylation and hydroxymethylation regulates distinct biological pathways in prostate carcinogenesis

BACKGROUND

Despite the significant global loss of DNA hydroxymethylation marks in prostate cancer tissues, the locus-specific role of hydroxymethylation in prostate tumorigenesis is unknown. We characterized hydroxymethylation and methylation marks by performing whole-genome next-generation sequencing in representative normal and prostate cancer-derived cell lines in order to determine functional pathways and key genes regulated by these epigenomic modifications in cancer.

RESULTS

Our cell line model shows disruption of hydroxymethylation distribution in cancer, with global loss and highly specific gain in promoter and CpG island regions. Significantly, we observed locus-specific retention of hydroxymethylation marks in specific intronic and intergenic regions which may play a novel role in the regulation of gene expression in critical functional pathways, such as BARD1 signaling and steroid hormone receptor signaling in cancer. We confirm a modest correlation of hydroxymethylation with expression in intragenic regions in prostate cancer, while identifying an original role for intergenic hydroxymethylation in differentially expressed regulatory pathways in cancer. We also demonstrate a successful strategy for the identification and validation of key candidate genes from differentially regulated biological pathways in prostate cancer.

CONCLUSIONS

Our results indicate a distinct function for aberrant hydroxymethylation within each genomic feature in cancer, suggesting a specific and complex role for the deregulation of hydroxymethylation in tumorigenesis, similar to methylation. Subsequently, our characterization of key cellular pathways exhibiting dynamic enrichment patterns for methylation and hydroxymethylation marks may allow us to identify differentially epigenetically modified target genes implicated in prostate cancer tumorigenesis.

Abstract A87: Targeting the mitochondrial quality control machinery in acute myeloid leukemia

Recently, we demonstrated that a subset of AML cells and stem cells have metabolic vulnerabilities in the mitochondria and oxidative phosphorylation (OXPHOS) chain that could impact on the ability of AML and AML stem cells to handle increased electron flux in the respiratory chain (Sriskanthadevan et al., Blood, 2015). To identify additional vulnerabilities in the mitochondria of AML cells and AML stem cells, we analyzed RNA expression levels of a panel of mitochondrial quality control proteins using the nCounter Analysis System (Nanostring technologies) in bulk as well as the progenitor enriched fraction of AML patients and normal donors. Among the top hits was the mitochondrial processing peptidase (MPP) that was upregulated in AML cells and progenitors compared to normal hematopoietic cells. MPP is a metallopeptidase composed of a regulatoryα subunit and a proteolytic β subunit that cleaves presequences from several nuclear encoded and mitochondrially imported proteins. To further analyze the expression of MPP in AML, we analyzed publicly available datasets (Eppert et al., (GSE30377), Laurenti et al., (GSE42414) and Norversthen et al., (GSE24759)). GSEA (Gene Set Enrichment Analysis) on stem enriched as well as bulk AML cells demonstrated upregulation of MPPα and β as well as increased expression of the mitochondrial protein import pathway in a subset of AML cells and stem cells compared to normal hematopoietic cells and stem cells.

To understand the importance of MPP in AML cells, we knocked down MPPα and β using shRNA in lentiviral vectors and confirmed target knockdown by immunoblotting. Knockdown of MPPα or β reduced the growth and viability of OCI-AML2 cells. Mechanistically, knockdown of MPP β increased mitochondrial ROS generation.

Thus, the mitochondrial protein import pathway is upregulated in a subset of AML cells and stem cells. Moreover inhibition of this pathway at the level of MPPα and β is cytotoxic to AML cells and disrupts mitochondrial function.

Citation Format: Danny V. Jeyaraju, Veronique Voisin, Ashwin Ramakrishnan, Rose Hurren, Neil Maclean, Marcela Gronda, Mark Minden, Gary Bader, Aaron D. Schimmer. Targeting the mitochondrial quality control machinery in acute myeloid leukemia. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A87.

Abstract B1-32: Genome-wide integrative analysis correlating locus-specific DNA methylation and hydroxymethylation to gene expression in normal prostate cells

Aberrant epigenetic modification in the form of regional hypermethylation and global hypomethylation has been implicated in the dysregulation of gene expression in various cancers, including prostate cancer (PCa). Recently discovered 5-hydroxymethylated marks (5hmC), considered to be key intermediates in the process of DNA demethylation, have also been shown to exhibit significant global loss in solid tumors as compared to normal tissue. Similar to cytosine base methylation (5mC), 5hmC may also play a key role in the regulation of gene expression and, consequently, gene function in PCa.

We hypothesize that dynamic interplay between 5mC and 5hmC enrichment in promoter, CpG island, and intragenic regions shows specific association patterns with gene expression. A systematic investigation of these methylation marks may provide novel insights into epigenomic architecture by elucidating novel pathways and candidate genes in prostate tumorigenesis.

Using Next Generation Sequencing (NGS), we characterized genome-wide 5mC and 5hmC marks and RNA expression data in a normal prostate tissue-derived representative cell line (RWPE-1). We have completed NGS following methyl-binding protein capture (MBD-seq) and hydroxymethyl-selective chemical labeling (hMe-Seal), and have performed integrative analysis correlating enriched genes stratified by region (intergenic regions proximal to DNase I hypersensitivity sites, as well as promoter, CpG island, and intragenic regions) to expression data obtained from RNA-seq and also validated using publicly available microarray expression data (GEO Accession Number: GSM375783)

We divided expression data into equal tiers representing genes with no expression, low expression, and high expression, and have performed pathway-based analysis on genes significantly enriched for either 5mC or 5hmC marks for each tier stratified by gene region. We found gene expression to exhibit a strong positive correlation with core promoter and CpG island hydroxymethylation, with a corresponding negative correlation to methylation of these regions. In contrast, gene expression was found to be positively correlated with both methylation and hydroxymethylation in both intragenic regions and intergenic regions proximal to ENCODE DNase I hypersensitivity sites (GEO Accession Number: GSM1008595), which are associated with open chromatin and may play a role in downstream gene regulation.

Interestingly, pathway-based analysis of these stratified tiers, grouped via the Molecular Complex Detection algorithm (MCODE) to identify pathway clusters with high biological significance, showed 5hmC and 5mC enrichment of the same pathways in each expression tier, suggesting a possible co-operative role for intragenic co-expression of these marks in regulating biological pathways. Clustered pathways co-enriched in intragenic 5mC and 5hmC showed strong enrichment in Gene Ontology terms related to core cellular functions within each expression tier, such as ion channel and transport regulation, primary metabolic processes, and protein and RNA binding. Currently, we are investigating these pathways to identify key candidate genes regulated by 5hmC and 5mC marks in normal prostate.

This is the first study to correlate locus-specific global 5hmC enrichment to expression in normal prostate cells. Our preliminary analysis has shown correlation between 5hmC and 5mC enrichment in genic, promoter, CpG island, and upstream DNase I hypersensitivity site-proximal regions and expression in RWPE-1 cells. Insights from this model will subsequently be explored via whole-genome differential analysis between normal prostate and PCa to determine the effect of epigenetic alterations in cancer on gene expression. Subsequently, our characterization of key cellular pathways exhibiting dynamic enrichment patterns for 5hmC or 5mC marks will potentially allow us to identify differentially epigenetically modified target genes implicated in prostate cancer tumorigenesis.

Citation Format: Shivani N. Kamdar, Linh T. Ho, Ruth Isserlin, Ken J. Kron, Theodorus van der Kwast, Alexandre R. Zlotta, Neil E. Fleshner, Gary Bader, Bharati Bapat. Genome-wide integrative analysis correlating locus-specific DNA methylation and hydroxymethylation to gene expression in normal prostate cells. [abstract]. In: Proceedings of the AACR Special Conference on Computational and Systems Biology of Cancer; Feb 8-11 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 2):Abstract nr B1-32.

[Severe post-obstetric perineal tears: Medium-term consequences on women's quality of life]

AIMS

To assess the prevalence of anal (AI) and urinary (UI) incontinence at medium term after 3rd and 4th degree anal sphincter tears and their impact on sexuality and women's quality of life.

MATERIAL

It is a case-control, single center study. Sixty-eight primiparous women delivered with severe anal sphincter tear (exposed group) were compared to 136 women without (control group). Questionnaires on anal and urinary incontinence, sexual function and quality of life, using validated scores, were sent between two and five years after the first delivery. Maternal and obstetric data were collected retrospectively on the medical files.

RESULTS

The answer rate was 22.5% (46/204) of which 30.9% (21/68) in the exposed group and 18.4% (25/136) in the unexposed group. In case of severe anal sphincter tear, 57.1% of women reported an AI vs 48% in the control group (P=0.76). The rate of AI for liquid stool was significantly higher in the exposed group (P=0.05). Patients with severe perineal tears reported a greater impact of symptoms on their quality of life but the difference with the control group was not significant.

CONCLUSIONS

The severity of symptoms related to anal sphincter tears is common and underestimated. Preventive measures must be improved in order to maintain women's quality of life.

LEVEL OF EVIDENCE

4.

Molecular Classification of Ependymal Tumors across All CNS Compartments, Histopathological Grades, and Age Groups

Ependymal tumors across age groups are currently classified and graded solely by histopathology. It is, however, commonly accepted that this classification scheme has limited clinical utility based on its lack of reproducibility in predicting patients' outcome. We aimed at establishing a uniform molecular classification using DNA methylation profiling. Nine molecular subgroups were identified in a large cohort of 500 tumors, 3 in each anatomical compartment of the CNS, spine, posterior fossa, supratentorial. Two supratentorial subgroups are characterized by prototypic fusion genes involving RELA and YAP1, respectively. Regarding clinical associations, the molecular classification proposed herein outperforms the current histopathological classification and thus might serve as a basis for the next World Health Organization classification of CNS tumors.

Novel function discovery with GeneMANIA: a new integrated resource for gene function prediction in Escherichia coli

MOTIVATION

The model bacterium Escherichia coli is among the best studied prokaryotes, yet nearly half of its proteins are still of unknown biological function. This is despite a wealth of available large-scale physical and genetic interaction data. To address this, we extended the GeneMANIA function prediction web application developed for model eukaryotes to support E.coli.

RESULTS

We integrated 48 distinct E.coli functional interaction datasets and used the GeneMANIA algorithm to produce thousands of novel functional predictions and prioritize genes for further functional assays. Our analysis achieved cross-validation performance comparable to that reported for eukaryotic model organisms, and revealed new functions for previously uncharacterized genes in specific bioprocesses, including components required for cell adhesion, iron-sulphur complex assembly and ribosome biogenesis. The GeneMANIA approach for network-based function prediction provides an innovative new tool for probing mechanisms underlying bacterial bioprocesses.

CONTACT

gary.bader@utoronto.ca; mohan.babu@uregina.ca

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Incidence of and risk factors for severe hypoglycaemia in treated type 2 diabetes mellitus patients in the UK--a nested case-control analysis

AIMS

To assess incidence rates (IRs) of and identify risk factors for incident severe hypoglycaemia in patients with type 2 diabetes newly treated with antidiabetic drugs.

METHODS

Using the UK-based General Practice Research Database, we performed a retrospective cohort study between 1994 and 2011 and a nested case-control analysis. Ten controls from the population at risk were matched to each case with a recorded severe hypoglycaemia during follow-up on general practice, years of history in the database and calendar time. Using multivariate conditional logistic regression analyses, we adjusted for potential confounders.

RESULTS

Of 130,761 patients with newly treated type 2 diabetes (mean age 61.7 ± 13.0 years), 690 (0.5%) had an incident episode of severe hypoglycaemia recorded [estimated IR 11.97 (95% confidence interval, CI, 11.11-12.90) per 10,000 person-years (PYs)]. The IR was markedly higher in insulin users [49.64 (95% CI, 44.08-55.89) per 10,000 PYs] than in patients not using insulin [8.03 (95% CI, 7.30-8.84) per 10,000 PYs]. Based on results of the nested case-control analysis increasing age [≥ 75 vs. 20-59 years; adjusted odds ratio (OR), 2.27; 95% CI, 1.65-3.12], cognitive impairment/dementia (adjusted OR, 2.00; 95% CI, 1.37-2.91), renal failure (adjusted OR, 1.34; 95% CI, 1.04-1.71), current use of sulphonylureas (adjusted OR, 4.45; 95% CI, 3.53-5.60) and current insulin use (adjusted OR, 11.83; 95% CI, 9.00-15.54) were all associated with an increased risk of severe hypoglycaemia.

CONCLUSIONS

Severe hypoglycaemia was recorded in 12 cases per 10,000 PYs. Risk factors for severe hypoglycaemia included increasing age, renal failure, cognitive impairment/dementia, and current use of insulin or sulphonylureas.

Quiescent sox2(+) cells drive hierarchical growth and relapse in sonic hedgehog subgroup medulloblastoma

Functional heterogeneity within tumors presents a significant therapeutic challenge. Here we show that quiescent, therapy-resistant Sox2(+) cells propagate sonic hedgehog subgroup medulloblastoma by a mechanism that mirrors a neurogenic program. Rare Sox2(+) cells produce rapidly cycling doublecortin(+) progenitors that, together with their postmitotic progeny expressing NeuN, comprise tumor bulk. Sox2(+) cells are enriched following anti-mitotic chemotherapy and Smoothened inhibition, creating a reservoir for tumor regrowth. Lineage traces from Sox2(+) cells increase following treatment, suggesting that this population is responsible for relapse. Targeting Sox2(+) cells with the antineoplastic mithramycin abrogated tumor growth. Addressing functional heterogeneity and eliminating Sox2(+) cells presents a promising therapeutic paradigm for treatment of sonic hedgehog subgroup medulloblastoma.

Real-life efficacy and safety of vildagliptin compared with sulfonylureas as add-on to metformin in patients with type 2 diabetes mellitus in Germany

OBJECTIVE

Metformin is an established first-line treatment for type 2 diabetes mellitus (T2DM) patients, but intensification of oral anti-diabetes therapy is usually required over time. A large observational study of 45,868 T2DM patients in 27 countries (EDGE) was conducted to compare the effectiveness and safety of vildagliptin as add-on therapy to another oral anti-diabetes drug (OAD) vs other dual OAD combinations. This report presents results from a post-hoc analysis of patients in Germany who received vildagliptin or a sulfonylurea (SU) in combination with metformin.

RESEARCH DESIGN AND METHODS

Patients inadequately controlled with monotherapy became eligible only after the add-on treatment was finalized. Patients included were assigned to receive either vildagliptin or another OAD (SUs, thiazolidinediones, glinides, α-glucosidase inhibitors, or metformin; DPP-4 inhibitors or glucagon-like peptide-1 [GLP-1] mimetics/analogs were excluded). The primary end-point was the proportion of patients achieving a reduction in HbA1c >0.3% without peripheral edema, hypoglycemia, discontinuation due to gastrointestinal event, or weight gain ≥5%.

RESULTS

Of 8887 patients enrolled in Germany, 6439 received vildagliptin and 971 received SUs as add-on to metformin. The primary end-point was reached in 34.9% and 29.6% of patients in the vildagliptin and SU groups, respectively, with an unadjusted odds ratio of 1.27 (95% CI = 1.09, 1.47; p = 0.001). HbA1c decreased in both cohorts from baseline (-0.7% with vildagliptin vs -0.5% with SUs), with a mean between-group difference of -0.2% (95% CI = -0.22, -0.09). The number of hypoglycemic events was 4-fold higher in the SU group than in the vildagliptin group (vildagliptin = 0.11%; SU = 0.41%).

CONCLUSIONS

In a real-life setting, vildagliptin was associated with a numerically greater reduction in HbA1c, less hypoglycemia, and more patients reaching target HbA1c without hypoglycemia or weight gain compared with SUs. Open-label design and under reporting of adverse events are limitations of this post hoc analysis.

Abstract B29: Defining subclonal signaling heterogeneity in glioblastoma multiforme (GBM)

Glioblastoma Multiforme (GBM, WHO grade IV) is the most common and malignant brain tumor of the adult central nervous system, with a median survival of between 12 and 15 months. Interestingly, the presence of genetically unique subclones in GBMs has been previously implicated in GBMs using Fluorescence in situ hybridization (FISH) and surgical multisampling approaches.1,2 The purpose of this study are to unequivocally demonstrate clinically relevant phenotypic heterogeneity in GBM subclones, and to identify genetic and phenotypic biomarkers predictive of subclonal drug responses. Previous work in the Dirks laboratory has allowed for the generation of 44 single-cell derived clonal cultures from 4 GBM tumors, by Fluorescence Activated Cell Sorting (FACS) and clonal expansion in vitro. Comparisons of clones derived from the same tumor uniquely allows for the identification and characterization of genetic and functional intratumoral diversity in GBM. We demonstrate that single-cell derived clonal cultures from the same primary tumor can differ in key phenotypes such as proliferation in vitro and responsiveness to the chemotherapeutic Temozolomide. Our work has also shown that expression of the oncogene EGFRvIII is exclusive to some clones within a tumor, and not others. Profiling of basal and activated EGFR signaling states also revealed subclonal variability in pERK and pS6 activity, suggesting subclonal differences in pathway dependencies which could be exploited for targeted therapies. Importantly, we observed clonal differences in sensitivity to the EGFR small molecule inhibitor Erlotinib, suggesting that clonal phenotypes can be correlated to differences in signaling activity between tumor subclones. The existence of inherently drug resistant clones in GBM tumors may lead to ineffective therapies and tumor relapses, and subclonal interrogation of patient specimens may lead to better treatment stratification.

References

1) Snuderl, M., L. Fazlollahi, et al. “Mosaic amplification of multiple receptor tyrosine kinase genes in glioblastoma.” Cancer Cell 20, 810-817(2011).

2) Sottoriva, A., I. Spiteri, et al. (2013). “Intratumor heterogeneity in human glioblastoma reflects cancer evolutionary dynamics.” Proc Natl Acad Sci USA 110, 4009-4014(2013).

Citation Format: Xiaoyang Lan, Mona Meyer, Jüri Reimand, Xueming Zhu, Michelle Kushida, Renee Head, Ian Clarke, Gary Bader, Peter Dirks. Defining subclonal signaling heterogeneity in glioblastoma multiforme (GBM). [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B29.

Effectiveness and tolerability of second-line therapy with vildagliptin vs. other oral agents in type 2 diabetes: a real-life worldwide observational study (EDGE)

AIM

Real-life studies are needed to confirm the clinical relevance of findings from randomised controlled trials (RCTs). This study aimed to assess the effectiveness and tolerability of vildagliptin add-on vs. other oral antihyperglycaemic drugs (OADs) added to OAD monotherapy in a real-life setting, and to explore the advantages and limitations of large-scale 'pragmatic' trials.

METHODS

EDGE was a prospective, 1-year, worldwide, real-life observational study in which 2957 physicians reported on the effects of second-line OADs in 45,868 patients with T2DM not reaching glycaemic targets with monotherapy. Physicians could add any OAD, and patients entered either vildagliptin or (pooled) comparator cohort. The primary effectiveness and tolerability end-point (PEP) evaluated proportions of patients decreasing HbA(1c) > 0.3%, without hypoglycaemia, weight gain, peripheral oedema or gastrointestinal side effects. The most clinically relevant secondary end-point (SEP 3) was attainment of end-point HbA(1c) < 7% without hypoglycaemia or ≥ 3% increase in body weight.

RESULTS

In this large group of T2DM patients, a second OAD was added at mean HbA(1c) of 8.2 ± 1.3%, with no baseline HbA(1c) difference between cohorts. Second-line OAD therapy attained the PEP in the majority of patients, with higher attainment in those prescribed a vildagliptin-based regimen. The adjusted odds ratio was 1.49 (95% CI: 1.42, 1.55; p < 0.001). In patients with baseline HbA(1c) ≥ 7%, SEP 3 was achieved by 35% of patients on a vildagliptin-based combination and by 23% of those receiving comparator combinations. The adjusted odds ratio was 1.96 (95% CI: 1.85, 2.07; p < 0.001). Safety events were reported infrequently and safety profiles of vildagliptin and other OADs were consistent with previous data.

CONCLUSION

EDGE demonstrates that in a 'real-life' setting, vildagliptin as second OAD can lower HbA(1c) to target without well-recognised OAD side effects, more frequently than comparator OADs. In addition, EDGE illustrates that conducting large-scale, prospective, real-life studies poses challenges but yields valuable clinical information complementary to RCTs.

[Advanced uterine prolapse during pregnancy: pre- and postnatal management]

Pelvic organ prolapse is a common pelvic floor disorder in postmenopausal women. The literature is quite poor concerning the management of prolapse during pregnancy in young women. We report the case of a 39-year-old multiparous woman referred for the treatment of an exteriorized uterine prolapse at 13 weeks of gestation. The management of cervical prolapse depends on its stage, its evolution and on gestational age. It combines local antiseptics, rest and manual reintegration or reduction of the prolapsus using a pessary to prevent ulceration of the cervix. In case of stage IV (POP-Q) uterine prolapse, vaginal delivery may be compromised. No recommendation is actually available about route of delivery in case of exteriorized uterine prolapse. It should be clearly discussed regarding the potential risk of cesarean section for dystocia. Surgical repair of the prolapse will be discussed after childbirth according to functional impairment and women's desire for pregnancy.

Treatment persistence, hypoglycaemia and clinical outcomes in type 2 diabetes patients with dipeptidyl peptidase-4 inhibitors and sulphonylureas: a primary care database analysis

AIMS

To investigate therapy persistence, frequency of hypoglycaemia and macrovascular outcomes among type 2 diabetes patients with dipeptidyl peptidase-4 (DPP-4) inhibitors (DPP-4) and sulphonylureas (SU).

METHODS

Data from 19,184 DPP-4 (mean age: 64 years; 56% males) and 31,110 SU users (69 years; 51%) with new prescriptions (index date), without additional antidiabetics except metformin, in 1201 general practises in Germany were analysed. Therapy discontinuation (prescription gap >90 days), hypoglycaemia [International Classification of Diseases (ICD-10)] and macrovascular outcomes (ICD-10) (2-year follow-up) were compared adjusting for age, sex, diabetes duration, metformin, previous hypoglycaemia, health insurance, hypertension, hyperlipidaemia, antihypertensives, lipid-lowering and antithrombotic drugs, microvascular complications and Charlson co-morbidity score using logistic or Cox regression models.

RESULTS

Two years after index date, DDP-4 (non-persistence: 39%) were associated with a lower risk of discontinuation compared to SU (49%) [adjusted hazard ratio (HR): 0.74; 95% confidence interval (CI): 0.71-0.76]. Hypoglycaemias (≥1) were documented in 0.18% patients with DPP-4 and in 1.00% with SU [odds ratio (OR): 0.21; 95%CI: 0.08-0.57]. Hypoglycaemias were significantly associated with incident macrovascular complications (HR: 1.6; 95% CI: 1.1-2.2). Risk of macrovascular events was 26% lower in DPP-4 than in SU users.

CONCLUSIONS

Lack of persistence with antidiabetic therapy is frequently found in primary care patients. DPP-4 was associated with lower therapy discontinuation and a fivefold reduced frequency of patients with hypoglycaemia compared to SU. The low absolute numbers of hypoglycaemias are most likely due to the fact that only severe events were documented. DPP-4 treatment was associated with reduced incidence of macrovascular events relative to SU in type 2 diabetes patients in primary care practises.

Efficacy and tolerability of vildagliptin as add-on therapy to metformin in Chinese patients with type 2 diabetes mellitus

AIM

To investigate the efficacy and tolerability of vildagliptin as add-on therapy to metformin in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin.

METHODS

This was a 24-week, randomized, double-blind, placebo-controlled study. Patients with T2DM (N = 438) with haemoglobin A1c (HbA1c) of 7.0-10.0% and fasting plasma glucose (FPG) <15 mmol/l (<270 mg/dl) were randomized (1 : 1 : 1) to vildagliptin 50 mg bid, vildagliptin 50 mg qd or placebo in addition to metformin.

RESULTS

The treatment groups were well balanced at baseline [mean HbA1c, 8.0%, FPG, 8.8 mmol/l (158 mg/dl); body mass index, 25.5 kg/m(2) ]. The adjusted mean change (AMΔ) in HbA1c at endpoint was -1.05 ± 0.08%, -0.92 ± 0.08% and -0.54 ± 0.08% in patients receiving vildagliptin 50 mg bid, 50 mg qd and placebo, respectively. The between-treatment difference (vildagliptin 50 mg bid-placebo) was -0.51 ± 0.11%, p < 0.001. A greater proportion of vildagliptin-treated patients met at least one responder criterion (82.1 and 70.7%) compared to placebo-treated patients (60.4%). The AMΔ at endpoint for FPG with vildagliptin 50 mg bid, -0.95 mmol/l (-17.1 mg/dl); 50 mg qd, -0.84 mmol/l (-15.1 mg/dl) was significantly different compared with the placebo -0.26 mmol/l (-4.68 mg/dl) (p ≤ 0.001). Adverse events (AEs) were reported as 34.2, 36.5 and 37.5% for patients receiving vildagliptin 50 mg bid, 50 mg qd or placebo, respectively. Two patients in the vildagliptin 50 mg qd and one in the placebo group reported serious AEs, which were not considered to be related to the study drug; one incidence of hypoglycaemic event was reported in the vildagliptin 50 mg bid group.

CONCLUSION

Vildagliptin as add-on therapy to metformin improved glycaemic control and was well tolerated in Chinese patients who were inadequately controlled by metformin only.