Generation of TWO G51D SNCA missense mutation iPSC lines (CRICKi011-A, CRICKi012-A) from two individuals at risk of Parkinson's disease

Mutations or multiplications of the SNCA (Synuclein Alpha) gene cause rare autosomal dominant Parkinson's disease (PD). The SNCA G51D missense mutation is associated with a synucleinopathy that shares PD and multiple system atrophy (MSA) characteristics. We generated induced pluripotent stem cell (iPSC) lines from two individuals with SNCA G51D missense mutations at risk of PD. Dermal fibroblasts were reprogrammed to pluripotency using a non-integrating mRNA-based protocol. The resulting human iPSCs displayed normal morphology, expressed markers associated with pluripotency, and differentiated into the three germ layers. The iPSC lines could facilitate disease-modelling and therapy development studies for synucleinopathies.

Generation of an MTM1-mutant iPSC line (CRICKi008-A) from an individual with X-linked myotubular myopathy (XLMTM)

Centronuclear myopathies (CNMs) are a group of inherited rare muscle disorders characterised by the abnormal position of the nucleus in the center of the muscle fiber. One of CNM is the X-Linked Myotubular Myopathy, caused by mutations in the myotubularin (MTM1) gene (XLMTM), characterised by profound muscle hypotonia and weakness, severe bulbar and respiratory involvement. Here, we generated an induced pluripotent stem cell (iPSC) line from a patient with a severe form of XLMTM. Dermal fibroblasts were reprogrammed to pluripotency using a non-integrating mRNA-based protocol. This new MTM1-mutant iPSC line could facilitate disease-modelling and therapy development studies for XLMTM.

Generation of FOUR iPSC lines (CRICKi004-A; CRICKi005-A; CRICKi006-A, CRICKi007-A) from Spinal muscle atrophy patients with lower extremity dominant (SMALED) phenotype

Spinal muscular atrophy with lower extremity dominant (SMALED) is a hereditary neuromuscular disorder characterized by degeneration of spinal cord motor neurons resulting in lower limbs muscle weakness and paralysis. Mutations in DYNC1H1, which encodes BICD2, a multifunctional adaptor for microtubule motor proteins, cause the disorder. Here, we generated four induced pluripotent stem cell (iPSC) lines from patients with SMALED. Dermal fibroblasts were obtained from the MRC neuromuscular disease biobank and reprogrammed using non-integrating mRNA-based protocol. Characterization of the four iPSC lines included karyotyping and Sanger sequencing, while the expression of associated markers confirmed pluripotency and differentiation potential.

168 AN EXPLORATION OF ATRIAL FIBRILLATION AND ANTICOAGULATION IN STROKE PATIENTS WHO UNDERGO THROMBECTOMY IN A TERTIARY THROMBECTOMY CENTRE

Background

Atrial Fibrillation is a significant cause of ischaemic stroke. Prevalence of atrial fibrillation in patients requiring thrombectomy is approximately 33%. Embolic thrombi which develop due to Atrial fibrillation may become targets for clot removal by thrombectomy in appropriate patients. Anticoagulation is one of the mainstays of treatment for atrial fibrillation.

Methods

A list of patients who had thrombectomy performed for ischaemic stroke in 2021 was compiled. Charts were reviewed to establish the prevalence of atrial fibrillation and the rates of appropriate dosing of anticoagulant. Of those who were not anticoagulated, we aimed to establish if there was a clear reason for this. This was performed in a tertiary referral centre with 24/7 access to thrombectomy.

Results

97 patients had thrombectomy performed for ischaemic stroke in 2021. 34/97(35%) had atrial fibrillation (21/97 pre-existing , 13/97 newly diagnosed on admission). 15/21 were anticoagulated and 6/21 were not anticoagulated at the time of their stroke. 5/6 had a clear reason documented for stopping anticoagulation. One patient had stopped anticoagulation due to cost. Of those with atrial fibrillation who were anticoagulated at the time of their stroke, 11 were anticoagulated with a Direct-Acting AntiCoagulant (DOAC) and four were anticoagulated with Warfarin. Of the Warfarin group, just one patients’ INR was therapeutic at the time of their stroke. Of the DOAC group, all were on the appropriate dose.

Conclusion

Stroke patients requiring thrombectomy are a group who may suffer the largest strokes. Incidence of atrial fibrillation was similar to previous studies. It was encouraging that there was a documented reason for all patients who were not anticoagulated, and that the DOAC dose was appropriate. Issues with therapeutic levels of Warfarin are further highlighted here. This study concludes that we may not be as bad at anticoagulation as we may think.

Toxoplasma-proximal and distal control by GBPs in human macrophages

Human guanylate binding proteins (GBPs) are key players of interferon-gamma (IFNγ)-induced cell intrinsic defense mechanisms targeting intracellular pathogens. In this study, we combine the well-established Toxoplasmagondii infection model with three in vitro macrophage culture systems to delineate the contribution of individual GBP family members to control this apicomplexan parasite. Use of high-throughput imaging assays and genome engineering allowed us to define a role for GBP1, 2 and 5 in parasite infection control. While GBP1 performs a pathogen-proximal, parasiticidal and growth-restricting function through accumulation at the parasitophorous vacuole of intracellular Toxoplasma, GBP2 and GBP5 perform a pathogen-distal, growth-restricting role. We further find that mutants of the GTPase or isoprenylation site of GBP1/2/5 affect their normal function in Toxoplasma control by leading to mis-localization of the proteins.

An isoform of Dicer protects mammalian stem cells against multiple RNA viruses

In mammals, early resistance to viruses relies on interferons, which protect differentiated cells but not stem cells from viral replication. Many other organisms rely instead on RNA interference (RNAi) mediated by a specialized Dicer protein that cleaves viral double-stranded RNA. Whether RNAi also contributes to mammalian antiviral immunity remains controversial. We identified an isoform of Dicer, named antiviral Dicer (aviD), that protects tissue stem cells from RNA viruses-including Zika virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-by dicing viral double-stranded RNA to orchestrate antiviral RNAi. Our work sheds light on the molecular regulation of antiviral RNAi in mammalian innate immunity, in which different cell-intrinsic antiviral pathways can be tailored to the differentiation status of cells.

505 INTERLEUKIN-6, C-REACTIVE PROTEIN, FIBRINOGEN, AND RISK OF RECURRENCE AFTER ISCHEMIC STROKE: SYSTEMATIC REVIEW AND META-ANALYSIS

Background

Recent randomised trials showed benefit for anti-inflammatory therapies in coronary disease but excluded stroke. The prognostic value of blood inflammatory markers after stroke is uncertain and guidelines do not recommend their routine measurement for risk stratification.

Methods

We performed a systematic review and meta-analysis of studies investigating the association of C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen and risk of recurrent stroke or major vascular events (MVEs). We searched EMBASE and Ovid Medline until 10/1/19. Random-effects meta-analysis was performed for studies reporting comparable effect measures.

Results

Of 2,515 reports identified, 39 met eligibility criteria (IL-6, n = 10; CRP, n = 33; fibrinogen, n = 16). An association with recurrent stroke was reported in 12/26 studies (CRP), 2/11 (fibrinogen) and 3/6 (IL-6). On random-effects meta-analysis of comparable studies, CRP was associated with an increased risk of recurrent stroke [pooled hazard ratio (HR) per 1 standard-deviation (SD) increase in loge-CRP (1.14, 95% CI 1.06-1.22, p < 0.01)] and MVEs (pooled HR 1.21, CI 1.10-1.34, p < 0.01). Fibrinogen was also associated with recurrent stroke (HR 1.26, CI 1.07-1.47, p < 0.01) and MVEs (HR 1.31, 95% CI 1.15-1.49, p < 0.01). Trends were identified for IL-6 for recurrent stroke (HR per 1-SD increase 1.17, CI 0.97-1.41, p = 0.10) and MVEs (HR 1.22, CI 0.96-1.55, p = 0.10).

Conclusion

Despite evidence suggesting an association between inflammatory markers and post-stroke vascular recurrence, substantial methodological heterogeneity was apparent between studies. Individual-patient pooled analysis and standardisation of methods are needed to determine the prognostic role of blood inflammatory markers and to improve patient selection for randomised trials of inflammatory therapies.

The International Stem Cell Banking Initiative (ISCBI)

The International Stem Cell Banking Initiative(ISCBI) was started in 2007 to bring together the leading stem cell banks distributing human pluripotent stem cell (hPSC) lines for research and development, to discuss best practice across a range of issues from donor consent to delivery of cells for use in research, diagnostics and cell-based medicines. ISCBI holds workshops around the world and on-line and regularly publishes summaries of discussions and consensus amongst experts in stem cell biology, biobanking technology, regulation and policy making. To date, experts from more than 28 countries have contributed to ISCBI activities which are frequently run in collaboration with other stem cell organisations and has co-ordinated closely with the International Stem Cell Initiative and the hPSCreg European Commission funded database of hPSC lines and clincal trials.

Interleukin-6, C-reactive protein, fibrinogen, and risk of recurrence after ischaemic stroke: Systematic review and meta-analysis

Background

Recent randomised trials showed benefit for anti-inflammatory therapies in coronary disease but excluded stroke. The prognostic value of blood inflammatory markers after stroke is uncertain and guidelines do not recommend their routine measurement for risk stratification.

Methods

We performed a systematic review and meta-analysis of studies investigating the association of C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen and risk of recurrent stroke or major vascular events (MVEs). We searched EMBASE and Ovid Medline until 10/1/19. Random-effects meta-analysis was performed for studies reporting comparable effect measures.

Results

Of 2,515 reports identified, 39 met eligibility criteria (IL-6, n = 10; CRP, n = 33; fibrinogen, n = 16). An association with recurrent stroke was reported in 12/26 studies (CRP), 2/11 (fibrinogen) and 3/6 (IL-6). On random-effects meta-analysis of comparable studies, CRP was associated with an increased risk of recurrent stroke [pooled hazard ratio (HR) per 1 standard-deviation (SD) increase in log_e-CRP (1.14, 95% CI 1.06-1.22, p < 0.01)] and MVEs (pooled HR 1.21, CI 1.10-1.34, p < 0.01). Fibrinogen was also associated with recurrent stroke (HR 1.26, CI 1.07-1.47, p < 0.01) and MVEs (HR 1.31, 95% CI 1.15-1.49, p < 0.01). Trends were identified for IL-6 for recurrent stroke (HR per 1-SD increase 1.17, CI 0.97-1.41, p = 0.10) and MVEs (HR 1.22, CI 0.96-1.55, p = 0.10).

Conclusion

Despite evidence suggesting an association between inflammatory markers and post-stroke vascular recurrence, substantial methodological heterogeneity was apparent between studies. Individual-patient pooled analysis and standardisation of methods are needed to determine the prognostic role of blood inflammatory markers and to improve patient selection for randomised trials of inflammatory therapies.

IGF1-mediated human embryonic stem cell self-renewal recapitulates the embryonic niche

Our understanding of the signalling pathways regulating early human development is limited, despite their fundamental biological importance. Here, we mine transcriptomics datasets to investigate signalling in the human embryo and identify expression for the insulin and insulin growth factor 1 (IGF1) receptors, along with IGF1 ligand. Consequently, we generate a minimal chemically-defined culture medium in which IGF1 together with Activin maintain self-renewal in the absence of fibroblast growth factor (FGF) signalling. Under these conditions, we derive several pluripotent stem cell lines that express pluripotency-associated genes, retain high viability and a normal karyotype, and can be genetically modified or differentiated into multiple cell lineages. We also identify active phosphoinositide 3-kinase (PI3K)/AKT/mTOR signalling in early human embryos, and in both primed and naïve pluripotent culture conditions. This demonstrates that signalling insights from human blastocysts can be used to define culture conditions that more closely recapitulate the embryonic niche.

Cell Lines as Biological Models: Practical Steps for More Reliable Research

Research in toxicology relies on in vitro models such as cell lines. These living models are prone to change and may be described in publications with insufficient information or quality control testing. This article sets out recommendations to improve the reliability of cell-based research.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Science-based assessment of source materials for cell-based medicines: report of a stakeholders workshop

Human pluripotent stem cells (hPSCs) have the potential to transform medicine. However, hurdles remain to ensure safety for such cellular products. Science-based understanding of the requirements for source materials is required as are appropriate materials. Leaders in hPSC biology, clinical translation, biomanufacturing and regulatory issues were brought together to define requirements for source materials for the production of hPSC-derived therapies and to identify other key issues for the safety of cell therapy products. While the focus of this meeting was on hPSC-derived cell therapies, many of the issues are generic to all cell-based medicines. The intent of this report is to summarize the key issues discussed and record the consensus reached on each of these by the expert delegates.

Authentication of M14 melanoma cell line proves misidentification of MDA-MB-435 breast cancer cell line

A variety of analytical approaches have indicated that melanoma cell line UCLA‐SO‐M14 (M14) and breast carcinoma cell line MDA‐MB‐435 originate from a common donor. This indicates that at some point in the past, one of these cell lines became misidentified, meaning that it ceased to correspond to the reported donor and instead became falsely identified (through cross‐contamination or other means) as a cell line from a different donor. Initial studies concluded that MDA‐MB‐435 was the misidentified cell line and M14 was the authentic cell line, although contradictory evidence has been published, resulting in further confusion. To address this question, we obtained early samples of the melanoma cell line (M14), a lymphoblastoid cell line from the same donor (ML14), and donor serum preserved at the originator's institution. M14 samples were cryopreserved in December 1975, before MDA‐MB‐435 cells were established in culture. Through a series of molecular characterizations, including short tandem repeat (STR) profiling and cytogenetic analysis, we demonstrated that later samples of M14 and MDA‐MB‐435 correspond to samples of M14 frozen in 1975, to the lymphoblastoid cell line ML14, and to the melanoma donor's STR profile, sex and blood type. This work demonstrates conclusively that M14 is the authentic cell line and MDA‐MB‐435 is misidentified. With clear provenance information and authentication testing of early samples, it is possible to resolve debates regarding the origins of problematic cell lines that are widely used in cancer research.

What's new?

A variety of analytical approaches have indicated that melanoma cell line M14 and breast carcinoma cell line MDA‐MB‐435 originate from a common donor, but there is ongoing debate regarding which is the misidentified cell line. Here, authentication testing of M14 from 1975 (prior to the establishment of MDA‐MB‐435), with comparison to donor serum and lymphoblastoid cell line ML14, shows that M14 is the authentic cell line and MDA‐MB‐435 is a misidentified derivative. With clear provenance information and authentication testing of early samples, debates regarding the origins of problematic cell lines that are widely used in cancer research can be resolved.

Rapid establishment of the European Bank for induced Pluripotent Stem Cells (EBiSC) - the Hot Start experience

A fast track "Hot Start" process was implemented to launch the European Bank for Induced Pluripotent Stem Cells (EBiSC) to provide early release of a range of established control and disease linked human induced pluripotent stem cell (hiPSC) lines. Established practice amongst consortium members was surveyed to arrive at harmonised and publically accessible Standard Operations Procedures (SOPs) for tissue procurement, bio-sample tracking, iPSC expansion, cryopreservation, qualification and distribution to the research community. These were implemented to create a quality managed foundational collection of lines and associated data made available for distribution. Here we report on the successful outcome of this experience and work flow for banking and facilitating access to an otherwise disparate European resource, with lessons to benefit the international research community. ETOC: The report focuses on the EBiSC experience of rapidly establishing an operational capacity to procure, bank and distribute a foundational collection of established hiPSC lines. It validates the feasibility and defines the challenges of harnessing and integrating the capability and productivity of centres across Europe using commonly available resources currently in the field.

Leptin and adiponectin receptor expression in oesophageal cancer

BACKGROUND

Oesophageal adenocarcinoma is an exemplar model of an obesity-associated adenocarcinoma. Altered secretion of adipokines by visceral fat is believed to play a key role in tumorigenesis. This study examined leptin receptor (ObR) and adiponectin receptor (AdipoR1 and AdipoR2) expression in oesophageal cancer, and its relationship with patient obesity status, clinicopathological data and patient survival.

METHODS

Tissue microarrays were constructed from paraffin-embedded oesophagectomy specimens. ObR, AdipoR1 and AdipoR2 expression was quantified by immunohistochemistry. Anthropometric data were measured at the time of diagnosis, and obesity status was assessed using visceral fat area determined by computed tomography and body mass index. Receptor expression was correlated with various clinicopathological and anthropometric variables. Patient survival was estimated using the Kaplan-Meier method, and results compared between those with low versus high receptor expression. A Cox multivariable regression model was used to assess the relationship between survival and a number of co-variables.

RESULTS

All 125 tumours analysed expressed AdipoR1 and AdipoR2, whereas 96·8 per cent expressed ObR. There was no significant difference in tumour pathological features or patient obesity status between tumours with low versus high ObR expression. A high level of AdipoR1 expression was significantly associated with increased patient age, obesity and less advanced tumour (T) category. Expression of AdipoR2 was inversely associated with T category (P = 0.043). Low AdipoR1 expression was an independent predictor of improved overall survival (hazard ratio 0.56, 95 per cent confidence interval 0.35 to 0.90; P = 0.017).

CONCLUSION

The association between adiponectin receptor expression, obesity status and tumour category and survival suggests a potential mechanism linking obesity and oesophageal cancer.

The potential lost hospital income from miscoded emergency department boarders in Ireland

BACKGROUND

Emergency department (ED) boarders, namely patients who have been admitted under an in-patient service but remain on a trolley in the ED, have long been a problem in the Irish healthcare system.

METHODS

We conducted a retrospective analysis of all ED boarders in Cork University Hospital (CUH) for a 6-month period from January to July 2011. Data were obtained from the Hospital In-Patient Enquiry Office (HIPE). The income generated by the hospital for a subset of these patients (January and February attendances) was obtained from the Finance Office in the hospital, based on diagnoses as recorded on the HIPE system. A convenience sample of two-thirds of the 39 acute hospitals nationally was surveyed to ascertain whether ED boarders were coded by individual HIPE offices as hospital in-patients or as ED attendees.

RESULTS

A total of 806 patients were admitted to an in-patient service from January to July 2011 in CUH and subsequently discharged, having completed their entire stay in the ED. The income generated by a sub-sample of 228 patients (January and February ED boarders) was determined. The hospital was remunerated by <euro>685,111 for these patients, i.e. an average income of <euro>3,098 per patient. Only 8 hospitals of the 27 surveyed hospitals coded overnight ED Boarders as in-patients and were thus able to request income for these patients appropriately.

CONCLUSION

Discrepancies in coding of ED boarders may result in significant revenue losses for certain hospitals.

Reconsidering pluripotency tests: do we still need teratoma assays?

The induction of teratoma in mice by the transplantation of stem cells into extra-uterine sites has been used as a read-out for cellular pluripotency since the initial description of this phenomenon in 1954. Since then, the teratoma assay has remained the assay of choice to demonstrate pluripotency, gaining prominence during the recent hype surrounding human stem cell research. However, the scientific significance of the teratoma assay has been debated due to the fact that transplanted cells are exposed to a non-physiological environment. Since many mice are used for a result that is heavily questioned, it is time to reconsider the teratoma assay from an ethical point of view. Candidate alternatives to the teratoma assay comprise the directed differentiation of pluripotent stem cells into organotypic cells, differentiation of cells in embryoid bodies, the analysis of pluripotency-associated biomarkers with high correlation to the teratoma forming potential of stem cells, predictive epigenetic footprints, or a combination of these technologies. Each of these assays is capable of addressing one or more aspects of pluripotency, however it is essential that these assays are validated to provide an accepted robust, reproducible alternative. In particular, the rapidly expanding number of human induced pluripotent stem cell lines, requires the development of simple, affordable standardized in vitro and in silico assays to reduce the number of animal experiments performed.

The ToxBank Data Warehouse: Supporting the Replacement of In Vivo Repeated Dose Systemic Toxicity Testing

The aim of the SEURAT-1 (Safety Evaluation Ultimately Replacing Animal Testing-1) research cluster, comprised of seven EU FP7 Health projects co-financed by Cosmetics Europe, is to generate a proof-of-concept to show how the latest technologies, systems toxicology and toxicogenomics can be combined to deliver a test replacement for repeated dose systemic toxicity testing on animals. The SEURAT-1 strategy is to adopt a mode-of-action framework to describe repeated dose toxicity, combining in vitro and in silico methods to derive predictions of in vivo toxicity responses. ToxBank is the cross-cluster infrastructure project whose activities include the development of a data warehouse to provide a web-accessible shared repository of research data and protocols, a physical compounds repository, reference or "gold compounds" for use across the cluster (available via wiki.toxbank.net), and a reference resource for biomaterials. Core technologies used in the data warehouse include the ISA-Tab universal data exchange format, REpresentational State Transfer (REST) web services, the W3C Resource Description Framework (RDF) and the OpenTox standards. We describe the design of the data warehouse based on cluster requirements, the implementation based on open standards, and finally the underlying concepts and initial results of a data analysis utilizing public data related to the gold compounds.

Production and validation of a good manufacturing practice grade human fibroblast line for supporting human embryonic stem cell derivation and culture

Introduction

The development of reproducible methods for deriving human embryonic stem cell (hESC) lines in compliance with good manufacturing practice (GMP) is essential for the development of hESC-based therapies. Although significant progress has been made toward the development of chemically defined conditions for the maintenance and differentiation of hESCs, efficient derivation of new hESCs requires the use of fibroblast feeder cells. However, GMP-grade feeder cell lines validated for hESC derivation are not readily available.

Methods

We derived a fibroblast cell line (NclFed1A) from human foreskin in compliance with GMP standards. Consent was obtained to use the cells for the production of hESCs and to generate induced pluripotent stem cells (iPSCs). We compared the line with a variety of other cell lines for its ability to support derivation and self-renewal of hESCs.

Results

NclFed1A supports efficient rates (33%) of hESC colony formation after explantation of the inner cell mass (ICM) of human blastocysts. This compared favorably with two mouse embryonic fibroblast (MEF) cell lines. NclFed1A also compared favorably with commercially available foreskin fibroblasts and MEFs in promoting proliferation and pluripotency of a number of existing and widely used hESCs. The ability of NclFed1A to maintain self-renewal remained undiminished for up to 28 population doublings from the master cell bank.

Conclusions

The human fibroblast line Ncl1Fed1A, produced in compliance with GMP standards and qualified for derivation and maintenance of hESCs, is a useful resource for the advancement of progress toward hESC-based therapies in regenerative medicine.

Standardization of pluripotent stem cell cultures for toxicity testing

INTRODUCTION

Pluripotent stem cell (PSC) lines offer a unique opportunity to derive various human cell types that can be exploited for human safety assessments in vitro and as such contribute to modern mechanistically oriented toxicity testing.

AREAS COVERED

This article reviews the two major types of PSC cultures that are currently most promising for toxicological applications: human embryonic stem cell lines and human induced PSC lines. Through the review, the article explains how these cell types will improve the current safety evaluations of chemicals and will allow a more efficient selection of drug candidates. Additionally, the article discusses the important issues of maintaining PSCs as well as their differentiation efficiency.

EXPERT OPINION

The demonstration of the reliability and relevance of in vitro toxicity tests for a given purpose is mandatory for their use in regulatory toxicity testing. Given the peculiar nature of PSCs, a high level of standardization of undifferentiated cell cultures as well as of the differentiation process is required in order to ensure the establishment of robust test systems. It is, therefore, of pivotal importance to define and internationally agree on crucial parameters to judge the quality of the cellular models before enrolling them for toxicity testing.

Screening ethnically diverse human embryonic stem cells identifies a chromosome 20 minimal amplicon conferring growth advantage

The International Stem Cell Initiative analyzed 125 human embryonic stem (ES) cell lines and 11 induced pluripotent stem (iPS) cell lines, from 38 laboratories worldwide, for genetic changes occurring during culture. Most lines were analyzed at an early and late passage. Single-nucleotide polymorphism (SNP) analysis revealed that they included representatives of most major ethnic groups. Most lines remained karyotypically normal, but there was a progressive tendency to acquire changes on prolonged culture, commonly affecting chromosomes 1, 12, 17 and 20. DNA methylation patterns changed haphazardly with no link to time in culture. Structural variants, determined from the SNP arrays, also appeared sporadically. No common variants related to culture were observed on chromosomes 1, 12 and 17, but a minimal amplicon in chromosome 20q11.21, including three genes expressed in human ES cells, ID1, BCL2L1 and HM13, occurred in >20% of the lines. Of these genes, BCL2L1 is a strong candidate for driving culture adaptation of ES cells.

Stem cell banks: preserving cell lines, maintaining genetic integrity, and advancing research

The ability to cryopreserve and successfully recover cell lines has been critical to the conservation of all cell lines, especially the preservation of pristine early-stage cultures and the preparation of well-characterized cell banks. Indeed, the systematic storage and establishment of cryopreserved banks of cells for the stem cell research community is fundamental to the promotion of standardisation in stem cell research and their use in clinical applications. In spite of the significant potential for the use of stem cells in research and therapy, they are challenging to maintain and have been shown to be unstable after prolonged culture that often results in permanent alterations in their genetic make-up, which ultimately alters the phenotype of the culture. This chapter will review the principles of cell bank production, techniques for the scale-up of human pluripotent stem cells, quality control, and characterisation methods for banked cell lines.

Comparison of defined culture systems for feeder cell free propagation of human embryonic stem cells

There are many reports of defined culture systems for the propagation of human embryonic stem cells in the absence of feeder cell support, but no previous study has undertaken a multi-laboratory comparison of these diverse methodologies. In this study, five separate laboratories, each with experience in human embryonic stem cell culture, used a panel of ten embryonic stem cell lines (including WA09 as an index cell line common to all laboratories) to assess eight cell culture methods, with propagation in the presence of Knockout Serum Replacer, FGF-2, and mouse embryonic fibroblast feeder cell layers serving as a positive control. The cultures were assessed for up to ten passages for attachment, death, and differentiated morphology by phase contrast microscopy, for growth by serial cell counts, and for maintenance of stem cell surface marker expression by flow cytometry. Of the eight culture systems, only the control and those based on two commercial media, mTeSR1 and STEMPRO, supported maintenance of most cell lines for ten passages. Cultures grown in the remaining media failed before this point due to lack of attachment, cell death, or overt cell differentiation. Possible explanations for relative success of the commercial formulations in this study, and the lack of success with other formulations from academic groups compared to previously published results, include: the complex combination of growth factors present in the commercial preparations; improved development, manufacture, and quality control in the commercial products; differences in epigenetic adaptation to culture in vitro between different ES cell lines grown in different laboratories.

Is Metabolic Syndrome and Central Obesity Relevent to Biology and Progression of Postmenopausal Breast Cancer?

Introduction: Obesity isassociated with both an increased risk of postmenopausal breast cancer and increased mortality rates. The mechanism is unclear, and central (visceral) obesity, insulin resistance, altered sex steroids, and altered adipokines, are mooted as possible factors. These features may cluster in the so-called Metabolic Syndrome (MetS), and the focus of this study was to systematically relate MetS to standard clinicopathological indices of breast cancer.Methods: Postmenopausal women with newly diagnosed breast cancer (n=105) were prospectively recruited. A detailed clinical and dietary history was performed, as well as body composition analysis, metabolic screen, and plasma measurement of adipokines and inflammatory markers. MetS was defined according to the International Diabetes Federation definition.Results: One hundred and five patients were recruited, the median age was 68 years (40-94) and the mean BMI was 28.3 ± 5.2 kg/m2, with 87% of patients centrally obese. MetS was diagnosed in 39% of patients, and was significantly (p&lt;0.005) associated with 13cm greater waist circumference, higher total and trunk fat mass and increased inflammation with CRP levels almost double for MetS patietns compared to non MetS (10.3 ± 2.7 V's 5.8 ± 1.0 mg/L; p=0.084).Patients with later pathological stage (II- IV) were significantly more likely to be obese (BMI) (45% Vs 16%; p=0.007), centrally obese (waist circumference) (94% Vs 72%; p=0.009), hyperglycaemic (31% Vs 12%; p=0.047), hyperinsulinaemia (19% Vs 0; p=0.026) and 51% had MetS compared to 12% for early stage disease (Path stage 0-I). Patients with node positive disease were significantly more likely to be hyperinsulaemic (22% V's 5%; p=0.030) and have MetS (50% V's 30%; p=0.028) than node negative disease.MetS was not associated with hormone receptor status or serum levels of oestradiol, progesterone, testosterone, or SHBG levels. However, SHBG levels decreased with obesity (p=0.002) and as the number of features of MetS increased (0 features: 87 ± 15.8 compared to 5 features: 32 ±2.7; p=0.003). Insulin levels increased with obesity (p=0.006), and with increasing number of features of MetS.Discussion: MetS and central obesity are common in Irish postmenopausal breast cancer patients. MetS appears to be associated with aggressive tumour biology, and this may have significance in preventive and novel treatment approaches.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1051.

Mammary adipose tissue and cancer cell growth: The role of adipose tissue in the tumor microenvironment

e22009

Background: Worldwide, the prevalence of obesity is rapidly increasing, correlating with a direct increase in cancer rates1. Adipose tissue is considered an important endocrine organ producing several important hormones and cytokines including leptin and adiponectin. Mechanisms for the role of obesity in cancer states includes the excess or unregulated secretion of adipocytokines from adipose tissue, and potentially the metabolic syndrome (a cluster of co-morbidities linked to metabolic dysregulation). Mammary adipose tissue is proposed to play a vital role in the microenvironment of normal and tumour states within the breast2. Breast adipose tissue is a good candidate to investigate effects of obesity and metabolic disturbances on cancer states. Methods: Peritumoural (PT) adipose tissue adjacent to the tumour and distal adipose tissue (D) within the breast was sampled in 10 patients. The tissue was processed and cultured for 72hrs in serum free minimal cytokine media. A-MB-231 and MCF-7 breast cancer cell lines were then cultured with this adipocyte conditioned media (ACM) and cell proliferation response was then measured using BrDU assays. The adipocytokine profile at the mRNA and protein level was measured in ACM and adipose tissue for comparative differences using RT-PCR, ELISA and Cytokine Profiler technology. Results: ACM from both sites promoted tumour cell survival. There was however, a differential cell proliferation response noted between the peritumoural (PT) ACM and that from the distant (D) ACM. Pro-inflammatory mediators (VEGF, TNF-α, EGF) were also demonstrated a trend to be differentially expressed between the 2 sites. Conclusions: Proliferation of breast cancer cell lines occurs in response to ACM, with differential effects seen between peritumoural ACM and distant ACM. This may be mediated through increased pro-inflammatory or pro- mitogenic adipocytokine production in adipose tissue surrounding tumour. Further analysis will determine what role obesity and the metabolic syndrome plays in the results noted.

No significant financial relationships to disclose.

Comparison of survival rates in carcinoma in situ of the breast treated with total mastectomy to breast-conserving surgery and radiotherapy

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Background: Carcinoma in situ (CIS) of the breast is a precancerous lesion with the potential to progress to invasive cancer. In 2003, CIS accounted for 19% of all newly diagnosed invasive and non-invasive breast lesions combined in the United States. Current treatment options are mastectomy ± tamoxifen, and breast-conserving surgery with radiotherapy ± tamoxifen. As there are no randomized comparisons of these 2 treatments, data from the Surveillance Epidemiology and End Results (SEER) database was used to compare their survival rates. Methods: 88,285 patients were identified with CIS from 1988 - 2003. Of these, 27,728 patients were treated with a total mastectomy, and 25,240 patients received breast-conserving surgery with radiotherapy. Kaplan-Meier survival analyses and Cox proportional hazards regression were used to compare overall survival and disease specific survival at 5 and 10 years. Results: Kaplan-Meier analyses demonstrated 5 year overall survival rates for total mastectomy vs. breast conserving surgery with radiotherapy of 95.46% vs. 97.59% respectively (Log-rank P < 0.0001). The 5 year rates for disease specific survival were 99.16% vs. 99.72% respectively (Log-rank P < 0.0001). At 10 years the overall survival rates had fallen to 91.96% vs. 96.09% respectively (Log-rank P < 0.0001). The 10 year disease specific survival rates were 98.61% vs. 99.50% respectively (Log-rank P < 0.0001). Cox proportional hazards regression demonstrated a relative risk of 0.847 (95% confidence interval (CI) 0.790 - 0.907) and 1.110 (95% CI 0.931 - 1.324) for 5 year overall survival and disease specific survival respectively, when total mastectomy was compared with breast conserving surgery and radiotherapy. At 10 years, the relative risks were 0.865 (95% CI 0.820 - 0.913) and 1.035 (95% CI 0.900 - 1.190) for overall survival and disease specific survival respectively. Conclusions: Overall, when looking at disease-specific survival rates by multi-variate analysis, there does not appear to be a significant difference between total mastectomy and breast-conserving surgery with radiotherapy in the treatment of CIS.

No significant financial relationships to disclose.

The development of ‘feeder’ cells for the preparation of clinical grade hES cell lines: Challenges and solutions

The development of human embryonic stem cell (hESC) lines for research and therapy is hampered by the need to improve the basic methodologies for cell culture expansion. In most current methods hESC lines are cultured on a mouse or human feeder cell layer which appears to be the most reliable way to maintain cells stably in the undifferentiated state. However, co-culture introduces complications for studying stem cell biology and the delivery of safe therapies for the future. This article reviews the specific risks associated with any proposed clinical use of feeder cells of mouse origin and compares these with the benefits and risks of using human feeder cells. The further work required to establish clinical grade feeder cell lines for hESC line culture is significant and costly. Much work is being done to find feeder-free culture systems but these are at an early stage of development and there may be consequences that affect the value of the hESCs for research and development. These challenges should be viewed in the context of the huge amount of work that will be required over many years to develop robust differentiation protocols and establish fully defined procedures and adequate safety data for embryonic stem cell products.

The UK Stem Cell Bank: its role as a public research resource centre providing access to well-characterised seed stocks of human stem cell lines

The rapidly expanding field of stem cell research offers the potential to develop therapeutic agents to treat diseases such as Parkinson's, diabetes and heart disease. It is important that stem cell lines derived from quality-controlled and well-characterised cell banks should be made available to both the scientific and clinical communities to promote high-quality research and development. The requirement in the United Kingdom (UK) for rigorous regulation of the procurement and use of embryonic stem (ES) cell lines led the UK government to fund the establishment of a national bank for stem cell lines. The UK Stem Cell Bank (UKSCB) hosted at the National Institute for Biological Standards and Control (NIBSC) is committed to working closely with the clinical and research communities to provide qualified stocks of human stem cell lines of adult, foetal and embryonic origin for both research use and for use in emerging human therapy.

The histone deacetylase 9 gene encodes multiple protein isoforms

Histone deacetylases (HDACs) perform an important function in transcriptional regulation by modifying the core histones of the nucleosome. We have now fully characterized a new member of the Class II HDAC family, HDAC9. The enzyme contains a conserved deacetylase domain, represses reporter activity when recruited to a promoter, and utilizes histones H3 and H4 as substrates in vitro and in vivo. HDAC9 is expressed in a tissue-specific pattern that partially overlaps that of HDAC4. Within the human hematopoietic system, expression of HDAC9 is biased toward cells of monocytic and lymphoid lineages. The HDAC9 gene encodes multiple protein isoforms, some of which display distinct cellular localization patterns. For example, full-length HDAC9 is localized in the nucleus, but the isoform lacking the region encoded by exon 7 is in the cytoplasm. HDAC9 interacts and co-localizes in vivo with a number of transcriptional repressors and co-repressors, including TEL and N-CoR, whose functions have been implicated in the pathogenesis of hematological malignancies. These results suggest that HDAC9 plays a role in hematopoiesis; its deregulated expression may be associated with some human cancers.

Structural and functional features of the CD34 antigen: an update

CD34 is a heavily glycosylated type I transmembrane molecule, that can be phoshorylated by a variety of kinases including Protein kinase C and Tyrosine kinases. The classification of epitopes detected by different CD34 MAbs has aided the selection of appropriate antibodies for use in specific clinical and research laboratory settings. Detailed structural analyses and cloning studies have confirmed that CD34 is a sialomucin, and have suggested that the fine composition of the carbohydrate moieties contained in its extended N-terminal region is important in determining its interactions with a variety of different ligands. For high endothelial venules (HEV) CD34 to serve as a ligand for L-selectin, the O-linked glycans of HEV CD34 are modified in an exquisitely specific manner with a variety of sialyl- and sulfo-transferases. In contrast, CD34 is not the ligand for L-selectin in hematopoietic stem/progenitor cells (HSPCs) and despite much endeavour, ligands for hematopoietic CD34 remain to be identified.

Stromal expression of Jagged 1 promotes colony formation by fetal hematopoietic progenitor cells

The Notch signaling system regulates proliferation and differentiation in many tissues. Notch is a transmembrane receptor activated by ligands expressed on adjacent cells. Hematopoietic stem cells and early progenitors express Notch, making the stromal cells which form cell-cell contacts with progenitor cells candidate ligand-presenting cells in the hematopoietic microenvironment. Therefore, we examined primary stromal cell cultures for expression of Notch ligands. Using reverse transcription-polymerase chain reaction, in situ hybridization, immunohistochemistry, and Western blotting, we demonstrate expression of Jagged 1 in primary stromal cultures. To investigate if the stromal expression of Jagged 1 has functional effects on hematopoietic progenitors, we cultured CD34(+), c-kit+ hematopoietic progenitor cells derived from the aorto gonadal mesonephros region of day 11 mouse embryos on the Jagged 1(-) stromal cell line S17 and on S17 cells engineered to express Jagged 1. The presence of Jagged 1 increased the number of colonies formed in subsequent methylcellulose culture fourfold. Larger increases in colony numbers were observed under the same culture conditions with CD34(+), c-kit+ hematopoietic progenitor cells derived from d11 fetal liver. These results obtained in vitro table Jagged 1 as a candidate regulator of stem cell fate in the context of stromal microenvironments in vivo.

CD34 expression patterns during early mouse development are related to modes of blood vessel formation and reveal additional sites of hematopoiesis

CD34 is a cell surface glycoprotein that is selectively expressed within the human hematopoietic system on stem and progenitor cells, and in early blood vessels. To elucidate its functions during early blood vessel formation and hematopoiesis, we analyzed the expression patterns, in day 8 to day 10 mouse embryos, of CD34 RNA by in situ hybridization and protein by immunohistochemistry using the monclonal antibody RAM 34. Levels of expression in embryonic blood vessels were correlated with the mode of vessel formation, being high in pre-endothelial cells and in vessels forming by vasculogenesis (particularly the dorsal aortae) or angiogenesis, but low in vessels forming by coalescence (the cardinal veins). CD34+ erythroid cells, presumably of yolk sac origin, were present in the liver of day 10 embryos; at the same stage, putative definitive hematopoietic cells, strongly CD34+, were present in the para-aortic mesenchyme. Possible sites of hemangioblastic differentiation were detected in the form of CD34+ endothelium-attached hematopoietic cells in the dorsal aorta and in two previously unreported locations, the proximal umbilical and vitelline arteries. These observations suggest functions for CD34 in relation to specific modes of blood vessel formation, and a hemangioblastic role in both embryonic and extraembryonic sites.

BCR/ABL-negative progenitors are enriched in the adherent fraction of CD34+ cells circulating in the blood of chronic phase chronic myeloid leukemia patients

Philadelphia chromosome-positive (Ph+) hemopoietic cells predominate in patients with chronic myeloid leukemia (CML) in chronic phase, but some Ph presumably normal stem cells persist in most patients. Ph cells are relatively frequent, compared to mature cell populations, in primitive hemopoietic cell populations from CML patients. We have purified CD34+ cells from chronic phase CML blood and separated them into two fractions on the basis of adherence or non-adherence to tissue culture plastic. We also separated CD34+ CML cell populations into HLA-DR(hi) and HLA-DR(lo) fractions and CD38(hi) and CD38(lo) fractions by flow cytometry. The CD34+ cells that adhered to plastic were predominantly CD33-, CD38- and HLA(-)-DR; cells with these phenotypic properties were significantly rarer in the CD34+ non-adherent cell population (P = 0.008-0.02). Expression of p210 BCR/ABL mRNA by adherent, non-adherent, HLA-DR(hi) and HLA-DR(lo)CD34+ cell subpopulations was demonstrated by RT-PCR. Using fluorescence in situ hybridization (FISH) in conjunction with BCR and ABL probes we detected Ph+ and Ph- cells in both adherent and non-adherent CD34+ cell fractions of 15/15 patients studied and in the HLA-DR(lo) or CD38(lo) sorted CD34+ cell fractions. The concentration of Ph- cells in the adherent CD34+ cell fraction was three-fold higher than in the non-adherent fraction (P = 0.001). Ph- adherent cells were detected in untreated CML patients and as late as 6 years after diagnosis of CML in patients treated with hydroxyurea (HU) or interferon-alpha (IFN-alpha). We conclude that whilst appreciable numbers of Ph- primitive hemopoietic progenitors are present in the circulation in untreated patients and also in treated patients in late chronic phase, the majority of cells expressing CD34 but not CD33, CD38 or HLA-DR antigens, are part of the CML clone.

In vivo enzymatic removal of alpha 2-->6-linked sialic acid from the glomerular filtration barrier results in podocyte charge alteration and glomerular injury

The epithelial polyanion (podocalyxin) on the foot processes (pedicels) of podocytes plays a pivotal role in maintaining slit pore integrity and excluding proteins from the glomerular filtrate. Chromatographically purified recombinant sialidase from Vibrio cholerae, a corresponding heat-inactivated enzyme, truncated enzyme (missing the last 17 amino acids from the carboxyl terminus), and the sialidase from Salmonella typhimurium strain LT2 were inoculated intraperitoneally into mice, and the resultant renal alterations were documented by a variety of functional, morphologic, and histochemical techniques. Proteinuria and renal failure developed in a dose-dependent manner after a single inoculation of sialidase from Vibrio cholerae, but not with the corresponding heat-inactivated enzyme, truncated enzyme, or the sialidase from Salmonella typhimurium strain LT2. Biotinylated lectins of known sialyl linkage specificity demonstrated that Vibrio cholerae sialidase primarily removed alpha 2-->6-linked sialic acids from the glomerulus. Furthermore, the use of a poly-L-lysine cationic gold ultrastructural probe confirmed a transient loss of charge from the endothelium and epithelium of the glomerular filtration barrier. Loss of the epithelial polyanion was accompanied by the effacement of pedicels and the apparent formation of tight junctions between adjacent podocytes. The anionic charge returned to endothelial and epithelial sites within 2 days of sialidase inoculation, but the foot process loss remained. This animal model, in addition to providing an opportunity to study basic mechanisms of renal physiology, seems to mimic minimal change disease in children, diabetic nephropathy, and the renal effects of some bacterial infections.

The stem cell antigen CD34 functions as a regulator of hemopoietic cell adhesion

Although the CD34 antigen is widely used in the identification and purification of hemopoietic stem and progenitor cells, its function within hemopoiesis is unknown. We have investigated this issue by ectopically expressing human (hu) CD34 on the surface of murine hemopoietic cells. Forced expression of hu-CD34 in the thymocytes of transgenic mice did not appear to affect the development, maturation, or distribution of murine T cells but did significantly increase their ability to adhere to bone marrow stromal layers of human but not mouse origin. Ectopic expression of hu-CD34 on murine 416B cells, a multipotential progenitor that expresses murine CD34, yielded similar results. In both cases hu-CD34-dependent adhesion was enhanced by molecular engagement of the hu-CD34 protein using anti-CD34 antibodies. These results provide evidence that CD34 promotes the adhesive interactions of hemopoietic cells with the stromal microenvironment of the bone marrow thereby implicating CD34 in regulation and compartmentalization of stem cells. We propose that CD34 regulates these processes in part via an indirect mechanism, signaling changes in cellular adhesion in response to molecular recognition of an as yet unidentified stromal CD34 counterreceptor or ligand.

Age-related changes in oxygen saturation over the first year of life: a longitudinal study

Stability of oxygen saturation depends on maturation and function of individual components of the respiratory system. The aim of this study was to record and analyse comprehensive oxygen saturation data in a longitudinal study over the first year of life. Detailed sleep studies were performed on 15 normal infants eight times in the first year of life. The accrued oxygen saturation data were analysed on a computerized oximetry data analysis system. Results show the mean sleep saturation levels trending upwards and stabilizing by 185 days. There was an inverse curvilinear relationship between mean age and median desaturation time and the median number of desaturations at < or = 95, < or = 92 and < or = 90% saturation. The mean cumulative desaturation time < or = 90% in the first 4 months was 11.08 min (range 2.5-36.57 min). This study demonstrates monotonic patterns of increasing saturation and decreasing number and time of desaturations < or = 95% and < or = 90% but a random pattern of desaturations < or = 85% occurs across the first 6 months of life. Cumulative desaturation times over the first 4 months of life were high and could be important to the development of maturity of the respiratory system. After 6 months, all indices of saturation and desaturation point to a stable and mature respiratory system.

Proliferative but not nonproliferative responses to granulocyte colony-stimulating factor are associated with rapid activation of the p21ras/MAP kinase signalling pathway

Granulocyte colony-stimulating factor (G-CSF) can elicit responses that include proliferation, granulocytic differentiation, and activation of cellular functions in target cells. The biochemical pathways responsible for transduction of these signals from the G-CSF receptor (G-CSFR) have not been defined. In this report, we show that, in murine (NFS-60) and human (OCI-AML 1) myeloid leukemia cell lines and in murine pro-B-lymphocytic cells, BAF/B03, transfected with the murine G-CSFR, proliferative responses to G-CSF are associated with rapid activation of p42 and p44 MAP kinases and p21ras. Truncation of the cytoplasmic portion of the murine G-CSFR at residue 646 but not at residue 739 abolished G-CSF-induced stimulation of cellular proliferation as well as activation of MAP kinase and p21ras in transfected BAF/B03 cells. G-CSF-induced granulocytic differentiation of the murine leukemic cell line 32DC13(G) occurred in the absence of detectable activation of p42 MAP kinase. Nonproliferative responses to G-CSF in the human promyelocytic cell line HL-60 and in human neutrophils were similarly associated with no MAP kinase activation. These results imply that differing cellular effects of G-CSF may be involve the recruitment of differing signal transduction pathways with the p21ras/MAP kinase pathway being limited to proliferative responses.

Painting the phase space portrait of an integrable dynamical system

For an integrable dynamical system with one degree of freedom, "painting" the integral over the phase space proves to be very effective for uncovering the global flow down to minute details. Applied to the main problem in artificial satellite theory, for instance, the technique reveals an intricate configuration of equilibria and bifurcations when the polar component of the angular momentum approaches zero.