Expanding the DNA editing toolbox: Novel lambda integrase variants targeting microalgal and human genome sequences

Recombinase enzymes are extremely efficient at integrating very large DNA fragments into target genomes. However, intrinsic sequence specificities curtail their use to DNA sequences with sufficient homology to endogenous target motifs. Extensive engineering is therefore required to broaden applicability and robustness. Here, we describe the directed evolution of novel lambda integrase variants capable of editing exogenous target sequences identified in the diatom Phaeodactylum tricornutum and the algae Nannochloropsis oceanica. These microorganisms hold great promise as conduits for green biomanufacturing and carbon sequestration. The evolved enzyme variants show >1000-fold switch in specificity towards the non-natural target sites when assayed in vitro. A single-copy target motif in the human genome with homology to the Nannochloropsis oceanica site can also be efficiently targeted using an engineered integrase, both in vitro and in human cells. The developed integrase variants represent useful additions to the DNA editing toolbox, with particular application for targeted genomic insertion of large DNA cargos.

The FGFR inhibitor PD173074 binds to the C-terminus of oncofetal HMGA2 and modulates its DNA-binding and transcriptional activation functions

The architectural chromatin factor high-mobility group AT-hook 2 (HMGA2) is causally involved in several human malignancies and pathologies. HMGA2 is not expressed in most normal adult somatic cells, which renders the protein an attractive drug target. An established cell-based compound library screen identified the fibroblast growth factor receptor (FGFR) inhibitor PD173074 as an antagonist of HMGA2-mediated transcriptional reporter gene activation. We determined that PD173074 binds the C-terminus of HMGA2 and interferes with functional coordination of the three AT-hook DNA-binding domains mediated by the C-terminus. The HMGA2-antagonistic effect of PD173074 on transcriptional activation may therefore result from an induced altered DNA-binding mode of HMGA2. PD173074 as a novel HMGA2-specific antagonist could trigger the development of derivates with enhanced attributes and clinical potential.

A versatile genomic transgenesis platform with enhanced λ integrase for human Expi293F cells

Reliable cell-based platforms to test and/or produce biologics in a sustainable manner are important for the biotech industry. Utilizing enhanced λ integrase, a sequence-specific DNA recombinase, we developed a novel transgenesis platform involving a fully characterized single genomic locus as an artificial landing pad for transgene insertion in human Expi293F cells. Importantly, transgene instability and variation in expression were not observed in the absence of selection pressure, thus enabling reliable long-term biotherapeutics testing or production. The artificial landing pad for λ integrase can be targeted with multi-transgene constructs and offers future modularity involving additional genome manipulation tools to generate sequential or nearly seamless insertions. We demonstrated broad utility with expression constructs for anti PD-1 monoclonal antibodies and showed that the orientation of heavy and light chain transcription units profoundly affected antibody expression levels. In addition, we demonstrated encapsulation of our PD-1 platform cells into bio-compatible mini-bioreactors and the continued secretion of antibodies, thus providing a basis for future cell-based applications for more effective and affordable therapies.

Versatile seamless DNA vector production in E. coli using enhanced phage lambda integrase

Seamless DNA vectors derived from bacterial plasmids are devoid of bacterial genetic elements and represent attractive alternatives for biomedical applications including DNA vaccines. Larger scale production of seamless vectors employs engineered Escherichia coli strains in order to enable tightly regulated expression of site-specific DNA recombinases which precisely delete unwanted sequences from bacterial plasmids. As a novel component of a developing lambda integrase genome editing platform, we describe here strain MG1655-ISC as a means to easily produce different scales of seamless vectors, ranging in size from a few hundred base pairs to more than ten kilo base pairs. Since we employed an engineered lambda integrase that is able to efficiently recombine pairs of DNA crossover sites that differ in sequence, the resulting seamless vectors will be useful for subsequent genome editing in higher eukaryotes to accommodate variations in target site sequences. Future inclusion of single cognate sites for other genome targeting systems could enable modularity. These features, together with the demonstrated simplicity of in vivo seamless vector production, add to their utility in the biomedical space.

The RNA interactome of human telomerase RNA reveals a coding-independent role for a histone mRNA in telomere homeostasis

Telomerase RNA (TR) provides the template for DNA repeat synthesis at telomeres and is essential for genome stability in continuously dividing cells. We mapped the RNA interactome of human TR (hTR) and identified a set of non-coding and coding hTR-interacting RNAs, including the histone 1C mRNA (HIST1H1C). Disruption of the hTR-HIST1H1C RNA association resulted in markedly increased telomere elongation without affecting telomerase enzymatic activity. Conversely, over-expression of HIST1H1C led to telomere attrition. By using a combination of mutations to disentangle the effects of histone 1 RNA synthesis, protein expression, and hTR interaction, we show that HIST1H1C RNA negatively regulates telomere length independently of its protein coding potential. Taken together, our data provide important insights into a surprisingly complex hTR-RNA interaction network and define an unexpected non-coding RNA role for HIST1H1C in regulating telomere length homeostasis, thus offering a glimpse into the mostly uncharted, vast space of non-canonical messenger RNA functions.

In vitro susceptibility to 19 agents other than β-lactams among third-generation cephalosporin-resistant Enterobacteriaceae recovered on hospital admission

Objectives

As part of the multicentre Antibiotic Therapy Optimisation Study, MIC values of 19 non-β-lactam agents were determined for third-generation cephalosporin-resistant Escherichia coli , Klebsiella species and Enterobacter species (3GCREB) isolates collected in German hospitals.

Methods

A total of 328 E. coli , 35 Klebsiella spp. (1 Klebsiella oxytoca and 34 Klebsiella pneumoniae ) and 16 Enterobacter spp. (1 Enterobacter aerogenes and 15 Enterobacter cloacae ) isolates were submitted to broth microdilution antimicrobial susceptibility testing with the MICRONAUT system. MICs of fluoroquinolones (levofloxacin and moxifloxacin), aminoglycosides (gentamicin, tobramycin, amikacin, streptomycin, neomycin and paromomycin), tetracyclines (tetracycline, minocycline and tigecycline), macrolides (erythromycin, clarithromycin and azithromycin) and miscellaneous agents [trimethoprim/sulfamethoxazole, chloramphenicol, nitrofurantoin, colistin and fosfomycin intravenous (iv)] were determined and reviewed against 2016 EUCAST breakpoints.

Results

The MIC of levofloxacin was >2 mg/L for 128 of 328 E. coli and 8 of 35 Klebsiella spp., but only 1 of 16 Enterobacter spp. Rates of resistance to trimethoprim/sulfamethoxazole were high (>70%), except for Enterobacter spp. Rates of resistance to colistin and fosfomycin iv were still low. About 20% of the tested isolates were resistant to chloramphenicol. Only 1 (of 328) E. coli isolate had an MIC of amikacin >16 mg/L and only 33 of 328 E. coli and 1 of 35 Klebsiella spp. had an MIC of tobramycin >4 mg/L, whereas average gentamicin MICs were in general more elevated. A tigecycline MIC >2 mg/L was only found for 1 of 16 Enterobacter spp., but in none of the E. coli or Klebsiella spp. isolates.

Conclusions

Our study gives insight into previously unreported non-β-lactam MIC distributions of 3GCREB isolates.

Home-based vs inpatient education for children newly diagnosed with type 1 diabetes

BACKGROUND

Initial management of children diagnosed with type 1 diabetes (T1D) varies worldwide with sparse high quality evidence regarding the impact of different models of care.

AIM

To compare the inpatient model of care with a hybrid home-based alternative, examining metabolic and psychosocial outcomes, diabetes knowledge, length of stay, and patient satisfaction.

SUBJECTS AND METHODS

The study design was a randomized-controlled trial. Inclusion criteria were: newly diagnosed T1D, aged 3 to 16 years, living within approximately 1 hour of the hospital, English-speaking, access to transport, absence of significant medical or psychosocial comorbidity. Patients were randomized to standard care with a 5 to 6 day initial inpatient stay or discharge after 2 days for home-based management. All patients received practical skills training in the first 48 hours. The intervention group was visited twice/day by a nurse for 2 days to assist with injections, then a multi-disciplinary team made 3 home visits over 2 weeks to complete education. Patients were followed up for 12 months. Clinical outcomes included HbA1c, hypoglycemia, and diabetes-related readmissions. Surveys measured patient satisfaction, diabetes knowledge, family impact, and quality of life.

RESULTS

Fifty patients were recruited, 25 to each group. There were no differences in medical or psychosocial outcomes or diabetes knowledge. Average length of admission was 1.9 days shorter for the intervention group. Families indicated that with hindsight, most would choose home- over hospital-based management.

CONCLUSIONS

With adequate support, children newly diagnosed with T1D can be safely managed at home following practical skills training.

Abstract S1-08: Prognostic associations of tumor-infiltrating lymphocytes (TIL) in metastatic HER2-positive breast cancer (BC) treated with trastuzumab and pertuzumab: A secondary analysis of the CLEOPATRA study

Background

The presence of stromal TILs (sTILs) is associated with a better prognosis with anti-HER2 therapy in primary HER2-positive BC. The prognostic value of TILs in the advanced setting with pertuzumab-based therapy is unknown.

Methods

The CLEOPATRA trial randomly assigned 808 patients with metastatic HER2-positive BC to receive pertuzumab or placebo in combination with trastuzumab and docetaxel. We evaluated %TILs using our previously described method. For concordance evaluation, 40 slides from metastatic samples were independently analysed by two pathologists. TILs were examined for associations with clinicopathological factors, progression-free survival (PFS), overall survival (OS), and treatment interactions using Cox regression models fitting sTILs as a continuous variable (per 10%) adjusting for treatment arm, age, estrogen receptor (ER) status, PIK3CA genotype, and visceral vs. non-visceral disease at screening.

Results

Tumour samples from 678 (84%) participants were available. 519 (76.5%) were archival and 155 (22.9%) were obtained fresh, ≤45 days prior to study treatment start. Median follow-up for OS was 50 months, with 519 PFS events and 358 deaths. 54% of patients were treatment naïve i.e. had not received prior chemotherapy nor trastuzumab. The median sTIL level was 10% (1-95%). sTIL evaluation was highly concordant between pathologists (R=0.93). Fresh vs. archival samples had significantly lower sTILs (10% vs 15%, p=0.0004). sTIL levels significantly differed by ethnicity (15% Asians, 10% white, 5% African-Americans, p=0.0007), but not age (p=0.26). Higher sTILs were observed in ER-negative vs. ER-positive tumors (15% vs 10%, p<0.001).

In the whole cohort for PFS, higher sTIL levels trended towards a better outcome independent of treatment (adjusted HR:0.95, 95%CI:0.90-1.00, p=0.06). For OS, the prognostic effect of sTILs reached statistical significance, with each 10% increase in sTILs associated with an 11% reduction in the risk of death (adjusted HR:0.89, 95%CI:0.83-0.96, p=0.001). The prognostic effect was observed independent of treatment arm, ER status, PIK3CA genotype, prior treatment or presence of visceral disease at screening, and in both fresh and archival tissue samples.

There was no significant interaction (int) between pertuzumab and sTILs for PFS (Pint=0.4) nor OS (Pint=0.6). There were no significant interactions between pertuzumab and sTILs for OS in subgroups of PIK3CA mutated (Pint=0.2) or PIK3CA WT (Pin=0.2), nor treatment naive (Pint=0.3) vs prior treatment (Pint=0.5).

The 5-year estimates of OS according to median ≤10% vs >10% sTILs in the placebo arm were 26% (95%CI:19-37) vs. 39% (95%CI:32-48), while in the pertuzumab arm 42% (95%CI:33-53) vs. 56% (95%CI:47-66) respectively.

Conclusion

In advanced HER2-positive disease, sTILs are still evident, though at lower levels, but are nevertheless significantly associated with prognosis, with effects stronger for OS than PFS. This suggests that the influence of anti-tumour immunity persists in the advanced first line setting and that enhancement by immunotherapeutic approaches could potentially further improve survival.

Citation Format: Luen S, Salgado R, Stephen F, Peter S, Jennifer E-W, Emma C, Astrid K, Sandra SM, Jose B, Stefan M, Sherene L. Prognostic associations of tumor-infiltrating lymphocytes (TIL) in metastatic HER2-positive breast cancer (BC) treated with trastuzumab and pertuzumab: A secondary analysis of the CLEOPATRA study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S1-08.

Endometrial mRNA expression of selected pro-inflammatory factors and mucins in repeat breeder cows with and without subclinical endometritis

Repeat breeder cows (RBC) are defined as cyclic cows without clinical abnormalities that fail to conceive after at least three subsequent inseminations. Previous studies have elucidated cellular defence mechanisms in the bovine uterus but detailed information on inflammatory events of endometrial cells in RBC is still lacking. Thus, the objective of this study was to analyse endometrial mRNA expression of selected transcripts associated with uterine inflammatory processes. Cytobrush samples from 91 RBC and 11 synchronised heifers with no history of gynaecological abnormalities (controls, CON) were collected. The proportion of polymorphonuclear neutrophils in these samples was used for the diagnosis of subclinical endometritis (SE). Ultrasonography and progesterone blood concentrations were used to determine ovarian activity and the stage of the oestrous cycle. Total RNA was isolated from the cytobrush samples and subjected to reverse transcription-quantitative PCR for interleukins (IL) 1A, IL1B, IL6, IL8, chemokine CXL ligand (CXCL) 3, CXCL5, prostaglandin-endoperoxide synthase 2 (PTGS2), tracheal antimicrobial peptide (TAP) and mucin (MUC) 4, MUC5, MUC6, MUC12 and MUC16. CXCL3 mRNA was higher (2-fold) and PTGS2 mRNA lower (6-fold) expressed in RBC compared with CON (P < 0.05). After subdivision of RBC in animals with (RBC-SE) and without SE (RBC-noSE), these differences remained significant between RBC-noSE and CON. Higher mRNA abundances of IL1A and IL1B were found in RBC-SE compared with RBC-noSE (3- and 4-fold; P < 0.05). No differences in the mRNA expression of IL6, IL8, CXCL5 and TAP were observed between RBC-SE, RBC-noSE and CON. MUC4 and MUC12 mRNA was more highly expressed in RBC than in CON (P < 0.05). In RBC-noSE, a 5- and 14-fold higher MUC4 and MUC12 mRNA expression was noticed compared with CON (P < 0.05). A significantly lower mRNA expression of MUC5 and MUC16 (7- and 4-fold) was detected in RBC in the luteal phase compared with RBC in the follicular phase, whereas such a down-regulation was not observed for MUC4 and MUC12. In conclusion, we demonstrated different PTGS2 and CXCL3 mRNA expression between RBC and control heifers, which might be related to subfertility in RBC. Further studies are required to confirm that an unregulated MUC4 and MUC12 mRNA expression may contribute to subfertility of RBC. These findings provide a valid basis for further research on regulatory mechanisms of mRNA expression in subfertile cows.

Cell-based high-throughput compound screening reveals functional interaction between oncofetal HMGA2 and topoisomerase I

HMGA2 is an important chromatin factor that interacts with DNA via three AT-hook domains, thereby regulating chromatin architecture and transcription during embryonic and fetal development. The protein is absent from differentiated somatic cells, but aberrantly re-expressed in most aggressive human neoplasias where it is causally linked to cell transformation and metastasis. DNA-binding also enables HMGA2 to protect cancer cells from DNA-damaging agents. HMGA2 therefore is considered to be a prime drug target for many aggressive malignancies. Here, we have developed a broadly applicable cell-based reporter system which can identify HMGA2 antagonists targeting functionally important protein domains, as validated with the known AT-hook competitor netropsin. In addition, high-throughput screening can uncover functional links between HMGA2 and cellular factors important for cell transformation. This is demonstrated with the discovery that HMGA2 potentiates the clinically important topoisomerase I inhibitor irinotecan/SN-38 in trapping the enzyme in covalent DNA-complexes, thereby attenuating transcription.

Colonization with third-generation cephalosporin-resistant Enterobacteriaceae on hospital admission: prevalence and risk factors

OBJECTIVES

The objectives of this study were to prospectively assess the rectal carriage rate of third-generation cephalosporin-resistant Enterobacteriaceae (3GCREB) in non-ICU patients on hospital admission and to investigate resistance mechanisms and risk factors for carriage.

METHODS

Adult patients were screened for 3GCREB carriage at six German tertiary care hospitals in 2014 using rectal swabs or stool samples. 3GCREB isolates were characterized by phenotypic and molecular methods. Each patient answered a questionnaire about potential risk factors for colonization with MDR organisms (MDROs). Univariable and multivariable risk factor analyses were performed to identify factors associated with 3GCREB carriage.

RESULTS

Of 4376 patients, 416 (9.5%) were 3GCREB carriers. Escherichia coli was the predominant species (79.1%). ESBLs of the CTX-M-1 group (67.3%) and the CTX-M-9 group (16.8%) were the most frequent β-lactamases. Five patients (0.11%) were colonized with carbapenemase-producing Enterobacteriaceae. The following risk factors were significantly associated with 3GCREB colonization in the multivariable analysis (P < 0.05): centre; previous MDRO colonization (OR = 2.12); antibiotic use within the previous 6 months (OR = 2.09); travel outside Europe (OR = 2.24); stay in a long-term care facility (OR = 1.33); and treatment of gastroesophageal reflux disease (GERD) (OR = 1.22).

CONCLUSIONS

To our knowledge, this is the largest admission prevalence study of 3GCREB in Europe. The observed prevalence of 9.5% 3GCREB carriage was higher than previously reported and differed significantly among centres. In addition to previously identified risk factors, the treatment of GERD proved to be an independent risk factor for 3GCREB colonization.

Conservative site-specific and single-copy transgenesis in human LINE-1 elements

Genome engineering of human cells plays an important role in biotechnology and molecular medicine. In particular, insertions of functional multi-transgene cassettes into suitable endogenous sequences will lead to novel applications. Although several tools have been exploited in this context, safety issues such as cytotoxicity, insertional mutagenesis and off-target cleavage together with limitations in cargo size/expression often compromise utility. Phage λ integrase (Int) is a transgenesis tool that mediates conservative site-specific integration of 48 kb DNA into a safe harbor site of the bacterial genome. Here, we show that an Int variant precisely recombines large episomes into a sequence, term edattH4X, found in 1000 human Long INterspersed Elements-1 (LINE-1). We demonstrate single-copy transgenesis through attH4X-targeting in various cell lines including hESCs, with the flexibility of selecting clones according to transgene performance and downstream applications. This is exemplified with pluripotency reporter cassettes and constitutively expressed payloads that remain functional in LINE1-targeted hESCs and differentiated progenies. Furthermore, LINE-1 targeting does not induce DNA damage-response or chromosomal aberrations, and neither global nor localized endogenous gene expression is substantially affected. Hence, this simple transgene addition tool should become particularly useful for applications that require engineering of the human genome with multi-transgenes.

Puerperal influence of bovine uterine health status on the mRNA expression of pro-inflammatory factors

After parturition, uterine bacterial infections lead to inflammatory processes such as subclinical/clinical endometritis with high prevalence in dairy cows. Endometrial epithelial cells participate in this immune response with the production of pro-inflammatory factors. The objective of the present study was to evaluate the endometrial mRNA expression pattern of pro-inflammatory factors during a selected postpartum (pp) period. Dairy cows with three different uterine health conditions on days 24-30 pp (healthy: n = 11, subclinical endometritis: n = 10, clinical endometritis: n = 10) were sampled using the cytobrush technique. Subsequently, each cow was sampled 3 more times in weekly intervals (days 31-37 pp; days 38-44 pp; days 45-51 pp). Samples were subjected to mRNA analysis performed by RT-qPCR. Additionally, an analysis of cultivable bacteria was performed at the early/late stage of the selected puerperal period. mRNA expression of 16 candidate genes was analyzed by using two different approaches. The first approach referred to the initial grouping on days 24-30 pp to reveal long-term effects of the uterine health on the subsequent puerperal period. The second approach considered the current uterine health status at each sampling to elucidate the impact of different points in time. Long-term effects seem to appear for chemokines, prostacyclin synthase and prostaglandin D2 synthase. If related to the current uterine health, the majority of candidate genes were significantly higher expressed in endometritic cows on days 45-51 pp in contrast to earlier stages of the puerperium. Microbiological analysis revealed the significantly higher prevalence of Trueperella pyogenes findings in cows with clinical endometritis on days 24-30 pp, but no correlations were found on days 45-51 pp. In conclusion, a strong immune response to subclinical/clinical endometritis in the late puerperium may be related to the negative impact of these conditions on reproductive performance in dairy cows.

[Pulmonary infection in neutropenia]

MEDICAL HISTORY AND CLINICAL COURSE: A 42-year-old patient with hairy cell leukemia had been treated for 3 years by a hematologist in private practice. Initially the patient received 1 course of cladribine upon which the disease went into complete remission. 6 weeks ago a relapse was diagnosed and combination therapy with cladibrin and rituximab was initiated. Now the patient presented to the emergency room with shortness of breath and pain when breathing.

INVESTIGATIONS, TREATMENT AND COURSE

In the chest x-ray, patchy infiltrates and pleural effusions were found on both sides. The subsequently performed computed tomography showed bilateral compactions with an Halo suspicious for fungal infiltrates. Upon admission to the hospital, an empirical antibiotic therapy with clarithromycin and piperacillin/tazobactam was initiated, which was later escalated to meropenem and linezolid. Additionally, an antifungal therapy with voriconazole was started and later switched to liposomal amphotericin B. At his admission, a positive aspergillus antigen could be detected in the microbiological laboratory. Under antimycotic treatment the aspergillus antigen was repeatedly negative. The patient presented with pronounced cytopenias and after a switch of therapy to vemurafenib and filgrastim, the hematopoiesis could only be stimulated insufficiently. The patient was transferred to the intensive care unit three days after admission with severe respiratory failure. He died on day 8 after admission. AUTOPSY AND DIAGNOSIS: Diagnosis was consistent with relapse of hairy cell leukemia with positive BRAF mutation and a bone marrow infiltration > 80 %. Autopsy revealed a significant hepato-splenomegaly, a lack of erythro-, granulo- and thrombopoiesis. Clots interspersed with fungal hyphae were found in both lungs and an infarction of the spleen with evidence of fungal hyphae was detected. The cultural findings post mortem on yeast or mold were negative.

CONCLUSION

Patients with refractory hairy cell leukemia and prolonged neutropenia are at increased risk for systemic fungal infections. Therefore, prohylactic antimycotic therapy should be considered early in this group of patients. The therapeutic approach of vemurafenib in treatment-refractory hairy cell leukemia is promising and offers an additional treatment option. In the present case, the patient could unfortunately not be stabilized due to the septic complications.

Emergence of Citrobacter freundii carrying IMP-8 metallo-β-lactamase in Germany

Metallo-β-lactamases (MBLs) in Enterobacteriaceae are an increasing problem worldwide. This report describes the isolation of Citrobacter freundii carrying IMP-8 MBL from three patients during the period from March 2012 until March 2013 in Germany. The bla_IMP-8 enzyme is predominantly found in Asia, where IMP-8 has spread to various enterobacterial species causing serious infections. To our best knowledge, this is the first report of bla_IMP-8 habouring Enterobacteriaceae in Europe.

Isolated Bell's palsy - an unusual presentation of dengue infection

Dengue fever is a very common arthropod - borne infection in tropical countries. Neurological complications in dengue fever are relatively uncommon and among these, isolated cranial neuropathies have been reported only very rarely. We present an unusual neurological complication of Bell's palsy (lower motor neuron 7 th nerve palsy) associated with dengue infection. To the best of our knowledge, there have been very few documented cases of Flavivirus causing isolated Bell's palsy.

[Corneal opacity in a contact lens wearer on hemodialysis for renal failure]

A 53-year-old contact lens wearer on renal dialysis developed visual impairment due to corneal opacity. The opacity was of a crystalline type and diffusely scattered in the anterior cornea. As oxalosis was suspected ascorbic acid was immediately omitted from the dialysis treatment schedule. Within a few weeks the visual acuity recovered and the corneas became nearly clear. The cornea is an uncommon manifestation site for oxalosis. Nevertheless, one should be aware of this possible sign for oxalosis, which can be a life-threatening complication of treatment with high dose ascorbic acid.

Combined airway and oesophageal stenting in malignant airway-oesophageal fistulas: a prospective study

Malignant airway-oesophageal fistulas (AEF) are a serious complication of advance oesophageal or lung cancer. The aim of this study was to assess the quality of life before and after stent insertion, and to examine the role of treatment and location of AEF as factors influencing survival in AEF patients managed with airway and/or oesophageal stent insertion. 112 patients with AEF were included prospectively. 83 (74%) patients had advanced lung cancer and 29 (26%) patients had oesophageal cancers. Airway stents were inserted in 65 (58%) patients, oesophageal stents in 37 (33%) patients, and both airway and oesophageal stents in 10 (9%) patients. Seven (6%) patients developed respiratory failure and required transient ventilator support in the intensive care unit (four patients with airway stenting, two patients with double stents and one patient in the oesophageal stenting group). None of the patients developed stent migration or needed stent repositioning. Overall, mean survival was 236.6 days (airway stent 219.1 days, oesophageal stent 262.8 days and combined airway-oesophageal stent 252.9 days). Backward, stepwise regression revealed the site of stent placement (airway and/or oesophagus; p < 0.028), exact location of the fistula in airway (p = 0.011) and additional treatment with chemotherapy and/or radiation (p < 0.001) as independent risk factors predicting increased survival. The mean quality of life score (QoL) was 81 prior to stent insertion and 72 post-stent insertion (p < 0.001). Airway and/or oesophageal stent insertion provides an effective approach to improve the QoL in patients with malignant AEF.

Insights into the regulation of a common variant of HMGA2 associated with human height during embryonic development

Early genetic studies in the mouse and chicken identified the HMGA oncogene as a candidate that regulates body height. Subsequent genome-wide SNP studies revealed a significant association of rs1042725 genotypes CT and CC in the 3' UTR of HMGA2 with human height. Together, these studies indicated that HMGA2 expression levels during prenatal development might be a critical factor that contributes to the height phenotype. In the present study, we sought to gain insight into the regulation of HMGA2 during human embryonic development and provide evidence that the rs1042725 genotype is unlikely to affect HMGA2 levels in pluripotent human embryonic stem cells (hESCs). This implies that hESCs in the inner cell mass of blastocysts are most likely not involved in determining the human height phenotype associated with this SNP. By applying a computational approach and cell-based reporter assays, we then identified miR-196b as a candidate microRNA that could contribute to SNP-specific expression of HMGA2 during human prenatal development. We briefly discuss this result in the context of other known functions for miR-196b during vertebrate development.

Progress in the management of advanced renal cell carcinoma (RCC)

A more profound understanding in the pathophysiological mechanism of renal cell cancer has led to a shift in the treatment approach. Traditionally, cytokines were the frontline drugs, but recently this has transitioned to drugs interacting vascular endothelial growth factor (VEGF) related pathway. Sorafenib, sunitinib, bevacizumab, temsirolimus and everolimus have demonstrated clinical improvements in randomized trials. The purpose of this review is to summarise the current management of advanced RCC.