Cancer-associated circulating large extracellular vesicles in cholangiocarcinoma and hepatocellular carcinoma

BACKGROUND & AIMS

Large extracellular vesicles, specifically AnnexinV⁺ EpCAM⁺ CD147⁺ tumour-associated microparticles (taMPs), facilitate the detection of colorectal carcinoma (CRC), non-small cell lung carcinoma (NSCLC) as well as pancreas carcinoma (PaCa). Here we assess the diagnostic value of taMPs for detection and monitoring of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). Specifically, the aim of this study was to differentiate liver taMPs from other cancer taMPs, such as CRC and NSCLC.

METHODS

Fluorescence-activated cell scanning (FACS) was applied to detect various taMP populations in patients' sera that were associated with the presence of a tumour (AnnexinV⁺ EpCAM⁺ CD147⁺ taMPs) or could discriminate between cirrhosis (due to HCV or HBV) and liver cancers (AnnexinV⁺ EpCAM⁺ ASGPR1⁺ taMPs). In total 172 patients with liver cancer (HCC or CCA), 54 with cirrhosis and no liver neoplasia, and 202 control subjects were enrolled.

RESULTS

The results indicate that AnnexinV⁺ EpCAM⁺ CD147⁺ taMPs were elevated in HCC and CCA. Furthermore, AnnexinV⁺ EpCAM⁺ ASGPR1⁺ CD133⁺ taMPs allowed the distinction of liver malignancies (HCC or CCA) and cirrhosis from tumour-free individuals and, more importantly, from patients carrying other non-liver cancers. In addition, AnnexinV⁺ EpCAM⁺ ASGPR1⁺ taMPs were increased in liver cancer-bearing patients compared to patients with cirrhosis that lacked any detectable liver malignancy. The smallest sizes of successfully detected cancers were ranging between 11-15mm. AnnexinV⁺ EpCAM⁺ ASGPR1⁺ taMPs decreased at 7days after curative R0 tumour resection suggesting close correlations with tumour presence. ROC values, sensitivity/specificity scores and positive/negative predictive values (>78%) indicated a potent diagnostic accuracy of AnnexinV⁺ EpCAM⁺ ASGPR1⁺ taMPs.

CONCLUSION

These data provide strong evidence that AnnexinV⁺ EpCAM⁺ ASGPR1⁺ taMPs are a novel biomarker of HCC and CCA liquid biopsy that permit a non-invasive assessment of the presence and possible extent of these cancers in patients with advanced liver diseases.

LAY SUMMARY

Microparticles (MPs) are small vesicles that bleb from the membrane of every cell, including cancer cells, and are released to circulate in the bloodstream. Since their surface composition is similar to the surface of their underlying parental cell, MPs from the bloodstream can be isolated and by screening their surface components, the presence of their parental cells can be identified. This way, it was possible to detect and discriminate between patients bearing liver cancer and chronic liver cirrhosis.

Intensive care and health outcomes of open abdominal treatment: long-term results of vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM)

PURPOSE

The study's purpose is to evaluate the long-term outcome after vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM) and to identify predictors of quality of life associated with intensive care.

METHODS

Fifty-five patients who underwent open abdomen management at our institution from 2006 to 2013 were prospectively enrolled in this study. After a median follow-up period of 3.8 years, 27 patients completed the 36-Item Short Form Survey (SF-36) quality of life questionnaire. As this is a report solely focused on quality of life, direct treatment-related outcome measures like mortality, closure rates, and incisional hernia development of this study cohort have been reported previously.

RESULTS

 = 0.50, β = -0.70, p = 0.02).

CONCLUSIONS

Despite high short-term mortality and morbidity rates for these critically ill patients, open abdomen treatment using VAWCM allows patients to recover to an acceptable long-term quality of life. The complex intensive care score can be used as a surrogate parameter for the global severity of illness and was the only predictor of physical functioning (SF-36).

The Open Abdomen Route by EuraHS: introduction of the data set and initial results of procedures and procedure-related complications

INTRODUCTION

Open abdomen management has become a well-established strategy in the treatment of serious intra-abdominal pathologies. Key objectives are fistula prevention and high fascial closure rates. The current level of evidence on laparostoma is insufficient. This is due to the rareness of laparostomas, the heterogeneity of study cohorts, and broad diversity of techniques. Collecting data in a standardised, multicentre registry is necessary to draw up evidence-based guidelines.

MATERIALS AND METHODS

In order to improve the level of evidence on laparostomy, CAMIN (surgical working group for military and emergency surgery) of DGAV (German Society for General and Visceral Surgery), initiated the implementation of a laparostomy registry. This registry was established as the Open Abdomen Route by EuraHS (European Registry of Abdominal Wall Hernias). Key objectives include collection of data, quality assurance, standardisation of therapeutic concepts and the development of guidelines. Since 1 May 2015, the registry is available as an online database called Open Abdomen Route of EuraHS (European Registry of Abdominal Wall Hernias). It includes 11 categories for data collection, including three scheduled follow-up examinations.

RESULTS

As part of this pilot study, all entries of the first 120 days were analysed, resulting in a review of 82 patients. At 44%, secondary peritonitis was the predominant indication. The mortality rate was 22%. A comparison of methods with and without fascial traction reveals fascial closure rates of 67% and 25%, respectively (intention-to-treat analysis, p < 0.03). Inert visceral protection was used in 67% of patients and achieved a small bowel fistula incidence of only 5.5%.

DISCUSSION

Optimising laparostomy management techniques in order to achieve low incidence of fistulation and high fascial closure rates is possible. The method that ensures the best possible outcome-based on current evidence-would involve fascial traction, visceral protection and negative pressure. The laparostomy registry is a useful tool for quickly generating sufficient evidence for open abdomen treatment.

Abdominal wall integrity after open abdomen: long-term results of vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM)

PURPOSE

The open abdomen has become a standard technique in the management of critically ill patients undergoing surgery for severe intra-abdominal conditions. Negative pressure and mesh-mediated fascial traction are commonly used and achieve low fistula rates and high fascial closure rates. In this study, long-term results of a standardised treatment approach are presented.

METHODS

Fifty-five patients who underwent OA management for different indications at our institution from 2006 to 2013 were enrolled. All patients were treated under a standardised algorithm that uses a combination of vacuum-assisted wound closure and mesh-mediated fascial traction. Structured follow-up assessments were offered to patients and included a medical history, a clinical examination and abdominal ultrasonography. The data obtained were statistically analysed.

RESULTS

The fascial closure rate was 74 % in an intention-to-treat analysis and 89 % in a per-protocol analysis. The fistula rate was 1.8 %. Thirty-four patients attended follow-up. The median follow-up was 46 months (range 12-88 months). Incisional hernias developed in 35 %. Patients with hernias needed more operative procedures (10.3 vs 3.4, p = 0.03) than patients without hernia formation. A Patient Observer Scar Assessment Scale (POSAS) of 31.1 was calculated. Patients with symptomatic hernias (NAS of 2-10) had a significantly lower mean POSAS score (p = 0.04).

CONCLUSIONS

Vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM) seem to result in low complication rates and high fascial closure rates. Abdominal wall reconstruction, which is a challenging and complex procedure and causes considerable patient discomfort, can thus be avoided in the majority of cases. Available results are based on studies involving only a small number of cases. Multi-centre studies and registry-based data are therefore needed to validate these findings.

Human Engineered Heart Tissue: Analysis of Contractile Force

Analyzing contractile force, the most important and best understood function of cardiomyocytes in vivo is not established in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). This study describes the generation of 3D, strip-format, force-generating engineered heart tissues (EHT) from hiPSC-CM and their physiological and pharmacological properties. CM were differentiated from hiPSC by a growth factor-based three-stage protocol. EHTs were generated and analyzed histologically and functionally. HiPSC-CM in EHTs showed well-developed sarcomeric organization and alignment, and frequent mitochondria. Systematic contractility analysis (26 concentration-response curves) reveals that EHTs replicated canonical response to physiological and pharmacological regulators of inotropy, membrane- and calcium-clock mediators of pacemaking, modulators of ion-channel currents, and proarrhythmic compounds with unprecedented precision. The analysis demonstrates a high degree of similarity between hiPSC-CM in EHT format and native human heart tissue, indicating that human EHTs are useful for preclinical drug testing and disease modeling.

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Engineered heart tissues (EHTs) from hiPSC-CM are generated with high reproducibility

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EHTs show aligned cardiomyocytes with organized sarcomeres and immature t tubules

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Spontaneous beating is regulated by both, membrane- and calcium-clock mechanisms

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EHTs respond to physiological and pharmacological interventions like human heart tissue

Analysis of Tyrosine Kinase Inhibitor-Mediated Decline in Contractile Force in Rat Engineered Heart Tissue

Introduction

Left ventricular dysfunction is a frequent and potentially severe side effect of many tyrosine kinase inhibitors (TKI). The mode of toxicity is not identified, but may include impairment of mitochondrial or sarcomeric function, autophagy or angiogenesis, either as an on-target or off-target mechanism.

Methods and Results

We studied concentration-response curves and time courses for nine TKIs in three-dimensional, force generating engineered heart tissue (EHT) from neonatal rat heart cells. We detected a concentration- and time-dependent decline in contractile force for gefitinib, lapatinib, sunitinib, imatinib, sorafenib, vandetanib and lestaurtinib and no decline in contractile force for erlotinib and dasatinib after 96 hours of incubation. The decline in contractile force was associated with an impairment of autophagy (LC3 Western blot) and appearance of autophagolysosomes (transmission electron microscopy).

Conclusion

This study demonstrates the feasibility to study TKI-mediated force effects in EHTs and identifies an association between a decline in contractility and inhibition of autophagic flux.

Cetuximab-induced skin rash: A molecular map relating polymorphisms, cell-adhesion, and autoimmunity

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Background: Colorectal cancer (CRC) treatment with the EGFR-inhibitory antibody Cetuximab (CTX) is known to cause skin rashes (SR) of varying degree in most patients. Severity of SR is positively associated with tumor response. The underlying molecular mechanism linking both effects is still unknown. Detangling its genetic background would allow a simultaneous understanding of SR and response. Stratification of patients based on the related polymorphisms (PMs) is of clinical relevance. Methods: A systematic literature review was performed to develop a molecular map which incorporates specific pathways related to cancer, CTX specific mechanisms of action, skin rash, and autoimmunity. Exome data was generated from blood samples of 23 KRAS wild type patients taken prior to CTX treatment. Under CTX, eleven of the 23 patients showed SR of grades 3-4, twelve reacted with a grade 1 SR. Differential somatic PMs were analyzed between both groups. A gene set enrichment analysis for the imbalanced PMs was performed against gene sets of our molecular map. Imbalance was stated if at least seven patients more in the one group compared to the other carried this specific PM. Results: A total of 591 genes containing imbalanced PMs were found. Bioinformatic validation focused on the following findings of potential clinical interest: (1) PMs in genes specifically related to cell adhesion (CDH1, LAMC1, FBN2, NCAM1) or its regulation (WNT9B), (2) to autoimmunity (CXCL16, ADAM12, OS9, DOCK2), (3) in the central regulator TP53, (4) in genes playing a role in immunity and cell adhesion (DOCK2 and THBS2). PMs in the mentioned genes enabled to discriminate patients with and without severe skin rash. Validation of these findings is needed based on new independent CTX treated patients. Conclusions: Our findings suggest that genomic predisposition may exist which interact with CTX treatment by inducing alteration of cell adhesion. Altering adhesion between tumor cells makes them more accessible to the EGFR-inhibitory effect of CTX. Altering cell adhesion between epithelial cells introduces the acne like phenotypes of skin rash, presumably via the mechanism of epithelial activation. This will be the starting point for further research.

Management of the open abdomen using vacuum-assisted wound closure and mesh-mediated fascial traction

BACKGROUND

The open abdomen has become an accepted treatment option of critically ill patients with severe intra-abdominal conditions. Fascial closure is a particular challenge in patients with peritonitis. This study investigates whether fascial closure rates can be increased in peritonitis patients by using an algorithm that combines vacuum-assisted wound closure and mesh-mediated fascial traction. Moreover, fascial closure rates for patients with peritonitis, trauma or abdominal compartment system (ACS) are compared.

METHODS

Data were collected prospectively from all patients who underwent open abdomen management at our institution from 2006 to 2012. All patients were treated under a standardised algorithm that combines vacuum-assisted closure and mesh placement at the fascial level.

RESULTS

During the study period, 53 patients (mean age 53 years) underwent open abdomen management for a mean duration of 15 days. Indications for leaving the abdomen open were peritonitis (51 %), trauma (26 %), and ACS or abdominal wall dehiscence (23 %). The fascial closure rate was 79 % in an intention-to-treat analysis and 89 % in a per-protocol analysis. Mortality was 13 %. No patient developed an enteroatmospheric fistula or abdominal wall dehiscence after closure. The mean duration of treatment was significantly longer in peritonitis patients (20 days) than in patients without peritonitis (10 days) (p = 0.03). There were no significant differences in fascial closure rates between patients with peritonitis (87 %), trauma (85 %), and ACS or abdominal wall dehiscence (100 %) (p = 0.647).

CONCLUSIONS

Regardless of the underlying pathology, high fascial closure rates can be achieved using a combination of vacuum-assisted closure and mesh-mediated fascial traction.

Functional improvement and maturation of rat and human engineered heart tissue by chronic electrical stimulation

Spontaneously beating engineered heart tissue (EHT) represents an advanced in vitro model for drug testing and disease modeling, but cardiomyocytes in EHTs are less mature and generate lower forces than in the adult heart. We devised a novel pacing system integrated in a setup for videooptical recording of EHT contractile function over time and investigated whether sustained electrical field stimulation improved EHT properties. EHTs were generated from neonatal rat heart cells (rEHT, n=96) or human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hEHT, n=19). Pacing with biphasic pulses was initiated on day 4 of culture. REHT continuously paced for 16-18 days at 0.5Hz developed 2.2× higher forces than nonstimulated rEHT. This was reflected by higher cardiomyocyte density in the center of EHTs, increased connexin-43 abundance as investigated by two-photon microscopy and remarkably improved sarcomere ultrastructure including regular M-bands. Further signs of tissue maturation include a rightward shift (to more physiological values) of the Ca(2+)-response curve, increased force response to isoprenaline and decreased spontaneous beating activity. Human EHTs stimulated at 2Hz in the first week and 1.5Hz thereafter developed 1.5× higher forces than nonstimulated hEHT on day 14, an ameliorated muscular network of longitudinally oriented cardiomyocytes and a higher cytoplasm-to-nucleus ratio. Taken together, continuous pacing improved structural and functional properties of rEHTs and hEHTs to an unprecedented level. Electrical stimulation appears to be an important step toward the generation of fully mature EHT.

Automated analysis of contractile force and Ca2+ transients in engineered heart tissue

Contraction and relaxation are fundamental aspects of cardiomyocyte functional biology. They reflect the response of the contractile machinery to the systolic increase and diastolic decrease of the cytoplasmic Ca(2+) concentration. The analysis of contractile function and Ca(2+) transients is therefore important to discriminate between myofilament responsiveness and changes in Ca(2+) homeostasis. This article describes an automated technology to perform sequential analysis of contractile force and Ca(2+) transients in up to 11 strip-format, fibrin-based rat, mouse, and human fura-2-loaded engineered heart tissues (EHTs) under perfusion and electrical stimulation. Measurements in EHTs under increasing concentrations of extracellular Ca(2+) and responses to isoprenaline and carbachol demonstrate that EHTs recapitulate basic principles of heart tissue functional biology. Ca(2+) concentration-response curves in rat, mouse, and human EHTs indicated different maximal twitch forces (0.22, 0.05, and 0.08 mN in rat, mouse, and human, respectively; P < 0.001) and different sensitivity to external Ca(2+) (EC50: 0.15, 0.39, and 1.05 mM Ca(2+) in rat, mouse, and human, respectively; P < 0.001) in the three groups. In contrast, no difference in myofilament Ca(2+) sensitivity was detected between skinned rat and human EHTs, suggesting that the difference in sensitivity to external Ca(2+) concentration is due to changes in Ca(2+) handling proteins. Finally, this study confirms that fura-2 has Ca(2+) buffering effects and is thereby changing the force response to extracellular Ca(2+).

Generation of strip-format fibrin-based engineered heart tissue (EHT)

This protocol describes a method for casting fibrin-based engineered heart tissue (EHT) in standard 24-well culture dishes. In principle, a hydrogel tissue engineering method requires cardiomyocytes, a liquid matrix that forms a gel, a casting mold, and a device that keeps the developing tissue in place. This protocol refers to neonatal rat heart cells as the cell source; the matrix of choice is fibrin, and the tissues are generated in rectangular agarose-casting molds (12 × 3 × 3 mm) prepared in standard 24-well cell culture dishes, in which a pair of flexible silicone posts is suspended from above. A master mix of freshly isolated cells, medium, fibrinogen, and thrombin is pipetted into the casting mold and, over a period of 2 h, polymerizes and forms a fibrin cell block around two silicone posts. Silicone racks holding four pairs of silicone posts each are used to transfer the fresh fibrin cell blocks into new 24-well dishes with culture medium. Without further handling, the cells start to remodel the fibrin gel, form contacts with each other, elongate, and condense the gel to approximately ¼ of the initial volume. Spontaneous and rhythmic contractions start after 1 week. EHTs are viable and relatively stable for several weeks in this format and can be subjected to repeated measurements of contractile function and final morphological and molecular analyses.

Increased afterload induces pathological cardiac hypertrophy: a new in vitro model

Increased afterload results in 'pathological' cardiac hypertrophy, the most important risk factor for the development of heart failure. Current in vitro models fall short in deciphering the mechanisms of hypertrophy induced by afterload enhancement. The aim of this study was to develop an experimental model that allows investigating the impact of afterload enhancement (AE) on work-performing heart muscles in vitro. Fibrin-based engineered heart tissue (EHT) was cast between two hollow elastic silicone posts in a 24-well cell culture format. After 2 weeks, the posts were reinforced with metal braces, which markedly increased afterload of the spontaneously beating EHTs. Serum-free, triiodothyronine-, and hydrocortisone-supplemented medium conditions were established to prevent undefined serum effects. Control EHTs were handled identically without reinforcement. Endothelin-1 (ET-1)- or phenylephrine (PE)-stimulated EHTs served as positive control for hypertrophy. Cardiomyocytes in EHTs enlarged by 28.4 % under AE and to a similar extent by ET-1- or PE-stimulation (40.6 or 23.6 %), as determined by dystrophin staining. Cardiomyocyte hypertrophy was accompanied by activation of the fetal gene program, increased glucose consumption, and increased mRNA levels and extracellular deposition of collagen-1. Importantly, afterload-enhanced EHTs exhibited reduced contractile force and impaired diastolic relaxation directly after release of the metal braces. These deleterious effects of afterload enhancement were preventable by endothelin-A, but not endothelin-B receptor blockade. Sustained afterload enhancement of EHTs alone is sufficient to induce pathological cardiac remodeling with reduced contractile function and increased glucose consumption. The model will be useful to investigate novel therapeutic approaches in a simple and fast manner.