AQP1 in the Gastrointestinal Tract of Mice: Expression Pattern and Impact of AQP1 Knockout on Colonic Function

Aquaporin 1 (AQP1) is one of thirteen known mammalian aquaporins. Its main function is the transport of water across cell membranes. Lately, a role of AQP has been attributed to other physiological and pathological functions including cell migration and peripheral pain perception. AQP1 has been found in several parts of the enteric nervous system, e.g., in the rat ileum and in the ovine duodenum. Its function in the intestine appears to be multifaceted and is still not completely understood. The aim of the study was to analyze the distribution and localization of AQP1 in the entire intestinal tract of mice. AQP1 expression was correlated with the hypoxic expression profile of the various intestinal segments, intestinal wall thickness and edema, as well as other aspects of colon function including the ability of mice to concentrate stools and their microbiome composition. AQP1 was found in a specific pattern in the serosa, the mucosa, and the enteric nervous system throughout the gastrointestinal tract. The highest amount of AQP1 in the gastrointestinal tract was found in the small intestine. AQP1 expression correlated with the expression profiles of hypoxia-dependent proteins such as HIF-1α and PGK1. Loss of AQP1 through knockout of AQP1 in these mice led to a reduced amount of bacteroidetes and firmicutes but an increased amount of the rest of the phyla, especially deferribacteres, proteobacteria, and verrucomicrobia. Although AQP-KO mice retained gastrointestinal function, distinct changes regarding the anatomy of the intestinal wall including intestinal wall thickness and edema were observed. Loss of AQP1 might interfere with the ability of the mice to concentrate their stool and it is associated with a significantly different composition of the of the bacterial stool microbiome.

Dysfunctional Voiding and Incontinence Scoring System for Children and Adolescents: A Tool to Predict Clinical Course and Outcome

INTRODUCTION

 Lower urinary tract symptoms (LUTS) in children are common. In 2005, Akbal et al published the dysfunctional voiding and incontinence scoring system (DVAISS) to assess patient's symptoms. Our study aimed to determine the value of this scoring system for predicting the severity and clinical course of voiding abnormalities in children and adolescents.

MATERIAL AND METHODS

 Patients' symptoms were scored using the DVAISS in children and adolescents with LUTS presenting for the first time to our pediatric urology department between January 2010 and December 2015. We correlated the calculated score with voiding volume, clinical course, and outcome.

RESULTS

 A total of 168 patients (113 boys, 55 girls; age 5-18 years) with isolated LUTS were included. In 53 patients (group 1), the DVAISS score was less than or equal to 8.5 and in the other 115 patients (group 2), the score was greater than 8.5 suggestive for relevant voiding abnormalities. Patients in group 1 showed a significantly higher average voiding volume (200 vs. 110 mL, p = 0.001). The median time for symptom resolution was significantly higher in group 2 than group 1 (14 vs. 8 months; p = 0.018). The severity of LUTS could be determined by these parameters.

CONCLUSION

 Based on the DVAISS, a prediction of the clinical course and approximate treatment duration is possible. Therefore, the DVAISS is useful to assess LUTS in children and is also a valuable tool in rating the severity of the disease. It is also a quite precise predictor of the time needed to resolve the symptoms.

Perfusion-Based Bioreactor Culture and Isothermal Microcalorimetry for Preclinical Drug Testing with the Carbonic Anhydrase Inhibitor SLC-0111 in Patient-Derived Neuroblastoma

Neuroblastoma is a rare disease. Rare are also the possibilities to test new therapeutic options for neuroblastoma in clinical trials. Despite the constant need to improve therapy and outcomes for patients with advanced neuroblastoma, clinical trials currently only allow for testing few substances in even fewer patients. This increases the need to improve and advance preclinical models for neuroblastoma to preselect favorable candidates for novel therapeutics. Here we propose the use of a new patient-derived 3D slice-culture perfusion-based 3D model in combination with rapid treatment evaluation using isothermal microcalorimetry exemplified with treatment with the novel carbonic anhydrase IX and XII (CAIX/CAXII) inhibitor SLC-0111. Patient samples showed a CAIX expression of 18% and a CAXII expression of 30%. Corresponding with their respective CAIX expression patterns, the viability of SH-EP cells was significantly reduced upon treatment with SLC-0111, while LAN1 cells were not affected. The inhibitory effect on SH-SY5Y cells was dependent on the induction of CAIX expression under hypoxia. These findings corresponded to thermogenesis of the cells. Patient-derived organotypic slice cultures were treated with SLC-0111, which was highly effective despite heterogeneity of CAIX/CAXII expression. Thermogenesis, in congruence with the findings of the histological observations, was significantly reduced in SLC-0111-treated samples. In order to extend the evaluation time, we established a perfusion-based approach for neuroblastoma tissue in a 3D perfusion-based bioreactor system. Using this system, excellent tissue quality with intact tumor cells and stromal structure in neuroblastoma tumors can be maintained for 7 days. The system was successfully used for consecutive drug response monitoring with isothermal microcalorimetry. The described approach for drug testing, relying on an advanced 3D culture system combined with a rapid and highly sensitive metabolic assessment, can facilitate development of personalized treatment strategies for neuroblastoma.

Failed preoperative vacuum bell therapy does not affect outcomes following minimally invasive repair of pectus excavatum

PURPOSE

It is unknown if failed preoperative vacuum bell (VB) treatment in patients undergoing minimally invasive repair of pectus excavatum (MIRPE), delays repair and/or affects postoperative outcomes.

METHODS

A retrospective data analysis including all consecutive patients treated at one single institution undergoing MIRPE was performed between 2000 and 2016. Patients were stratified into preoperative VB therapy versus no previous VB therapy.

RESULTS

In total, 127 patients were included. Twenty-seven (21.3%) patients had preoperative VB treatment for 17 months (median, IQR 8-34). All 27 patients stopped VB treatment due to the lack of treatment effect. Eight (47.1%) of 17 assessed VB patients showed signs of skin irritation or hematoma. VB treatment had no effect on length of hospital stay (p = 0.385), postoperative complications (p = 1.0), bar dislocations (p = 1.0), and duration of bar treatment (p = 0.174). Time spent in intensive care unit was shorter in patients with VB therapy (p = 0.007). Long-term perception of treatment including rating of primary operation (p = 0.113), pain during primary operation (p = 0.838), own perspective of look of chest (p = 0.545), satisfaction with the procedure (p = 0.409), and intention of doing surgery again (p = 1.0) were not different between groups.

CONCLUSIONS

Failed preoperative VB therapy had no or minimal effect on short-term outcomes and long-term perceptions following MIRPE.

Increased Proliferation of Neuroblastoma Cells under Fructose Metabolism Can Be Measured by Isothermal Microcalorimetry

Neuroblastoma, like other cancer types, has an increased need for energy. This results in an increased thermogenic profile of the cells. How tumor cells optimize their energy efficiency has been discussed since Warburg described the fact that tumor cells prefer an anaerobic to an aerobic metabolism in the 1920s. An important question is how far the energy efficiency is influenced by the substrate. The aim of this study was to investigate how the metabolic activity of neuroblastoma cells is stimulated by addition of glucose or fructose to the medium and if this can be measured accurately by using isothermal microcalorimetry. Proliferation of Kelly and SH-EP Tet-21/N cells was determined in normal medium, in fructose-enriched, in glucose-enriched and in a fructose/glucose-enriched environment. Heat development of cells was measured by isothermal microcalorimetry. The addition of fructose, glucose or both to the medium led to increases in the metabolic activity of the cells, resulting in increased proliferation under the influence of fructose. These changes were reflected in an enhanced thermogenic profile, mirroring the results of the proliferation assay. The tested neuroblastoma cells prefer fructose metabolism over glucose metabolism, a quality that provides them with a survival benefit under unfavorable low oxygen and low nutrient supply when fructose is available. This can be quantified by measuring thermogenesis.

MIS-C-Implications for the Pediatric Surgeon: An Algorithm for Differential Diagnostic Considerations

BACKGROUND

multisystem inflammatory syndrome in children (MIS-C) is a new disease associated with a recent infection with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). Affected children can present predominantly with abdominal symptoms, fever and high inflammatory parameters that might lead to a consult by the pediatric surgeon and an indication for surgery.

METHODS

clinical data of three patients with MIS-C that underwent surgery were collected. Histopathological analysis of the appendix was performed.

RESULTS

we present the clinical course of three children with fever, abdominal pain and vomiting for several days. Clinical examination and highly elevated inflammation markers led to indication for laparoscopy; appendectomy was performed in two patients. Because of intraoperative findings or due to lack of postoperative improvement, all patients were reevaluated and tested positive for MIS-C associated laboratory parameters and were subsequently treated with corticosteroids, intravenous immunoglobulins, acetyl salicylic acid and/or light molecular weight heparin.

CONCLUSIONS

we discuss the implications of MIS-C as a new differential diagnosis and stress the importance of assessing the previous medical history, identifying patterns of symptoms and critically surveilling the clinical course. We implemented an algorithm for pediatric surgeons to consider MIS-C as a differential diagnosis for acute abdomen that can be integrated into the surgical workflow.

Testicular Torsion in the Absence of Severe Pain: Considerations for the Pediatric Surgeon

Testicular torsion is a surgical emergency. Early diagnosis and surgical treatment are vital in order to preserve the affected gonad. Current surgical teaching emphasizes sudden, severe, persistent, unilateral scrotal pain as a cardinal symptom of testicular torsion. We present the case of unilateral testicular torsion in a 14-year-old patient who presented with the absence of severe pain. Despite a delayed presentation to the emergency department, the gonad could be salvaged successfully. Literature on the topic of testicular torsion presenting with minimal pain is limited. Nevertheless, pediatric surgeons might be faced with cases similar to the one we describe. Underestimating this phenomenon might lead to a delay of treatment. In such cases, ultrasound can be a beneficial addition in the diagnosis and accelerate definitive operative treatment. The presented case clearly demonstrates that, although we do not include testicular torsion without severe pain in our surgical teaching algorithms, we might encounter it in our clinical practice.

Perspective on Similarities and Possible Overlaps of Congenital Disease Formation-Exemplified on a Case of Congenital Diaphragmatic Hernia and Neuroblastoma in a Neonate

The coincidence of two rare diseases such as congenital diaphragmatic hernia (CDH) and neuroblastoma is exceptional. With an incidence of around 2–3:10,000 and 1:8000 for either disease occurring on its own, the chance of simultaneous presentation of both pathologies at birth is extremely low. Unfortunately, the underlying processes leading to congenital malformation and neonatal tumors are not yet thoroughly understood. There are several hypotheses revolving around the formation of CDH and neuroblastoma. The aim of our study was to put the respective hypotheses of disease formation as well as known factors in this process into perspective regarding their similarities and possible overlaps of congenital disease formation. We present the joint occurrence of these two rare diseases based on a patient presentation and immunochemical prognostic marker evaluation. The aim of this manuscript is to elucidate possible similarities in the pathogeneses of both disease entities. Discussed are the role of toxins, cell differentiation, the influence of retinoic acid and NMYC as well as of hypoxia. The detailed discussion reveals that some of the proposed pathophysiological mechanisms of both malformations have common aspects. Especially disturbances of the retinoic acid pathway and NMYC expression can influence and disrupt cell differentiation in either disease. Due to the rarity of both diseases, interdisciplinary efforts and multi-center studies are needed to investigate the reasons for congenital malformations and their interlinkage with neonatal tumor disease.

AQP1 Is Up-Regulated by Hypoxia and Leads to Increased Cell Water Permeability, Motility, and Migration in Neuroblastoma

The water channel aquaporin 1 (AQP1) has been implicated in tumor progression and metastasis. It is hypothesized that AQP1 expression can facilitate the transmembrane water transport leading to changes in cell structure that promote migration. Its impact in neuroblastoma has not been addressed so far. The objectives of this study have been to determine whether AQP1 expression in neuroblastoma is dependent on hypoxia, to demonstrate whether AQP1 is functionally relevant for migration, and to further define AQP1-dependent properties of the migrating cells. This was determined by investigating the reaction of neuroblastoma cell lines, particularly SH-SY5Y, Kelly, SH-EP Tet-21/N and SK-N-BE(2)-M17 to hypoxia, quantitating the AQP1-related water permeability by stopped-flow spectroscopy, and studying the migration-related properties of the cells in a modified transwell assay. We find that AQP1 expression in neuroblastoma cells is up-regulated by hypoxic conditions, and that increased AQP1 expression enabled the cells to form a phenotype which is associated with migratory properties and increased cell agility. This suggests that the hypoxic tumor microenvironment is the trigger for some tumor cells to transition to a migratory phenotype. We demonstrate that migrating tumor cell express elevated AQP1 levels and a hypoxic biochemical phenotype. Our experiments strongly suggest that elevated AQP1 might be a key driver in transitioning stable tumor cells to migrating tumor cells in a hypoxic microenvironment.

AQP1-Driven Migration Is Independent of Other Known Adverse Factors but Requires a Hypoxic Undifferentiated Cell Profile in Neuroblastoma

Neuroblastoma is a biologically very heterogeneous tumor with its clinical manifestation ranging from spontaneous regression to highly aggressive metastatic disease. Several adverse factors have been linked to oncogenesis, tumor progression and metastases of neuroblastoma including NMYC amplification, the neural adhesion molecule NCAM, as well as CXCR4 as a promoter of metastases. In this study, we investigate to what extent the expression of AQP1 in neuroblastoma correlates with changing cellular factors such as the hypoxic status, differentiation, expression of known adverse factors such as NMYC and NCAM, and CXCR4-related metastatic spread. Our results show that while AQP1 expression leads to an increased migratory behavior of neuroblastoma cells under hypoxic conditions, we find that hypoxia is associated with a reduction of NMYC in the same cells. A similar effect can be observed when using the tetracycline driven mechanism of SH-EP/Tet cells. When NMYC is not expressed, the expression of AQP1 is increased together with an increased expression of HIF-1α and HIF-2α. We furthermore show that when growing cells in different cell densities, they express AQP1, HIF-1α, HIF-2α, NMYC and NCAM to different degrees. AQP1 expression correlates with a hypoxic profile of these cells with increased HIF-1α and HIF-2α expression, as well as with NMYC and NCAM expression in two out of three neuroblastoma cell lines. When investigating cell properties of the cells that actually migrate, we find that the increased APQ1 expression in the migrated cells correlates with an increased NMYC and NCAM expression again in two out of three cell lines. Expression of the tumor cell homing marker CXCR4 varies between different tumor areas and between cell lines. While some migrated tumor cells highly express CXCR4, cells of other origin do not. In the initial phase of migration, we determined a dominant role of AQP1 expression of migrating cells in the scratch assay.

Personalized Treatment Response Assessment for Rare Childhood Tumors Using Microcalorimetry-Exemplified by Use of Carbonic Anhydrase IX and Aquaporin 1 Inhibitors

We present a novel approach to a personalized therapeutic concept for solid tumors. We illustrate this on a rare childhood tumor for which only a generalized treatment concept exists using carbonic anhydrase IX and aquaporin 1 inhibitors. The use of microcalorimetry as a refined in vitro method for evaluation of drug susceptibility in organotypic slice culture has not previously been established. Rapid microcalorimetric drug response assessment can refine a general treatment concept when it is applied in cases in which tumors do not respond to conventional chemo-radiation treatment. For solid tumors, which do not respond to classical treatment, and especially for rare tumors without an established protocol rapid microcalorimetric drug response testing presents an elegant novel approach to test alternative therapeutic approaches. While improved treatment concepts have led to improved outcome over the past decades, the prognosis of high risk disease is still poor and rethinking of clinical trial design is necessary. A small patient population combined with the necessity to assess experimental therapies for rare solid tumors rather at the time of diagnosis than in relapsed or refractory patients provides great challenges. The possibility to rapidly compare established protocols with innovative therapeutics presents an elegant novel approach to refine and personalize treatment.

Intestinal IMINO transporter SIT1 is not expressed in human newborns

The expression of amino acid transporters in small intestine epithelia of human newborns has not been studied yet. It is further not known whether the maturation of imino acid (proline) transport is delayed as in the kidney proximal tubule. The possibility to obtain small intestinal tissue from patients undergoing surgery for jejunal or ileal atresia during their first days after birth was used to address these questions. As control, adult terminal ileum tissue was sampled during routine endoscopies. Gene expression of luminal imino and amino acid transporter SIT1 (SLC6A20) was approximately threefold lower in newborns versus adults. mRNA levels of all other luminal and basolateral amino acid transporters and accessory proteins tested were similar in newborn mucosa compared with adults. At the protein level, the major luminal neutral amino acid transporter B⁰AT1 (SLC6A19) and its accessory protein angiotensin-converting enzyme 2 were shown by immunofluorescence to be expressed similarly in newborns and in adults. SIT1 protein was not detectable in the small intestine of human newborns, in contrast to adults. The morphology of newborn intestinal mucosa proximal and distal to the obstruction was generally normal, but a decreased proliferation rate was visualized distally of the atresia by lower levels of the mitosis marker K_i-67. The mRNA level of the 13 tested amino acid transporters and accessory proteins was nonetheless similar, suggesting that the intestinal obstruction and interruption of amniotic fluid passage through the small intestinal lumen did not affect amino acid transporter expression. NEW & NOTEWORTHY System IMINO transporter SIT1 is not expressed in the small intestine of human newborns. This new finding resembles the situation in the proximal kidney tubule leading to iminoglycinuria. Lack of amniotic fluid passage in small intestinal atresia does not affect amino acid transporter expression distal to intestinal occlusion.

CAIX furthers tumour progression in the hypoxic tumour microenvironment of esophageal carcinoma and is a possible therapeutic target

The hypoxic tumour microenvironment of solid tumours represents an important starting point for modulating progression and metastatic spread. Carbonic anhydrase IX (CAIX) is a known HIF-1α-dependent key player in maintaining cell pH conditions under hypoxia. We show that CAIX is strongly expressed in esophageal carcinoma tissues. We hypothesize that a moderate CAIX expression facilitates metastases and thereby worsens prognosis. Selective inhibition of CAIX by specific CAIX inhibitors and a CAIX knockdown effectively inhibit proliferation and migration in vitro. In the orthotopic esophageal carcinoma model, the humanized HER2 antibody trastuzumab down-regulates CAIX, possibly through CAIX’s linkage with HER2 in the hypoxic microenvironment. Our results show CAIX to be an essential part of the tumour microenvironment and a possible master regulator of tumour progression. This makes CAIX a highly effective and feasible therapeutic target for selective cancer treatment.

Water permeability is a measure of severity in acute appendicitis

Acute appendicitis is the most common indication for pediatric abdominal emergency surgery. Determination of the severity of appendicitis on clinical grounds is challenging. Complicated appendicitis presenting with perforation, abscess or diffuse peritonitis is not uncommon. The question remains why and when acute appendicitis progresses to perforation. The aim of this study was to assess the impact of water permeability on the severity of appendicitis. We show that AQP1 expression and water permeability in appendicitis correlate with the stage of inflammation and systemic infection parameters, leading eventually to perforation of the appendix. AQP1 is also expressed within the ganglia of the enteric nervous system and ganglia count increases with inflammation. Severity of appendicitis can be correlated with water permeability measured by AQP1 protein expression and increase of ganglia count in a progressive manner. This introduces the question if regulation of water permeability can present novel curative or ameliorating therapeutic options.

Regenerative Capacity of the Enteric Nervous System after Ileoileal Anastomoses in a Rat Model

Purpose The aim of the study was to investigate the regeneration and migration of neuronal progenitor cells of the enteric nervous system during wound healing after intestinal anastomosis in the rat ileum. Methods Experiments were performed in a rat model of ileoileal anastomosis. Rats were humanely killed on day 2 or day 10 after anastomosis, and the anastomotic region was compared with ileum of healthy rats. Immunofluorescent staining was performed with protein gene product 9.5, nestin, and S100 antibodies. Ganglia of the anastomotic region in both the myenteric and submucosal plexus were counted, and their diameters were measured and compared between groups. Results Analysis of number and diameter of ganglia in both myenteric and submucosal plexus showed individual alterations as a reaction to the surgical manipulation. Significantly less ganglia were found in the submucosal plexus in the operated groups at both day 2 (p < 0.01) and day 10 (p < 0.01) than in the control group. In the myenteric plexus in the operated group, there was a difference in the number of ganglia at day 2, but ganglia count had recovered at day 10 and was not significantly different from the control group. However, the diameter of ganglia in the myenteric plexus still significantly decreasing on day 10 after surgery than in the control group (p = 0.046). Nestin and S100 double-staining showed an increased expression of nestin around the anastomotic wound. Conclusion Our findings suggest a regenerative potential of the enteric nervous system after the surgical ileoileal anastomosis. The myenteric plexus appears to recover faster than the submucosal plexus. This recovery might be driven by nestin-positive neuronal progenitor cells.

Carbonic anhydrase IX correlates with survival and is a potential therapeutic target for neuroblastoma

Carbonic anhydrase IX (CAIX) is involved in pathological processes including tumorgenicity, metastases and poor survival in solid tumors. Twenty-two neuroblastoma samples of patients who were surgically treated at the University Medical Center Hamburg-Eppendorf were evaluated immunohistochemically for expression of CAIX. Results were correlated with clinical parameters and outcome. Neuroblastoma Kelly and SH-EP-Tet-21/N cells were examined for CAIX expression and inhibited with specific inhibitors, FC5-207A and FC8-325A. 32% of neuroblastoma tumors expressed CAIX. This was significantly associated with poorer survival. Kelly and SH-EP-Tet-21/N cells showed a major increase of CAIX RNA under hypoxic conditions. Proliferation of Kelly cells was significantly decreased by CAIX inhibitors, FC5-207A and FC8-325A, while proliferation of SH-EP-Tet-21/N cells was only significantly affected by FC8-325A. CAIX is a potent biomarker that predicts survival in neuroblastoma patients. CAIX-targeted therapy in neuroblastoma cell lines is highly effective and strengthens the potential of CAIX as a clinical therapeutic target in a selected patient collective.

ErbB2 signaling activates the Hedgehog pathway via PI3K-Akt in human esophageal adenocarcinoma: identification of novel targets for concerted therapy concepts

The Hedgehog pathway plays an important role in the pathogenesis of several tumor types, including esophageal cancer. In our study, we show an expression of the ligand Indian hedgehog (Ihh) and its downstream mediator Gli-1 in primary resected adenocarcinoma tissue by immunohistochemistry and quantitative PCR in fifty percent of the cases, while matching healthy esophagus mucosa was negative for both proteins. Moreover, a functionally important regulation of Gli-1 by ErbB2-PI3K-mTORC signaling as well as a Gli-1-dependent regulation of Ihh in the ErbB2 amplified esophageal adenocarcinoma cell line OE19 was observed. Treatment of OE19 cells with the Her2 antibody trastuzumab, the PI3K-mTORC1 inhibitor NVP BEZ235 (BEZ235) or the knockdown of Akt1 resulted in a downregulation of Gli-1 and Ihh as well as in a reduction of viable OE19 cells in vitro. Interestingly, the Hedgehog receptor Smo, which acts upstream of Gli-1, was not expressed in OE19 cells and in the majority of primary human esophageal adenocarcinoma, suggesting a non-canonical upregulation of Gli-1 expression by the ErbB2-PI3K axis. To translate our findings into a therapeutic concept, we targeted ErbB2-PI3K-mTORC1 by trastuzumab and BEZ235, combining both compounds with the Gli-1/2 inhibitor GANT61. The triple combination led to significantly stronger reduction of tumor cell viability than cisplatinum or each biological alone. Therefore, concomitant blockage of the ErbB2-PI3K pathway and the Hedgehog downstream mediator Gli-1 may provide a new therapeutic strategy for esophageal cancer.

PGK1 as predictor of CXCR4 expression, bone marrow metastases and survival in neuroblastoma

Background and Aim

A close relationship between phosphoglycerate kinase 1 (PGK1) and the CXCR4/SDF1 axis (chemokine receptor 4/stromal cell derived factor 1) has been shown for several cancers. However, the role of PGK1 has not been investigated for neuroblastoma, and PGK1 might be a therapeutic target for this tumor entity. The aim of the current study was to evaluate the role of PGK1 expression in neuroblastoma patients, to determine the impact of PGK1 expression levels on survival, and to correlate PGK1 expression with CXCR4 expression and bone marrow dissemination.

Materials and Methods

Samples from 22 patients with neuroblastoma that were surgically treated at the University Medical Center Hamburg-Eppendorf were evaluated for expression of PGK1 and CXCR4 using immunohistochemistry. Results were correlated with clinical parameters, metastases and outcome of patients. Immunocytochemistry, proliferation and expression analysis of CXCR4 and PGK1 were performed in neuroblastoma cell lines.

Results

PGK1 is expressed in neuroblastoma cells. PGK1 expression is significantly positively correlated with CXCR4 expression and tumor dissemination to the bone marrow. Moreover the expression of PGK1 is significantly associated with a negative impact on survival in patients with neuroblastoma. PGK1 is downregulated by inhibition of CXCR4 in neuroblastoma cells.

Conclusion

PGK1 appears to play an important role for neuroblastoma, predicting survival and tumor dissemination. Further in vivo studies outstanding, it is a candidate target for novel therapeutic strategies.

Effective inhibition of metastases and primary tumor growth with CTCE-9908 in esophageal cancer

BACKGROUND

In spite of multimodular treatment, the therapeutic options for esophageal carcinoma are limited, and metastases remain the leading cause of tumor-related mortality. Expression of the chemokine receptor CXCR4 significantly correlates with poor survival rates in patients with esophageal carcinoma and is associated with lymph node and bone marrow metastases. The aim of this study was to evaluate the effect of the CXCR4 antagonist CTCE-9908 on metastatic homing and primary tumor growth in vitro and in vivo in an orthotopic xenograft model of esophageal cancer.

MATERIALS AND METHODS

OE19 cells were examined for stromal cell-derived factor 1 alpha-mediated migration under CTCE-9908 treatment. The CTCE-9908 treatment was further evaluated in an in vitro proliferation assay and orthotopic esophageal model, accompanied by magnetic resonance imaging. Tumor and metastases were immunohistochemically examined for CXCR4 expression.

RESULTS

CTCE-9908 has an inhibitory effect on stromal cell-derived factor 1 alpha-mediated migration and proliferation of OE19 cells. Treatment with CTCE-9908 in the orthotopic esophageal model leads to a reduction of metastatic spread and primary tumor growth. This was confirmed by magnetic resonsance imaging. Treatment with CTCE-9908 results in altered CXCR4 expression pattern exhibiting a high degree of variability.

CONCLUSION

CTCE-9908 effectively inhibits OE19 cell migration and proliferation in vitro, reduces metastases to lung, liver, and lymph nodes in vivo, and moreover leads to tumor growth reduction in an orthotopic model of esophageal carcinoma.

CXCR4/SDF-1α-mediated chemotaxis in an in vivo model of metastatic esophageal carcinoma

BACKGROUND/AIM

The chemokine receptor CXCR4 and its ligand (stromal cell-derived factor-1alpha; SDF-1α) play an important role in tumor cell chemotaxis and metastatic homing of esophageal carcinoma. Several methods are available to examine tumor cell migration in vitro. However, in vivo chemotaxis is subject to complex tumor-host interactions. The aim of this study was to establish an in vivo model of chemotaxis for esophageal carcinoma that allows the examination of tumor cell migration and metastatic homing in the complex microenvironment.

MATERIALS AND METHODS

CXCR4 expression of OE19 adenocarcinoma cells was determined by immunostaining in an orthotopic esophageal model. SDF-1α-mediated migration of cells was examined in vitro. An in vivo model of chemotaxis and metastasis was established by subcutaneous injection of OE19 cells into NMRI/nu mice and by daily stimulation with SDF-1α.

RESULTS

CXCR4 is expressed in the primary tumor and in the metastatic tissue. CXCR4-positive OE19 cells are susceptible to SDF-1α-mediated migration. The novel in vivo model leads to developement of metastases in liver, lung, peritoneum and retroperitoneum after stimulation with SDF-1α but not with PBS, and revealed an SDF-1α dose-dependent migratory effect.

CONCLUSION

As metastasis is still the leading cause of tumor-related death, it is essential to investigate the complex tumor-host interactions involved in metastatic homing. We established an in vivo model of chemotaxis and metastasis for esophageal carcinoma, which allows investigation and inhibition of CXCR4/SDF-1α-mediated cell survival and proliferation, chemotaxis and homing, adhesion, and tumor angiogenesis.

Orthotopic models of esophageal carcinoma and their use in drug discovery

The protocol detailed in this unit is for the establishment of an orthotopic model of human esophageal adenocarcinoma in NMRI/nu mice. The resultant tumor has high metastatic potential, spreading readily to liver, lungs, and lymph nodes. This model is useful for studying primary esophageal carcinoma, tumor biology, pathogenesis, tumor progression, metastatic homing, and the efficacy of therapeutic approaches for treating this condition. The practical use of this preclinical model for drug discovery is illustrated with data from a study on the chemotherapeutic effects of HER2-targeted therapy.

Abstract 1674: Significant reduction of primary growth and metastases through combined CXCR4 and HER-2 inhibition in an esophageal carcinoma orthotopic model

Metastatic disease is the main cause of morbidity and mortality in esophageal carcinoma and the leading cause of death. While in the early stages surgical resection is the best therapeutic option, in late stages the conventional therapies surgery, chemotherapy, and radiation are limited. The expression of the chemokine receptor CXCR4 is known to be involved in metastatic homing and is associated with a poor prognosis in esophageal cancer patients. Trastuzumab treatment leads to significant tumor growth reduction in a model of HER-2 positive esophageal carcinoma. In the present report, we show the effects of the humanized monoclonal antibody trastuzumab, the CXCR4 inhibitor AMD3100 and their combined use in a metastastic orthotopic nude mouse model of esophageal cancer. Although both single therapies lead to tumor growth reduction the effect is further enhanced by their combination and leads to significant reduction of metastases. Tumor progression was monitored by non invasive MR imaging. High correlation between HER-2 and CXCR4 expression in primary tumor and metastatic organs was observed and might suggest a link between the chemokine receptor CXCR4 and receptor tyrosine kinase HER-2 in tumor progression and metastases. The results of this study suggest an effective treatment of metastatic prostate cancer by the combined use of drugs that target HER-2 and CXCR4.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1674. doi:10.1158/1538-7445.AM2011-1674

L1 is highly expressed in tumors of the nervous system: a study of over 8000 human tissues

BACKGROUND

L1 cell adhesion molecule (CD171) has been detected in different malignant tumors and is associated with unfavorable outcome. It thus represents a target for tumor diagnosis and therapy. In this study, we assessed L1 expression in more than 8000 normal human tissues and different types of tumors, both malignant and non-malignant, and neural and non-neural.

MATERIALS AND METHODS

Tissue micro-arrays, including a multi-tumor-array of 128 different tumor types, up to 50 samples of each type (approximately 5500 different samples), arrays with approximately 3000 different prostate and 600 mesenchymal tumor samples, and a normal human tissue-array were analyzed by immunohistochemistry with a monoclonal antibody using immunoperoxidase staining.

RESULTS

L1 expression was detected in tumors of neural and neural crest origin and other types of non-neural tumors, but not in those of epithelial origin. In normal human tissues, L1 was detected in skin basal cells and small blood vessels, most notably in the mature placenta and peripheral nerves.

CONCLUSION

This first comprehensive study of the importance of L1 expression in human demonstrates strong L1 overexpression in tumors of neuroectodermal and neural crest origin and an expression in only very few normal human tissues. L1 thus is a potentially important therapeutic target, particularly with respect to malignant melanoma, gastrointestinal stromal tumor, neuroblastoma, and certain subtypes of non-neural tumors.

Orthotopic fluorescent peritoneal carcinomatosis model of esophageal cancer

AIM

Orthotopic models utilizing orthotopic implantation have been used for developing cancer models of multiple tumor entities. The aim of this study was to evaluate the role of orthotopic injection in establishing a model of esophageal cancer using a human green fluorescent protein (GFP) cell line of human esophageal carcinoma.

MATERIALS AND METHODS

Nude mice were orthotopically injected in the abdominal esophagus with stably transfected GFP-PT1590 cells. Tumor progression was examined by fluorescence imaging.

RESULTS

Fifty percent of animals developed extensive peritoneal spread without a distinct primary tumor at the injection site. Continuous and metastatic spread to the liver, lungs, and lymph nodes was also observed. Fluorescence imaging enabled fast and specific visualization of tumor progression without the need for anesthesia. Intraperitoneal and metastatic tumor spread of GFP-PT1590 esophageal carcinoma demonstrated a highly aggressive but heterogeneous behaviour. Although injection of the esophageal carcinoma cell line GFP-PT1590 did not lead to primary esophageal tumor development at the site of injection, 50% of the mice developed extensive peritoneal spread, as well as lymph node and organ metastasis.

CONCLUSION

The orthotopic cell injection model resulted in peritoneal carcinomatosis of esophageal adenocarcinoma, which could be visualized in real time using fluorescence imaging.

Complementary use of fluorescence and magnetic resonance imaging of metastatic esophageal cancer in a novel orthotopic mouse model

We describe the development of an aggressive orthotopic metastatic model of esophageal cancer, which is visualized in real time with combined magnetic resonance imaging (MRI) and fluorescence imaging. The aim of the study was to describe the development of a novel model of metastatic tumor disease of esophageal carcinoma and use this model to evaluate fluorescence and MRI in early detection of local and metastatic disease. The human esophageal adenocarcinoma cell line PT1590 was stably transfected with green fluorescent protein (GFP). Nude mice were orthotopically implanted with PT1590-GFP cells. Orthotopic tumor growth as well as metastatic spread was examined by fluorescence imaging and high-resolution MRI at defined intervals after orthotopic implantation. Highly aggressive novel fluorescent cell lines were isolated from metastatic tissues and put into culture. After implantation of these cells, 100% of the animals developed orthotopic primary tumors. In 83% of animals, metastatic spread to liver, lung and lymph nodes was observed. Primary tumor growth could be visualized with fluorescence imaging and with MRI with high correlation between the 2 methods. Fluorescence imaging allows fast, sensitive, and economical imaging of the primary and metastatic tumor without anesthesia. With MRI, anatomical structures are visualized more precisely and tumors can be more accurately localized to specific organs. This model should prove highly useful to understand esophageal carcinoma and to identify novel therapeutics for this treatment-resistant disease.

Abstract 1458: Orthotopic imageable peritoneal carcinomatosis GFP nude mouse model of human esophageal cancer

The aim of this study was to establish an imageable orthotopic GFP-expressing nude-mouse model of human esophageal cancer peritoneal carcinomatosis. Nude mice were orthotopically injected in the abdominal esophagus with stably transfected GFP- PT1590 human esophageal cancer cells. Tumor progression was visualized by fluorescence imaging. Fifty percent of the animals developed extensive peritoneal spread without a distinct primary tumor at the injection site. Continuous and metastatic spread to liver, lung, and lymph node was also observed. Fluorescence imaging enabled rapid and specific visualization of tumor progression without anaesthesia. Intraperitoneal and metastatic tumor spread of GFP-PT1590 esophageal carcinoma demonstrated a highly aggressive but heterogenous behaviour. Although injection of the esophageal carcinoma cell line PT1590-GFP did not lead to primary esophageal tumor development at the site of injection, 50% of the mice developed extensive peritoneal spread as well as lymph node and organ metastasis. The orthotopic cell injection model resulting in peritoneal carcinomatosis of esophageal adenocarcinoma, which can be visualized in real time using fluorescence imaging, will be a valuable tool for the study of esophageal cancer metastasis and its treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1458.

Frequent homogeneous HER-2 amplification in primary and metastatic adenocarcinoma of the esophagus

HER-2 is the target for antibody based treatment of breast cancer (Herceptin). In order to evaluate the potential role of such a treatment in esophageal cancers, HER-2 amplification and overexpression was investigated in primary and metastatic cancers of the esophagus. A tissue microarray was constructed from 255 primary esophageal cancers (110 adenocarcinomas and 145 squamous cell carcinomas), 89 nodal and 33 distant metastases. Slides were analyzed by immunohistochemistry (HercepTest; DAKO) and fluorescence in situ hybridization (FISH; PathVysion; Vysis-Abbott) for HER-2 amplification and overexpression. Amplification was seen in 16/110 (15%) adenocarcinomas and in 7/145 (5%) squamous cell carcinomas. There was a strong association between HER-2 amplification and overexpression, especially in adenocarcinomas (P<0.0001, log rank). There was a 100% concordance of the HER-2 results in primary tumor and corresponding metastases in 84 analyzed pairs. Amplification was typically high-level with more than 10-15 HER-2 copies per tumor cell. Amplification was unrelated to survival, grading, pT, pN, pM or UICC stage. We conclude that esophageal adenocarcinomas belong to those cancer types with relevant frequency high-level HER-2 gene amplification clinical trials or individual case studies investigating the response of metastatic HER-2-positive esophageal cancers to Herceptin((R)) should be undertaken. The strong concordance of the HER-2 status in primary and metastatic cancers argues for a possible response of metastases from patients with HER-2-positive primary tumors to Herceptin.