Perioperative care of children with sickle cell disease: A systematic review and clinical recommendations.

Children with sickle cell disease (SCD) require specific perioperative care, and clinical practice in this area remains poorly defined. We aimed to conduct a systematic, PRISMA-based review of the literature, available clinical guidelines and practice recommendations. We also aimed to extract any valuable information for the "best of available-evidence"-based prevention of perioperative adverse events in children with SCD, and highlight the most urgent priorities in clinical research. As data sources, US National Library of Medicine, Medline, National Guideline Clearinghouse, International Guideline Network, TRIP databases were searched for any content until January 2019. We also included institutional, consortia and expert group guidelines. Included were reports/guidelines in English, French, German, and Italian. Excluded were reports on obstetrical and fetal management. We identified 202 reports/guidelines fulfilling the criteria outlined above. A majority focused on visceral, cardiovascular and orthopedic surgery procedures, and only five were multicenter randomized controlled trials and two prospective randomized studies. After grading of the quality of the evidence, the extracted data was summarized into clinical recommendations for daily practice. Additionally, we designed a risk-grading algorithm to identify contexts likely to be associated with adverse outcomes. In conclusion, we provide a systematic PRISMA-based review of the existing literature and ancillary practice and delineate a set of clinical recommendations and priorities for research.

EWS-FLI-1 modulates miRNA145 and SOX2 expression to initiate mesenchymal stem cell reprogramming toward Ewing sarcoma cancer stem cells.

Cancer stem cells (CSCs) display plasticity and self-renewal properties reminiscent of normal tissue stem cells, but the events responsible for their emergence remain obscure. We recently identified CSCs in Ewing sarcoma family tumors (ESFTs) and showed that they retain mesenchymal stem cell (MSC) plasticity. In the present study, we addressed the mechanisms that underlie ESFT CSC development. We show that the EWS-FLI-1 fusion gene, associated with 85%-90% of ESFTs and believed to initiate their pathogenesis, induces expression of the embryonic stem cell (ESC) genes OCT4, SOX2, and NANOG in human pediatric MSCs (hpMSCs) but not in their adult counterparts. Moreover, under appropriate culture conditions, hpMSCs expressing EWS-FLI-1 generate a cell subpopulation displaying ESFT CSC features in vitro. We further demonstrate that induction of the ESFT CSC phenotype is the result of the combined effect of EWS-FLI-1 on its target gene expression and repression of microRNA-145 (miRNA145) promoter activity. Finally, we provide evidence that EWS-FLI-1 and miRNA-145 function in a mutually repressive feedback loop and identify their common target gene, SOX2, in addition to miRNA145 itself, as key players in ESFT cell differentiation and tumorigenicity. Our observations provide insight for the first time into the mechanisms whereby a single oncogene can reprogram primary cells to display a CSC phenotype.

Aldehyde dehydrogenase activity plays a Key role in the aggressive phenotype of neuroblastoma.

BACKGROUND: The successful targeting of neuroblastoma (NB) by associating tumor-initiating cells (TICs) is a major challenge in the development of new therapeutic strategies. The subfamily of aldehyde dehydrogenases 1 (ALDH1) isoenzymes, which comprises ALDH1A1, ALDH1A2, and ALDH1A3, is involved in the synthesis of retinoic acid, and has been identified as functional stem cell markers in diverse cancers. By combining serial neurosphere passages with gene expression profiling, we have previously identified ALDH1A2 and ALDH1A3 as potential NB TICs markers in patient-derived xenograft tumors. In this study, we explored the involvement of ALDH1 isoenzymes and the related ALDH activity in NB aggressive properties. METHODS: ALDH activity and ALDH1A1/A2/A3 expression levels were measured using the ALDEFLUOR™ kit, and by real-time PCR, respectively. ALDH activity was inhibited using the specific ALDH inhibitor diethylaminobenzaldehyde (DEAB), and ALDH1A3 gene knock-out was generated through the CRISPR/Cas9 technology. RESULTS: We first confirmed the enrichment of ALDH1A2 and ALDH1A3 mRNA expression in NB cell lines and patient-derived xenograft tumors during neurosphere passages. We found that high ALDH1A1 expression was associated with less aggressive NB tumors and cell lines, and correlated with favorable prognostic factors. In contrast, we observed that ALDH1A3 was more widely expressed in NB cell lines and was associated with poor survival and high-risk prognostic factors. We also identified an important ALDH activity in various NB cell lines and patient-derived xenograft tumors. Specific inhibition of ALDH activity with diethylaminobenzaldehyde (DEAB) resulted in a strong reduction of NB cell clonogenicity, and TIC self-renewal potential, and partially enhanced NB cells sensitivity to 4-hydroxycyclophosphamide. Finally, the specific knock-out of ALDH1A3 via CRISPR/Cas9 gene editing reduced NB cell clonogenicity, and mediated a cell type-dependent inhibition of TIC self-renewal properties. CONCLUSIONS: Together our data uncover the participation of ALDH enzymatic activity in the aggressive properties and 4-hydroxycyclophosphamide resistance of NB, and show that the specific ALDH1A3 isoenzyme increases the aggressive capacities of a subset of NB cells.

Is It Ovarian Torsion? A Systematic Literature Review and Evaluation of Prediction Signs.

OBJECTIVES: This study aimed to identify, through systematic literature review, the most reliable clinical, biological, and radiological signs of ovarian torsion in the pediatric population and to compare their diagnostic value. METHODS: This is a systematic review of the literature, searching MEDLINE, EMBASE, and Cochrane Databases for articles published between January 1990 and January 2014. RESULTS: From the 946 references initially identified, 14 retrospective publications fulfilled the inclusion criteria, involving a total of 663 episodes of ovarian torsion. Sudden onset abdominal pain with nausea and/or vomiting is the most frequent symptom of ovarian torsion. It can occur at any age, not only in menarchal or perimenarchal patients. Abdominal tenderness is present in 88.4% of patients, whereas only 24% have a palpable mass. Blood tests are commonly requested (51.4% of cases) but are not diagnostic. Abnormalities on plain abdominal radiograph include masses, calcifications, and ossified images. Ultrasound has a sensitivity for ovarian torsion of 79% and computerized tomographic scan of 42.2%. There is a significant diagnostic delay at 101.8 hours (median). CONCLUSIONS: Abdominal pain in children and adolescents is difficult to evaluate, and the diagnosis of ovarian torsion remains a challenge. Because of its potential complications, we need effective clinical tools. From our review of the literature, it was not possible to develop a diagnostic algorithm. Further research is needed to improve our practice and shorten the delay to diagnosis. Considering the low incidence of ovarian torsion, a multicenter prospective study would be required.

Bilateral anterior sternothoracotomy (clamshell incision): a suitable alternative for bilateral lung sarcoma metastasis in children.

BACKGROUND: The aim of our study was to assess the postoperative course of bilateral anterior sternothoracotomy (BAT) in children with sarcoma metastases, in a curative care perspective. METHODS: We reviewed the records of seven patients younger than 18 years old, who underwent surgical procedures for sarcoma metastasis to the lung between 2000 and 2012. We compared the postoperative course of the BAT group with that of patients who underwent unilateral posterolateral thoracotomies (PLTs) for the same etiology. RESULTS: Of 17 surgical procedures, there were seven BAT and 10 unilateral PLT. Mean ages at the time of the procedures were 12.9 ± 5.4 years old for BAT, and 17.4 ± 1.9 years old for PLT. Mean operative time was 173 ± 37 minutes in the BAT group, and 145 ± 39 minutes in the PLT group (P = 0.19). Patients received epidural analgesia in all cases; this was for a mean time of 3.8 ± 1.3 days in the BAT group, and 3.21 ± 4 days in the PLT group (P = 0.36). Chest tubes were removed after 3.6 ± 1.3 days in the BAT group, and 3 ± 1.2 days in the PLT group (P = 0.69). Total hospital stay was 7.7 ± 6.6 days in the BAT group, and 7 ± 1.2 days in the PLT group (P = 0.72). CONCLUSION: In our experience, BAT seems suitable and shows outcomes similar to those of PLT for sarcoma metastasis resection. The BAT procedure allows the manual exploration of both lungs during a single surgical intervention, and so reduces the delay of further therapies.

Osteosarcoma metastasis causing ileo-ileal intussusception.

Osteosarcoma metastasis causing intussusception is a very rare entity, with a pejorative prognosis. Based on a case, we performed a literature review in order to better assess this situation. We conclude that, in patients with a history of osteosarcoma lung metastasis, echographic and/or computed tomography scan evidence of a small bowel obstruction with intussusception should lead to an open surgical procedure if the laparoscopic approach does not allow to accurately explore and resect the lesion, in order to prevent misdiagnosis and to avoid further delay in the management.

Evidence-based optimisation of empirical antibiotic regimens in paediatric complicated appendicitis: a retrospective study of 94 patients.

BACKGROUND: Acute appendicitis is the most frequent surgical emergency in the paediatric population. Complicated appendicitis accounts for 30% of cases and is inextricably linked to postoperative infectious complications. A study at our institution showed that amoxicillin-clavulanate resistant Escherichia coli in complicated appendicitis was significantly linked to postoperative infectious complications. These findings led to a change in the empirical antibiotic protocol (amoxicillin-clavulanate changed to ceftriaxone + metronidazole as of 2017), intending to reduce postoperative infectious complications in complicated appendicitis in our institution. AIM OF THE STUDY: This study aimed to analyse the microbiology and resistance profiles of pathogens of complicated appendicitis at our institution since implementing the new antibiotic protocol and the postoperative infectious complications rate. METHODS: We designed a retrospective comparative cohort study. During the defined study period (01 January 2017 to 31 July 2020), medical records were analysed for cases of acute appendicitis, complicated appendicitis and postoperative infectious complications, retaining only those who fulfilled inclusion criteria. Postoperative outcomes, microbiology and antibiotic resistance of peritoneal swabs were analysed. RESULTS: During the study period, 95 patients presented with a complicated appendicitis, and 11 (12%) developed postoperative infectious complications. The most frequent pathogens found in complicated appendicitis were E. coli (66%), Streptococcus anginosus (45%), and Bacteroides fragilis (22%). Pseudomonas aeruginosa was present in 17% of complicated appendicitis. Pathogens involved in postoperative infectious complications mirrored the distribution found in complicated appendicitis without postoperative infectious complications. Antibiotic susceptibility analysis showed that 10 (15%) of E. coli strains were resistant to amoxicillin-clavulanate but sensitive to ceftriaxone + metronidazole, with only one strain responsible for causing a postoperative infectious complication. Six additional strains of E. coli (9%) were resistant to amoxicillin-clavulanate and our empirical antibiotic regimen but were not associated with an increase in postoperative infectious complications. Compared with our previous study, there was a decrease in postoperative infectious complications from 16% to 12%. Postoperative infectious complications caused by amoxicillin-clavulanate-resistant E. coli decreased from 28% to 9%. CONCLUSION: This retrospective study demonstrated a decrease in the rate of postoperative infectious complications due to amoxicillin-clavulanate-resistant E. coli in complicated appendicitis. These findings accentuate the need to implement evidence-based treatment protocols based on local microbiology profiles and resistance rates to optimise post-operative antibiotics in complicated appendicitis.

Operative Planning of Chest Wall Reconstructions Illustrated by a Large Defect in a Child.

Reconstruction of large chest wall defects is challenging. Here we discuss the process of decision-making in planning chest wall reconstruction, considering the requirements of tumor removal, stabilization of the chest wall, and soft tissue coverage, illustrated by a case of a hemi-chest wall defect in a child. Ewing sarcoma measuring 10 × 9 × 13 cm was resected in a 9-year-old boy, followed by stabilization using a Gore-Tex patch. Due to extension of the oncologic resection far into the superomedial quadrant of the chest, tension-free coverage with a classical latissimus-dorsi flap could not be achieved. Integrating the serratus-anterior muscle into the flap creating a chimeric latissimus-dorsi/serratus-anterior flap allowed for excellent soft tissue coverage of the foreign body. As the skin could be preserved, careful incision planning was necessary to allow for best possible exposure during oncologic resection and flap harvest, while ensuring skin vascularization impaired by underlying tumor resection. Two vertical skin incisions were chosen, one presternal and a second in the mid-axillary fold delineating a large bipedicled skin flap. Postoperative recovery was excellent. Solid skin vascularization and adequate soft tissue coverage of the alloplastic material allowed for the patient to receive two cycles of postoperative radiotherapy without developing wound dehiscence. Careful interdisciplinary planning of skin incisions allowed for good exposure for tumor resection and flap harvest while preserving skin vascularization. Choosing a chimeric latissimus-dorsi/serratus-anterior flap provided larger coverage than a classical latissimus-dorsi flap with minimal additional donor site morbidity. Taken together, we here present a pragmatic solution to a complex problem.

TWIST1 expression is associated with high-risk neuroblastoma and promotes primary and metastatic tumor growth.

The embryonic transcription factors TWIST1/2 are frequently overexpressed in cancer, acting as multifunctional oncogenes. Here we investigate their role in neuroblastoma (NB), a heterogeneous childhood malignancy ranging from spontaneous regression to dismal outcomes despite multimodal therapy. We first reveal the association of TWIST1 expression with poor survival and metastasis in primary NB, while TWIST2 correlates with good prognosis. Secondly, suppression of TWIST1 by CRISPR/Cas9 results in a reduction of tumor growth and metastasis colonization in immunocompromised mice. Moreover, TWIST1 knockout tumors display a less aggressive cellular morphology and a reduced disruption of the extracellular matrix (ECM) reticulin network. Additionally, we identify a TWIST1-mediated transcriptional program associated with dismal outcome in NB and involved in the control of pathways mainly linked to the signaling, migration, adhesion, the organization of the ECM, and the tumor cells versus tumor stroma crosstalk. Taken together, our findings confirm TWIST1 as promising therapeutic target in NB.

HSD17B7 gene in self-renewal and oncogenicity of keratinocytes from Black versus White populations.

Human populations of Black African ancestry have a relatively high risk of aggressive cancer types, including keratinocyte-derived squamous cell carcinomas (SCCs). We show that primary keratinocytes (HKCs) from Black African (Black) versus White Caucasian (White) individuals have on average higher oncogenic and self-renewal potential, which are inversely related to mitochondrial electron transfer chain activity and ATP and ROS production. HSD17B7 is the top-ranked differentially expressed gene in HKCs and Head/Neck SCCs from individuals of Black African versus Caucasian ancestries, with several ancestry-specific eQTLs linked to its expression. Mirroring the differences between Black and White HKCs, modulation of the gene, coding for an enzyme involved in sex steroid and cholesterol biosynthesis, determines HKC and SCC cell proliferation and oncogenicity as well as mitochondrial OXPHOS activity. Overall, the findings point to a targetable determinant of cancer susceptibility among different human populations, amenable to prevention and management of the disease.

Influence of Surgical Excision on the Survival of Patients With Stage 4 High-Risk Neuroblastoma: A Report From the HR-NBL1/SIOPEN Study.

PURPOSE: To evaluate the impact of surgeon-assessed extent of primary tumor resection on local progression and survival in patients in the International Society of Pediatric Oncology Europe Neuroblastoma Group High-Risk Neuroblastoma 1 trial. PATIENTS AND METHODS: Patients recruited between 2002 and 2015 with stage 4 disease > 1 year or stage 4/4S with MYCN amplification < 1 year who had completed induction without progression, achieved response criteria for high-dose therapy (HDT), and had no resection before induction were included. Data were collected on the extent of primary tumor excision, severe operative complications, and outcome. RESULTS: A total of 1,531 patients were included (median observation time, 6.1 years). Surgeon-assessed extent of resection included complete macroscopic excision (CME) in 1,172 patients (77%) and incomplete macroscopic resection (IME) in 359 (23%). Surgical mortality was 7 (0.46%) of 1,531. Severe operative complications occurred in 142 patients (9.7%), and nephrectomy was performed in 124 (8.8%). Five-year event-free survival (EFS) ± SE (0.40 ± 0.01) and overall survival (OS; 0.45 ± 0.02) were significantly higher with CME compared with IME (5-year EFS, 0.33 ± 0.03; 5-year OS, 0.37 ± 0.03; P < .001 and P = .004). The cumulative incidence of local progression (CILP) was significantly lower after CME (0.17 ± 0.01) compared with IME (0.30 ± 0.02; P < .001). With immunotherapy, outcomes were still superior with CME versus IME (5-year EFS, 0.47 ± 0.02 v 0.39 ± 0.04; P = .038); CILP was 0.14 ± 0.01 after CME and 0.27 ± 0.03 after IME (P < .002). A hazard ratio of 1.3 for EFS associated with IME compared with CME was observed before and after the introduction of immunotherapy (P = .030 and P = .038). CONCLUSION: In patients with stage 4 high-risk neuroblastoma who have responded to induction therapy, CME of the primary tumor is associated with improved survival and local control after HDT, local radiotherapy (21 Gy), and immunotherapy.

Latissimus dorsi muscle-flap over Gore-Tex patch for coverage of large thoracic defects in paediatric Ewing sarcoma.

Primary rib involvement accounts for 16% of paediatric Ewing sarcoma (ES). Neo-adjuvant chemotherapy and surgical tumor resection may leave large thoracic wall defects requiring complex reconstruction in a growing individual. We report our experience in three children aged 3, 10, and 12 years, in whom single-stage resection and reconstruction were performed using a Gore-Tex Dualmesh patch, covered by a latissimus dorsi rotation flap harvested in continuity with the thoracolumbar fascia. The youngest patient also had a vertical expandable prosthetic titanium rib (VEPTR) anchored to help prevent subsequent scoliosis throughout growth.

Impact of co-amoxicillin-resistant Escherichia coli and Pseudomonas aeruginosa on the rate of infectious complications in paediatric complicated appendicitis.

BACKGROUND: Choice of antibiotics for complicated appendicitis should address local antibiotic resistance patterns. As our local data showed a less than 15% resistance of Escherichia coli to co-amoxicillin (amoxicillin + clavulanic acid), we opted for this antibiotic in 2013. Subsequently, the increasing prevalence of Pseudomonas aeruginosa challenged this choice. AIM OF THE STUDY: The aim of this study was to describe the bacteriology of peritoneal swabs from cases of complicated appendicitis in our paediatric patients, and to determine the risk of infectious complications (wound and/or intra-abdominal abscesses). METHODS: We designed a retrospective cohort study including all children (<18 years old) who had surgery for complicated appendicitis between 1 January 2010 and 31 December 2016 and had a peritoneal swab culture. Microbiological results are presented descriptively. Univariate analyses were performed for potential determinants of infectious complications. All variables with a p-value <0.05 were then included in a multivariable logistic regression model, for which adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: One hundred and thirty-three patients were treated for complicated appendicitis and had cultures of peritoneal fluid. Median age was 9.5 years old (IQR 5.7–12.4), and there were 53 girls (40%). E. coli was isolated in 94 patients (71%) and was resistant to co-amoxicillin in 14% of cases. P. aeruginosa was isolated in 31 patients (23%). The rate of infectious complications was 38% (8/21 patients) when the empiric antibiotic did not cover P. aeruginosa and 0% (0/10 patients) when P. aeruginosa was covered adequately (p = 0.03). In a multivariable analysis, only co-amoxicillin-resistant E. coli significantly predicted infectious complications (OR 4.7; 95% CI 1.4–16.6; p = 0.015). CONCLUSION: Results of the multivariable analysis of this small, retrospective study revealed a statistically significant increase in the risk of postoperative complications in the presence of co-amoxicillin-resistant E. coli. The choice of antibiotic should be adapted accordingly. More data are needed to justify the systematic coverage of P. aeruginosa in children with complicated appendicitis.  .

Complex molecular mechanisms cooperate to mediate histone deacetylase inhibitors anti-tumour activity in neuroblastoma cells.

BACKGROUND: Histone deacetylase inhibitors (HDACi) are a new class of promising anti-tumour agent inhibiting cell proliferation and survival in tumour cells with very low toxicity toward normal cells. Neuroblastoma (NB) is the second most common solid tumour in children still associated with poor outcome in higher stages and, thus NB strongly requires novel treatment modalities. RESULTS: We show here that the HDACi Sodium Butyrate (NaB), suberoylanilide hydroxamic acid (SAHA) and Trichostatin A (TSA) strongly reduce NB cells viability. The anti-tumour activity of these HDACi involved the induction of cell cycle arrest in the G2/M phase, followed by the activation of the intrinsic apoptotic pathway, via the activation of the caspases cascade. Moreover, HDACi mediated the activation of the pro-apoptotic proteins Bid and BimEL and the inactivation of the anti-apoptotic proteins XIAP, Bcl-xL, RIP and survivin, that further enhanced the apoptotic signal. Interestingly, the activity of these apoptosis regulators was modulated by several different mechanisms, either by caspases dependent proteolytic cleavage or by degradation via the proteasome pathway. In addition, HDACi strongly impaired the hypoxia-induced secretion of VEGF by NB cells. CONCLUSION: HDACi are therefore interesting new anti-tumour agents for targeting highly malignant tumours such as NB, as these agents display a strong toxicity toward aggressive NB cells and they may possibly reduce angiogenesis by decreasing VEGF production by NB cells.

Histone deacetylase inhibitors strongly sensitise neuroblastoma cells to TRAIL-induced apoptosis by a caspases-dependent increase of the pro- to anti-apoptotic proteins ratio.

BACKGROUND: Neuroblastoma (NB) is the second most common solid childhood tumour, an aggressive disease for which new therapeutic strategies are strongly needed. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in most tumour cells, but not in normal tissues and therefore represents a valuable candidate in apoptosis-inducing therapies. Caspase-8 is silenced in a subset of highly malignant NB cells, which results in full TRAIL resistance. In addition, despite constitutive caspase-8 expression, or its possible restoration by different strategies, NB cells remain weakly sensitive to TRAIL indicating a need to develop strategies to sensitise NB cells to TRAIL. Histone deacetylase inhibitors (HDACIs) are a new class of anti-cancer agent inducing apoptosis or cell cycle arrest in tumour cells with very low toxicity toward normal cells. Although HDACIs were recently shown to increase death induced by TRAIL in weakly TRAIL-sensitive tumour cells, the precise involved sensitisation mechanisms have not been fully identified. METHODS: NB cell lines were treated with various doses of HDACIs and TRAIL, then cytotoxicity was analysed by MTS/PMS proliferation assays, apoptosis was measured by the Propidium staining method, caspases activity by colorimetric protease assays, and (in)activation of apoptotic proteins by immunoblotting. RESULTS: Sub-toxic doses of HDACIs strongly sensitised caspase-8 positive NB cell lines to TRAIL induced apoptosis in a caspases dependent manner. Combined treatments increased the activation of caspases and Bid, and the inactivation of the anti-apoptotic proteins XIAP, Bcl-x, RIP, and survivin, thereby increasing the pro- to anti-apoptotic protein ratio. It also enhanced the activation of the mitochondrial pathway. Interestingly, the kinetics of caspases activation and inactivation of anti-apoptotic proteins is accelerated by combined treatment with TRAIL and HDACIs compared to TRAIL alone. In contrast, cell surface expression of TRAIL-receptors or TRAIL is not affected by sub-toxic doses of HDACIs. CONCLUSION: HDACIs were shown to activate the mitochondrial pathway and to sensitise NB cells to TRAIL by enhancing the amplitude of the apoptotic cascade and by restoring an apoptosis-prone ratio of pro- to anti-apoptotic proteins. Combining HDACIs and TRAIL could therefore represent a weakly toxic and promising strategy to target TRAIL-resistant tumours such as neuroblastomas.

Negative control of CSL gene transcription by stress/DNA damage response and p53.

CSL is a key transcriptional repressor and mediator of Notch signaling. Despite wide interest in CSL, mechanisms responsible for its own regulation are little studied. CSL down-modulation in human dermal fibroblasts (HDFs) leads to conversion into cancer associated fibroblasts (CAF), promoting keratinocyte tumors. We show here that CSL transcript levels differ among HDF strains from different individuals, with negative correlation with genes involved in DNA damage/repair. CSL expression is negatively regulated by stress/DNA damage caused by UVA, Reactive Oxygen Species (ROS), smoke extract, and doxorubicin treatment. P53, a key effector of the DNA damage response, negatively controls CSL gene transcription, through suppression of CSL promoter activity and, indirectly, by increased p21 expression. CSL was previously shown to bind p53 suppressing its activity. The present findings indicate that p53, in turn, decreases CSL expression, which can serve to enhance p53 activity in acute DNA damage response of cells.

Drug-mediated sensitization to TRAIL-induced apoptosis in caspase-8-complemented neuroblastoma cells proceeds via activation of intrinsic and extrinsic pathways and caspase-dependent cleavage of XIAP, Bcl-xL and RIP.

Neuroblastoma (NB) is a childhood neoplasm which heterogeneous behavior can be explained by differential regulation of apoptosis. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces rapid apoptosis in most tumor cells and thus represents a promising anticancer agent. We have reported silencing of caspase-8 expression in highly malignant NB cells as a possible mechanism of resistance to TRAIL-induced apoptosis. To explore the particular contribution of caspase-8 in such resistance, retroviral-mediated stable caspase-8 expression was induced in the IGR-N91 cells. As a result, sensitivity to TRAIL was fully restored in the caspase-8-complemented cells. TRAIL-induced cell death could be further enhanced by cotreatment of IGR-N91-C8 and SH-EP cells with cycloheximide or subtoxic concentrations of chemotherapeutic drugs in a caspase-dependent manner. Sensitization to TRAIL involved enhanced death receptor DR5 expression, activation of Bid and the complete caspases cascade. Interestingly, combined treatments also enhanced the cleavage-mediated inactivation of antiapoptotic molecules, XIAP, Bcl-x(L) and RIP. Our results show that restoration of active caspase-8 expression in a caspase-8-deficient NB cell line is necessary and sufficient to fully restore TRAIL sensitivity. Moreover, the synergistic effect of drugs and TRAIL results from activation of the caspase cascade via a mitochondrial pathway-mediated amplification loop and from the inactivation of apoptosis inhibitors.

A survey on surgeons' perceived quality of the informed consent process in a Swiss paediatric surgery unit.

AIM: To evaluate the levels of satisfaction and opinions on the usefulness of the informed consent form currently in use in our Paediatric Surgery Department. DESIGN: Qualitative study carried out via interviews of senior paediatric surgeons, based on a questionnaire built up from reference criteria in the literature and public health law. RESULTS: Physicians with between 2 and 35 years experience of paediatric surgery, with a participation rate of 92 %, agreed on the definition of an informed consent form, were satisfied with the form in use and did not wish to modify its structure. The study revealed that signing the form was viewed as mandatory, but meant different things to different participants, who diverged over whom that signature protected. Finally, all respondents were in agreement over what information was necessary for parents of children requiring surgery. CONCLUSION: Paediatric surgeons seemed to be satisfied with the informed consent form in use. Most of them did not identify that the first aim of the informed consent form is to give the patient adequate information to allow him to base his consent, which is a legal obligation, the protection of physicians by the formalisation and proof of the informed consent being secondary. Few surgeons brought up the fact that the foremost stakeholder in paediatric surgery are the children themselves and that their opinions are not always sought. In the future, moving from informed consent process to shared decision-making, a more active bidirectional exchange may be strongly considered. Involving children in such vital decisions should become the norm while keeping in mind their level of maturity.

The CXCR4/CXCR7/CXCL12 Axis Is Involved in a Secondary but Complex Control of Neuroblastoma Metastatic Cell Homing.

Neuroblastoma (NB) is one of the most deadly solid tumors of the young child, for which new efficient and targeted therapies are strongly needed. The CXCR4/CXCR7/CXCL12 chemokine axis has been involved in the progression and organ-specific dissemination of various cancers. In NB, CXCR4 expression was shown to be associated to highly aggressive undifferentiated tumors, while CXCR7 expression was detected in more differentiated and mature neuroblastic tumors. As investigated in vivo, using an orthotopic model of tumor cell implantation of chemokine receptor-overexpressing NB cells (IGR-NB8), the CXCR4/CXCR7/CXCL12 axis was shown to regulate NB primary and secondary growth, although without any apparent influence on organ selective metastasis. In the present study, we addressed the selective role of CXCR4 and CXCR7 receptors in the homing phase of metastatic dissemination using an intravenous model of tumor cell implantation. Tail vein injection into NOD-scid-gamma mice of transduced IGR-NB8 cells overexpressing CXCR4, CXCR7, or both receptors revealed that all transduced cell variants preferentially invaded the adrenal gland and typical NB metastatic target organs, such as the liver and the bone marrow. However, CXCR4 expression favored NB cell dissemination to the liver and the lungs, while CXCR7 was able to strongly promote NB cell homing to the adrenal gland and the liver. Finally, coexpression of CXCR4 and CXCR7 receptors significantly and selectively increased NB dissemination toward the bone marrow. In conclusion, CXCR4 and CXCR7 receptors may be involved in a complex and organ-dependent control of NB growth and selective homing, making these receptors and their inhibitors potential new therapeutic targets.

High level of stabilized angiostatin mediated by adenovirus delivery does not impair the growth of human neuroblastoma xenografts.

Human neuroblastoma (NB) is a highly heterogeneous childhood cancer secreting a high level of vascular endothelial growth factor (VEGF). Its vascularization has been clearly correlated with metastatic progression and poor outcome. Thus, molecules that target the vascular endothelium are regarded as new therapeutics of clinical interest. Angiostatin, an internal fragment of plasminogen containing the first four kringle structures, has been described as a powerful angiogenic inhibitor. We used a recombinant adenovirus encoding the human angiostatin kringle 1-3 directly fused to human serum albumin HSA (AdK3-HSA). Coupling to HSA has been previously shown to increase the in vivo half-life of this angiostatic factor, and to lead to tumor growth inhibition in the MDA-MB-231 carcinoma model. For the assessment of antiangiogenic gene therapy in the human NB IGR-N835 tumor model, 5 x 10(9) PFU of AdK3-HSA were intravenously injected in tumor-bearing athymic mice presenting either of the following experimental settings: early stage, established, and minimal residual tumors. No delay in tumor growth was observed in animals treated with AdK3-HSA as compared to those treated with the empty virus AdCO1. In early-stage tumors, kinetics of tumor occurrence and tumor growth were similar in AdK3-HSA- and AdCO1-treated animals. K3-HSA was found to be expressed at high levels (the mean value for the three experiments being 19.4+/-15.9 microg/ml) in the circulation of all animals up to 21-35 days after virus injection. In addition, IGR-N835 tumors were found to be highly vascularized and to release high amounts of angiogenic factors, in particular VEGF (665+/-370 pg/mg total protein). Thus, in spite of high circulating levels, K3-HSA may be unable to displace the NB proangiogenic switch. In this regard, a more promising target to inhibit NB angiogenesis seems to be the VEGF/VEGFR system.