Comprehensive characterization of RB1 mutant and MYCN amplified retinoblastoma cell lines.

In retinoblastoma research tumor-derived cell lines remain an important model to investigate tumorigenesis and new therapy options, due to limited tumor material and lack of adequate animal models. A panel of 10 retinoblastoma cell lines was characterized with respect to mutation, methylation and expression of RB1 and MYCN. These established retinoblastoma cell lines represent the most frequent types of RB1 inactivation and together with the MYCN amplification status, three classes can be distinguished: RB1mut/MYCNnonA, RB1mut/MYCNA and RB1wt/MYCNA. MYCN amplification was identified in five cell lines, whereby two of them, RB522 and RB3823, harbor no aberration in RB1. Targeted sequencing of 160 genes often mutated in cancer identified only few variants in tumor-associated genes other than in RB1. None of these variants was recurrent. mRNA expression analyses of retinal markers, cell cycle regulators and members of the TP53 signaling pathway revealed a high variability between cell lines but no class-specific differences. The here presented thorough validation of retinoblastoma cell lines, including microsatellite analysis for cell line authentication, provides the basis for further in vitro studies on retinoblastoma.

[Primary meningioma of the optical nerve sheet in infancy as initial presentation of neurofibromatosis type 2]. / Primäres Meningeom des Nervus opticus im Säuglingsalter als Erstmanifestation einer Neurofibromatose Typ 2.

Intraorbital meningiomas are rare tumors, making up less than 4% of all intraorbital tumors. Intraorbital meningiomas of childhood are curiosities with only few documented cases. We present the case of an 8­month-old male infant, presenting with strabismus and nystagmus. Magnetic resonance imaging showed a long segment thickening of the optical nerve and an intraocular tumor. The tumor was suspicious for retinal dysplasia and enucleation of the eye was performed to exclude malignancy. Histological examination revealed a meningothelial meningioma (WHO grade I), extending along the optical nerve and into the eye accompanied by retinal dysplasia and epiretinal membranes. Meningiomas of childhood, retinal dysplasia, and epiretinal membranes are regularly associated with neurofibromatosis type 2. Subsequent genetic analysis led to the final diagnosis. This case documents a very unusual early beginning of a neurofibromatosis type 2.

[Diagnosis and treatment of retinoblastoma: current strategies for effective tumour control and preservation of vision]. / Diagnose und behandlung des retinoblastoms: aktuelle konzepte zur sicheren tumorkontrolle bei erhalt des sehvermögens.

There are approximately 40 new cases of retinoblastoma in Germany per year. Children in whom the tumour is detected when still intraocular have an excellent overall survival rate (> 95%). However, the prognosis of metastasised retinoblastoma remains poor. About 40% of retinoblastoma patients have tumours in both eyes. For these children in particular it is important to save the eye and visual function as much as possible. There are several options for conservative treatment of localised retinoblastoma including laser coagulation, thermotherapy, cryotherapy, brachytherapy and chemotherapy. In recent years, systemic chemotherapy has become the established standard for primary treatment of intraocular retinoblastoma. In case series, intra-arterial, intravitreal and periocular applications of chemotherapy were also shown to be effective in treating intraocular retinoblastoma. Genetic testing is an integral part of the routine diagnostics of all patients. Mutation analysis of tumour material is invaluable for identification of somatic mutations including mutational mosaicism. Genetic testing also identifies children with heritable retinoblastoma, which represent 50% of cases. These children also have a predisposition for the development of tumours outside of the eye (second primary neoplasm). To adequately address these and other late effects in survivors of retinoblastoma, a multidisciplinary approach is needed that optimises therapy and long-term follow-up. Upcoming multicentre clinical trials will evaluate treatment concepts for localised and metastasised retinoblastoma to improve survival rates and quality of life of children with retinoblastoma. This article was translated and modified and was primarily published in Klin Padiatr 2012; 224: 339-347.

Current concepts for diagnosis and treatment of retinoblastoma in Germany: aiming for safe tumor control and vision preservation.

Retinoblastoma affects approximately 40 children in Germany per year. Most children are diagnosed early with localized intraocular disease, and the overall survival rate exceeds 95%. However, the prognosis of metastasized retinoblastoma remains poor. In 40% of the patients, retinoblastoma occurs bilaterally and, especially for these children, the salvage of the eye and visual function is of major importance. The variety of conservative treatment options for localized retinoblastoma includes laser coagulation, thermotherapy, cryotherapy, brachytherapy and chemotherapy. While systemic chemotherapy has nearly completely replaced external beam radiotherapy in the primary treatment of intraocular retinoblastoma, intra-arterial, intravitreal and periocular application of chemotherapy was also shown to be effective in treating intraocular retinoblastoma in case series. Genetic testing is an integral part of the routine diagnostics of all patients. Available tumor material should be analyzed to detect mutational mosaicism, that affects >10% of children with unilateral retinoblastoma. Genetic testing also identifies children with heritable (50% of patients) retinoblastoma. These children have a genetic predisposition for second malignancies. For this reason, late effects are an increasing concern and the care of patients with retinoblastoma requires a multidisciplinary approach to tailor therapy and long-term follow-up. Multicenter clinical trials are being developed to evaluate evidence-based treatment concepts for localized and metastasized retinoblastoma to improve survival rates and quality of life of children with retinoblastoma.

The neurodevelopmental sequelae of childhood leukaemia and its treatment.

The overall survival of childhood leukaemia has increased dramatically over recent decades. With the increasing number of survivors, chemotherapy protocols are designed not only to improve cure rates but also to minimise long-term sequelae. Central-nervous-system-directed therapy given as intrathecal chemotherapy and/or cranial irradiation plays a crucial part in acute leukaemia treatment but can also result in adverse effects on the developing brain. The elimination of cranial irradiation from current treatment protocols has improved the neurocognitive outcome without compromising survival rates. Although neurodevelopmental long-term sequelae after chemotherapy-only central-nervous-system-directed therapies may be more subtle, survivors of childhood leukaemia will continue to require methodical follow-up and appropriate rehabilitation.

Attenuation of monocyte proinflammatory cytokine responses to Neisseria meningitidis in children by erythropoietin.

Meningococcal disease is a leading infectious cause of death in children in industrialized countries. The induction of high levels of proinflammatory cytokines has been implicated in the pathogenesis of Neisseria meningitidis-related multi-organ failure. Here, we demonstrate that N. meningitidis serotypes A and B induce significantly higher levels of tumour necrosis factor (TNF)-alpha positive cells in vitro in infants and young children compared with adults (serotype A/B; infants: 64.9%/63.9%; children: 77.8%/64.3% versus adults: 27.7%/32%; P < 0.005). Serotype A induces also higher levels of interleukin (IL)-6 positive cells in neonates and infants compared with adults (serotype A; newborn 55.4%; infants 58.8% versus adults 49%; P < 0.05). Treatment with human recombinant erythropoietin in vitro resulted in significant attenuation of the N. meningitidis-induced proinflammatory response in all age groups (reduction rate of erythropoietin for IL-6 after stimulation with serotype B: newborn 28%, infants 15%, children 23% and adults 28% and for TNF-alpha after stimulation with serotype B: newborn 27%, infants 22%, children 20% and adults 28%; P < 0.05). We conclude that (i) Neisseria meningitidis induces a higher TNF-alpha response in infants and children compared with adults and (ii) erythropoietin was able to attenuate IL-6 and TNF-alpha production in all investigated age groups. These data may explain the high incidence of meningococcal infection in infants and makes erythropoietin a potentially attractive candidate for interventional strategies in an otherwise devastating course of the disease.

Reduced IL-10 production and -receptor expression in neonatal T lymphocytes.

AIM: To further evaluate the underlying mechanism of a formerly demonstrated immature anti-inflammatory response in neonates (1). METHODS: Interleukin (IL)-10 production was measured by enzyme-linked immunosorbent-assay (ELISA) after anti-CD3/anti-CD28 costimulation of neonatal and adult T cells. IL-10 receptor expression on T lymphocytes, B lymphocytes and monocytes were analysed by flow cytometry in neonates and adult controls. RESULTS: After anti-CD3/anti-CD28 costimulation, IL-10 production of neonatal T lymphocytes was profoundly reduced (median 247 pg/mL vs. 1062 pg/mL, p < 0.0001). IL-10 receptor expression was diminished on neonatal T lymphocytes compared to adults (3% vs. 39.5% IL-10 receptor positive lymphocytes; p < 0.0001). On neonatal B lymphocytes and monocytes the IL-10 receptor expression was comparable to adult controls. CONCLUSION: The strongly reduced IL-10 receptor expression on the main immune regulative T lymphocytes in conjunction with a significantly impaired synthesis of IL-10 may play a crucial role in the formerly demonstrated deficient anti-inflammatory immune response in neonates.

Cytokine responses correlate differentially with age in infancy and early childhood.

The functional differentiation of immune cells at early age plays a central role in immune physiology, e.g. for the sufficient eradication of pathogens. However, imbalances in effector cell responses may also have an impact in the pathophysiology of childhood diseases such as atopy and autoimmune disorders. As information on immune cell responses in infancy and early childhood is scarce, we conducted an observational, cross-sectional study in healthy newborns (n = 18), infants and young children (n = 54) aged 1-96 months and adult controls (n = 19) to assess cytokine mRNA and protein expression upon phorbol 12-myristate 13-actate/ionomycin stimulation and LPS-induced IL-12 expression in monocytes. The intracellular expression of interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha (R = 0.748, P < 0.0001; R = 0.784, P < 0.0001, respectively) and interleukin (IL)-2 protein expression (R = 0.384, P = 0.008) was demonstrated to increase progressively with age. While a correlation between IL-4 protein expression and age was noted (R = 0.342, P = 0.007), the levels of IL-5 and IL-10 protein expression tended to be regulated on an individual basis during infancy and early childhood. An age correlation was also observed for intracellular IL-12 expression (R = 0.331, P = 0.009) in monocytes. These findings are valuable for further assessment of normal variations and maturation processes in immune cell responses and for the clinical-therapeutic monitoring of immunological status in various childhood diseases.

Immature anti-inflammatory response in neonates.

The inflammatory response plays a major role in the induction of several neonatal diseases. We hypothesize that an imbalance between the pro- and anti-inflammatory response is crucial for the previously shown enhanced production of proinflammatory cytokines in term and preterm infants during infection. To test this hypothesis, we compared the capacity to produce the main anti-inflammatory cytokines IL-10 and TGF-beta in term infants, preterm infants and adults at different levels of synthesis by quantitative real time reverse-transcribed PCR, flow cytometry, as well as enzyme-linked immunoassay. Term and preterm infants showed a profoundly diminished IL-10 mRNA-expression and IL-10 production after stimulation. In addition, the amount of TGF-beta-positive lymphocytes was significantly less in neonates than adults. Furthermore, there was a considerably lower inhibition of production of IL-1alpha, IL-6, IL-8 and TNF-alpha by the use of recombinant IL-10 in term and preterm infants compared with adults. These results demonstrate not only a diminished anti-inflammatory capacity but also a reduced response to anti-inflammatory stimuli in term and preterm infants. From these data we conclude that neonates display an immature compensatory anti-inflammatory response syndrome (CARS) which may predispose preterm infants to harmful effects of proinflammatory cytokines resulting in severe organ sequelae during infection.