Pablo Hernáiz Driever

SODIUM VALPROATE INHIBITS IN VIVO GROWTH OF HUMAN NEUROBLASTOMA CELLS

Sodium valproate (VPA) belongs to the group of simple branched-chain fatty acids and due its anticonvulsive activity is broadly applied in the treatment of epilepsy. We previously showed that VPA is able to induce cellular differentiation, to enhance immunogenicity and to inhibit proliferation of human neuroblastoma (NB) cells in vitro. Furthermore, we demonstrated that VPA inhibits proliferation, enhances neural cell adhesion molecule expression and decreases CD44 expression of human and rat glioma cells in vitro. In the present study we investigated the antitumoral effects of VPA on established human NB xenografts from UKF-NB-3 human NB cells in athymic (nude) mice. When the animals developed s.c. tumors of about 100 mm3 volume they were treated with 400 or 200 mg/kg/day VPA i.p. At the end of the treatment period (40 days) tumor volumes in animals treated with 400 and 200 mg/kg VPA were about 4- (p < 0.0001) and 2-fold (p < 0.0005) smaller than in the saline-treated control group, respectively. Histological examination of the remnant tumors of treated animals revealed induction of differentiation by induction of stroma-rich tumors and nodules that contained elongated NB cells. Pyknotic nuclei and apoptotic bodies indicated induction of apoptosis. We conclude that VPA is able to abrogate NB growth in vivo and may therefore be useful in the treatment of NB patients.

Antitumor activity of sodium valproate in cultures of human neuroblastoma cells.

Valproic acid (VPA) is a simple branched-chain fatty acid that has anticonvulsant activity and is widely used in the treatment of epilepsy. VPA was found to effect growth and differentiation of human neuroblastoma (NB) cells in vitro at concentrations that have been achieved in humans with no significant adverse effects. Treatment of UKF-NB-2 and UKF-NB-3 NB cell lines with VPA at concentrations ranging from 0.5 to 2 mM resulted in neuronal morphological differentiation characterized by extension of cellular processes without significant effects on cell viability. Ultra-structural features of VPA-treated cells were consistent with the neuronal type of differentiation. VPA treatment of NB cells was associated with decreased expression of N-myc oncoprotein and increased expression of neural cell adhesion molecule in their membrane. Treatment of NB cells with 0.5 mM VPA increased their sensitivity to lymphokine-activated killer lysis. The results indicate that VPA, at non-toxic pharmacological concentrations, arrests the growth, induces differentiation and increases immunogenicity of NB cells through non-toxic mechanisms.

Intensive chemotherapy improves survival in pediatric high‐grade glioma after gross total resection: results of the HIT‐GBM‐C protocol

The authors hypothesized that intensified chemotherapy in protocol HIT‐GBM‐C would increase survival of pediatric patients with high‐grade glioma (HGG) and diffuse intrinsic pontine glioma (DIPG).

Influence of age and movement complexity on kinematic hand movement parameters in childhood and adolescence

Development of fine motor functions, especially drawing and handwriting, are crucial for performance in school, autonomy in everyday life and the general human development. A variety of neurological and psychiatric conditions in childhood and adolescence stunt the normal development of fine motor skills. We sought to define the normal development of the kinematic parameters of fine motor movement and determine the influence of gender, laterality of handedness and extracurricular training on fine motor skills.

Acupuncture against chemotherapy-induced nausea and vomiting in pediatric oncology

GoalsIn this multicenter crossover study, our aim was to evaluate the efficacy and acceptance of acupuncture as a supportive antiemetic approach during highly emetogenic chemotherapy in pediatric oncology.Patients and methodsEleven children receiving several courses of highly emetogenic chemotherapy for treatment of solid tumors were included. Randomization allocated patients to start chemotherapy either with antiemetic medication plus acupuncture or antiemetic medication alone. During all study courses, patients continued to receive their programmed and additional antiemetic medication as needed. Acupuncture was given at day 1 of chemotherapy and at subsequent days on patient’s demand. The amount of baseline and additional antiemetic medication during chemotherapy was documented. Patients maintained a daily diary of vomiting episodes and completed an evaluated nausea score at the end of every course. Their body weight was taken before and after a chemotherapy course.Main resultsTwenty-two courses with or without acupuncture were compared. The benefits of acupuncture in adolescents with respect to the reduction of additional antiemetic medication were observed. Acupuncture enabled patients to experience higher levels of alertness during chemotherapy and reduced nausea and vomiting. Except for needle pain, no side effects were noted. Patient’s acceptance of acupuncture was high.ConclusionOur data indicate that acupuncture might reduce antiemetic medication and episodes of vomiting in pediatric oncology.

Development of resistance to vincristine and doxorubicin in neuroblastoma alters malignant properties and induces additional karyotype changes: a preclinical model.

Cytotoxic drug treatment of neuroblastoma often leads to the development of drug resistance and may be associated with increased malignancy. To study the effects of long‐term cytotoxic treatment on malignant properties of tumor cells, we established 2 neuroblastoma cell sublines resistant to vincristine (VCR) and doxorubicin (DOX). Both established cell lines (UKF‐NB‐2rVCR20 and UKF‐NB‐2rDOX100) were highly resistant to VCR, DOX and vice‐versa but retained their sensitivity to cisplatin. UKF‐NB‐2rVCR20 and UKF‐NB‐2rDOX100 expressed significant amounts of P‐glycoprotein, while parental cells were P‐glycoprotein negative. GD2 expression was upregulated, whereas NCAM expression was decreased in both resistant cells. Spectral karyotype (SKY) analysis revealed complex aberrant karyotypes in all cell lines and additional acquired karyotype changes in both resistant cells. All cell lines harbored high levels of N‐myc amplification. Compared to parental cells, UKF‐NB‐2rVCR20 and UKF‐NB‐2rDOX100 exhibited more than 2‐fold increase in clonal growth in vitro, accelerated adhesion and transendothelial penetration and higher tumorigenicity in vivo. We conclude that development of drug resistance and acquisition of certain karyotypic alterations is associated with an increase of additional malignant properties that may contribute to the poor prognosis in advanced forms of NB. The 2 novel neuroblastoma cell sublines also provide useful models for the study of drug resistance in aggressive forms of neuroblastoma.

DIFFERENCES IN SUPRATENTORIAL DAMAGE OF WHITE MATTER IN PEDIATRIC SURVIVORS OF POSTERIOR FOSSA TUMORS WITH AND WITHOUT ADJUVANT TREATMENT AS DETECTED BY MAGNETIC RESONANCE DIFFUSION TENSOR IMAGING

PURPOSE To elucidate morphologic correlates of brain dysfunction in pediatric survivors of posterior fossa tumors by using magnetic resonance diffusion tensor imaging (DTI) to examine neuroaxonal integrity in white matter. PATIENTS AND METHODS Seventeen medulloblastoma (MB) patients who had received surgery and adjuvant treatment, 13 pilocytic astrocytoma (PA) patients who had been treated only with surgery, and age-matched healthy control subjects underwent magnetic resonance imaging on a 3-Tesla system. High-resolution conventional T1- and T2-weighted magnetic resonance imaging and DTI data sets were obtained. Fractional anisotropy (FA) maps were analyzed using tract-based spatial statistics, a part of the Functional MRI of the Brain Software Library. RESULTS Compared with control subjects, FA values of MB patients were significantly decreased in the cerebellar midline structures, in the frontal lobes, and in the callosal body. Fractional anisotropy values of the PA patients were not only decreased in cerebellar hemispheric structures as expected, but also in supratentorial parts of the brain, with a distribution similar to that in MB patients. However, the amount of significantly decreased FA was greater in MB than in PA patients, underscoring the aggravating neurotoxic effect of the adjuvant treatment. CONCLUSIONS Neurotoxic mechanisms that are present in PA patients (e.g., internal hydrocephalus and damaged cerebellar structures affecting neuronal circuits) contribute significantly to the alteration of supratentorial white matter in pediatric posterior fossa tumor patients.

Oncomodulation by human cytomegalovirus: novel clinical findings open new roads

The question whether human cytomegalovirus may affect cancer diseases has been discussed (very controversially) for decades. There are convinced believers and strict opponents of the idea that HCMV might be able to play a role in the course of cancer diseases. In parallel, the number of published reports on the topic is growing. Recently published and presented (Ranganathan P, Clark P, Kuo JS, Salamat S, Kalejta RF. A Survey of Human Cytomegalovirus Genomic Loci Present in Glioblastoma Multiforme Tissue Samples. 35th Annual International Herpes Workshop, Salt Lake City, 2010) data on HCMV detection in glioblastoma tissues and colocalisation of HCMV proteins with cellular proteins known to be relevant for glioblastoma progression motivated us to recapitulate the current state of evidence.

Valproic acid treatment of glioblastoma multiforme in a child

Histone deacetylase-inhibitors (HDACi) are currently evaluated as a novel class of anti-cancer agents [1]. Valproic acid, a drug used for the treatment of epilepsy in children, has recently been shown to have HDAC inhibitory activity and may be useful in paediatric oncology [2,3]. We report the case of a 10-year-old boy with glioblastoma multiforme of 5 cm diameter located in the area of the pineal gland (Fig. 1a). The patient was treated with partial surgical resection and radiochemotherapy (54 Gy, vincristine/cisplatin/etoposide/ifosfamide) according to the German protocol for malignant gliomas in children (HIT-GBM-C). Because of severe therapy related side-effects and no evidence of tumour response (Fig. 1b/c) the chemotherapy was changed to topotecan after 20 weeks. However, the clinical condition progressively worsened as the patient developed psychomotoric seizures and topotecan was discontinued after 10 weeks. Repeat MRI of the brain demonstrated no tumour-response to the treatment (Fig. 1d,e). The patient was then started on oral valproic acid with gradual increase of dosage aiming for plasma trough-levels of greater than 1 mmol/L which is 2to 3-fold above concentrations commonly obtained in children with epilepsy. At this concentration, valproic acid has been shown to possess anti-tumour activities on cultured glioma cells in vitro [2]. Following valproic acid treatment, the clinical condition improved and the boy was able to go to school again. Fourteen weeks after onset of valproic acid, the tumoursize decreased with a documented complete remission after 10 months on MRI scans (Fig. 1e–h). However, the patient reduced the dosage himself because of drugrelated drowsiness, and subsequently the tumour relapsed 16 months after beginning of valproic acid treatment. We wish to point out that the patient achieved a remarkable response of a radiochemotherapy-refractory glioblastoma multiforme to an oral therapy on an ambulatory basis. In our view, the anti-tumoral potential of valproic acid should be further evaluated in clinical trials in paediatric oncology.

Circulating Growth Factor Levels Are Associated with Tumorigenesis in Neurofibromatosis Type 1

Purpose: Neurofibromatosis type 1 (NF1) is characterized by systemic development of neurofibromas. Early clinical diagnosis can be ambiguous, and genetic diagnosis can be prohibitively difficult. Dysregulation of a number of growth factors has been suggested to be a mechanism of pathogenesis. This study was performed to assess the contribution of circulating growth factors for diffuse tumorigenesis and the diagnostic value of circulating growth factor identification in serum. Experimental Design: The growth stimulation of neurofibroma-derived cells by serum from NF1 patients was tested, and serum growth factor levels in a cohort of NF1 patients (n = 39) between the ages of 7 and 70 years were analyzed. Results: Concentrations of midkine (MK) and stem cell factor, but not epidermal growth factor, were substantially increased in serum of NF1 patients when compared with healthy controls. Within the NF1 group, MK levels increased dramatically at puberty from an average of 0.79 ng/mL in patients <18 years to 1.18 ng/mL in patients >18 years old. Stem cell factor and MK concentrations above a defined threshold in serum of NF1 patients are of diagnostic benefit for 96% of patients in the cohort tested. Furthermore, serum from NF1 patients enhanced proliferation of human neurofibroma-derived primary Schwann cells and endothelial cells substantially better than normal serum. Conclusions: Enhanced circulating growth factor levels contribute to diffuse tumorigenesis in NF1 and may provide the basis for molecular diagnosis.