Jaroslav Štěrba

Lessons from the Fourth Metronomic and Anti-angiogenic Therapy Meeting, 24-25 June 2014, Milan.

The Fourth Metronomic and Anti-angiogenic Therapy Meeting was held in Milan 24–25 June 2014. The meeting was a true translational meeting where researchers and clinicians shared their results, experiences, and insights in order to continue gathering useful evidence on metronomic approaches. Several speakers emphasised that exact mechanisms of action, best timing, and optimal dosage are still not well understood and that the field would learn a lot from ancillary studies performed during the clinical trials of metronomic chemotherapies. From the pre-clinical side, new research findings indicate additional possible mechanisms of actions of metronomic schedule on the immune and blood vessel compartments of the tumour micro-environment. New clinical results of metronomic chemotherapy were presented in particular in paediatric cancers [especially neuroblastoma and central nervous system (CNS) tumours], in angiosarcoma (together with beta-blockers), in hepatocellular carcinoma, in prostate cancer, and in breast cancer. The use of repurposed drugs such as metformin, celecoxib, or valproic acid in the metronomic regimen was reported and highlighted the potential of other candidate drugs to be repurposed. The clinical experiences from low- and middle-income countries with affordable regimens gave very encouraging results which will allow more patients to be effectively treated in economies where new drugs are not accessible. Looking at the impact of metronomic approaches that have been shown to be effective, it was admitted that those approaches were rarely used in clinical practice, in part because of the absence of commercial interest for companies. However, performing well-designed clinical trials of metronomic and repurposing approaches demonstrating substantial improvement, especially in populations with the greatest unmet needs, may be an easier solution than addressing the financial issue. Metronomics should always be seen as a chance to come up with new innovative affordable approaches and not as a cheap rescue strategy.

Technique for PBSC harvesting in children of weight under 10 kg

Peripheral blood stem cell (PBSC) harvesting in the smallest children (weight <10 kg) using separators is complicated by specific problems. The volume of the separation set exceeds 25% of the total blood volume and the vascular access is generally not sufficient. Therefore, a simple manual technique for PBSC harvesting was developed. Three children (6–9 kg), with newly diagnosed tumours were scheduled to be treated with three to six sequential courses of high-dose chemotherapy, each followed by PBSC support. PBSC harvests were started after mobilization using cyclophosphamide and G-CSF when the peripheral blood CD34+ cell count exceeded 50/μl. About 50 ml of blood was drawn from a venous catheter, injected into a transfer bag containing ACD-A, and centrifuged. The buffy coat obtained was pooled in a collection bag, remaining plasma and erythrocytes were immediately reinfused and a subsequent cycle started. From three to 13 cycles were performed in 1–3 days and 18.0–32.2 × 106 CD34+cells/kg were collected. We did not detect any bacterial contamination or any notable complications. Fifteen PBSC reinfusions have been performed to date, each with rapid engraftment taking between 7 and 13 days. Patients are in very good PR (18 months from diagnosis) or in CR (6 and 8 months). We can conclude that this procedure is feasible and safe.Bone Marrow Transplantation (2002) 29, 57–61. doi:10.1038/sj.bmt.1703334

Profile of thrombin generation in children with acute lymphoblastic leukemia treated by Berlin-Frankfurt-Münster (BFM) protocols.

Treatment with L-asparaginase is associated with coagulation disturbances with deep venous thrombosis being the most common clinical consequence. Use of the calibrated automated thrombogram allows precise estimation of thrombin generated in vitro. We show the first data on thrombin generation, measured by calibrated automated thrombography (CAT), in children with acute lymphoblastic leukemia treated with L-asparaginase. Thrombin generation was measured by means of CAT in 23 children treated for acute lymphoblastic leukemia. Samples were obtained at predefined time points during the induction and reinduction phase of acute lymphoblastic leukemia-intercontinental Berlin–Frankfurt–Münster (BFM) 2000 or Associazione Italiana Ematologica Oncologia Pedaitrica Interim BFM 2000 protocols. Antihrombin and fibrinogen were measured on the same sample. Twenty-eight sets of thrombin generation measurements were collected from 23 patients. We observed no significant effect of antithrombin deficiency and/or hypofibrinogenemia on thrombin generation. Endogenous thrombin generation and peak thrombin were significantly higher during induction than in the reinduction phase (P < 0.001). Four patients with severe infection experienced an increase in thrombin generation, reaching maximum in a median of 7.5 days after the onset of infection. Two of those patients developed deep venous thrombosis at the time of peaked endogenous thrombin generation. Thrombin generation in children with acute lymphoblastic leukemia treated according to BFM protocols is significantly higher during the induction phase compared with reinduction and is not substantially affected by hypofibrinogenemia and/or antithrombin deficiency. Severe infection during the induction phase enhances thrombin generation with subsequent risk of thrombosis.

Analysis of the intracellular localization of p73 N-terminal protein isoforms TAp73 and ∆Np73 in medulloblastoma cell lines

The protein homologous to the tumor suppressor p53, p73, has essential roles in development and tumorigenesis. This protein exists in a wide range of isoforms with different, even antagonistic, functions. However, there are virtually no detailed morphological studies analyzing the endogenous expression of p73 isoforms at the cellular level in cancer cells. In this study, we investigated the expression and subcellular distribution of two N-terminal isoforms, TAp73 and ΔNp73, in medulloblastoma cells using immunofluorescence microscopy. Both proteins were observed in all cell lines examined, but differences were noted in their intracellular localization between the reference Daoy cell line and four newly established medulloblastoma cell lines (MBL-03, MBL-06, MBL-07 and MBL-10). In the new cell lines, TAp73 and ΔNp73 were located predominantly in cell nuclei. However, there was heterogeneity in TAp73 distribution in the cells of all MBL cell lines, with the protein located in the nucleus and also in a limited non-random area in the cytoplasm. In a small percentage of cells, we detected cytoplasmic localization of TAp73 only, i.e., nuclear exclusion was observed. Our results provide a basis for future studies on the causes and function of distinct intracellular localization of p73 protein isoforms with respect to different protein–protein interactions in medulloblastoma cells.

Malignant intracranial germinoma in Smith-Lemli-Opitz syndrome: cholesterol homeostasis possibly connecting morphogenesis and cancer development.

Smith-Lemli-Opitz syndrome is a rare hereditary autosomal recessive disease characterized by deficiency of 7-dehydrocholesterol reductase. Clinical picture encompasses prenatal and postnatal growth abnormalities and multisystemic structural malformations. To date, predisposition for tumor development is not considered a feature associated with this syndrome. Here, we describe a 16-year-old boy with Smith-Lemli-Opitz syndrome who developed cerebral germinoma. To our knowledge, this is the first report of association of this syndrome with malignant intracranial germ-cell tumor.

Bone marrow metastasis of malignant melanoma in childhood arising within a congenital melanocytic nevus

BACKGROUND Malignant melanoma in childhood is infrequent and can arise within congenital melanocytic nevi. Spread of malignant melanoma to the bone marrow, especially in children, is extremely rare. METHODS AND RESULTS Reported is a case of a 5-year-old boy with a congenital large melanocytic nevus of the head and neck who presented with a short history of low back and leg pain, fever and cervical lymphadenopathy. Despite regular follow-up by a dermatologist and plastic surgeon and repeatedly negative histology of previous partial excisions, diffuse bone marrow infiltration with malignant melanoma was diagnosed. The primary site was identified in the post-excision area. The disease progressed rapidly on ipilimumab immunotherapy and led to death at four months from the diagnosis. CONCLUSION Surveillance is indispensable in children with a predisposition to melanoma and nonspecific symptoms such as bone pain, gait impairment or cytopenia, should always be taken into account.

[The role of MicroRNAs in the pathophysiology of neuroblastoma and their possible use in diagnosis, prognosis and therapy].

Neuroblastoma (NBL) is a typical childhood tumor developing from the precursor cells of the sympathetic nervous tissue and accounting for approximately 7% of total malignancies in pediatrics and 15% of deaths associated with this malignancy. MicroRNAs (miRNAs) are small single-stranded RNA molecules that are involved in posttranscriptional regulation of gene expression, whereas the pathophysiology of neuroblastoma tumor growth involves both upregulation of the protooncogenic miRNAs as well as downregulation of the tumor-suppresor ones. Comparison of the expression profiles of miRNAs in specific subtypes of neuroblastoma seems to be a useful tool adding to the classification of the diseases, and the assessment of the levels of specific miRNAs may be useful for estimation of the individual treatment response as well as prognosis of the patient. This paper provides the basic review of the studies focused on the role of miRNAs in pathogenesis of neuroblastoma and provides a survey of current/ possible use of these miRNAs in diagnostics, therapy or prognosis estimation in the neuroblastoma patients.

Possibility of Endoscopic Third Ventriculostomy Instead of Internal Drainage System to Treat Obstructive Hydrocephalus in Children with Posterior Fossa Tumours

Introduction: Neuroendoscopy, as a mini-invasive neurosurgical procedure, is an alternative to implantation of drainage systems in particular. In indicated cases, this method could lower morbidity and increase the quality of life in children with brain tumours. In children with a tumour of posterior fossa, endoscopic third ventriculostomy (ETV) could be used instead of internal drainage system implantation. In patients with deep-seated intraventricular expansions, the diagnosis may be refined using endoscopic sample biopsy, and simultaneously, definitive treatment can be provided of the secondary hydrocephalus.