Max Lakomek

Poor Outcome for Children and Adolescents With Progressive Disease or Relapse of Lymphoblastic Lymphoma: A Report From the Berlin-Frankfurt-Muenster Group

PURPOSE Little is known about the outcome of pediatric patients with lymphoblastic lymphoma (LBL) who suffer from progressive disease or relapse. PATIENTS AND METHODS We analyzed the pattern of LBL relapses after current non-Hodgkins lymphoma Berlin-Frankfurt-Muenster (BFM) frontline therapy between April 1990 and March 2003. Relapse therapy was according to acute lymphoblastic leukemia (ALL) -Relapse-BFM protocols or ALL-BFM protocols for high-risk patients. RESULTS Twenty-eight (11%) of 251 registered patients with precursor T-cell LBL (T-LBL) and six (8%) of 73 patients with precursor B-cell LBL (pB-LBL) suffered from relapse. Of the 28 patients with T-LBL, one died from infection during relapse chemotherapy, 18 failed to achieve stable remission and died from disease progression, and nine reached allogeneic stem-cell transplantation (SCT). Two of these nine patients who underwent SCT died from transplantation-associated toxicity, three died from disease progression, and four are still alive. These four patients are in second remission of their lymphoma for 48, 68, 125, and 131 months, respectively, after allogeneic SCT. One of the four patients developed colon adenocarcinoma 47 months after SCT. Of the six patients with pB-LBL who experienced relapse, one patient died as a result of toxicity of relapse chemotherapy, two died from disease progression after chemotherapy, and three received allogeneic SCT. Of these, two died from subsequent disease progression, and one is still alive 57 months after allogeneic SCT. CONCLUSION Using modern conventional therapy in the frontline treatment of LBL, 10% of patients suffer from progressive disease or relapse. Because of the extremely poor reinduction success, the salvage rate for these patients is poor, with only a 14% (SE = 6%) overall survival. Long-term survival was only achieved in those few patients who were able to undergo an allogeneic SCT.

Alkylglycerol opening of the blood-brain barrier to small and large fluorescence markers in normal and C6 glioma-bearing rats and isolated rat brain capillaries.

The blood–brain barrier (BBB) represents the major impediment to successful delivery of therapeutic agents to target tissue within the central nervous system. Intracarotid alkylglycerols have been shown to increase the transfer of chemotherapeutics across the BBB. We investigated the spatial distribution of intracarotid fluorescein sodium and intravenous lissamine‐rhodamine B200 (RB 200)–albumin in the brain of normal and C6 glioma‐bearing rats after intracarotid co‐administration of 1‐O‐pentylglycerol (200 mM). To elucidate the mechanisms involved in the alkylglycerol‐mediated BBB opening, intraluminal accumulation of fluorescein isothiocyanate (FITC)–dextran 40,000 was studied in freshly isolated rat brain capillaries using confocal microscopy during incubation with different alkylglycerols. Furthermore, 1‐O‐pentylglycerol‐induced increase in delivery of methotrexate (MTX) to the brain was evaluated in nude mice. Microscopic evaluation showed a marked 1‐O‐pentylglycerol‐induced extravasation of fluorescein and RB 200–albumin in the ipsilateral normal brain. In glioma‐bearing rats, increased tissue fluorescence was found in both tumor tissue and brain surrounding tumor. Confocal microscopy revealed a time‐ and concentration‐dependent accumulation of FITC–dextran 40,000 within the lumina of isolated rat brain capillaries during incubation with 1‐O‐pentylglycerol and 2‐O‐hexyldiglycerol, indicating enhanced paracellular transfer via tight junctions. Intracarotid co‐administration of MTX and 1‐O‐pentylglycerol (200 mM) in nude mice resulted in a significant increase in MTX concentrations in the ipsilateral brain as compared to controls without 1‐O‐pentylglycerol (P<0.005). In conclusion, 1‐O‐pentylglycerol increases delivery of small and large compounds to normal brain and brain tumors and this effect is mediated at least in part by enhanced permeability of tight junctions.

Impact of conventional chemotherapy on levels of antibodies against vaccine-preventable diseases in children treated for cancer.

Intensive chemotherapy in children with malignancies causes partial immune deficiency, including long-term impairment of humoral immunity. We investigated the levels of antibodies against measles, mumps, polio, rubella, diphtheria, tetanus, and Haemophilus type b (Hib) in 139 children at the time of diagnosis of the malignant disease, during chemotherapy, after cessation of intensive treatment, and after re-vaccination. In general, cytostatic therapy resulted in a significant lowering of antibody levels. A decline of antibodies below the protective level as a consequence of cytostatic treatment was observed in 6% of the children for measles and mumps, in 18%, 12%, and 25% for polio types 1, 2, and 3, and in 21% for diphtheria. By contrast, rubella and tetanus antibodies remained within the protective range in all cases of this study. Re-vaccination 3 to 5 months after cessation of chemotherapy produced antibody levels about as high as those measured prior to therapy. Only 6 out of 83 children with previously positive antigen titres did not respond to re-vaccination. Vaccination or re-vaccination failed in 5 of 13 non-responders for more than 1 antigen, indicating a decreased reactability to vaccinations in some patients.

Ligands of the mitochondrial 18 kDa translocator protein attenuate apoptosis of human glioblastoma cells exposed to erucylphosphohomocholine

Background: We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires the mitochondrial 18 kDa Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor (PBR), to induce cell death via the mitochondrial apoptosis pathway. Methods: With the aid of the dye JC-1 and cyclosporin A, applied to glioblastoma cells, we now investigated the significance of opening of the mitochondrial permeability transition pore (MPTP) for ErPC3-induced apoptosis in interaction with the TSPO ligands, PK 11195 and Ro5 4864. Furthermore, we measured cytochrome c release, and caspase-9 and -3 activation in this paradigm. Results: The human glioblastoma cell lines, U87MG, A172 and U118MG express the MPTP-associated TSPO, voltage-dependent anion channel and adenine nucleotide transporter. Indeed, ErPC3-induced apoptosis was inhibited by the MPTP blocker cyclosporin A and by PK 11195 and Ro5 4864 in a concentration-dependent manner. Furthermore, PK 11195 and Ro5 4864 inhibited collapse of the mitochondrial membrane potential, cytochrome c release, and caspase-9 and -3 activation caused by ErPC3 treatment. Conclusions: This study shows that PK 11195 and Ro5 4864 inhibit the pro-apoptotic function of ErPC3 by blocking its capacity to cause a collapse of the mitochondrial membrane potential. Thus, the TSPO may serve to open the MPTP in response to anti-cancer drugs such as ErPC3.

Favourable outcome of patients with childhood acute promyelocytic leukaemia after treatment with reduced cumulative anthracycline doses

Acute promyelocytic leukaemia (APL) treatment often includes high cumulative doses of anthracyclines, which can cause long‐term cardiotoxicity. Here, we report the favourable outcome in 81 paediatric APL patients treated according to the consecutive acute myeloid leukaemia‐Berlin/Frankfurt/Muenster (AML‐BFM) trials ‐93/‐98/‐2004 with an anthracycline‐cytarabine regimen in combination with all‐trans‐retinoid acid (ATRA). Outcomes achieved by treatment with a reduced cumulative anthracycline dose (350 mg/m2) were comparable to those reported for studies with higher doses. Five‐year overall survival of the total cohort was 89 ± 4% and event‐free survival (pEFS) was 73 ± 6%. Overall survival was similar when comparing AML‐BFM trial periods (trial 93: 88 ± 8%, 98: 85 ± 7% and 2004: 94 ± 8%, P(logrank) = 0·63). Seventy‐five (93%) patients achieved complete remission. Most fatal events occurred during the first 6 weeks of treatment. Long‐term cardiotoxicity was observed in one patient. Two patients suffered from secondary haematological malignancies. Salvage treatment was effective in 7/9 patients (78%) with relapsed APL, who now are long‐term survivors after second line combination treatment with arsenic trioxide (4/7 patients) and stem cell transplantation (5/7 patients). Our results demonstrate that – combined with ATRA – a lower cumulative anthracycline dose can be used safely to maintain high cure rates and promote the reduction of long‐term sequelae, such as cardiotoxicity in APL patients.

On the diagnosis of erythrocyte enzyme defects in the presence of high reticulocyte counts

Summary. The separation of red blood cells into reticulocytes and young and old erythrocytes enables investigations of fractions with different contents of reticulocytes. Activities of hexokinase, glucose phosphate isomerase, phosphofructokinase, pyruvate kinase and glucose‐6‐phosphate dehydrogenase showed a linear relationship to reticulocyte counts. The dependence of these enzyme activities on the age of the red blood cells exhibited a strong decline from the reticulocyte to the young erythrocyte stage followed by only little further loss of activity, thus leading to a biphasic decay of enzyme activities.

Erucylphosphocholine‐induced apoptosis in glioma cells: involvement of death receptor signalling and caspase activation

Erucylphosphocholine (ErPC) is a promising anti‐neoplastic drug for the treatment of malignant brain tumours. It exerts strong anti‐cancer activity in vivo and in vitro and induces apoptosis even in chemoresistant glioma cell lines. The purpose of this study was to expand on our previous observations on the potential mechanisms of ErPC‐mediated apoptosis with a focus on death receptor activation and the caspase network. A172 and T98G glioma cells were treated with ErPC for up to 48 h. ErPC effects on the expression of the tumour necrosis factor (TNF) and TNF‐related apoptosis‐inducing ligand (TRAIL) receptor system, and on caspase activation were determined. ErPC had no effect on the expression of TNFα or TRAIL. Inhibition of the TNF or TRAIL signalling pathway with antagonistic antibodies or fusion proteins did not affect apoptosis induced by ErPC, and a dominant‐negative FADD construct did not abolish ErPC‐induced effects. Western blot analysis indicated that ErPC‐triggered apoptosis resulted in a time‐dependent processing of caspases‐3, ‐7, ‐8 and ‐9 into their respective active subunits. Co‐treatment of A172 cells with different caspase inhibitors prevented apoptosis but did not abrogate cell death. These data suggest that A172 cells might have an additional caspase‐independent pathway that insures cell death and guarantees killing of those tumour cells whose caspase pathway is incomplete.

The 18 kDa translocator protein influences angiogenesis, as well as aggressiveness, adhesion, migration, and proliferation of glioblastoma cells.

Background It is known that the mitochondrial 18 kDa translocator protein (TSPO) is present in almost all peripheral tissues and also in glial cells in the brain. TSPO levels are typically enhanced in correlation with tumorigenesis of cancer cells including glioblastoma. Relevant for angiogenesis, TSPO is also present in almost all cells of the cardiovascular system. Methods We studied the effect of TSPO knockdown by siRNA on various aspects of tumor growth of U118MG glioblastoma cells in two in-vivo models: a nude mouse model with intracerebral implants of U118MG glioblastoma cells and implantation of U118MG glioblastoma cells on the chorionallantoic membrane (CAM) of chicken embryos. In vitro, we further assayed the influence of TSPO on the invasive potential of U118MG cells. Results TSPO knockdown increased tumor growth in both in-vivo models compared with the scrambled siRNA control. Angiogenesis was also increased by TSPO knockdown as determined by a CAM assay. TSPO knockdown led to a decrease in adhesion to the proteins of the extracellular matrix, including fibronectin, collagen I, collagen IV, laminin I, and fibrinogen. TSPO knockdown also led to an enhancement in the migratory capability of U118MG cells, as determined in a modified Boyden chamber. Application of the TSPO ligand 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK 11195) at a concentration of 25 µmol/l in the in-vitro models yielded results similar to those obtained on TSPO knockdown. We found no effects of PK 11195 on TSPO protein expression. Interestingly, at low nmol/l concentrations (around 1 nmol/l), PK 11195 enhanced adhesion to collagen I, suggesting a bimodal concentration effect of PK 11195. Conclusion Intact TSPO appears to be able to counteract the invasive and angiogenic characteristics related to the aggressiveness of U118MG glioblastoma cells in vivo and in vitro.

Eight novel mutations and consequences on mRNA and protein level in pyruvate kinase-deficient patients with nonspherocytic hemolytic anemia.

Pyruvate kinase (PK) deficiency (PKD) is an autosomal recessive disorder with the typical manifestation of nonspherocytic hemolytic anemia. We analyzed the mutant enzymes of 10 unrelated patients with PKD, whose symptoms ranged from a mild, chronic hemolytic anemia to a severe anemia, by sequence analysis for the presence of alterations in the PKLR gene. In all cases the patients were shown to be compound heterozygous. Eight novel mutations were identified: 458T→C (Ile153Thr), 656T→C (Ile219Thr), 877G→A (Asp293Asn), 991G→A (Asp331Asn), 1055C→A (Ala352Asp), 1483G→A (Ala495Thr), 1649A→T (Asp550Val), and 183‐184ins16bp. This 16 bp duplication produces a frameshift and subsequent stop codon resulting in a drastically reduced mRNA level, and probably in an unstable gene product. Surprisingly, the existence of M2‐type PK could be demonstrated in the patients red blood cells. The study of different polymorphic sites revealed, with one exception, a strict linkage of the 1705C, 1738T, IVS5(+51)T, T(10) polymorphisms and the presence of 14 ATT repeats in intron 11. Our analyses show the consequences of a distorted structure on enzyme function and we discuss the correlations between the mutations identified and the parameters indicative for enzyme function. Hum Mutat 15:261–272, 2000.

Effects of 18-kDa translocator protein knockdown on gene expression of glutamate receptors, transporters, and metabolism, and on cell viability affected by glutamate.

Objective Previously, several important roles for glutamate have been described for the biology of primary brain tumors. For example, glutamate has been suggested to promote glioma cell proliferation by the activation of the 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic acid (AMPA) subtype of glutamate receptors. In the present study, we determined the potential regulatory roles of the 18-kDa translocator protein (TSPO) in the glutamatergic system in relation to cell death of brain tumor cells through knockdown of the TSPO by genetic manipulation. Materials and methods With microarray analysis and validation of gene expression of particular genes using real-time PCR, we found effects because of small inhibitory RNA knockdown of the TSPO in human U118MG glioblastoma cells on gene expression of glutamate receptors, glutamate transporters, and enzymes for glutamate metabolism. We also applied antisense RNA to silence TSPO in rat C6 glioblastoma cells and assayed the effects on DNA fragmentation, indicative of apoptosis, because of glutamate exposure. Results In particular, the effects of TSPO silencing in human U118MG cells related to glutamate metabolism indicate a net effect of a reduction in glutamate levels, which may potentially protect the cells in question from cell death. The TSPO knockdown in C6 cells showed that TSPO is required for the induction of apoptosis because of glutamate exposure. Conclusion These findings show that interactions between the TSPO and the glutamatergic system may play a role in tumor development of glioblastoma cells. This may also have implications for our understanding of the involvement of the TSPO in secondary brain damage and neurodegenerative diseases.