Leukemia-initiating cells of patient-derived acute lymphoblastic leukemia xenografts are sensitive toward TRAIL.

Cancer stem cells represent the most important target cells for antitumor therapy. TRAIL (TNF-related apoptosis-inducing ligand) is a potential anticancer agent that induces apoptosis in a wide variety of tumor cells, but its ability to target cancer stem cells is currently unknown. Here we investigated whether TRAIL targets leukemia-initiating cells. Limiting dilution transplantation assays were performed on xenografts from pediatric patients with precursor B-cell acute lymphoblastic leukemia (pre-B ALL) in NSG mice. In vitro treatment of xenograft cells with TRAIL significantly reduced and delayed their engraftment and procrastinated animal death from leukemia. Systemic TRAIL treatment of mice injected with patient-derived pre-B ALL xenograft cells abrogated leukemia in 3 of 5 mice in 1 sample. In conclusion, our data suggest that TRAIL targets leukemia-initiating cells derived from pre-B ALL xenografts in vitro and in vivo, and hence constitutes an attractive candidate drug for treatment of ALL.

Optimized anti-tumor effects of anthracyclines plus Vinca alkaloids using a novel, mechanism-based application schedule.

Application of anthracyclines and Vinca alkaloids on the same day represents a hallmark of polychemotherapy protocols for hematopoietic malignancies. Here we show, for the first time, that both drugs might act most efficiently if they are applied on different days. Proof-of-concept studies in 18 cell lines revealed that anthracyclines inhibited cell death by Vinca alkaloids in 83% of cell lines. Importantly, in a preclinical mouse model, doxorubicin reduced the anti-tumor effect of vincristine. Both drugs acted in a sequence-dependent manner and the strongest anti-tumor effect was obtained if both drugs were applied on different days. Most notably for clinical relevance, in 34% of 35 fresh primary childhood leukemia cells tested in vitro, doxorubicin reduced the anti-tumor effect of vincristine. As underlying mechanism, doxorubicin activated p53, p53 induced cell-cycle arrest, and cell-cycle arrest disabled inactivation of antiapoptotic Bcl-2 family members by vincristine; therefore, vincristine was unable to activate downstream apoptosis signaling. As molecular proof, antagonism was rescued by knockdown of p53, whereas knockdown of cyclin A inhibited vincristine-induced apoptosis. Our data suggest evaluating anthracyclines and Vinca alkaloids on different days in future trials. Selecting drug combinations based on mechanistic understanding represents a novel conceptional strategy for potent polychemotherapy protocols.

Administration of recombinant erythropoietin alone does not improve the phenotype in iron refractory iron deficiency anemia patients.

Mutations in transmembrane protease, serine 6 (TMPRSS6) cause iron refractory iron deficiency anemia (IRIDA). Parenteral iron administration may slightly improve hemoglobin level but is troublesome for patients. Optimal treatment has yet to be determined. We identified five patients from four independent families displaying the IRIDA picture with truncating biallelic mutations in TMPRSS6, one of which is novel. Liver iron determined by superconducting quantum interference device biosusceptometry ranged from 390 to 720 µg Fe/g wet weight (normal range 100-500; n = 3). Intestinal iron absorption (12 and 32 %, normal range 10-50; n = 2) and 59Fe erythrocyte incorporation after ingestion of 59Fe (57 and 38 %, normal range 70-90; n = 2) were inadequately low for iron-deficient anemic individuals. Baseline serum erythropoietin was elevated or borderline high in four patients. Administration of recombinant human erythropoietin (rhEPO) at up to 273 and 188 U/kg body weight/week alone did not improve anemia or result in a decrease of urinary hepcidin in two individuals. In conclusion, the ability of exogenous rhEPO to increase hemoglobin level appears to be impaired in IRIDA.

The long-term impact of in vitro drug sensitivity on risk stratification and treatment outcome in acute lymphoblastic leukemia of childhood (CoALL 06-97).

BACKGROUND: In a study of childhood acute lymphoblastic leukemia (CoALL 06-97 study), the in vitro sensitivity of the patients' cells to prednisolone, vincristine and asparaginase was introduced as a new additional risk parameter for treatment stratification. In parallel in vivo treatment response was assessed by determining the presence and extent of minimal residual disease in a subset of patients (n=224). Here we report the long-term impact of in vitro sensitivity-based risk stratification according to survival and compare the results of in vitro sensitivity with in vivo response. DESIGN AND METHODS: Patients with a sensitive in vitro profile were treated with a reduced intensity protocol (n=167) whereas patients defined as low risk according to conventional parameters but with a resistant in vitro profile were given intensified therapy (n=47). RESULTS: At a median follow-up of 6.8 years event-free survival was 0.80±0.03 for patients with a sensitive profile, 0.73±0.03 for those with an intermediate profile and 0.67±0.08 for those with a resistant profile (P=0.015). Overall, the treatment results of the cases stratified according to in vitro sensitivity were similar to those of the historical control group stratified based on conventional risk factors. Minimal residual disease at the end of induction was a strong predictor of outcome in B-precursor and T-cell acute lymphoblastic leukemia. There was no correlation between in vitro and in vivo treatment response in B-precursor leukemia (Spearman's r=0.13; P=0.15) in contrast to T-cell acute lymphoblastic leukemia (Spearman's r=0.63; P<0.001) CONCLUSIONS: A moderate reduction in treatment intensity for patients with a sensitive in vitro profile was possible without jeopardizing treatment outcome. However, in vitro drug testing was affected by a decrease in risk predictive power over time and was not correlated with in vivo assessment of minimal residual disease in B-precursor acute lymphoblastic leukemia. It was, therefore, abandoned in favor of the assessment of in vivo response in subsequent CoALL trials.

Impact of reduction of therapy on infectious complications in childhood acute lymphoblastic leukemia.

BACKGROUND: Infections are a major cause of morbidity and mortality in childhood acute lymphoblastic leukemia (ALL) and only limited information is available on infectious complications. PATIENTS AND METHODS: We investigated infectious complications in 293 children during different treatment phases of the multicenter protocol COALL-06-97. We also evaluated whether therapy reduction in prognostically good risk patients receiving either the low risk or high risk treatment arm would lead to fewer infectious complications. RESULTS: Thirty of 293 patients had no infections; 263 patients had 682 infectious complications (median 2, range 1-9), five of them lethal. Two thirds of the infections occurred during periods of neutropenia. The most frequent infectious episodes were fever of unknown origin (FUO): 483/682 (70.8%), microbiologically documented infections (MDI): 100/682 (14.6%), (61 gram-positive, 36 gram-negative, 3 fungal isolates), and clinically documented infections (CDI): 99/682 (14.5%). With standard reinduction, 44% low risk and 57% high risk patients had infections versus 26% low risk and 38% high risk patients with reduced reinduction therapy (P < 0.01). CONCLUSIONS: Most patients treated with intensive combination therapy for ALL experience one to several serious infections during treatment. The wide range in number of infectious episodes and the lack of infections in a small subset of patients in spite of uniform treatment suggest genetic as well as possibly environmental factors to have a role. Moderate reduction of chemotherapy may significantly reduce the rate of infectious episodes.

Laparoscopic partial adrenalectomy for recurrent pheochromocytoma in a boy with Von Hippel-Lindau disease.

We describe a case of a boy with Von Hippel-Lindau disease who presented with recurrent right adrenal pheochromocytoma 4.5 years after laparoscopic bilateral partial adrenalectomy. The boy had a second laparoscopic adrenal-sparing removal of the tumor. By this technique, not only the recurrent tumor was successfully removed but also the unaffected adrenal cortex could be preserved for the second time. To our knowledge, this is the first published case of its type.

Effective treatment of kaposiform hemangioendotheliomas associated with Kasabach-Merritt phenomenon using four-drug regimen.

We report a case of a 6-month-old girl suffering from a kaposiform hemangioendothelioma of the chest wall, associated with Kasabach-Merritt phenomenon. Despite rapid intervention with cortisone and interferon alpha the tumor led to a life-threatening clinical condition with progressive growth and consumption coagulopathy under therapy. Because therapy for kaposiform hemangioendotheliomas with a single anti-angiogenic or anti-proliferative agent has not been reported to be very successful, we administered vincristine, combined with cyclophosphamide, actinomycin D, and methotrexate in a critically ill patient. After six cycles of the applied four-drug regiment, the infant was in remission, which has been maintained for 5 months since stopping therapy.

The expression of 70 apoptosis genes in relation to lineage, genetic subtype, cellular drug resistance, and outcome in childhood acute lymphoblastic leukemia.

Childhood acute lymphoblastic leukemia (ALL) consists of various subtypes that respond differently to cytotoxic drugs and therefore have a markedly different clinical outcome. We used microarrays to investigate, in 190 children with ALL at initial diagnosis, whether 70 key apoptosis genes were differentially expressed between leukemic subgroups defined by lineage, genetic subtype, in vitro drug resistance, and clinical outcome. The expression of 44 of 70 genes was significantly different in T-versus B-lineage ALL, 22 genes differed in hyperdiploid versus nonhyperdiploid, 16 in TEL-AML1-positive versus-negative, and 13 in E2A-rearranged versus germ-line B-lineage ALL. Expression of MCL1 and DAPK1 was significantly associated with prednisolone sensitivity, whereas BCL2L13, HRK, and TNF were related to L-asparaginase resistance. BCL2L13 overexpression was also associated with unfavorable clinical outcome (P < .001). Multivariate analysis including known risk factors revealed that BCL2L13 expression was an independent prognostic factor (P = .011). The same trend was observed in a validation group of 92 children with ALL treated on a different protocol at St Jude (P = .051). In conclusion, ALL subtypes have a unique expression pattern of apoptosis genes and our data suggest that selective genes are linked to cellular drug resistance and prognosis in childhood B-lineage ALL.

Expression of the outcome predictor in acute leukemia 1 (OPAL1) gene is not an independent prognostic factor in patients treated according to COALL or St Jude protocols.

New prognostic factors may result in better risk classification and improved treatment of children with acute lymphoblastic leukemia (ALL). Recently, high expression of a gene named OPAL1 (outcome predictor in acute leukemia) was reported to be associated with favorable prognosis in ALL. Therefore, we investigated whether OPAL1 expression was of prognostic importance in 2 independent cohorts of children with ALL treated on Cooperative Study Group for Childhood Acute Lymphoblastic Leukemia (COALL)-92/97 (n = 180) and St Jude Total 13 protocols (n = 257). We observed a consistently higher (2.8-fold) expression of OPAL1 in TEL-AML1-positive ALL compared with TEL-AML1-negative ALL in both cohorts, but higher OPAL1 expression was not consistently associated with other favorable prognostic indicators such as age and white blood cell count, or ALL genetic subtype. Lower OPAL1 expression was also not associated with increased in vitro drug resistance. Multivariate analyses including known risk factors showed that OPAL1 expression was not independently related to prognosis in either the COALL or St Jude cohorts. In conclusion, OPAL1 expression may not be an independent prognostic feature in childhood ALL, and its previously reported prognostic impact appears to be treatment dependent.

Laparoscopic adrenal surgery for recurrent tumours in patients with hereditary phaeochromocytoma.

OBJECTIVE: To report our experience with Laparoscopic Partial Adrenalectomy (LPA) for recurrent tumours in patients with hereditary phaeochromocytoma. PATIENTS AND METHODS: Five patients with hereditary phaeochromocytoma (4 with von Hippel-Lindau disease and 1 with Multiple Endocrine Neoplasia 2B), who had undergone adrenal surgery previously, presented with recurrent adrenal tumours. One patient was pregnant at 20 weeks of gestation. All patients underwent hormonal evaluation, genetic screening and imaging with CT or MRI, metaiodobenzylguanidine (MIBG) scintigraphy. RESULTS: Of the 7 attempted LPA in five patients, five procedures (71%) were successfully completed and total adrenalectomy was needed on two occasions. The adrenal vein could be spared in all patients except one. There were no intra-operative complications. The adrenal function was adequate in all patients without need for steroid supplementation except one patient who lost both adrenals eventually. There was no correlation between the preservation of adrenal vein and adrenocortical function. CONCLUSION: Laparoscopic partial adrenalectomy is feasible, safe and effective in recurrent phaeochromocytoma, despite previous adrenal surgery and is technically easier if the previous approach had been laparoscopic as well. Patients with hereditary phaeochromocytoma are prone for recurrent tumours and may need repeated surgical procedures. Hence, minimally invasive approach is ideal for these patients.

Successful antifungal combination therapy with voriconazole and caspofungin.

A 12-year-old boy in third remission of an acute lymphoblastic leukaemia developed infection of lung and paranasal sinuses with Aspergillus flavus in neutropenia. Because of the high risk of leukaemia-relapse bone marrow transplantation (BMT) from a matched unrelated donor was carried out despite invasive pulmonary aspergillosis (IPA). It is the first reported patient with IPA, who was successfully treated by the antifungal combination therapy with voriconazole and caspofungin therapy during myeloablative BMT. Despite 6 weeks of aplasia, a dramatic decrease of lesions highly suggestive of aspergillosis was observed after BMT. Since discharge-oral voriconazole monotherapy has been continued.

Laparoscopic adnexectomy of a persistent ovarian tumor in a girl with acute lymphoblastic leukemia relapse.

The management of children with acute lymphoblastic leukemia (ALL) relapse and an ovarian tumor remains controversial. The authors report about a 4-year-old girl who developed a late bone marrow and cutaneous relapse of her pre-B-cell ALL and revealed an enlargement of her left ovary (4 x 3 x 2 cm). Chemotherapy (ALL-REZ-BFM pilot-protocol 2002) achieved effective remission, but the ovarian mass depicted no regression. Laparoscopic adnexectomy was performed and the tumor could be extracted in a specimen-bag through a 12-mm umbilical incision. Histology detected no viable lymphoblasts, but a fibrotic enlargement due to previous cellular infiltration. The authors conclude that in children with ALL relapse and an ovarian tumor, malignant infiltration as well as local response to chemotherapy can be judged only by surgical excision and histopathologic examination. Laparoscopic oophoradnexectomy is a valuable management option in these children.

Thioguanine offers no advantage over mercaptopurine in maintenance treatment of childhood ALL: results of the randomized trial COALL-92.

The German cooperative study group for childhood acute lymphoblastic leukemia (COALL-92) was designed to examine the clinical effectiveness of thioguanine (TG) versus mercaptopurine (MP) in maintenance treatment of childhood acute lymphoblastic leukemia (ALL) in a randomized multicenter trial. TG and MP are prodrugs and have to be converted intracellularly to 6-thioguanine nucleotides (TGNs) for cytostatic activity. TG is converted into TGN in fewer steps and has been shown to be more cytotoxic in equimolar doses in vitro compared with 6-MP. Therefore, a higher effectiveness of TG in maintenance treatment was postulated. Of 521 patients enrolled into the protocol, 474 were randomized to receive either MP or TG during maintenance therapy in a daily oral dose. After a median observation time of 6.6 years, the probability of event-free survival was 79% +/- 3% for the MP group (238 children) and 78% +/- 3% in the TG group (236 patients). In spite of TGN levels, exceeding those of the MP group 7 times, treatment with TG did not improve the outcome but was more complicated to handle due to a specific toxicity profile of prolonged myelosuppression with marked thrombocytopenia. Therefore, MP should remain the preferred drug for maintenance treatment of ALL, unless other studies demonstrate superiority of TG in larger trials or selected patient groups.

Novel tumor antigens identified by autologous antibody screening of childhood medulloblastoma cDNA libraries.

Medulloblastoma is an embryonal childhood malignancy with poor prognosis. By screening 4 medulloblastoma cDNA expression libraries (SEREX) with autologous sera, 15 different antigens were identified. These antigens were encoded by 3 novel genes, genes of unknown function (KIAA0445, KIAA1853, KIAA0665, FLJ13942, HSPC213), a proto-oncogene (rab18), candidate tumor suppressor genes (BAP1, PRDM13) and genes encoding a motor protein (kinesin-2), a histone (H2A1.2), the ankyrin residue-rich nasopharyngeal cancer susceptibility protein (NZ16) and the transcription factor TZP, which is homologous to the tumor-associated antigens HCA58 and GLEA2. In a consecutive analysis of serum antibody titers and tumor load, a more than 10-fold increase in serum antibodies against PRDM13 preceded the clinical diagnosis of recurrent tumor growth in a patient with aggressive large cell medulloblastoma. When sera of pediatric patients with cancer (n = 40) and healthy controls (n = 40) were tested for humoral responses against the SEREX-defined antigens, 5 antigens were exclusively recognized by sera from cancer patients. These antigens included a novel rab18 gene product translated from mRNA sequences formerly described as 3' untranslated region. Humoral responses against 2 of the remaining 10 antigens were found preferentially in cancer patients. Antibodies against these antigens were detected in 8/40 and 12/40 cancer patients, respectively, but in only 1 healthy control. The 2 antigens were characterized by a tumor-specific deletion and a tumor-specific mutation, respectively. These findings indicate that the humoral immune response against medulloblastoma is directed against diverse antigens that may be useful as diagnostic markers or targets for immunotherapy.