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Background: A major issue in the treatment of acute myeloid leukemia (AML) is resistance to chemotherapeutic drugs. Multidrug resistance can be caused by ATP-binding cassette (ABC) transporters that function as drug efflux pumps. The majority of these proteins have not yet been examined in malignant diseases.Experimental Design: A newly developed microarray for the simultaneous quantification of 38 ABC transporter genes and Taqman real-time PCR was used to analyze the expression of ABC transporters in pediatric AML and healthy bone marrow. Small interfering RNA was used to verify the role of ABCA3 in drug resistance.Results: Using the microarray, we identified four new ABC transporters, which were overexpressed in many AML samples compared with healthy bone marrow: ABCA2, ABCA3, ABCB2, and ABCC10. The overexpression of these four genes was verified by real-time PCR in 42 samples from children with AML and 18 samples of healthy bone marrow. The median expression of ABCA3 was three times higher in 21 patients who had failed to achieve remission after the first course of chemotherapy than in a well-matched group of 21 patients who had achieved remission at this stage (P = 0.023). Incubation of cell lines with a number of different cytostatic drugs induced an up-regulation of ABCA3. Down-regulation of ABCA3 by small interfering RNA sensitized cells to doxorubicin.Conclusion: Our results show that ABCA2, ABCA3, ABCB2, and ABCC10 are overexpressed in childhood AML compared with healthy bone marrow. ABCA3 is the most likely transporter to cause drug resistance.

Supplementary Figures 1-2 from ABCA3 as a Possible Cause of Drug Resistance in Childhood Acute Myeloid Leukemia

In recent years, vegetarian and vegan diets became increasingly important as they are associated with beneficial health outcomes. Therefore, the NuEva study compares the impact of flexitarian, vegetarian, or vegan diets with omnivorous nutritional habits on nutrient intake and risk factors for non-communicable diseases.A dietary protocol was kept over five days and blood and 24h urine samples were collected to examine the impact of dietary habits [omnivores,The increased exclusion of animal based foods in the diet (omnivoresflexitariansvegetariansvegans) is associated with a decreased intake of energy, saturated fat, cholesterol, disaccharides, and total sugar as well an increased intake of dietary fibers, beta carotene, vitamin E and K. The combined index of the B12 status (4cB12 score) in vegetarians (0.02/0.75) was lower compared to omnivores (0.34/0.58;The NuEva study confirms the position of the Academy of Nutrition and Dietetics that adequately planned vegetarian diets are healthy, nutritionally adequate, and may provide health benefits in the prevention and treatment of non-communicable diseases. Nevertheless, critical nutrients were identified for all groups studied. This highlights the need to develop individual nutritional concepts to ensure an adequate nutrient intake.

Zusammenfassung Ziel Bestimmung des quantitativen Ultraschallparameters Schallgeschwindigkeit (Speed of Sound, SOS) bei Neugeborenen zur Erhebung von Referenzdaten und Untersuchung von Einflussfaktoren. Material und Methoden 219 Neu- und 14 Frühgeborene (28. – 41. Schwangerschaftswoche) mit Geburtsgewicht zwischen 590 und 4930 g wurden in den ersten Lebenstagen mit Sunlight Omnisense 7000 P untersucht. Referenzdaten für SOS wurden bei 178 eutrophen Neugeborenen an der Tibia erhoben. Ergebnisse SOS-Referenzwerte an der Tibia liegen bei 3028±92 m/s Schlussfolgerungen Der Ultraschallparameter SOS kann bei Früh- und Neugeborenen suffizient an der Tibia ermittelt werden. Die erhobenen Referenzdaten von kaukasischen Neugeborenen sind geeignet, um eine Frühgeborenen-Osteopenie zu identifizieren.

A primiparous pregnant woman was admitted due to preterm premature rupture of membranes (PPROM) at 27+0 week of gestational age (WGA). Conventional vaginal microbiological analysis had no pathological finding. Management decisions based on national guidelines included antenatal corticoids, tocolytics and antibiotics. Unstoppable efforts of preterm labor in 28+0 WGA and supposed amniotic infection syndrome necessitated emergency cesarean section. The preterm infant underwent NICU therapy, developed an early-onset neonatal sepsis and therapy-refractory pulmonary insufficiency with consecutive right heart failure, resulting in death on the 36th day of life. Microbiota analyses by 16Sr DNA sequencing was performed from maternal vaginal swabs and from neonatal pharyngeal swabs. Maternal antibiotic treatment resulted in depletion of physiological vaginal colonization with Lactobacillus crispatus. Ureaplasma parvum became the dominant vaginal microorganism at delivery and was detected in high relative abundance in the neonatal specimen. Progressive radiological air-space changes and interstitial pathologies associated with Ureaplasma infection (bronchopulmonary dysplasia type III) were seen early at the 3rd and distinctly from 14th day of life. This clearly demonstrates the need of vaginal colonization diagnostics in PPROM patients and awareness of the consecutive risks in the preterm. Vaginal microbiome analysis may allow individualized and targeted maternal and fetal diagnostic, prophylactic and therapeutic strategies to identify, protect and treat the high-risk neonates after PPROM.

MALDI-TOF mass spectrometry (MS) may be used as a rapid typing method for nosocomial pathogens. Here, we evaluated MALDI-TOF MS for discrimination of hospital outbreak-related clusters of Serratia marcescens and carbapenemase-producing Citrobacter freundii. Thirty-three S. marcescens isolates collected from neonatal intensive care unit (NICU) patients, and 23 C. freundii isolates including VIM-positive isolates from a hospital colonization outbreak were measured by Vitek MS. Consensus spectra of each isolate were clustered using SARAMIS software. Genotyping was performed by whole-genome sequencing (WGS). First, a set of 21 S. marcescens isolates from 2014 with seven genotypes including three monoclonal clusters was used for the evaluation of MALDI-TOF typing. MS clustering was largely in agreement with genotyping results when the similarity cut-off for clonal identity was set on 90%. MALDI-TOF cluster analysis was then investigated for the surveillance of S. marcescens in the NICU in 2017 and demonstrated the introduction of new strains into the hospital and nosocomial transmissions. MS analysis of the C. freundii outbreak in 2016 revealed a monoclonal cluster of VIM-positive isolates and the separation of epidemiologically non-related VIM-positive and negative isolates. Two additional VIM-positive Citrobacter isolates from food samples were closely related to the large monoclonal cluster. WGS confirmed the MS results. MALDI-TOF MS may be used as a first-line typing tool for S. marcescens and C. freundii to detect transmission events in the hospital because isolates of an identical WGS type were grouped into the same MS cluster.

Summary Background The prevalence of nasopharyngeal colonization with Staphylococcus aureus can reach 20–30% among the population, which can lead to invasive infection. Aim To investigate the prevalence of colonization among different age groups, and analyse S. aureus strain-specific virulence patterns. Method For analysis of the prevalence of colonization, groups consisting of newborns, healthy volunteers aged 5–60 years, and nursing home residents aged >80 years were examined with nasopharyngeal swabs. After S. aureus was cultured, genetic analysis and phenotypic virulence testing were performed by cell-based assays. Findings Among 924 volunteers, the overall colonization rate was approximately 30%, with a peak in subjects aged 5–10 years (49%). Neonates and subjects aged >80 years showed different distributions of clonal clusters. Overall, the strains of all age groups exhibited virulence characteristics that can contribute to the development of infection. In particular, the neonatal strains exhibited a high incidence of toxin genes that resulted in increased cytotoxic effects compared with the other strains tested. Conclusions Colonizing strains showed a virulence profile in all age groups, which may lead to the establishment of invasive infection. Consequently, decolonization measures could be considered for selected patients depending on the risk of infection.

The diagnostic proof of fungal infection in preterm infants is difficult. Antifungal treatment (AFT) is often initiated empirically when infants with suspected infection do not improve despite broad-spectrum antibiotic therapy. It was the aim of our study to determine the rate of exposure to empirical AFT in a large cohort of very low birth weight infants (VLBWI) of the German Neonatal Network and to address associated risks and outcomes.The epidemiologic database consisted of n = 13,343 VLBWI born in 54 German Neonatal Network centers between 2009 and 2015. AFT was defined as number of neonates who got any dose of at least one of the following antifungal drugs: fluconazole, amphotericin B, voriconazole and caspofungin (denominator: number of infants enrolled in German Neonatal Network) for treatment (not prophylaxis) of (suspected) fungal infection. Univariate and logistic regression analyses were used to identify risk factors for exposure to AFT and associated short-term morbidities and long-term outcomes at 5-year follow-up.In our cohort, 724 out of 13,343 (5.4%) VLBWI were exposed to empiric AFT and had a mean gestational age of 25.7 (±2.1) weeks. Forty-four out of 13,343 (0.3%) had proven bloodstream infection with Candida spp. The main risk factors for exposure to AFT were gestational age, postnatal steroid treatment, need for abdominal surgery and use of carbapenems. Notably, AFT was associated with adverse outcomes such as bronchopulmonary dysplasia [adjusted odds ratio (OR): 1.9; 95% confidence interval (CI): 1.6-2.3; P0.001) and retinopathy of prematurity requiring intervention (adjusted OR: 1.69; 95% CI: 1.3-2.3; P0.001) but not mortality. In the subgroup of infants available for 5-year follow-up (n = 895), exposure to AFT was associated with a risk for cerebral palsy (adjusted OR: 2.79; 95% CI: 1.11-7.04; P = 0.04) and intelligence quotient85 (adjusted OR: 2.07; 95% CI: 1.01-4.28; P = 0.049).A significant proportion of VLBWI is exposed to AFT, specifically those born26 weeks. Exposed infants were found to have a higher risk for adverse outcomes, which may reflect their significant vulnerability in general. Given the observational design of our study, it remains unclear whether potential side effects of empirical or target AFT itself contribute to adverse outcome. Future studies need to include risk-based strategies and stewardship programs to restrict the use of antifungal management in VLBWI.

Aim: Assessment of dental health in the primary dentition of preterm infants (PTI) including investigation of mother- and infant-related risk factors in a case-control study design. Material and Methods: One hundred twenty-eight infants aged 3-4 years were included. Sixty-four PTI (27 males) were randomly selected from the preterm registry of the Jena University Hospital. As a control group served 64 full-term infants (FTI) recruited from the Department of Paediatric Dentistry, matched for age and sex. Dental examinations were provided by one dentist under standard clinical conditions. Caries was scored using the International Caries Detection and Assessment System (ICDAS II) and the DMFT, gingival health using the Periodontal Screening Index, and developmental defects of enamel using the DDE index. Mother- and infant-related factors were collected via a questionnaire and from medical records. Results: The caries prevalence was 50.0% (ICDAS II >0) in PTI and 12.5% (ICDAS II >0) in FTI. The caries experience was higher in PTI (DMFT 1.0 ± 3.1) than in FTI (DMFT 0.3 ± 1.0). PTI had a higher risk of caries (OR 7.0), initial lesions (OR 6.2), DDE (OR 7.5), and gingivitis (OR 6.5) than FTI. The highest risk occurred in PTI with an extremely low birth weight (Conclusions: PTI had less healthy teeth than FTI and are at a higher risk for DDE, caries, and gingivitis. The poorer dental health in PTI is associated with a low birth weight, a low socioeconomic status, and mothers' illness during pregnancy.

The aim was to determine whether the quantitative ultrasound (QUS) parameter speed of sound (SOS) is sufficient for evaluation of reference data in the newborn and how they are influenced.219 full-term and 14 preterm infants (gestational age 28-41 weeks (GA), birth weight 590-4,930 g) were evaluated by Omnisense 7000 P on their tibia. Reference values were sampled in 178 eutrophic infants.SOS reference values at the tibia were 3028 m/s for GA40 and 3057 m/s for ≥ 40 weeks. There was a significant correlation between SOS and gestational age. SOS was significantly higher in male (3058.3±93.3 vs. 3022.8±93.4 m/s; p 0.012) infants. If birth weight was below 3,800 g, there was a correlation between SOS and weight (p0.05). Preterm infants showed lower SOS than term babies (p0.05).Speed of sound can be evaluated sufficiently in preterm and term infants on the tibia. The estimated reference data can be used to identify osteopenia in the preterm infant with low birth weight.ZIEL: Bestimmung des quantitativen Ultraschallparameters Schallgeschwindigkeit (Speed of Sound, SOS) bei Neugeborenen zur Erhebung von Referenzdaten und Untersuchung von Einflussfaktoren.219 Neu- und 14 Frühgeborene (28. – 41. Schwangerschaftswoche) mit Geburtsgewicht zwischen 590 und 4930 g wurden in den ersten Lebenstagen mit Sunlight Omnisense 7000 P untersucht. Referenzdaten für SOS wurden bei 178 eutrophen Neugeborenen an der Tibia erhoben.SOS-Referenzwerte an der Tibia liegen bei 3028±92 m/s40. SSW und 3057±96 m/s ≥ 40. SSW. Zwischen SOS und Gestationsalter besteht eine signifikante Korrelation, männliche Neugeborene weisen signifikant höhere SOS auf. Bei Geburtsgewicht3800 g besteht eine Korrelation zwischen SOS und Gewicht (p0,05). Frühgeborene haben signifikant niedrigere SOS als eutrophe Neugeborene (p0,05).Der Ultraschallparameter SOS kann bei Früh- und Neugeborenen suffizient an der Tibia ermittelt werden. Die erhobenen Referenzdaten von kaukasischen Neugeborenen sind geeignet, um eine Frühgeborenen-Osteopenie zu identifizieren.

Systematische Erfassung der praktischen Umsetzung aktueller Empfehlungen der KRINKO zur Pravention nosokomialer Infektionen bei Fruh- und Neugeborenen an Thuringer Kinderkliniken. Alle 18 Behandlungszentren Thuringens wurden eingeschlossen, 83% davon (15/18) haben geantwortet. Der Erfullungsgrad betrug jeweils 100% bei Level-1 (3/3) und Level-2 Zentren (5/5), sowie 70% bei Level-3 Zentren (7/10). Evaluiert wurden angewandte Infektions-Praventionsmasnahmen sowie die strukturell-organisatorische Parameter. Das wochentliche mikrobiologische Kolonisationsscreening wurde von allen Zentren bei Fruhgeborenen mit einem Geburtsgewicht Diese deskriptive Bestandsaufnahme zeigt intensive Kolonisation-Surveillance-Masnahmen in Thuringen. Gleichzeitig werden Defizite hinsichtlich strukturell-organisatorischer Voraussetzungen aufgezeigt. In wie weit strukturelle und praventive Masnahmen eine Reduktion von nosokomialen Infektionen erkennen lassen, sollte in weiteren prospektiven Untersuchungen uberpruft werden.

Systematic recording of practical implementation of current recommendations of KRINKO for the prevention of nosocomial infections in premature and newborn infants in children's hospitals in Thuringia. All neonatal treatment centers in Thuringia (n=18) were included in this survey. Answer were received from 83% (15/18). Degree of compliance was 100% in level-1 (3/3) and level-2 centers (5/5), and 70% in level-3 centers (7/10). The aim of the questionnaire was to evaluate infection prevention measures as well as structural/organizational parameters in neonatal centers in Thuringia. Preventive measures as well as weekly screening for colonization was fully performed in patients with a birth weight1 500 g (n=205) at all centers. Additionally, prolonged screening and colonization surveillance measures were performed in 60% of all units until discharge from the hospital. Results related to structural/organizational parameters and especially structural conditions in neonatal centers in Thuringia pointed up challenges (2 m minimum distance between incubators in 27% (n=4/15), isolation in single room in 53% (n=8/15)). Insufficient number of staff also hamper the complete implementation of KRINKO recommendations (intensive care unit: patient/staff ratio (MW±SD) 2.5±1.1; newborn area 4.3±0.9). Analysis shows actual rate of implementation of KRINKO recommendations as well as structural/organizational parameters in neonatal treatment centers in Thuringia. It provides important points for discussion regarding necessary staff numbers and structural conditions. Analysis could also be used for future surveys in other regions in Germany.

Insulin-like growth factor (IGF) system as regulator for cellular proliferation is of particular interest in search for new prognostic approaches in cancer treatment.We analyzed the mRNA expression profile of IGF-I, -II, and IGFBP-2, -3 in 50 children with previously untreated AML (mean age 10.8 +/- 4.8 years; patients in CCR n = 20, patients with relapse during later course of disease n = 15). MNC samples from peripheral blood as well as bone marrow of healthy donors were used as controls.IGFBP-2 expression was significantly higher in AML cells than in healthy cells of peripheral MNC (P0.001) and of bone marrow cells (P0.01). Conversely, AML cells showed significantly lower IGFBP-3 and IGF-I gene expression compared to controls (P = 0.02; P0.001). Patients with relapse (median +/- range: 0.0929 +/- 0.049) during later course of disease demonstrated higher IGFBP-2 expression compared to patients in CCR (0.0121 +/- 0.047; P = 0.06) at time of diagnosis. A multivariate analysis identified the IGFBP-2 mRNA expression as an independent factor for the prediction of relapse. Furthermore, the probability of relapse-free survival (RFS) in patients with IGFBP-2 mRNA level0.1000 was 28%; whereas, the probability of RFS in patients with IGFBP-2 mRNA level0.1000 was 62% (P = 0.04, log-rank test). No prognostic influence could be found for the other investigated genes.Results identified different expressions of IGF components between normal and AML cells. Patients with IGFBP-2 mRNA levels up to 0.1000 (relative to KG1 cell line) more likely developed a relapse. Identification of these patients at diagnosis may allow more individualized treatment.

In 2013, the German Commission for Hospital Hygiene and Infectious Disease Prevention (KRINKO) stated that extending weekly colonisation screening from very low birth weight (VLBW) infants (

Objective To assess whether breastmilk feeding is associated with a reduced risk of bronchopulmonary dysplasia (BPD). Secondary outcome measures analyzed were retinopathy of prematurity (ROP) and necrotizing enterocolitis (NEC). Study design In an ongoing multicenter cohort study, the data of 1433 very low birth weight infants born before 32 weeks of gestation and discharged in 2013 were analyzed. We compared growth and neonatal complications of infants who received breastmilk exclusively (N = 223) with those who received formula feedings exclusively (N = 239). Logistic regression models were estimated for BPD, ROP, and NEC using nutrition as an independent variable. The Firth logistic regression model and Lasso were used for sensitivity analyses. Results Exclusively breastmilk-fed infants gained less weight compared with formula-fed infants. SDS for weight decreased between birth and discharge (median (Q1-Q3): formula −0.9 (−1.4 to [−0.5]) vs breastmilk −1.1 (−1.7 to [−0.6])). Exclusive formula feeding of very low birth weight infants was associated with increased risks of BPD (OR 2.6) as well as NEC (OR 12.6) and ROP (OR 1.80) after controlling for known risk factors. Conclusions Exclusive breastmilk feeding was associated with lower growth rates and a reduced risk of BPD as well as NEC and ROP.

Background: A major issue in the treatment of acute myeloid leukemia (AML) is resistance to chemotherapeutic drugs. Multidrug resistance can be caused by ATP-binding cassette (ABC) transporters that function as drug efflux pumps. The majority of these proteins have not yet been examined in malignant diseases. Experimental Design: A newly developed microarray for the simultaneous quantification of 38 ABC transporter genes and Taqman real-time PCR was used to analyze the expression of ABC transporters in pediatric AML and healthy bone marrow. Small interfering RNA was used to verify the role of ABCA3 in drug resistance. Results: Using the microarray, we identified four new ABC transporters, which were overexpressed in many AML samples compared with healthy bone marrow: ABCA2, ABCA3, ABCB2, and ABCC10. The overexpression of these four genes was verified by real-time PCR in 42 samples from children with AML and 18 samples of healthy bone marrow. The median expression of ABCA3 was three times higher in 21 patients who had failed to achieve remission after the first course of chemotherapy than in a well-matched group of 21 patients who had achieved remission at this stage (P = 0.023). Incubation of cell lines with a number of different cytostatic drugs induced an up-regulation of ABCA3. Down-regulation of ABCA3 by small interfering RNA sensitized cells to doxorubicin. Conclusion: Our results show that ABCA2, ABCA3, ABCB2, and ABCC10 are overexpressed in childhood AML compared with healthy bone marrow. ABCA3 is the most likely transporter to cause drug resistance.

Drug resistance can be caused by ATP-binding-cassette (ABC)-transporters which function as outward pumps for chemotherapeutic drugs. The aim of the present study was to analyze the association between eight ABC-transporters (BCRP, MDR1, SMRP, MRP1, MRP2, MRP3, MRP4, and MRP5) and in vitro drug resistance. Leukemic cells from 52 children with previously untreated acute leukemia (ALL: n=37; AML: n=15) were analysed. The expression of the ABC-transporters was measured by TaqMan real-time PCR. In vitro drug resistance to cytarabine, vincristine, tioguanine, daunorubicin, etoposide, dexamethasone, and prednisone was analysed with methyl-thiazol-tetrazolium (MTT) assays.MDR1 was weakly associated with resistance to vincristine (p

OBJECTIVE Adiponectin (APN) may play a role in adapting energy metabolism at the maternal-fetal unit. The aim of the study was to investigate the relationship between placental APN mRNA expression, maternal serum APN concentration and umbilical cord serum APN concentration in full-term healthy newborns. METHODS Serum APN levels were compared in 46 samples (23 from healthy newborns; gestational age 37.0 to 41.5 weeks) and their mothers (n=23). The APN concentration was measured using enzyme linked immunosorbent assay (ELISA). We analyzed the mRNA expression profile of APN in 22 placenta tissue samples using real time polymerase chain reaction (RT-PCR). RESULTS The highest APN serum concentrations were found in umbilical cord blood, these were significantly higher than maternal APN levels (mean concentration±SD; 38.48±12.8 vs. 6.6±2.3 μg/mL, p

Background: Mesothelin is a promising candidate for tumor-specific therapy because of its limited expression in normal tissues and high expression in several cancers. The expression of the protein mesothelin in hematological malignancies has not yet been analyzed. SS1(dsFv)PE38 is a recombinant anti-mesothelin immunotoxin which is undergoing clinical evaluation in patients with mesothelin-expressing tumors. Methods and Results: In this study we show that the mesothelin protein is expressed in leukemic cells from children with acute myeloid leukemia (AML). This finding was confirmed by western blot, immunocytochemistry and real time polymerase chain reaction (PCR). Despite the expression of mesothelin, the patient samples were not sensitive to immunotoxin SS1(dsFv)PE38 in MTT assays. Conclusions: Primary AML cells express mesothelin but SS1(dsFv)PE38 is not active in killing these cells. Other approaches that utilize mesothelin as a target might be more effective and should be tested against AML cells.

Insulin-like growth factor binding protein (IGFBP)-2 has mitogenic effects in normal and neoplastic cells. The purpose of this study is to examine the diagnostic and prognostic significance of elevated IGFBP-2 levels in children with AML after hematopoietic stem cell transplantation (HSCT) at relapse and continuous complete remission (CCR). In 27 children with AML (mean age 13.6+/-5.3 years; patients in remission n=15 with relapse n=12) serum parameters of IGFBP-2, IGFBP-3, IGF-I and IGF-II were analyzed up to 18 months after HSCT by RIA. AML-patients with evidence of relapse demonstrated a continuous increase of IGFBP-2 levels during the follow-up. At day 100 after HSCT, IGFBP-2 concentrations were significantly higher in patients with relapse than in children without relapse (7.4+/-4.0 standard deviation score (SDS) vs 3.9+/-1.7 SDS; P=0.01). Serum IGFBP-2 was identified as an independent factor for the prediction of relapse. Furthermore, the probability of relapse-free survival (RFS) in patients with IGFBP-24.5 SDS at day 100 after HSCT was 31% compared to patients with IGFBP-24.5 SDS was 72% (P=0.004). Patients with IGFBP-2 concentration up to 4.5 SDS more likely developed a relapse and had a poorer outcome. Identification of these patients allows a more individualized and aggressive adjuvant treatment and follow-up.

Background: Monitoring of minimal residual disease (MRD) has become a strong diagnostic tool in acute lymphoblastic leukemia. It is used for risk-adapted therapy and for the recognition of pending relapses. In acute myeloid leukemia (AML), there is still a need for more suitable MRD markers. Experimental Design: A stepwise approach which combined genome-wide expression profiling, TaqMan low density arrays, and a TaqMan real-time PCR-based screening was used to identify new markers for the monitoring of MRD in AML. Leukemic cells from 52 children with AML and 145 follow-up samples from 25 patients were analyzed. Results: Seven genes were identified which are vastly overexpressed in many patients with AML compared with healthy bone marrow: CCL23, GAGED2, MSLN, SPAG6, and ST18 as well as the previously described markers WT1 and PRAME. The expression of all genes decreased to normal levels in patients who achieved a continuous complete remission. Elevated levels of at least one gene were found prior to relapse in 7 out of 10 patients who relapsed. Conclusions: This set of genes should allow a sensitive and specific monitoring of MRD in AML. Notably, some of these markers could also serve as therapeutic targets or might be involved in leukemogenesis. MSLN is already used as a target for immunotherapy in clinical trials in other malignancies.

Insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) may play an important role in tumor proliferation. This study aimed to investigate the IGF system in children with acute leukemia prior to and after hematological stem cell transplantation (HSCT). In 51 patients (AML n=27; ALL n=24; mean age 11.2+/-4.8 years), serum parameters (IGF-I,-II, IGFBP-2,-3) were investigated up to 18 months after HSCT by RIA. Patients with AML showed a significant increase of IGFBP-2 up to 100 days after HSCT (mean +/-s.d. prior to HSCT: 3.2+/-3.6 SDS vs 100 days after HSCT: 5.3 degrees +/-3.4 SDS, P=0.005). Furthermore, IGF-I and IGFBP-3 were significantly decreased (IGF-I: -0.3+/-1.5 vs -0.7 +/-1.2 SDS, P=0.001; IGFBP-3: -0.3+/-1.1 vs -1.0+/-1.1 SDS, P=0.02). Children with AML showed significantly higher IGFBP-2 (P=0.04) and significantly lower IGF-I (P=0.03) and IGFBP-3 (P=0.05) levels than children with ALL at day 100 after HSCT. We conclude that children with acute leukemia show important changes in the IGF system after HSCT. In particular, IGFBP-2 was significantly elevated at day 100 after HSCT. Increased IGFBP-2 and decreased IGF-I and IGFBP-3 may be associated with the increased proliferation rate of transplanted bone marrow.

A major issue in the treatment of acute myeloid leukemia (AML) is the development of resistance to chemotherapeutic drugs. While more than 80% of children with AML may initially achieve complete remission with current therapeutic regimens, a large number of these patients relapse with resistant disease; even with aggressive therapy, the event free survival rate is only about 50%. Several mechanisms of drug resistance have been identified. One of these is the overexpression of ATP-binding-cassette (ABC)-transporters that function as drug efflux pumps. The best characterized member of this family is the P-glycoprotein (P-gp or MDR1 or ABCB1), which is an important cause of drug resistance in adult AML but not in children with AML. We could recently show that the multidrug resistance-associated protein 3 (MRP3 or ABCC3) and the breast cancer resistance protein (BCRP or ABCG2) are associated with a poor response to therapy in childhood AML. The aim of the present study was to identify other members of this family of proteins which are involved in drug resistance. We were particularly interested in ABC-transporters which were overexpressed in AML samples compared to healthy bone marrow because this might be an important prerequisite for using such proteins as therapeutic targets. A new microarray (DualChip human ABC) was developed for the simultaneous detection and quantification of 38 ABC transporter genes. Samples from 30 children with AML were analyzed with this microarray and the results were compared with normal bone marrow. The expression of five genes (ABCA2, ABCA3, ABCB2, ABCC1, and ABCC10) which were overexpressed in most patient samples was then analyzed by real time PCR in 40 selected samples from children with previously untreated AML. Half of the patients had achieved complete remission after the first course of chemotherapy. The other 20 patients had also undergone the full induction therapy but had failed to achieve remission at this stage. Only the expression of ABCA3 was significantly higher (p=0.015) in patients with a poor response to therapy. There was a 4-fold difference between the median expressions in both groups. The expression of ABCA3 was not significantly associated with the expression of P-gp, MRP3 or BCRP. Our results show that ABCA3 is overexpressed in childhood AML compared to healthy bone marrow and that the expression of ABCA3 is associated with a poor response to therapy. Interestingly, there are two ways in which ABCA3 might influence the prognosis of AML. Like other ABC-transporters, it could be involved in drug efflux. On the other hand, it was recently shown that ABCA3 plays a role in apoptosis and that many cancer cell lines show amplifications of the ABCA3 gene. Further studies are warranted to analyze the clinical and biological relevance of ABCA3 in leukemia.

Insulin-like growth factor (IGF) system plays an important role in regulating cellular proliferation. Alterations to the Insulin-like growth factor system have been reported for different tumors. They are of particular interest in the search for new prognostic and therapeutic approaches to cancer treatment. This study aimed to investigate the expression of IGFBP-2, IGFBP-3, IGF-I and IGF-II genes in leukemic cells from children with previously untreated acute myeloblastic leukemia (AML).The expression of IGF-I and IGF-II genes as well as IGFBP-2 and IGFBP-3 genes were measured using TaqMan real-time PCR in 50 children (mean age 10.8±4.8 years). All four genes were expressed with a great variability. RNA samples were extracted from leukemic cells enriched by Ficoll-Hypaque density gradient separation of bone marrow or peripheral blood mononuclear cells (MNC). MNC samples from peripheral blood and bone marrow of healthy children were used as controls. The median expression of IGFBP-2 was 25 times higher in AML cells than in peripheral MNC (p