IntroductionMolecular aberrations involving the mixed lineage leukemia (MLL) gene on 11q23 are found in 5% to 10% of acute leukemia cases. 1 In B-cell precursor (BCP) acute lymphoblastic leukemia (ALL), these aberrations are largely restricted to the immature CD10 Ϫ immunophenotypes (pro-B and CD10 Ϫ pre-B). The translocation t(4;11)(q22;q23) with MLL-AF4 (MLL-AFF1) fusion is known to be the most prevalent MLL fusion gene in ALL, but precise and reliable data regarding the prevalence of the different MLL fusion partner genes, that is, the MLL "recombinome" in adult ALL are lacking. Knowledge of the MLL recombinome is warranted, since MLL fusions are of interest in detecting minimal residual disease in affected patients 2,3 and also because controversy exists over whether adult ALL patients with pro-B ALL immunophenotype with or without MLL aberration might have a different prognosis. [4][5][6] We report our experience within the framework of the German Multicenter Therapy Trials for Adult ALL (GMALL) between January 2001 and October 2007 at the central diagnostic laboratory of the GMALL study group.We investigated 184 patients with a CD10 Ϫ BCP immunophenotype by reverse transcription polymerase chain reactions (RT-PCRs) for different MLL fusion genes. Since the chromosomal breakpoints in the MLL gene cluster in a relatively restricted region between exons 8 and 13 (numbering according to Nilsson et al 7 ), encompassing approximately 8.2 kb, we additionally investigated all samples by a recently published long-distance inverse polymerase chain reaction (LDI-PCR) method that also allowed the identification of unknown MLL translocation partners at the DNA level. Methods Patient materialBone marrow (n ϭ 136) and peripheral blood (n ϭ 45) samples (n ϭ 3 samples unspecified) were obtained for diagnostic purposes within the framework of the GMALL therapy studies 6/99 and 7/03 between January 2001 and October 2007. A list of GMALL study participants appears in the Supplemental Materials and Methods (available on the Blood website; see the Supplemental Materials link at the top of the online article). All samples were taken at the time of primary diagnosis and had a high blast count, as revealed by flow cytometry. The genetic investigations were done retrospectively and prospectively on archived residual material. Preparation of samples, immunophenotyping, and all RT-PCR investigations were performed at the central diagnostic laboratory of the GMALL study group in Berlin. The samples were obtained within clinical studies that were approved by the institutional ethics committees of all participating institutions. The study design and our investigations were conducted in accordance with the Declaration of Helsinki. Nucleic acid isolation and reverse transcriptionTotal RNA was isolated using the TRIZOL method (Invitrogen, Carlsbad, CA) or the RNEasy kit (QIAGEN, Hilden, Germany). Genomic DNA was For personal use only. on May 12, 2018. by guest www.bloodjournal.org From isolated using the PureGene Kit (Gentra Systems, Mi...

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BackgroundDevelopment of clinically relevant tumor model systems for glioblastoma multiforme (GBM) is important for advancement of basic and translational biology. High molecular heterogeneity of GBM tumors is well recognized, forming the rationale for molecular tests required before administration of several of the novel therapeutics rapidly entering the clinics. One model that has gained wide acceptance is the primary cell culture model. The laborious and time consuming process is rewarded with a relative high success rate (about 60%). We here describe and evaluate a very simple cryopreservation procedure for GBM tissue prior to model establishment that will considerably reduce the logistic complexity.MethodsTwenty-seven GBM samples collected ad hoc were prepared for primary cell culture freshly from surgery (#1) and after cryopreservation (#2).ResultsTake rates after cryopreservation (59%) were as satisfactory as from fresh tissue (63%; p = 1.000). We did not observe any relevant molecular or phenotypic differences between cell lines established from fresh or vitally frozen tissue. Further, sensitivity both towards standard chemotherapeutic agents (Temozolomide, BCNU and Vincristine) and novel agents like the receptor tyrosine kinase inhibitor Imatinib did not differ.ConclusionsOur simple cryopreservation procedure facilitates collection, long-time storage and propagation (modeling) of clinical GBM specimens (potentially also from distant centers) for basic research, (pre-) clinical studies of novel therapies and individual response prediction.

The potential impact of different radiological features of glioblastoma multiforme (GBM) on overall survival (OS) like tumor volume, peritumoral edema (PTE), necrosis volume, necrosis-tumor ratio (NTR) and edema-tumor ratio (ETR) is still very controversial. To determine the influence of volumetric data on OS und to compare different measuring techniques described in literature. We prospectively evaluated preoperative MR images from 30 patients harboring a primary supratentorial GBM. All patients received gross-total tumor resection followed by standard radiation and chemotherapy (temozolomide). By 3D semi-automated segmentation, we measured tumor volume, necrosis volume, PTE, postoperative residual tumor volume and calculated ETR, NTR and the extent of resection. After critical review of the existing literature we compared alternative measuring techniques with the gold standard of 3D segmentation. Statistical analysis showed a significant impact of the preoperative tumor and necrosis volumes on OS (p = 0.041, respectively p = 0.039). Furthermore, NTR also showed a significant association with OS (p = 0.005). Comparison of previously described measuring techniques and scorings with our results showed that no other technique is reliable and accurate enough as a predictive tool. The critical review of previously published studies revealed mainly inaccurate measurement techniques and patient selection as potential reasons for inconsistent results. Preoperatively measured necrosis volume and NTR are the most important radiological features of GBM with a strong influence on OS. No other measuring techniques are specific enough and comparable with 3D segmentation.

Background: SET-NUP214 fusion resulting from a recurrent cryptic deletion, del(9)(q34.11q34.13) has recently been described in T-cell acute lymphoblastic leukemia (T-ALL) and in one case of acute myeloid leukemia (AML). The fusion protein appears to promote elevated expression of HOXA cluster genes in T-ALL and may contribute to the pathogenesis of the disease. We screened a panel of ALL and AML cell lines for SET-NUP214 expression to find model systems that might help to elucidate the cellular function of this fusion gene.