Long-term outcome of 6-month maintenance chemotherapy for acute lymphoblastic leukemia in children.

In the treatment of childhood acute lymphoblastic leukemia (ALL), excess shortening of maintenance therapy resulted in high relapse rate, as shown by our previous trial, TCCSG L92-13, in which maintenance therapy was terminated at 1 year from initiation of treatment. In this study, we aimed to confirm the long-term outcome of L92-13, and to identify who can or cannot be cured by shorter duration of maintenance therapy. To obtain sentinel cytogenetics information that had been missed before, we performed genetic analysis with genomic microarray and target intron-capture sequencing from diagnostic bone marrow smear. Disease-free survival (DFS) at 10 years from the end of therapy was 66.0±2.8%. Females (n=138) had better DFS (74.6±3.7%) than males (n=142, 57.5±4.2%, P=0.002). Patients with TCF3-PBX1 (n=11) and ETV6-RUNX1 (n=16) had excellent DFS (90.9±8.7% and 93.8±6.1%, respectively), whereas high hyperdiploidy (n=23) was the most unfavorable subgroup, with 56.6±10.3% of DFS. Short duration of therapy can cure more than half of pediatric ALL, especially females, TCF3-PBX1 and ETV6-RUNX1. Our retrospective observations suggest a gender/karyotype inhomogeneity on the impact of brief therapy.

ALK(R1275Q) perturbs extracellular matrix, enhances cell invasion and leads to the development of neuroblastoma in cooperation with MYCN.

Overexpression of MYCN is a hallmark of neuroblastoma (NB). ALK(R1275Q), an activating mutation of ALK (anaplastic lymphoma kinase), has been found in sporadic and familial NB patients. In this report, we demonstrated that ALK(R1275Q) knock-in, MYCN transgenic compound mice developed NB with complete penetrance. Transcriptome analysis revealed that ALK(R1275Q) globally downregulated the expression of extracellular matrix (ECM)- and basement membrane (BM)-associated genes in both primary neuronal cells and NB tumors. Accordingly, ALK(R1275Q)/MYCN tumors exhibited reduced expression of ECM/BM-related proteins as compared with MYCN tumors. In addition, on MYCN transduction, ALK(R1275Q)-expressing neuronal cells exhibited increased migratory and invasive activities. Consistently, enhanced invasion and metastasis were demonstrated in ALK(R1275Q)/MYCN mice. These results collectively indicate that ALK(R1275Q) confers a malignant potential on neuronal cells that overexpress MYCN by impairing normal ECM/BM integrity and enhancing tumor growth and dissemination. Moreover, we found that crizotinib, an ALK inhibitor, almost completely inhibited the growth of ALK(R1275Q)/MYCN tumors in an allograft model. Our findings provided insights into the cooperative mechanism of the mutated ALK and overexpressed MYCN in the pathogenesis of NB and demonstrated the effectiveness of crizotinib on ALK(R1275Q)-positive tumors.

Early use of allogeneic hematopoietic stem cell transplantation for infants with MLL gene-rearrangement-positive acute lymphoblastic leukemia.

Sixty-two infants with MLL gene-rearrangement-positive acute lymphoblastic leukemia (MLL-r ALL) were treated with the MLL03 protocol of the Japanese Pediatric Leukemia/Lymphoma Study Group: short-course intensive chemotherapy followed by early allogeneic hematopoietic stem cell transplantation (HSCT) within 4 months of the initial induction. The 4-year event-free survival and overall survival rates were 43.2% (95% confidence interval (CI)=30.7-55.1%) and 67.2% (53.8-77.4%), respectively. A univariate analysis showed younger age (<90 days at diagnosis), central nervous system disease and poor response to initial prednisolone therapy significantly associated with poor prognosis (P<0.05). In a multivariate analysis, younger age at diagnosis tended to be associated with poor outcome (hazard ratio=1.969; 95% CI=0.903-4.291; P=0.088). Although the strategy of early use of HSCT effectively prevented early relapse and was feasible for infants with MLL-r ALL, the fact that substantial number of patients still relapsed even though transplanted in their first remission indicates the limited efficacy of allogeneic HSCT for infants with MLL-r ALL. Considering the risk of severe late effects, indications for HSCT should be restricted to specific subgroups with poor risk factors. An alternative approach incorporating molecular-targeted drugs should be established.

Systemic lupus erythematosus complicated with liver cirrhosis in a patient with Papillon-Lefèvre syndrome.

We report the first case of a girl who presented with Papillon-Lefèvre syndrome (PLS) and subsequently developed systemic lupus erythematosus and liver cirrhosis. This indicates that autoimmune diseases can be a complication in patients with PLS. Cathepsin C gene mutations were not found in our patient or her mother. Thus, other genetic factors may have been involved in this patient.

Second allogeneic hematopoietic SCT for relapsed ALL in children.

A second SCT is generally accepted as the only potentially curative approach for ALL patients that relapse after SCT, but the role of second SCT for pediatric ALL is not fully understood. We performed a retrospective analysis of 171 pediatric patients who received a second allo-SCT for relapsed ALL after allo-SCT. OS at 2 years was 29.4 ± 3.7%, the cumulative incidence of relapse was 44.1 ± 4.0% and non-relapse mortality was 18.8 ± 3.5%. Relapse occurred faster after the second SCT than after the first SCT (117 days vs 164 days, P=0.04). Younger age (9 years or less), late relapse (180 days or more after first SCT), CR at the second SCT, and myeloablative conditioning were found to be related to longer survival. Neither acute GVHD nor the type of donor influenced the outcome of second SCT. Multivariate analysis showed that younger age and late relapse were associated with better outcomes. Our analysis suggests that second SCT for relapsed pediatric ALL is an appropriate treatment option for patients that have achieved CR, which is associated with late relapse after the first SCT.

Aberrant activation of ALK kinase by a novel truncated form ALK protein in neuroblastoma.

Anaplastic lymphoma kinase (ALK) was originally identified from a rare subtype of non-Hodgkin's lymphomas carrying t(2;5)(p23;q35) translocation, where ALK was constitutively activated as a result of a fusion with nucleophosmin (NPM). Aberrant ALK fusion proteins were also generated in inflammatory fibrosarcoma and a subset of non-small-cell lung cancers, and these proteins are implicated in their pathogenesis. Recently, ALK has been demonstrated to be constitutively activated by gene mutations and/or amplifications in sporadic as well as familial cases of neuroblastoma. Here we describe another mechanism of aberrant ALK activation observed in a neuroblastoma-derived cell line (NB-1), in which a short-form ALK protein (ALK(del2-3)) having a truncated extracellular domain is overexpressed because of amplification of an abnormal ALK gene that lacks exons 2 and 3. ALK(del2-3) was autophosphorylated in NB-1 cells as well as in ALK(del2-3)-transduced cells and exhibited enhanced in vitro kinase activity compared with the wild-type kinase. ALK(del2-3)-transduced NIH3T3 cells exhibited increased colony-forming capacity in soft agar and tumorigenicity in nude mice. RNAi-mediated ALK knockdown resulted in the growth suppression of ALK(del2-3)-expressing cells, arguing for the oncogenic role of this mutant. Our findings provide a novel insight into the mechanism of deregulation of the ALK kinase and its roles in neuroblastoma pathogenesis.

Expression of ADAMTS4 in Ewing's sarcoma.

Ewing's sarcoma (EWS) is a malignant bone tumor that frequently occurs in teenagers. Genetic mutations which cause EWS have been investigated, and the most frequent one proved to be a fusion gene between EWS gene of chromosome 22 and the FLI1 gene of chromosome 11. However, a limited numbers of useful biological markers for diagnosis of EWS are available. In this study, we identified ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin motifs) as a possible tumor marker for EWS using the retrovirus-mediated signal sequence trap method. ADAMTS4 is a secreted protein of 837 amino acids with a predicted molecular mass of 98-100 kDa. It is a member of metalloprotease family, is expressed mainly in cartilage and brain, and regulates the degradation of aggrecans. ADAMTS4 has been suggested to be involved in arthritic diseases and gliomas. Herein, we show that ADAMTS4 mRNA was expressed in all primary EWS samples and all EWS-derived cell lines examined, while its expression was detected only in small subpopulations of other solid tumors. Furthermore, ADAMTS4 expression was found to be regulated by EWS-FLI1 fusion gene-dependent manner. We also demonstrated that ADAMTS4 protein was highly expressed in tumor samples of the patients with EWS by using immunohistochemistry. These results suggest that ADAMTS4 is a novel tumor marker for EWS.

Impaired blood rheology in critically ill patients in an intensive care unit.

Critically ill patients are at increased risk of thromboembolic complications. Japanese patients admitted to the intensive care unit of Gunma University Hospital were divided into critically ill (high score) and moderately ill (low score) groups according to mean Acute Physiology and Chronic Health Evaluation (APACHE) II score. White blood cell count, potassium, creatinine, immunoglobulin G and blood passage time, measured using the microchannel method, were significantly higher and the platelet aggregation score and platelet count were significantly lower in the high-score group than in the low-score group, but other haemorheological parameters did not differ significantly between the two groups. White blood cell count, potassium, creatinine, APACHE II score and levels of immunoglobulins G, A and M were positively correlated with blood passage time in all patients. Critically ill patients had impaired blood rheology, which could result from increased white blood cell count, potassium, creatinine and immunoglobulins and may be associated with the pathophysiology of the thromboembolic process.

An immunohistochemical study of TIMP-3 expression in oesophageal squamous cell carcinoma.

Tissue inhibitor of metalloproteinase-3 (TIMP-3) inhibits the activity of matrix metalloproteinase, which may play an important role in carcinoma invasion and metastasis. We have investigated the relationship between TIMP-3 reduction and clinicopathological factors in oesophageal squamous cell carcinoma (ESCC). We examined tissue specimens that had been removed from 90 patients with thoracic oesophageal cancer who had undergone surgery between 1983 and 2001. Immunohistochemical staining was performed by the standard streptavidin-biotin method. Immunostaining of TIMP-3 was seen in the cytoplasm of cancer cells and normal oesophageal epithelial cells, particularly in cells located in shallow areas of the tumour. TIMP-3 preserved (+), moderate (+/-), and reduced (-) cases accounted for 30, 27, and 33 of the 90 patients, respectively (33, 30, 37%). Significant correlations were observed between TIMP-3 expression and depth of tumour invasion (P=0.001), number of lymph node metastases (P=0.003), infiltrative growth pattern (P=0.003), and disease stage (P=0.005). The survival rates of patients with TIMP-3 (-) cancer were significantly lower than those of patients with TIMP-3 (+) and TIMP-3 (+/-) cancer (P=0.0003). The mean 5-year survival rates of patients with TIMP-3 (+), (+/-), and (-) were 50, 58, and 21%, respectively. In conclusion, decreased expression of TIMP-3 protein correlates with invasive activity and metastasis. This makes the prognosis for patients with cancer that has lost TIMP-3 significantly less favourable than that for patients with cancer that has maintained TIMP-3.

Structural determination of an exocellular mannan from Rhodotorula mucilaginosa YR-2 using ab initio assignment of proton and carbon NMR spectra.

The structure of the title mannan was determined exclusively by NMR. Because of the short relaxation time of the native mannan (100 kDa), a partially hydrolyzed mannan (10 kDa) was used for proton assignments by COSY, to correlate proton and carbon signals by HMQC, and to determine linkage positions between residues by HMBC. A further hydrolyzed mannan (oligomers of approximately 1.5 kDa) was used to determine the anomeric configuration, using Wilker's quasi-3D method [Wilker, W.; Leibfritz, D. Magn. Reson. Chem. 1995, 33, 632-638]. The procedure presented here can be used to determine the structure of any polysaccharide.

Genomic structure and mutational analysis of the human KIF1B gene which is homozygously deleted in neuroblastoma at chromosome 1p36.2.

In order to clone candidate tumor suppressor genes whose loss contributes to the pathogenesis of neuroblastoma (NB), we performed polymerase chain reaction (PCR) screening using a high-density sequence tagged site-content map within a commonly deleted region (chromosome band 1p36) in 24 NB cell lines. We found a approximately 480 kb homozygously deleted region at chromosome band 1p36.2 in one of the 24 NB cell lines, NB-1, and cloned the human homologue (KIF1B-beta) of the mouseKif1B-beta gene in this region. The KIF1B-beta gene had at least 47 exons, all of which had a classic exon-intron boundary structure. Mouse Kif1B is a microtubule-based putative anterograde motor protein for the transport of mitochondria in neural cells. We performed mutational analysis of the KIF1B-beta gene in 23 cell lines using 46 sets of primers and also an allelic imbalance (AI) analysis of KIF1B-beta in 50 fresh NB samples. A missense mutation at codon 1554, GTG (Gly) to ATG (Met), silent mutations at codon 409 (ACG to ACA) and codon 1721 (ACC to ACT), and polymorphisms at codon 170, GAT (Asp) to GAA (Glu), and at codon 1087, TAT (Tyr), to TGT (Cys), were all identified, although their functional significances remain to be determined. The AI for KIF1B-beta was slightly higher (38%) than those for the other two markers (D1S244, D1S1350) (35 and 32%) within the commonly deleted region (1p36). Reverse transcriptase-PCR analysis of the KIF1B-beta gene revealed obvious expression in all NB cell lines except NB-1, although decreased expression of the KIF1B-beta gene was found in a subset of early- and advanced-stage NBs. These results suggest that the KIF1B-beta gene may not be a candidate for tumor suppressor gene of NB.

Homozygous deletion in a neuroblastoma cell line defined by a high-density STS map spanning human chromosome band 1p36.

Recent molecular studies have shown a relatively high rate of loss of heterozygosity (LOH) in neuroblastoma (NB) as well as other types of tumors in human chromosome band 1p36. To identify candidate tumor suppressor genes in NB, we searched for homozygous deletions in NB cell lines with PCR according to a high-density sequence tagged site (STS)-content map spanning 1p35-36. Among 25 NB cell lines examined, only one cell line, NB-1, showed no signal with 27 STSs in a 480 kb region in 1p36.2. The sequence analysis has revealed that the defective region included seven known genes (E4, KIF1B, SCYA5, PGD, Cortistatin, DFF45, and PEX14), nine expressed sequence tags (ESTs), and two microsatellite markers. These genes are related to apoptosis, an ubiquitin-proteasome pathway, a neuronal microtubule-associated motor molecule, and components of a common translocation machinery. The region between the DFF45 and KIF1B genes was defined as homozygous deletion by Southern blotting. The search in LOH regions with high-density STSs may be useful for the isolation and identification of tumor suppressor genes in other tumors as well as NBs.

Allelic imbalance on chromosome 2q and alterations of the caspase 8 gene in neuroblastoma.

We previously reported a high incidence of loss of heterozygosity (LOH) on chromosome 2q33 in neuroblastoma (NB), observed in various types of human cancers including lung cancer, head and neck cancer and follicular thyroid carcinoma. To better elucidate the role of chromosome 2q aberrations in NB, we examined common allelic imbalance (AI) regions on chromosome 2q in 82 NB patients using 10 polymorphic microsatellite markers. AI on 2q was detected in 26 (32%) of 82 NB cases. There was a distinct common AI region between the D2S115 and D2S307 markers on 2q33. The distance between these markers was about 2.0 cM. Recently, the caspase 8 and caspase 10 genes, both of which encode cystein protease, were mapped to chromosome 2q33. Since the common AI region on 2q33 includes the caspase 8 and caspase 10 genes, the alterations of these genes were examined further. Absent or reduced expression of caspase 8 and caspase 10 were found in 19 (70%) of 27 and two (7%) of 27 NB cell lines by reverse transcription-polymerase chain reaction, respectively. A missense mutation was detected at codon 96, GCT (Alanine) to GTT (Valine), of the caspase 8 gene in one of the NB cell lines lacking caspase 8 expression. Thirteen (68%) of 19 cell lines lacking caspase 8 expression displayed methylation of the CpG island of the caspase 8 gene, whereas only one (13%) of eight cell lines with caspase 8 expression showed caspase 8 methylation (P=0.031). Furthermore, there was a significant association between AI at 2q33 and loss of caspase 8 expression (P=0.026). These results indicated that there was a tumor suppressor gene in the common AI region on chromosome 2q33 involved in the pathogenesis of a subset of NB. It is possible that the caspase 8 gene is one of the candidate tumor suppressor genes for NB and inactivation of this gene plays an important role in the tumorigenesis of NB through mainly its methylation.