Clonal heterogeneity and chromosomal instability at disease presentation in high hyperdiploid acute lymphoblastic leukemia.

Although aneuploidy has many possible causes, it often results from underlying chromosomal instability (CIN) leading to an unstable karyotype with cell-to-cell variation and multiple subclones. To test for the presence of CIN in high hyperdiploid acute lymphoblastic leukemia (HeH ALL) at diagnosis, we investigated 20 patients (10 HeH ALL and 10 non-HeH ALL), using automated four-color interphase fluorescence in situ hybridization (I-FISH) with centromeric probes for chromosomes 4, 6, 10, and 17. In HeH ALL, the proportion of abnormal cells ranged from 36.3% to 92.4%, and a variety of aneuploid populations were identified. Compared with conventional cytogenetics, I-FISH revealed numerous additional clones, some of them very small. To investigate the nature and origin of this clonal heterogeneity, we determined average numerical CIN values for all four chromosomes together and for each chromosome and patient group. The CIN values in HeH ALL were relatively high (range, 22.2-44.7%), compared with those in non-HeH ALL (3.2-6.4%), thus accounting for the presence of numerical CIN in HeH ALL at diagnosis. We conclude that numerical CIN may be at the origin of the high level of clonal heterogeneity revealed by I-FISH in HeH ALL at presentation, which would corroborate the potential role of CIN in tumor pathogenesis.

No Role for Cerebrospinal Fluid Myelin Basic Protein Levels in Patients Treated for Childhood Acute Lymphoblastic Leukemia.

INTRODUCTION: Central nervous system prophylaxis of childhood acute lymphoblastic leukemia has dropped rates of relapses but has been associated with neurotoxicity and imaging abnormalities. Predictors of neurotoxicity are lacking, because of inconsistency between clinical symptoms and imaging. Some have suggested that cerebrospinal fluid myelin basic protein (MBP) levels to be of potential interest. A retrospective analysis of MBP levels in correlation with clinical and radiologic data is presented. MATERIALS AND METHODS: MBP levels obtained at the time of intrathecals, charts, and neuroradiology reports were retrospectively analyzed. Academic achievement data were obtained from phone contacts with patients and families. RESULTS: We retrieved 1248 dosages of MBP in 83 patients, 381 neurologic examinations in 34 patients and 69 neuroradiologic investigations in 27 patients. Fifty-two patients had abnormal MBP levels. Radiologic anomalies were present in 47% of those investigated, 14% of them having school difficulties. Proportions of patients with school difficulties in the groups with abnormal MBP levels but no radiologic anomalies or with no radiologic investigations were 0% and 3%, respectively, which was lower than in the group of patients with normal MBP levels (100%, 22%, and 5%, respectively). DISCUSSION: Notwithstanding the retrospective character of our study, we conclude that there is limited usefulness of systematic dosage of MBP as indicator of treatment-induced neurotoxicity in acute lymphoblastic leukemia patients.

ALK rearrangement in a selected population of advanced non small cell lung cancer patients. FISH and inmunohistochemistry diagnostic methods, prevalence and clinical outcomes

Anaplastic lymphoma kinase (ALK) rearrangements represents a new driver oncogenic event in non-small cell lung cancer (NSCLC). ALK positive patients account for a 1-7% of NSCLC patients. The objective of this study is to know the prevalence and clinical characteristics of ALK positive patients in a cohort of NSCLC patients and to compare inmunohistochemistry with D5F3 monoclonal antibody with gold standard method fluorescence in situ hybridation

BCR and TLR signalling pathways are recurrently targeted by genetic changes in splenic marginal zone lymphomas.

The genetics and pathogenesis of splenic marginal zone lymphoma are poorly understood. The lymphoma lacks chromosome translocation, and ~30% of cases are featured by 7q deletion, but the gene targeted by the deletion is unknown. A recent study showed inactivation of A20, a 'global' NF-kB negative regulator, in 1 of 12 splenic marginal zone lymphoma. To investigate further whether deregulation of the NF-kB pathway plays a role in the pathogenesis of splenic marginal zone lymphoma, we screened several NF-kB regulators for genetic changes by PCR and sequencing. Somatic mutations were found in A20 (6/46=13%), MYD88 (6/46=13%), CARD11 (3/34=8.8%), but not in CD79A, CD79B and ABIN1. Interestingly, these genetic changes are largely mutually exclusive from each other and MYD88 mutation was also mutually exclusive from 7q deletion. These results strongly suggest that deregulation of the TLR (toll like receptor) and BCR (B-cell receptor) signalling pathway may play an important role in the pathogenesis of splenic marginal zone lymphoma.

Cytogenetic characterisation of childhood acute lymphoblastic leukemia in Nicaragua

BACKGROUND: Within the frame of a twinning programme with Nicaragua, The La Mascota project, we evaluated in our study the contribution of cytogenetic characterization of acute lymphoblastic leukemia (ALL) as prognostic factor compared to clinical, morphological, and immunohistochemical parameters. METHODS: All patients with ALL treated at the only cancer pediatric hospital in Nicaragua during 2006 were studied prospectively. Diagnostic immunophenotyping was performed locally and bone marrow or blood samples were sent to the cytogenetic laboratory of Zurich for fluorescence in situ hybridization (FISH) analysis and G-banding. RESULTS: Sixty-six patients with ALL were evaluated. Their mean age at diagnosis was 7.3 years, 31.8% were >or=10 years. Thirty-four patients (51.5%) presented with hyperleucocytosis >or=50 x 10(9)/L, 45 (68.2%) had hepatosplenomegaly. Immunophenotypically 63/66 patients (95%) had a B-precursor, 2 (3%) a T- and 1 (1.5%) a B-mature ALL. FISH analysis demonstrated a TEL/AML1 fusion in 9/66 (14%), BCR/ABL fusion in 1 (1.5%), MLL rearrangement in 2 (3.1%), iAMP21 in 2 (3.1%), MYC rearrangement in 1 (1.5%), and high-hyperdiploidy in 16 (24%). All patients but two with TEL/AML1 fusion and high-hyperdiploidy were clinically and hematologically in the standard risk group whereas those with poor cytogenetic factors had clinical high-risk features and were treated intensively. CONCLUSIONS: Compared to Europe, the ALL population in Nicaragua is older, has a higher proportion of poor prognostic clinical and hematological features and receives more intensive treatment, while patients with TEL/AML1 translocations and high-hyperdiploidy are clinically in the standard risk group. Cytogenetics did not contribute as an additional prognostic factor in this setting.

The Rare Cancer Network: achievements from 1993 to 2012.

The Rare Cancer Network (RCN), founded in 1993, performs research involving rare tumors that are not common enough to be the focus of prospective study. Over 55 studies have either been completed or are in progress.The aim of the paper is to present an overview of the 30 studies done through the RCN to date, organized by disease site. Five studies focus on breast pathology, including sarcoma, lymphoma, phyllodes tumor, adenoid cystic carcinoma, and ductal carcinoma in situ in young women. Three studies on prostate cancer address prostatic small cell carcinoma and adenocarcinoma of young and elderly patients. Six studies on head and neck cancers include orbital and intraocular lymphoma, mucosal melanoma, pediatric nasopharyngeal carcinoma, olfactory neuroblastoma, and mucosa-associated lymphoid tissue lymphoma of the salivary glands. There were 4 central nervous system studies on patients with cerebellar glioblastoma multiforme, atypical and malignant meningioma, spinal epidural lymphoma and myxopapillary ependymoma. Outside of these disease sites, there is a wide variety of other studies on tumors ranging from uterine leiomyosarcoma to giant cell tumors of the bone. The studies done by the RCN represent a wide range of rare pathologies that were previously only studied in small series or case reports. With further growth of the RCN and collaboration between members our ability to analyze rare tumors will increase and result in better understanding of their behavior and ultimately help direct research that may improve patient outcomes.

I. Identification and characterisation of epigenetically altered tumor supressor genes by proteomic and genomic approches / II. Studies of genes regualted by MeCP2 union to its promoter regions by proteomic and genmomic approches

DNA methylation has an important impact on normal cell physiology, thus any defects in this mechanism may be related to the development of various diseases In this project we are interested in identifying epigeneticaliy modified genes, in general controlled by processes related to the DNA methylation, by means of a new strategy combining protomic and genomic analyses. First, the two Dimensional-Difference Gel Electrophoresis (2-DIGE) protein analyses of extracts obtained from HCT-116 wt and double knockout for DNMT1 and DNMT3b (DKO) cells revealed 34 proteins overexpressed in the condition of DNMTs depletion. From five genes with higher transcript lavels in DKO cells, comparing with HCT-116 wt. oniy AKR1B1, UCHLl and VIM are melhylated in HCT-116. As expected. the DNA methvlation 1s lost in DKO cells. The rneth,vl ation of VIM and UCHLl promoters in some cancer samples has already been repaired, thus further studies has been focused on AKRlBI. AKR1B1 expression due lo DNA methyiaton of promoter region seems to occur specilfically in the colon cancer cell Iines. which was confirmed in the DNA rnethylation status and expression analyses. performed on 32 different cancer cell lines (including colon, breast, lymphoma, leukemia, neuroblastoma, glioma and lung cancer cell Iines) as well as normal colon and normal lymphocytes samples. AKRIBI expression after treatments with DNA demethvlating agent (AZA) was rescued in 5 coloncancer cell lines (including genetic regulation of the candidate gene. The methylation status of the rest of the genes identified in proteomic analysis was checked by methylation specific PCR (MSP) experiment and all appeared to be unmethylated. The similar research has been done also bv means of Mecp2-null mouse model For 14 selected candidate genes the analyses of expression leveis, methylation Status and MeCP2 interaction with promoters are currently being performed.

Use of polymerase chain reaction and enzymatic cleavage in the identification of Helicobacter spp. in gastric mucosa of human beings from North Paraná, Brazil

Helicobacter pylori is the most common gastric bacteria of human beings. Animal-borne helicobacter have been associated with gastritis, ulceration, and gastric mucosa-associated lymphoid-tissue lymphoma in people. We attempted to identify the species of Helicobacter spp. that infect human beings in north Paraná, Brazil. Samples of gastric mucosa from 38 dyspeptic patients were analyzed by optic microscopy on silver stained slides, polimerase chain reaction (PCR), and enzymatic cleavage. Genus and species-specific primers to H. pylori, H. heilmannii, H. felis, and consensual primers to H. bizzozeronii or H. salomonis were used. The PCR products were submitted to enzymatic cleavage by VspI (Helicobacter spp. product) and HinfI (species products) enzymes. Thirty-two out of 38 patients evaluated had 3.2 to 5 µm long bacteria that resembled H. pylori in Warthin-Starry stained slides and were positive to the genus Helicobacter by PCR. In 30 of these patients the bacteria were identified as H. pylori. Two samples positive by silver stain were negative to all species tested by PCR. None of the 38 samples was positive to animal-origin helicobacter species. These results show that PCR and enzymatic restriction are practical methods to identify the species of helicobacters present in gastric mucosa of human beings. People in north Paraná appear to be infected mostly with H. pylori.

Persistent human parvovirus B19 infection in children under maintenance chemotherapy for acute lymphocytic leukemia.

OBJECTIVE: To report on B19 infection management and chemotherapy schedule consequences in five children treated for acute lymphocytic leukemia (ALL). PATIENTS AND METHODS: Between May 2001 and February 2002, five patients between 4 and 12 years of age, receiving maintenance chemotherapy for ALL, presented with symptoms suggesting B19 infection (pallor, fatigue, petechiae and pancytopenia in four patients; generalized rash in two patients; acute hepatitis in one patient). Qualitative polymerase chain reaction (PCR) on peripheral blood was used for diagnosis and follow-up of infection; quantitative PCR was used for viral load measurement. Intravenous nonspecific high-dose immunoglobulin therapy was administered until PCR was negative. RESULTS: Qualitative B19 DNA was found in the peripheral blood of all patients, confirming the infection. Viral load at diagnosis ranged from 10 to 10 particles/mL blood. B19 DNA was detectable in four patients at 45, 21, 40, and 44 weeks, respectively. Chemotherapy was delayed in all patients. No clear benefit of intravenous immunoglobulin was noted. CONCLUSIONS: Infection with B19 is rarely reported in patients with ALL, but it should be suspected when unexplained pancytopenia occurs during chemotherapy. Persistent B19 infection remains a challenge in the management of patients receiving maintenance chemotherapy for ALL, as no specific therapy such as a specific immunoglobulin or vaccine exists. The role of viral load measurement needs to be established in terms of its use in follow-up and evaluation of the therapeutic response.

Implication of DNA methylation and PAX5 factor in the transcriptional regulation of hTERT, the human telomerase reverse transcriptase gene

RESUME La télomérase est une enzyme dite "d'immortalité" qui permet aux cellules de maintenir la longueur de leurs télomères, ce qui confère une capacité de réplication illimitée aux cellules reproductrices et cancéreuses. A l'inverse, les cellules somatiques normales, qui n'expriment pas la télomérase, ont une capacité de réplication limitée. La sous-unité catalytique de la télomérase, hTERT, est définie comme le facteur limitant l'activité télomérasique. Entre activateurs et répresseurs, le rôle de la méthylation de l'ADN et de l'acétylation des histones, de nombreux modèles ont été suggérés. La découverte de l'implication de CTCF dans la régulation transcriptionnelle de hTERT explique en partie le mécanisme de répression de la télomérase dans la plupart des cellules somatiques et sa réactivation dans les cellules tumorales. Dans les cellules télomérase-positives, l'activité inhibitrice de CTCF est bloquée par un mécanisme dépendent ou non de la méthylation. Dans la plupart des carcinomes, une hyperméthylation de la région 5' de hTERT bloque l'effet inhibiteur de CTCF, alors qu'une petite région hypométhylée permet un faible niveau de transcription du gène. Nous avons démontré que la protéine MBD2 se lie spécifiquement sur la région 5' méthylée de hTERT dans différentes lignées cellulaires et qu'elle est impliquée dans la répression partielle de la transcription de hTERT dans les cellules tumorales méthylées. Par contre, nous avons montré que dans les lymphocytes B normaux et néoplasiques, la régulation de hTERT est indépendante de la méthylation. Dans ces cellules, le facteur PAX5 se lie sur la région 5' de hTERT en aval du site d'initiation de la traduction (ATG). L'expression exogène de PAX5 dans les cellules télomérase-négatives active la transcription de hTERT, alors que la répression de PAX5 dans les cellules lymphomateuses inhibe la transcription du gène. PAX5 est donc directement impliqué dans l'activation de l'expression de hTERT dans les lymphocytes B exprimant la télomérase. Ces résultats révèlent des différences entre les niveaux de méthylation de hTERT dans les cellules de carcinomes et les lymphocytes B exprimant la télomérase. La méthylation de hTERT en tant que biomarqueur de cancer a été évaluée, puis appliquée à la détection de métastases. Nous avons ainsi montré que la méthylation de hTERT est positivement corrélée au diagnostic cytologique dans les liquides céphalorachidiens. Nos résultats conduisent à un modèle de régulation de hTERT, qui aide à comprendre comment la transcription de ce gène est régulée par CTCF, avec un mécanisme lié ou non à la méthylation du gène hTERT. La méthylation de hTERT s'est aussi révélée être un nouveau et prometteur biomarqueur de cancer. SUMMARY Human telomerase is an "immortalizing" enzyme that enables cells to maintain telomere length, allowing unlimited replicative capacity to reproductive and cancer cells. Conversely, normal somatic cells that do not express telomerase have a finite replicative capacity. The catalytic subunit of telomerase, hTERT, is defined as the limiting factor for telomerase activity. Between activators and repressors, and the role of DNA methylation and histone acetylation, an abundance of hTERT regulatory models have been suggested. The discovery of the implication of CTCF in the transcriptional regulation of hTERT in part explained the mechanism of silencing of telomerase in most somatic cells and its reactivation in neoplastic cells. In telomerase-positive cells, the inhibitory activity of CTCF is blocked by methylation-dependent and -independent mechanisms. In most carcinoma cells, hypermethylation of the hTERT 5' region has been shown to block the inhibitory effect of CTCF, while a short hypomethylated region allows a low transcription level of the gene. We have demonstrated that MBD2 protein specifically binds the methylated 5' region of hTERT in different cell lines and is therefore involved in the partial repression of hTERT transcription in methylated tumor cells. In contrast, we have shown that in normal and neoplastic B cells, hTERT regulation is methylation-independent. The PAX5 factor has been shown to bind to the hTERT 5'region downstream of the ATG translational start site. Ectopic expression of PAX5 in telomerase-negative cells or repression of PAX5 expression in B lymphoma cells respectively activated and repressed hTERT transcription. Thus, PAX5 is strongly implicated in hTERT expression activation in telomerase-positive B cells. These results reveal differences between the hTERT methylation patterns in telomerase-positive carcinoma cells and telomerase-positive normal B cells. The potential of hTERT methylation as a cancer biomarker was evaluated and applied to the detection of metastasis. We have shown that hTERT methylation correlates with the cytological diagnosis in cerebrospinal fluids. Our results suggest a model of hTERT gene regulation, which helps us to better understand how hTERT transcription is regulated by CTCF in methylation-dependant and independent mechanisms. Our data also indicate that hTERT methylation is a promising new cancer biomarker.

Caspase-induced inactivation of the anti-apoptotic TRAF1 during Fas ligand-mediated apoptosis.

The activation of the transcription factor NF-kappaB often results in protection against apoptosis. In particular, pro-apoptotic tumor necrosis factor (TNF) signals are blocked by proteins that are induced by NF-kappaB such as TNFR-associated factor 1 (TRAF1). Here we show that TRAF1 is cleaved after Asp-163 when cells are induced to undergo apoptosis by Fas ligand (FasL). The C-terminal cleavage product blocks the induction of NF-kappaB by TNF and therefore functions as a dominant negative (DN) form of TRAF1. Our results suggest that the generation of DN-TRAF1 is part of a pro-apoptotic amplification system to assure rapid cell death.

Cellular origin of T-cell lymphomas.

In this issue of Blood, Iqbal et al, having compiled gene expression profiles from >300 peripheral T-cell lymphomas, expand previous findings on the diagnostic value of molecular signatures that correlate with different histological types of T-cell lymphomas. They report the discovery of 2 molecular subgroups of peripheral T-cell lymphomas, not otherwise specified (PTCL, NOS), characterized by high expression of either GATA-binding protein 3 (GATA-3) or t-box 21 (TBX21) transcription factors and corresponding target genes, with the GATA3 subgroup being associated with distinctly worse prognosis. In an independent study, Wang et al(2) also show that GATA3 expression in a subset of PTCL, NOS identifies a subgroup of patients with inferior survival.

Comparison of magnetic resonance enterography and video capsule endoscopy in evaluating small bowel disease.

PURPOSE: The goal of this study was to compare magnetic resonance enterography (MRE) and video capsule endoscopy (VCE) in suspected small bowel disease. MATERIALS AND METHODS: Nineteen patients with suspected small bowel disease participated in a prospective clinical comparison of MRE versus VCE. Both methods were evaluated separately and in conjunction with respect to a combined diagnostic endpoint based on clinical, laboratory, surgical, and histopathological findings. The Fisher's exact and j tests were used in comparing MRE and VCE. RESULTS: Small bowel pathologies were found in 15 out of 19 patients: Crohn's disease (n= 5), lymphoma (n= 4), lymphangioma (n= 1), adenocarcinoma (n= 1), postradiation enteropathy (n= 1), NSAID-induced enteropathy (n =1), angiodysplasia (n= 1), and small bowel adhesions (n= 1). VCE and MRE separately and in conjunction showed sensitivities of 92.9, 71.4, and 100% and specificities of 80, 60, and 80% (kappa= 0.73 vs. kappa = 0.29; P= 0.31/kappa = 0.85), respectively. In four patients, VCE depicted mucosal pathologies missed by MRE. MRE revealed 19 extraenteric findings in 11 patients as well as small bowel adhesions not detected on VCE (n= 1). CONCLUSION: VCE can readily depict and characterize subtle mucosal lesions missed at MRE, whereas MRE yields additional mural, perienteric, and extraenteric information. Thus, VCE and MRE appear to be complementary methods which, when used in conjunction, may better characterize suspected small bowel disease.

Multiple tumor types including leiomyoma and Wilms tumor in a patient with Gorlin syndrome due to 9q22.3 microdeletion encompassing the PTCH1 and FANC-C loci.

Gorlin syndrome or nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant condition mainly characterized by the development of mandibular keratocysts which often have their onset during the second decade of life and/or multiple basal cell carcinoma (BCC) normally arising during the third decade. Cardiac and ovarian fibromas can be found. Patients with NBCCS develop the childhood brain malignancy medulloblastoma (now often called primitive neuro-ectodermal tumor [PNET]) in 5% of cases. The risk of other malignant neoplasms is not clearly increased, although lymphoma and meningioma can occur in this condition. Wilms tumor has been mentioned in the literature four times. We describe a patient with a 10.9 Mb 9q22.3 deletion spanning 9q22.2 through 9q31.1 that includes the entire codifying sequence of the gene PTCH1, with Wilms tumor, multiple neoplasms (lung, liver, mesenteric, gastric and renal leiomyomas, lung typical carcinoid tumor, adenomatoid tumor of the pleura) and a severe clinical presentation. We propose including leiomyomas among minor criteria of the NBCCS.