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Christian Herens

Publications and source records attributed to Christian Herens.

17 recordsLinked to original sources
PubMed2006

Chromosomal patterns of gene expression from microarray data: methodology, validation and clinical relevance in gliomas.

BACKGROUND: Expression microarrays represent a powerful technique for the simultaneous investigation of thousands of genes. The evidence that genes are not randomly distributed in the genome and that their coordinated expression depends on their position on chromosomes has highlighted the need for mathematical approaches to exploit this dependency for the analysis of expression data-sets. RESULTS: We have devised a novel mathematical technique (CHROMOWAVE) based on the Haar wavelet transform and applied it to a dataset obtained with the Affymetrix HG-U133_Plus_2 array in 27 gliomas. CHROMOWAVE generated multi-chromosomal pattern featuring low expression in chromosomes 1p, 4, 9q, 13, 18, and 19q. This pattern was not only statistically robust but also clinically relevant as it was predictive of favourable outcome. This finding was replicated on a data-set independently acquired by another laboratory. FISH analysis indicated that monosomy 1p and 19q was a frequent feature of tumours displaying the CHROMOWAVE pattern but that allelic loss on chromosomes 4, 9q, 13 and 18 was much less common. CONCLUSION: The ability to detect expression changes of spatially related genes and to map their position on chromosomes makes CHROMOWAVE a valuable screening method for the identification and display of regional gene expression changes of clinical relevance. In this study, FISH data showed that monosomy was frequently associated with diffuse low gene expression on chromosome 1p and 19q but not on chromosomes 4, 9q, 13 and 18. Comparative genomic hybridisation, allelic polymorphism analysis and methylation studies are in progress in order to identify the various mechanisms involved in this multi-chromosomal expression pattern.

Biomarkers, Tumor↗
PubMed2006

Establishment and characterisation of two novel human KSHV- and EBV-negative Burkitt cell lines, GAL-01 and GAL-02, from a primary lymphomatous effusion.

OBJECTIVES: Burkitt's lymphoma (BL) is a highly aggressive mature B-cell neoplasm comprising endemic, sporadic and immunodeficiency-associated variants. Human cell lines constitute a very useful tool to investigate the biology of lymphoid neoplasia. In this study, we succeeded in establishing two human cell lines, GAL-01 and GAL-02, from a HIV-negative patient with Epstein-Barr virus (EBV) -negative sporadic BL presenting as an effusion. GAL-01 and GAL-02 were established at diagnosis and after one course of polychemotherapy, respectively. The in vivo effusion occurred in a very peculiar clinical setting; the patient having a previous history of intestinal diffuse large B-cell lymphoma. METHODS: The morphologic, immunophenotypic and molecular genetic features of GAL cell lines are reported and compared with those of the parental tumour. The findings clearly demonstrated that the Burkitt effusion did not represent disease progression of the intestinal tumour, but represented a second primary haematological malignancy. The in vivo tumorigenic properties of the cells were tested by subcutaneous injection to NOD/SCID mice. RESULTS: Both cell lines were composed of medium-sized lymphoid cells with clumped chromatin, multiple medium-sized nucleoli and moderate amounts of vacuolated cytoplasm. GAL cells display the phenotype and genotype of a B-cell lineage (positive for CD20, CD79a and clonal rearrangement of Ig heavy chain), carry the c-MYC rearrangement by t(8;22)(q24;q11) translocation and are characterised by the expression of the germinal centre-associated antigens CD10, BCL6, CD38 and absent to low BCL2 expression. EBV and HHV8 were not identified within parental tumour or in cultured cells. Subcutaneous injection of both cell lines to NOD/SCID mice induced tumour formation. CONCLUSIONS: GAL-01 and GAL-02, two novel EBV-negative human BL cell lines represent a potentially useful experimental model to study the biology of BL possibly including the resistance to chemotherapy.

Animals↗
PubMed2006

Abnormalities of the long arm of chromosome 21 in 107 patients with hematopoietic disorders: a collaborative retrospective study of the Groupe Français de Cytogénétique Hématologique.

Chromosome 21 is frequently rearranged in hematopoietic malignancies. In order to detect new chromosomal aberrations, the Groupe Français de Cytogénétique Hématologique collected a series of 107 patients with various hematologic disorders and acquired structural abnormalities of the long arm of chromosome 21. The abnormalities were subclassified into 10 groups, according to the location of the 21q breakpoint and the type of abnormality. Band 21q22 was implicated in 72 patients (excluding duplications, triplications, and amplifications). The involvement of the RUNX1 gene was confirmed in 10 novel translocations, but the gene partners were not identified. Eleven novel translocations rearranging band 21q22 with bands 1q25, 2p21, 2q37, 3p21, 3p23, 4q31, 6p24 approximately p25, 6p12, 7p15, 16p11, and 18q21 were detected. Rearrangements of band 21q11 and 21q21 were detected in six novel translocations with 5p15, 6p21, 15q21, 16p13, and 20q11 and with 1p33, 3q27, 5p14, 11q11, and 14q11, respectively. Duplications, triplications, amplifications, and isodicentric chromosomes were detected in eight, three, eight, and three patients, respectively. The present study shows both the wide distribution of the breakpoints on the long arm of chromosome 21 in hematopoietic malignancy and the diversity of the chromosomal rearrangements and the hematologic disorders involved. The findings invite further investigation of the 21q abnormalities to detect their associated molecular rearrangements.

Adolescent↗
PubMed2006

T-cell/histiocyte-rich large B-cell lymphoma associated with a near-tetraploid karyotype and complex genetic abnormalities.

Cytogenetic data for T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) are scarcely available. We report here a case of THRLBCL with a near-tetraploid karyotype and complex chromosomal aberrations, without rearrangement of BCL2 or BCL6, and characterized pathologically by a variegated morphologic appearance with areas resembling nodular lymphocyte-predominant Hodgkin's lymphoma (NLPHL).

Chromosome Aberrations↗
PubMed2005

Deletions of the 3'BCR and 5'ABL regions in patients with Philadelphia-positive chronic myeloid leukemia: a one-step process occurring in about 10% of the cases without any evidence of genetic instability in the target cells.

Deletions of the 5'ABL region adjacent to the t(9;22)(q34;q11) have recently been reported in 8-32.7% of patients with chronic myeloid leukemia (CML). The deletions were visualized with fluorescence in situ hybridization using, in the majority of the cases, the Vysis LSI BCR/ABL ES (extra signal) probe. In our series, 10 of 99 CML patients (10.1%) were characterized by a 5'ABL deletion. We show that 3'BCR losses are observed in nearly all the cases with 5'ABL deletions. Moreover, the different genetic events (Philadelphia chromosome formation; 5'ABL and 3'BCR deletions) occur simultaneously in a one-step process without any evidence for genetic instability in the target bone marrow cells.

Female↗
PubMed2005

Transgenic engineering of male-specific muscular hypertrophy.

Using a two-step procedure involving insertional gene targeting and recombinase-mediated cassette exchange in ES cells, we have produced two lines of transgenic mice expressing a dominant-negative latency-associated myostatin propeptide under control of the myosin light chain 1F promoter and 1/3 enhancer from the TSPY locus on the Y chromosome. Males of the corresponding lines are characterized by a 5-20% increase in skeletal muscle mass. This experiment demonstrates the feasibility of a more efficient cattle production system combining superior beef production abilities for bulls and dairy abilities for cows.

Animals↗
PubMed2005

PAX5/IGH rearrangement is a recurrent finding in a subset of aggressive B-NHL with complex chromosomal rearrangements.

We present an extensive characterization of 10 B-cell lymphomas with a t(9;14)(p13;q32). The presence of the PAX5/IGH gene rearrangement was demonstrated by fluorescence in situ hybridization (FISH) using a validated probe set, whereas complex karyotypic changes were reassessed by multiplex-FISH (M-FISH). Pathologic and clinical review revealed the presence of this rearrangement in 4 histiocyte-rich, T-cell-rich B-cell lymphomas (HRTR-BCLs) and 2 posttransplantation diffuse large B-cell lymphomas (PTLD-DLBCLs). In contrast to initial observations describing this translocation in lymphoplasmacytic lymphoma (LPL) and LPL-derived large B-cell lymphoma, our data showed a wide morphologic and clinical spectrum associated with the PAX5/IGH rearrangement, pointing to an association between this aberration and a subset of de novo DLBCLs presenting with advanced disease and adverse prognosis. In addition, the recurrent incidence of this rearrangement in both HRTR-BCL (4 cases) and PTLD-DLBCL (2 cases) was previously unrecognized and is intriguing.

Aged↗
PubMed2005

Transmission of an undiagnosed sarcoma to recipients of kidney and liver grafts procured in a non-heart beating donor.

Transmission of an undiagnosed cancer with solid organ transplantation is a rare but dreadful event. In this paper the authors report the transmission of an undiagnosed sarcoma to recipients of kidney and liver grafts procured in a Maastricht category 3 non-heart beating donor. To the authors' knowledge this case is the first report of such a transmission with a liver graft procured in a non-heart beating donor. The cancer transferal was diagnosed 1 year after transplantation in the recipients of the liver and of one kidney. The liver recipient died from multiple organ failure after a failed attempt of tumor resection. The kidney recipient underwent immunosuppression withdrawal and transplantectomy. Non-heart beating donors should not be particularly at risk for undiagnosed cancer transmission if the procurement is performed according to the same rules of careful inspection of the abdominal and thoracic organs. After diagnosis of donor cancer transmission, kidney recipients should have the graft removed, and immunosuppression should be interrupted. The management of liver graft recipients is very difficult in this setting, and long-term survival was very rarely reported.

Biopsy, Needle↗
PubMed2004

Novel types of mutation responsible for the dermatosparactic type of Ehlers-Danlos syndrome (Type VIIC) and common polymorphisms in the ADAMTS2 gene.

Ehlers-Danlos syndrome (EDS) type VIIC, or dermatosparactic type, is a recessively inherited connective tissue disorder characterized, among other symptoms, by an extreme skin fragility resulting from mutations inactivating ADAMTS-2, an enzyme excising the aminopropeptide of procollagens type I, II, and III. All previously described mutations create premature stop codons leading to a marked reduction in the level of mRNA. In this study, we analyzed the ADAMTS2 cDNA sequences from five patients displaying clinical and/or biochemical features consistent with a diagnosis of either typical or potentially mild form of EDS type VIIC. Three different alterations were detected in the two patients with typical EDS type VIIC. The first patient was homozygous for a genomic deletion causing an in-frame skipping of exons 3-5 in the transcript. In the second patient, the allele inherited from the mother lacks exon 3, generating a premature stop codon, whereas the paternal allele has a genomic deletion resulting in an in-frame skipping of exons 14-16 at the mRNA level. Although the exons 3-5 or 14-16 encode protein domains that have not been previously recognized as crucial for ADAMTS-2 activity, the aminoprocollagen processing was strongly impaired in vitro and in vivo, providing evidence for the requirement of these domains for proper enzyme function. The three other patients with a phenotype with some resemblance to EDS type VIIC only had silent and functionally neutral variations also frequently found in a normal population.

ADAM Proteins↗
PubMed2003

Subtle trisomy 12q24.3 and subtle monosomy 22q13.3: three new cases and review.

The high resolution G-bands (850 bands) karyotype have made it possible to identify small chromosome anomalies (5 megabases) which are now microscopically visible. New techniques have been improved, such as the Fluorescent in situ hybridization (FISH) with subtelomeric probes, which can be employed to detect cryptic chromosome alterations not visible microscopically. We present three cases which had been remitted for a high resolution karyotype. The high resolution G-band karyotype and the FISH techniques led us to conclude that the three cases were carriers of a similar subtle chromosomal alteration. Case I is a new born female with developmental and psychomotor delay, hypotonia, and long limbs with arachnodactily. A high resolution G-band karyotype showed an abnormal chromosome 22. FISH techniques confirmed a der(22)t(12;22)(q24.31;q13.3). Case II is a 12-year-old girl, with growth retardation, long shaped face with thick eyebrows, smooth philtrum, and thin upper lip with severe mental retardation (still no language), with a phenotype very similar to that of his sister: long shaped face, thick eyebrows, smooth philtrum, and thin upper lip. A high resolution G-band karyotype also showed in Case II and III an abnormal chromosome 22, studied by FISH techniques which confirmed a der(22)t(12;22)(q24.3;q13.3) in both cases.

Abnormalities, Multiple↗
PubMed2003

Deletion (6)(p22p25) is a recurrent anomaly of thymoma: report of a second case and review of the literature.

A patient with type AB thymoma and del(6)(p22p25) as the sole cytogenetic anomaly is described. This is the second report of a del(6)(p22p25) in a thymoma. The same deletion was previously found in association with a type A thymoma. Both patients presented with benign tumors. These data suggest that partial deletion of the short arm of chromosome 6 is a nonrandom change associated with benign thymomas.

Chromosomes, Human, Pair 6↗
PubMed2003

Expression analyses identify MLL as a prominent target of 11q23 amplification and support an etiologic role for MLL gain of function in myeloid malignancies.

MLL amplification was recently recognized as a recurrent aberration in acute myeloid leukemia (AML) and myelodys-plastic syndrome (MDS), associated with adverse prognosis and karyotype complexity. Here we present detailed results of fluorescence in situ hybridization (FISH) and expression analyses of MLL and 5 selected 11q candidate oncogenes (CBL, DDX6, ETS1, FLI1, and PLZF) in 31 patient samples and one cell line with 11q23 gain. FISH analyses revealed that the 11q23 amplicon invariably encompassed MLL, DDX6, ETS1, and FLI1, whereas expression analyses identified MLL and DDX6 as the most differentially expressed genes among samples with and without 11q23 copy gain or amplification. In MLL-amplified samples, a significant transcriptional up-regulation of MEIS1, PROML1, ADAM10, NKG2D, and ITPA was noted. Further analyses, designed to elucidate a possible role of the 11q overexpressed genes (MLL, DDX6, FLI1, and ETS1) in unselected MDS and AML samples, revealed a significant upregulation of MLL in MDS. Our findings confirm the MLL gene as a prominent target of 11q23 amplification and provide further evidence for an etiologic role for MLL gain of function in myeloid malignancies. In addition, our results indicate that the transcriptional program associated with MLL rearrangements and MLL overexpression displays significant similarities.

Adult↗
PubMed2003

Malignant solitary fibrous tumor of the pleura: report of a case with cytogenetic analysis.

The majority of solitary fibrous tumors (SFTs) of the pleura are benign, but 10-30% locally recur or metastasize. Pathogenic factors relevant to the determinism of their biological properties are largely unknown. Cytogenetic data on SFTs of the pleura are sparse. We report herein a case of a malignant SFT of the pleura where successful karyotyping was obtained from the primary and recurrent tumors. The initial karyotype showed two abnormal clones: 48, XY; +8; +8; del(9)(q22; q32) [19] and 46, XY, t(1;16)(q25;p12) [7]. Culture of the recurrent tumor yielded one clone identical to the dominant clone of the initial karyotype. Demonstration of a recurrent abnormal karyotype largely supports its relevance to the malignant clone and suggests a role of supernumerary chromosome(s) 8 in the determinism of malignant behavior in SFT.

Aneuploidy↗
PubMed2003

Clonal chromosome aberrations in Philadelphia-negative cells from chronic myelocytic leukemia patients treated with imatinib mesylate: report of two cases.

Imatinib mesylate (tested as STI571), an abl kinase inhibitor, induces sustained, complete hematologic and cytogenetic responses in chronic myelocytic leukemia (CML) patients; however, emergence of clonal chromosomal aberrations in Philadelphia-negative (Ph-) cells during treatment has been reported. We describe two CML patients in chronic phase who presented with complete cytogenetic responses during imatinib mesylate therapy but developed new clonal chromosomal rearrangements in Ph- cells. The first patient presented with a duplication of chromosome 1, dup(1)(q21q42), and the second showed two new clonal aberrations consisting of inv(1)(q12q32) and del(7)(q22) in the same clone.

Antineoplastic Agents↗
PubMed2002

Identification of cytogenetic subclasses and recurring chromosomal aberrations in AML and MDS with complex karyotypes using M-FISH.

Complex chromosomal aberrations (CCAs) can be detected in a substantial proportion of AML and MDS patients, de novo as well as secondary or therapy-related, and are associated with an adverse prognosis. Comprehensive analysis of the chromosomal rearrangements in these complex karyotypes has been hampered by the limitations of conventional cytogenetics. As a result, our knowledge concerning the cytogenetics of these malignancies is sparse. Here we describe a multiplex-FISH (M-FISH) study of CCAs in 36 patients with AML and MDS. M-FISH generated a genome-wide analysis of chromosomal aberrations in CCAs, establishing several cytogenetic subgroups. -5/5q- was demonstrated in the majority of patients (86%). Other rearrangements (present with or without -5/5q-) included: deletion of 7q (47%), 3q rearrangements (19%), and MLL copy gain or amplification (17%). These genetic subgroups seem to display biological heterogeneity: MLL copy gain or amplification in association with 5q- was detected only in AML patients and was significantly associated with extremely short survival (median overall survival: 30 days, P = 0.0102). A partially cryptic t(4;5)(q31;q31), a balanced t(1;8)(p31;q22), and an unbalanced der(7)t(7;14)(q21;q13) were detected as possible new recurrent rearrangements in association with CCAs. Novel reciprocal translocations included t(5;11)(q33;p15)del(5)(q13q31) and t(3;6)(q26;q25). We conclude that AML and MDS with CCAs can be subdivided into molecular cytogenetic subclasses, which could reflect different clinical behavior and prognosis, and that three recurrent chromosomal aberrations are associated with karyotype complexity.

Acute Disease↗
PubMed2002

Nonmyeloablative stem cell transplantation with CD8-depleted or CD34-selected peripheral blood stem cells.

To decrease the incidence of graft-versus-host disease (GVHD) observed after nonmyeloablative stem cell transplantation (NMSCT), we studied the feasibility of CD8-depleted or CD34-selected NMSCT followed by CD8-depleted preemptive donor lymphocyte infusion (DLI) given in incremental doses on days 40 and 80. Fourteen patients with high-risk malignancies and an HLA-identical sibling (n = 8) or alternative donor (n = 6) but ineligible for a conventional transplant were included. Nonmyeloablative conditioning regimen consisted in 2 Gy total body irradiation (TBI) alone, 2 Gy TBI and fludarabine (previously untreated patients) or cyclophosphamide and fludarabine (patients who had previously received > or =12 Gy TBI). Patients 1-4 (controls) received unmanipulated peripheral blood stem cells (PBSC) and DLI and patients 5-14 CD8-depleted or CD34-selected PBSC followed by CD8-depleted DLI. Post-transplant immunosuppression was carried out with cyclosporine A (CsA) and mycophenolate mofetil (MMF). Initial engraftment was seen in all patients, but 1 patient (7%) later rejected her graft. The actuarial 180-day incidence of grades II-IV acute GVHD was 75% for patients 1-4 versus 0% for patients 5-14 (p = 0.0019). Five of 14 patients were in complete remission (CR) 180 days after the transplant and 6/14 had partial responses. The 1-year survival rate was 69%, and nonrelapse and relapse mortality rates were 16 and 18%, respectively. We conclude that CD8-depleted or CD34-selected NMSCT followed by CD8-depleted DLI is feasible and considerably decreases the incidence of acute GVHD while preserving engraftment and apparently also the graft-versus-leukemia (GVL) effect. Further studies are needed to confirm this encouraging preliminary report.

Adolescent↗