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S W Morris

Publications and source records attributed to S W Morris.

At least 19 recordsLinked to original sources
PubMed2002

Disruption of the RanBP17/Hox11L2 region by recombination with the TCRdelta locus in acute lymphoblastic leukemias with t(5;14)(q34;q11).

The t(5;14)(q33-34;q11) translocation constitutes a recurrent rearrangement in acute lymphoblastic leukemia involving the T cell receptor (TCR) delta locus on chromosome 14. Breakpoint sequences of the derivative chromosome 5 were isolated by application of a ligation-mediated PCR technique using TCR delta-specific primers to amplify genomic DNA from the leukemic cells of a patient with t(5;14). Through exon trap analysis, we identified various putative exons of the chromosome 5 target gene of the translocation; compilation of sequence information of trapped exons and available expressed sequence tags (ESTs) from the GenBank database allowed us to assemble 1.2 kb of the cDNA. Full-length cDNAs were isolated from a human testis cDNA library and sequence analysis predicted a putative Ran binding protein, a novel member of the importin-beta superfamily of nuclear transport receptors, called RanBP17. The t(5;14) breakpoint maps to the 3' coding region of the gene. The breakpoint of a second t(5;14) positive patient was mapped about 8 kb downstream of the most 3' RanBP17 exon and 2 kb upstream of the first exon of the orphan homeobox gene, Hox11L2. In both cases TCR delta enhancer sequences are juxtaposed downstream of the truncated or intact RanBP17 gene, respectively on the derivative chromosome.

Acute Disease↗
PubMed2001

Expression of the oncogenic NPM-ALK chimeric protein in human lymphoid T-cells inhibits drug-induced, but not Fas-induced apoptosis.

Anaplastic large cell lymphomas (ALCLs) are frequently associated with the t(2;5)(p23;q35) translocation, leading to the expression of NPM-ALK, a fusion protein linking nucleophosmin and anaplastic lymphoma kinase, a receptor tyrosine kinase. In ALCLs, dimerization of NPM-ALK leads to constitutive autophosphorylation and activation of the kinase, necessary for NPM-ALK oncogenicity. To investigate whether NPM-ALK, like other oncogenic tyrosine kinases, can inhibit drug-induced apoptosis, we permanently transfected NPM-ALK into Jurkat T-cells. As in ALCLs, NPM-ALK was expressed as a constitutively kinase-active 80 kDa protein, and could be detected by immunocytochemistry in nucleoli, nuclei and cytoplasm. Doxorubicin-induced apoptosis (assessed by cell morphology and annexin V-FITC binding) was significantly inhibited in two independent NPM-ALK-expressing clones (5.2+/-1.8 and 7.5+/-0.8% apoptosis), compared to control vector-transduced cells (36+/-6.7%). Similar results were observed with etoposide. In contrast, Fas-induced apoptosis was not inhibited. Cytochrome c release into the cytosol was delayed in doxorubicin-, but not anti-Fas-treated transfectant cells, indicating that apoptosis inhibition occurred upstream of mitochondrial events. Using NPM-ALK mutants, we demonstrated that inhibition of drug-induced apoptosis: (1) requires functional kinase activity, (2) does not involve phospholipase C-gamma, essential for NPM-ALK-mediated mitogenicity and (3) appears to be phosphoinositide 3-kinase independent, despite a strong Akt/PKB activation observed in wild type NPM-ALK-expressing cells. These results suggest that the NPM-ALK antiapoptotic and mitogenic pathways are distinct.

Adenosine Triphosphate↗
PubMed2001

Translocations involving anaplastic lymphoma kinase (ALK).

Anaplastic large-cell lymphoma (ALCL) comprises a group of non-Hodgkin's lymphomas (NHLs) that were first described in 1985 by Stein and co-workers and are characterized by the expression of the CD30/Ki-1 antigen (Stein et al., 1985). Approximately half of these lymphomas are associated with a typical chromosomal translocation, t(2;5)(p23;q35). Much confusion about the exact classification and clinicopathological features of this subgroup of NHL was clarified with the identification of NPM-ALK (nucleophosmin-anaplastic lymphoma kinase) as the oncogene created by the t(2;5) (Morris et al., 1994). With the discovery of NPM-ALK as the specific lymphoma gene mutation, this NHL subtype could be redefined on the molecular level. This achievement was enhanced by the availability of specific antibodies that recognize ALK fusion proteins in paraffin-embedded lymphoma tissues. Several excellent recent reviews have summarized the histopathological and molecular findings of ALCL and their use in the classification of this lymphoma entity (Anagnostopoulos and Stein, 2000; Benharroch et al., 1998; Drexler et al., 2000; Foss et al., 2000; Gogusev and Nezelof, 1998; Kadin and Morris, 1998; Ladanyi, 1997; Morris et al., 2001; Shiota and Mori, 1996; Skinnider et al., 1999; Stein et al., 2000). This review will focus on the molecular function and signal transduction pathways activated by ALK fusion oncogenes, with recent advances and possible clinical implications to be discussed.

Amino Acid Sequence↗
PubMed2001

Role of signal transducer and activator of transcription 5 in nucleophosmin/ anaplastic lymphoma kinase-mediated malignant transformation of lymphoid cells.

The NPM/ALK fusion gene, formed by the t(2;5) translocation in anaplastic large-cell lymphoma, encodes a M(r) 75,000 hybrid protein that containsthe amino-terminal portion of the nucleolar phosphoprotein nucleophosmin(NPM) joined to the entire cytoplasmic portion of the receptor tyrosine kinase anaplastic lymphoma kinase (ALK). NPM/ALK encodes a constitutively activated tyrosine kinase that belongs to the family of tyrosine kinases activated by chromosomal translocation. Our studies show that NPM/ALK, similar to other members of this family, activates signal transducer and activator of transcription 5 (STAT5) and that this activation is essential for lymphomagenesis. NPM/ALK-mediated activation of STAT5 was demonstrated by detection of: (a) constitutive tyrosine phosphorylation and enhanced DNA binding ability of STAT5 in NPM/ALK-transformed cells; and (b) NPM/ALK-dependent stimulation of STAT5-mediated transactivation of the beta-casein promoter. Retroviral infection of NPM/ALK+ cells with a dominant-negative STAT5B mutant (STAT5-DNM) inhibited the antiapoptotic activity of NPM/ALK in growth factor and serum-free medium. In addition, STAT5-DNM inhibited proliferation and diminished the clonogenic properties of NPM/ALK-positive cells. Finally, SCID mice injected with NPM/ALK+ cells infected with a virus carrying STAT5-DNM survived significantly longer than mice inoculated with NPM/ALK+ cells infected with the empty virus. Necropsy identified a widespread ALK+ lymphoma in lymph nodes and liver of the affected animals. Together, our data indicate that NPM/ALK-induced activation of STAT5 may play an important role in NPM/ALK-mediated lymphomagenesis.

Animals↗
PubMed2001

Bifurcations in annular electroconvection with an imposed shear.

We report an experimental study of the primary bifurcation in electrically driven convection in a freely suspended film. A weakly conducting, submicron thick smectic liquid crystal film was supported by concentric circular electrodes. It electroconvected when a sufficiently large voltage V was applied between its inner and outer edges. The film could sustain rapid flows and yet remain strictly two dimensional. By rotation of the inner electrode, a circular Couette shear could be independently imposed. The control parameters were a dimensionless number R, analogous to the Rayleigh number, which is ~V2 and the Reynolds number Re of the azimuthal shear flow. The geometrical and material properties of the film were characterized by the radius ratio alpha, and a dimensionless number P, analogous to the Prandtl number. Using measurements of current-voltage characteristics of a large number of films, we examined the onset of electroconvection over a broad range of alpha, P, and Re. We compared this data quantitatively to the results of linear stability theory. This could be done with essentially no adjustable parameters. The current-voltage data above onset were then used to infer the amplitude of electroconvection in the weakly nonlinear regime by fitting them to a steady-state amplitude equation of the Landau form. We show how the primary bifurcation can be tuned between supercritical and subcritical by changing alpha and Re.

Journal Article↗
PubMed2001

Role of phosphatidylinositol 3-kinase-Akt pathway in nucleophosmin/anaplastic lymphoma kinase-mediated lymphomagenesis.

The NPM/ALK fusion gene, formed by the t(2;5) translocation in a subset of anaplastic large cell lymphomas, encodes a Mr 75,000 hybrid protein that contains the NH2-terminal portion of the nucleolar phosphoprotein nucleophosmin (NPM) joined to the entire cytoplasmic portion of the receptor tyrosine kinase anaplastic lymphoma kinase (ALK). NPM/ALK encodes a constitutively activated tyrosine kinase that belongs to the family of tyrosine kinases activated by chromosomal translocations. Our studies showed that NPM/ALK, similar to other members of this family, activates phosphatidylinositol 3-kinase (PI3K) and its downstream effector, serine/threonine kinase (Akt). PI3K was found in complex with NPM/ALK. Both PI3K and Akt kinase were permanently activated in NPM/ALK-transfected BaF3 murine hematopoietic cells and in NPM/ALK-positive, but not in NPM/ALK-negative, patient-derived anaplastic large cell lymphoma cell lines. In addition, Akt was phosphorylated/activated in protein samples isolated from four patients diagnosed with ALK-positive T/null-cell lymphomas. The PI3K inhibitors wortmannin and LY294002 induced apoptosis in NPM/ALK+ cells but exerted only minor effects on the control BaF3 parental cells and peripheral blood mononuclear cells stimulated by growth factors. Furthermore, retroviral infection of NPM/ALK+ BaF3 cells with a dominant-negative PI3K mutant (delta p85) or a dominant-negative Akt mutant (K179M) inhibited proliferation and clonogenic properties of the infected cells. Finally, the Akt mutant (K179M) suppressed the tumorigenicity of NPM/ALK-transfected BaF3 cells injected into syngeneic mice. In conclusion, our data indicate that NPM/ALK constitutively activates the PI3K-Akt pathway and that this pathway plays an important role in the NPM/ALK-mediated malignant transformation.

Animals↗
PubMed2001

A 6.9-Mb high-resolution BAC/PAC contig of human 4p15.3-p16.1, a candidate region for bipolar affective disorder.

Bipolar affective disorder (BPAD) is a complex disease with a significant genetic component and a population lifetime risk of 1%. Our previous work identified a region of human chromosome 4p that showed significant linkage to BPAD in a large pedigree. Here, we report the construction of an accurate, high-resolution physical map of 6.9 Mb of human chromosome 4p15.3-p16.1, which includes an 11-cM (5.8 Mb) critical region for BPAD. The map consists of 460 PAC and BAC clones ordered by a combination of STS content analysis and restriction fragment fingerprinting, with a single approximately 300-kb gap remaining. A total of 289 new and existing markers from a wide range of sources have been localized on the contig, giving an average marker resolution of 1 marker/23 kb. The STSs include 57 ESTs, 9 of which represent known genes. This contig is an essential preliminary to the identification of candidate genes that predispose to bipolar affective disorder, to the completion of the sequence of the region, and to the development of a high-density SNP map.

Bipolar Disorder↗
PubMed2001

Fusion of the ALK gene to the clathrin heavy chain gene, CLTC, in inflammatory myofibroblastic tumor.

Inflammatory myofibroblastic tumor (IMT) is a rare, but distinctive mesenchymal neoplasm composed of fascicles of bland myofibroblasts admixed with a prominent inflammatory component. Genetic studies of IMTs have demonstrated chromosomal abnormalities of 2p23 and rearrangement of the anaplastic lymphoma kinase (ALK) gene locus. In a subset of IMTs, the ALK C-terminal kinase domain is fused with a tropomyosin N-terminal coiled-coil domain. In the current study, fusion of ALK with the clathrin heavy chain (CTLC) gene localized to 17q23 was detected in two cases of IMT. One of these cases exhibited a 2;17 translocation in addition to other karyotypic anomalies [46,XX,t(2;17)(p23;q23),add(16)(q24)].

Adult↗
PubMed2001

Physical mapping: integrating computational and molecular genetic data.

A crucial step beyond the identification of genetic linkage of a disease to a chromosomal region is the production of a physical map that will allow the identification of candidate genes. Although the process of physical map building has been facilitated by the flow of data released by the Human Genome Project, gathering all the information together requires significant effort. In a previous study, we reported linkage between Bipolar Affective Disorder and the chromosomal location 4p15.3--p16.1. In this review we use this example to describe how to collect publicly available sequence, DNA fingerprint, and genetic marker data and integrate these with empirical data to build a large scale high resolution physical map of a region. Methods used to identify new genetic markers and candidate genes within a circumscribed region are also presented.

Databases, Factual↗
PubMed2001

Fusion of two novel genes, RBM15 and MKL1, in the t(1;22)(p13;q13) of acute megakaryoblastic leukemia.

t(1;22) is the principal translocation of acute megakaryoblastic leukemias. Here we show this chromosomal rearrangement to result in the fusion of two novel genes, RNA-binding motif protein-15 (RBM15), an RNA recognition motif-encoding gene with homology to Drosophila spen, and Megakaryoblastic Leukemia-1 (MKL1), a gene encoding an SAP (SAF-A/B, Acinus and PIAS) DNA-binding domain.

Chromosomes, Human, Pair 1↗
PubMed2001

Anaplastic lymphoma kinase (ALK) expression in the inflammatory myofibroblastic tumor: a comparative immunohistochemical study.

Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal neoplasm with a variable histologic appearance that may mimic other spindle cell processes, particularly nodular fasciitis, desmoid tumor, and in intra-abdominal locations, gastrointestinal stromal tumor. Recently, gene fusions involving ALK at chromosome 2p23 have been described in IMTs. The resultant ALK protein overexpression in the myofibroblastic component of these tumors is detectable by immunohistochemistry. We examined 73 IMTs, 20 cases of nodular fasciitis, 15 desmoid fibromatoses, and 15 gastrointestinal stromal tumors by immunohistochemistry using ALK-11, a rabbit polyclonal antibody that recognizes the C-terminus of the protein. ALK positivity was detected in 44 of 73 (60%) IMTs. All cases of nodular fasciitis, desmoid fibromatosis, and gastrointestinal stromal tumors were ALK negative (p < 0.001). These findings demonstrate that ALK positivity is common in IMTs, and immunohistochemistry using anti-ALK antibodies can be helpful in the differential diagnosis of these neoplasms. In addition, anti-ALK staining seems to correlate with those IMTs that have the typical tri-patterned histologic appearance and clinical presentation, providing additional support to the premise that IMT is a distinctive clinicopathologic entity within the broad category of inflammatory pseudotumors.

Adolescent↗
PubMed2001

Molecular features of B-cell lymphoma.

Malignant transformation of B cells can occur at various steps of lymphocyte development, starting from early B-cell progenitors up to mature B cells, which reflects the heterogeneity of B-cell malignancies with regard to their biologic and clinical behavior. The genetic characterization of B-cell neoplasms during the past two decades has elucidated the mechanisms underlying B-cell lymphomagenesis and led to a more precise definition of lymphoma subgroups. This progress is reflected in the upcoming World Health Organization classification for hematologic neoplasms, which stresses the diagnostic importance of recurrent genetic alterations in leukemias and lymphomas. In the recent past, several genes deregulated by such recurrent chromosomal aberrations have been identified. In addition, the recent introduction of microarray technology has now allowed a more global assessment of gene dysregulation in B-cell oncogenesis and provided a new means for more exactly defining the molecular hallmarks of distinct lymphoma subtypes. This review will focus on recently described molecular features of B-cell lymphomas discovered by the application of new molecular cytogenetic techniques, advanced breakpoint cloning strategies, and microarray approaches.

Cell Transformation, Neoplastic↗
PubMed2001

Anaplastic lymphoma kinase proteins and malignancy.

The anaplastic lymphoma kinase (ALK) gene fuses to the nucleophosmin (NPM) gene as a result of a (2;5) translocation associated with a subtype of human lymphoma (initially designated anaplastic large cell lymphoma [ALCL] or Ki-1/CD30-positive lymphoma). The immunocytochemical detection of NPM-ALK (and proteins encoded by other ALK fusion genes) has allowed the definition of a tumor entity, "ALK-positive lymphoma" (which shows only partial overlap with pathologists' diagnosis of ALCL), to be defined and is invaluable in distinguishing this disease from ALK-negative large cell lymphomas. Eight variant ALK fusion proteins have been identified. Some are expressed only in ALCL, some are found only in the nonhematopoietic neoplasm inflammatory myofibroblastic tumor (IMT), and some are present in both types of malignancy. The ALK gene is silent in adult tissues except for restricted sites within the nervous system (consequently, patients with ALK-positive lymphoma produce antibodies to the ALK protein) but is expressed in some neuroblastomas and rhabdomyosarcomas. Biochemical studies suggest an anti-apoptotic function of NPM-ALK, and this may contribute to oncogenesis. Although ALK-positive lymphomas have a generally good prognosis, new therapeutic regimens are still needed for patients whose disease is refractory to conventional treatment.

Anaplastic Lymphoma Kinase↗
PubMed2001

Lack of BCL10 mutations in multiple myeloma and plasma cell leukemia.

To determine whether the BCL10 mutation plays a role in the oncogenesis of plasma cell dyscrasias, we used polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing analysis and examined the genomic BCL10 mutations in 57 patients with multiple myeloma or plasma cell leukemia and 52 normal bone marrow samples. We found three polymorphic sequence variants, either alone or in combination, at codons 5 and 8, and in intron 1 at base 58 of the BCL10 gene in 37 patients with plasma cell dyscrasia. Identical aberrant band shifts were also observed in 34 normal marrow samples. No polymorphic variants were identified in exon 2 or 3 in either patient or control samples, and no pathogenic mutations were detected. Patients with plasma cell dyscrasias in Taiwan appeared to have a higher frequency of polymorphisms at codon 5 and intron 1 at base 58, and a lower frequency at codons 8 and 213. Our results suggest that BCL10 is not involved in the oncogenesis of plasma cell dyscrasias.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Nucleophosmin-anaplastic lymphoma kinase associated with anaplastic large-cell lymphoma activates the phosphatidylinositol 3-kinase/Akt antiapoptotic signaling pathway.

More than half of anaplastic large-cell lymphomas (ALCLs) have a chromosomal translocation t(2;5) that leads to the expression of a hybrid protein composed of the nucleolar phosphoprotein nucleophosmin (NPM) and the anaplastic lymphoma kinase (ALK) that exhibits an unregulated tyrosine kinase activity. We have previously identified PLC-gamma as a crucial downstream signaling molecule of NPM-ALK that contributes to its mitogenic potential. Here, we show that NPM-ALK recruits the C-terminal SH2 domain of the phosphatidylinositol 3-kinase (PI 3kinase) p85 subunit. PI 3-kinase assays revealed that the kinase is activated by NPM-ALK in vivo, in turn activating PKB/Akt in NPM-ALK-expressing cells. The use of 2 specific PI 3-kinase inhibitors, wortmannin and LY294002, demonstrated the requirement of PI 3-kinase for the growth of NPM-ALK-transformed cell lines, as well as a cell line established from a patient with ALCL. Primary murine bone marrow retrovirally transduced with NPM-ALK showed a transformed phenotype that was reversible on treatment with PI 3-kinase inhibitors. Flow cytometric analysis revealed that wortmannin-treated NPM-ALK-transformed cell lines underwent apoptosis. Furthermore, apoptosis induced by overexpression of the proapoptotic molecule Bad could be partially blocked by the overexpression of NPM-ALK. Thus, NPM-ALK activates the antiapoptotic PI 3-kinase/Akt pathway, which likely contributes to the molecular pathogenesis of ALCL. (Blood. 2000;96:4319-4327)

Amino Acid Substitution↗