Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Deletions in chromosomal band 13q14.3 occur in >50% of B-cell chronic lymphocytic leukemias (B-CLL) and mantle cell lymphoma, indicating the localization of a tumor suppressor gene involved in the pathomechanism of these diseases. Within a 400 kb recurrently deleted segment at least two minimally deleted subregions had been reported. For the two genes residing in the proximal subregion, initially named LEU1 and LEU2, a pathogenic role has not yet been established. We report here that LEU1 is only a small portion of a large gene, which spans all previously reported critical subregions including the distal subregion. This gene, designated B-cell neoplasia-associated gene with multiple splicing (BCMS), is composed of at least 50 exons spanning >or=560 kb of genomic DNA and is expressed in more than 20 RNA splicing variants. While tissue-specific expression of RNA variants was observed, there was no evidence for the expression of a variant specific for B-CLL. Sequence analysis of the RNA variants suggests that BCMS transcripts belong to the group of non-coding RNAs. The alignment of the gene with all critical subregions provides a strong argument for BCMS being the most likely candidate for the tumor suppressor gene in 13q14 involved in the leukemogenesis of B-CLL. Due to the limited understanding of functional RNAs, however, it remains difficult to prove the pathogenic role of BCMS.
Hum Mol Genet 2001 Jun 01
PMID:B-cell neoplasia associated gene with multiple splicing (BCMS): the candidate B-CLL gene on 13q14 comprises more than 560 kb covering all critical regions. 1140 9

Mouse immunoglobulin (Ig) molecules have previously been shown to bind to the surface of CD5(+) B cells from patients with B-cell chronic lymphocytic leukemia (B-CLL). The results indicated that surface IgM was involved in the interaction and suggested the phenomenon was an example of the polyreactive binding capacity of the surface Ig (sIg) expressed by these malignant cells. This article describes the further characterization of the interaction between human IgM and mouse Ig molecules and subunits. Mouse Ig molecules of both kappa and lambda light chain classes bound to the B-CLL cell surface. The dissociation constant for the interaction of mouse IgG1 (K121) with the B-CLL cell surface was 3.6 x 10(-7) M. To confirm the involvement of the human IgM expressed by the B-CLL cells in the interaction, the malignant cells were stimulated in vitro to induce secretion of human IgM. Enzyme immunoassay was used to show that secreted human IgM bound to intact mouse Ig, as occurred with the cell surface analysis. The mouse Ig epitope recognized by the purified secreted human IgM was shown by Western blot analysis to be located on the light chain of the mouse Ig molecule and to be conformationally dependent. K121 light chain was cloned and expressed in E. coli and the recombinant light chain bound to the surface of CLL B cells. The results confirm that human IgM is the reactive ligand in the interaction with mouse Ig and indicate that the interaction of polyreactive IgM with mouse IgG occurs via the light chain component of IgG.
J Mol Recognit
PMID:IgM expressed by leukemic CD5(+) B cells binds mouse immunoglobulin light chain. 1150 Sep 71

We have used a continuous fluorescence monitoring method to assess cyclin D1 mRNA expression in a variety of hematological and non-hematological processes. We examined 14 cell lines, 11 reactive lymphoid tissues, and 57 primary hematopoietic neoplasms including mantle cell lymphoma (MCL) (n = 10), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (n = 11), acute lymphoblastic leukemia/lymphoma (n = 15), follicular lymphoma (n = 6), peripheral T-cell lymphoma (PTCL) (n = 3), anaplastic large cell lymphoma (n = 3), hairy cell leukemia (n = 3), Burkitt lymphoma (n = 1), Burkitt-like lymphoma (n = 4), and plasmacytoma (n = 1) for the expression of cyclin D1 mRNA using fluorescently labeled sequence-specific hybridization probes. Fluorescence (F) was plotted against cycle (C) number over 45 cycles. The log-linear portion of the F versus C graph identified a fractional cycle number for threshold fluorescence. A beta-globin mRNA transcript with equivalent amplification efficiency to that of cyclin D1 was used for assessment of RNA integrity and normalization. In general, the MCLs demonstrated substantially higher levels of cyclin D1 mRNA than the other lymphoproliferative processes. Moderately high levels of cyclin D1 mRNA were detected in one PTCL. On average, the CLL/SLL cases showed cyclin D1 mRNA levels two to three orders of magnitude lower than observed in the MCLs. Cell lines derived from non-hematopoietic neoplasms such as fibrosarcoma, small cell carcinoma, and neuroblastoma showed comparable or higher levels of cyclin D1 mRNA than the MCLs. Our results indicate that quantitative real-time reverse transcription (RT) polymerase chain reaction is a simple, rapid, and accurate technique for assessing cyclin D1 expression, and while it is not specific, it can reliably be used in the distinction of MCL from CLL/SLL.
J Mol Diagn 2002 May
PMID:Fluorescence PCR quantification of cyclin D1 expression. 1198 99

Immunophenotyping of B-cell lymphoproliferative disorders is indispensable, especially in disorders with CD19(+) CD5(+) B lymphocytes, where we have to make the distinction between low grade neoplasia, such as chronic lymphocytic leukemia with CD23(+) malignant lymphocytes, and aggressive neoplasia such as mantle cell lymphoma with CD23(-) malignant lymphocytes. We found some cases of CD19(+) CD5(+) lymphoproliferative disorders that do not meet all criteria for diagnosis of chronic lymphocytic leukemia or mantle cell lymphoma. For instance, we found cases with a low or no expression of CD23, asociated with absence of expression of FMC7 and surface immunoglobulins. These cases could be classified as "borderline" CD19(+) CD5(+) B cell lymphoproliferative disorders, with an intermediate neoplasic grade.
J Cell Mol Med
PMID:Lymphoma immunophenotyping: "borderline" lymphomas. 1216 89

Chronic lymphocytic leukemia (CLL) is a B lymphocyte malignancy that remains a largely incurable disease. CLL B cells possess the ability to process and present tumor antigens but lack expression of costimulatory molecules, rendering them inefficient effectors of T-cell activation. We previously demonstrated that helper virus-free preparations of herpes simplex virus (HSV) amplicon vectors encoding CD40L efficiently transduce CLL B cells and render them capable of eliciting specific anti-tumor T-cell responses. LIGHT (TNFSF14), a member of the tumor necrosis factor (TNF) superfamily, efficiently activates both T cells and antigen-presenting cells (APCs). We employed an HSV amplicon vector expressing human LIGHT (hf-HSV-LIGHT) to transduce CLL B cells and compared the immunomodulatory function and T-cell activation induced by hf-HSV-LIGHT transduction to that observed with a CD40L-expressing HSV amplicon (hf-HSV-CD40L). hf-HSV-LIGHT transduction induced expression of endogenous B7.1, B7.2, and ICAM.1 on CLL cells, albeit to a lesser degree than that observed in response to transduction with hf-HSV-CD40L. hf-HSV-LIGHT enhanced the antigen-presenting capacity of CLL B cells, as measured by induction of T-cell proliferation in an allogeneic mixed lymphocyte tumor reaction. Finally, hf-HSV-LIGHT-transduced CLL B cells successfully stimulated the outgrowth of autologous cytotoxic T-lymphocytes in vitro. In aggregate, these data suggest that hf-HSV-LIGHT transduction may be useful for induction of immune responses to CLL and other B-cell lymphoid malignancies.
Mol Ther 2002 Oct
PMID:HSV amplicon-mediated delivery of LIGHT enhances the antigen-presenting capacity of chronic lymphocytic leukemia. 1237 86

Elevated DNA repair processes represent resistance mechanisms to the treatment of malignancies with alkylating agents. Recently, the cell cycle checkpoint abrogator, UCN-01, was reported to inhibit nucleotide excision repair in cell-free systems. We hypothesized that if UCN-01 was combined with DNA-damaging agents, UCN-01 might inhibit the damage repair processes, thereby enhancing cytotoxicity in quiescent cells. Here, we investigated the effect of UCN-01 on DNA repair and viability of quiescent normal lymphocytes and chronic lymphocytic leukemia lymphocytes treated with UV or the cyclophosphamide prodrug 4-hydroperoxycyclophosphamide (4-HC). DNA damage repair kinetics were determined as DNA single strand breaks by the alkaline single cell gel electrophoresis (comet) assay and by [3H]thymidine incorporation. Pretreatment with UCN-01 inhibited DNA repair initiated by UV or 4-HC in normal lymphocytes as well as chronic lymphocytic leukemia lymphocytes in a concentration-dependent manner at clinically relevant levels (50-300 nM). This inhibition was demonstrated by the decreases in incision capability, DNA resynthesis, and in rejoining, suggesting that UCN-01 inhibits the multiple sites of the repair processes. The higher UCN-01 concentration (300 nM) maximized the inhibitory effects and enhanced the UV- or 4-HC-induced cytotoxicity, as determined by annexin V binding or Hoechst 33342 staining. This enhancement was not obtained by the lower concentrations that incompletely inhibited the repair, suggesting the close association between the inhibition of the repair and the enhancement of the cytotoxicity. Our findings suggest that UCN-01 may be a good candidate for combination strategies of cancer treatment.
Mol Cancer Ther 2002 Feb
PMID:UCN-01 (7-hydroxystaurosporine) inhibits DNA repair and increases cytotoxicity in normal lymphocytes and chronic lymphocytic leukemia lymphocytes. 1246 24

Topoisomerase (Topo) IIalpha has proven to be an adequate anticancer target for tumors expressing this enzyme. In this study, we elucidated the effect of 2-[4-(7-chloro-2-quinoxalinyloxyphenoxy]-propionic acid (XK469; a new Topo IIbeta inhibitor) in the modulation of Topo IIalpha levels and sensitivity to Topo IIalpha poisons. We demonstrate by Western blot analysis that indolent B-cell tumors express undetectable levels of this enzyme and are refractory to the effects of Topo IIalpha poisons such as VP16. Using the Waldenstrom's macroglobulinemia (WM) cell line WSU-WM, we show that XK469 induced the expression of Topo IIalpha protein by 24 h compared with control. Immunofluorescence studies by confocal microscopy using a specific monoclonal antibody against Topo IIalpha supported the immunoblot findings with high intensity staining in XK469-exposed cells. To determine the effect of up-regulating Topo IIalpha on sensitivity of Topo IIalpha-directed inhibitors, WSU-WM cells were exposed to simultaneous, sequential, and reverse order XK469 and VP16. We demonstrate that 24 h of exposure to XK469 before VP16 resulted in a maximum synergistic response. In contrast, simultaneous or reverse order exposure resulted in an antagonistic effect. A similar trend was observed with cells obtained from chronic lymphocytic leukemia patients, but not in normal lymphocytes. This increase in VP16 sensitivity after 24 h of XK469 exposure was associated with VP16-dependent DNA cleavage, as demonstrated by formation of a smeared DNA band in a SDS-KCL DNA cleavage assay. From this study, we concluded that XK469 up-regulates Topo IIalpha levels and consequently sensitizes indolent malignant B cells to the cytotoxic effect of VP16 in a schedule-dependent manner.
Mol Cancer Ther 2002 Dec
PMID:2-[4-(7-chloro-2-quinoxalinyloxyphenoxy]-propionic acid (XK469), an inhibitor of topoisomerase (Topo) IIbeta, up-regulates Topo IIalpha and enhances Topo IIalpha-mediated cytotoxicity. 1251 65

B-chronic lymphocytic leukemia (B-CLL) is an adult-onset leukemia characterized by significant accumulation of apoptosis-resistant monoclonal B lymphocytes. In this study, we performed gene expression profiling on B cells obtained from 10 healthy age-matched individuals and CLL B cells from 38 B-CLL patients to identify key genetic differences between CLL and normal B cells. In addition, we leveraged recent independent studies to assess the reproducibility of our molecular B-CLL signature. We used a novel combination of several methods of data analysis including our own software and identified 70 previously unreported genes that differentiate leukemic cells from normal B cells, as well as confirmed recently reported B-CLL specific expression levels of an additional 10 genes. Importantly, many of these genes have previously been linked with other cancers, thus lending further support to their importance as candidate genes leading to B-CLL pathogenesis. We have also validated a subset of these genes using independent methodologies. Moreover, we show that our genes can be used to create a diagnostics signature that performs with perfect sensitivity and specificity in an independent cohort of 21 B-CLL and 20 normal subjects, thus strongly validating the informative nature of our set of genes. Finally, we identified a group of 31 genes that distinguish between low (Rai stage 0) and high (Rai stage 4) risk patients, suggesting that there may also be a gene expression signature that associates with disease progression.
Mol Cancer Res 2003 Mar
PMID:Identification of a global gene expression signature of B-chronic lymphocytic leukemia. 1265 8

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of lymphocytes that are arrested at an intermediate stage of B lymphocyte development. CLL B lymphocytes transform (mature) to a plasmacytic phenotype with loss of CD19 and CD20 and the appearance of cytoplasmic immunoglobulin when treated in vitro with phorbol esters. We have used array hybridization technology to describe gene expression patterns for untreated and tetradecanoyl phorbol acetate (TPA)-treated CLL B cells at 5, 10, and 20 min following initial TPA exposure. Three genes, early growth response factor 1 (EGR-1), dual specificity phosphatase 2, and CD69 (early T-cell activation antigen), showed a 2.0-fold or greater increase in mRNA transcription at four or more of six time points in two studies. Upregulation of expression of these genes was confirmed by real-time polymerase chain reaction in the TPA-treated cells of four CLL patients. A progressive increase in gene expression was observed during the 20-min time course for all three genes. In addition, protein expression of EGR-1 and CD69 was increased as measured by immunofluorescence cell analysis. Several genes (PKC, n-myc, jun D, and BCL-2) previously reported as overexpressed in CLL lymphocytes were overexpressed in these studies also, but were not altered by TPA treatment. Genes for proteins whose upregulation requires hours of TPA exposure (the 4F2hc component of the L-system amino acid transporter, prohibition, and hsp60) were assessed, and their later expression contrasted with the early expression of EGR-1, dual specificity phosphatase 2, and CD69. EGR-1 encodes a zinc-finger transcription factor that is induced by pokeweed mitogen and TPA and promotes B lymphocyte maturation. The dual specificity phosphatase 2 encodes an enzyme that reverses mitogen activated protein kinase cell activation by dephosphorylation. The CD69 protein is induced by TPA in thymocytes and is a type II transmembrane signaling molecule in hematopoietic cells. These findings suggest that the products of these three genes may be central to early steps in the TPA-induced evolution of CLL B cells to a plasmacytic phenotype.
Blood Cells Mol Dis
PMID:Early gene activation in chronic leukemic B lymphocytes induced toward a plasma cell phenotype. 1273 46

External source radiotherapy and beta radioimmunotherapy (RIT) are effective treatments for lymphoid malignancies. The development of RIT with alpha emitters is attractive because of the high linear energy transfer (LET) and short path length, allowing higher tumour cell kill and lower toxicity to healthy tissues. We assessed the relative biological efficacy (RBE) of alpha RIT (in vitro) compared to external gamma irradiation with respect to induction of apoptosis in B chronic lymphocytic leukaemia (B-CLL) and induction of chromosomal damage in healthy donor B and T lymphocytes. The latter was measured by a micronucleus assay. 213Bi was eluted from a 225Ac generator and conjugated to CD20 antibody (rituximab) with CHX-A"-DTPA as a chelator. B-CLL cells from five patients were cultured for 24 h in RPMI/10% FCS while exposed to 213Bi conjugated to CD20 antibody or after external 60Co gamma irradiation. Binding assays were performed in samples of all patients to calculate the total absorbed dose. Apoptosis was scored by flow cytometric analyses of the cells stained with annexin V-FITC and 7-AAD. Apoptosis was expressed as % excess over spontaneous apoptosis in control. Full dose range experiments demonstrated 213Bi-conjugated CD20 antibody to be more effective than equivalent doses of external gamma irradiation, but showed that similar plateau values were reached at 10 Gy. The RBE for induction of apoptosis in B-CLL was 2 between 1.5 and 7 Gy. The micronucleus yield in lymphocytes of healthy volunteers was measured to assess the late toxicity caused by induction of chromosomal instability. While gamma radiation induced a steady increase in micronucleus yields in B and T cells, the damage induced by 213Bi was more dramatic, with RBE ranging from 5 to 2 between 0.1 Gy and 2 Gy respectively. In contrast to gamma irradiation, 213Bi inhibited mitogen-stimulated mitosis almost completely at 2 Gy. In conclusion, high-LET targeted alpha particle exposure killed B-CLL cells more effectively than did external gamma irradiation at a low dose (RBE=2), while a plateau was reached at a high dose. Long-term toxicity on healthy B and T lymphocytes was systematically higher for the alpha emitter (RBE=5 to 2).
Eur J Nucl Med Mol Imaging 2003 Oct
PMID:In vitro evaluation of 213Bi-rituximab versus external gamma irradiation for the treatment of B-CLL patients: relative biological efficacy with respect to apoptosis induction and chromosomal damage. 1284 84


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