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)

Dysregulated JAK2 signaling has been shown to play a significant role in the pathogenesis of myeloproliferative disorders. Recently, our work comparing gene expression signatures of primary mediastinal large B-cell lymphomas (PMLBCL) versus nodal diffuse large B-cell lymphomas revealed a relative increase in JAK2 transcripts in the former, suggesting a role for increased JAK2 signaling in a subset of these tumors. Given the likelihood of increased JAK2 signaling in PMLBCL, we sought to determine whether JAK2 activating mutations were an alternative mechanism for increased JAK2 signaling in untreated PMLBCLs. We performed amplification refractory mutation analysis for the JAK2 (V617F) mutation and bidirectional sequencing for the recently described JAK2 exon 12 mutations on genomic DNA isolated from a well-characterized cohort of PMLBCLs. No evidence of the mutant JAK2 (V617F) allele or JAK2 exon 12 mutations was detected in 31 PMLBCL cases tested. Analysis using cell lines derived from PMLBCLs (n = 1) and from the molecularly similar classic Hodgkin lymphoma (n = 4) also failed to reveal involvement of a mutant JAK2 allele. Taken together, these results suggest that JAK2 signaling in PMLBCLs occurs by mechanisms distinct from JAK2 (V617F) or JAK2 exon 12 activating mutations.
Diagn Mol Pathol 2009 Sep
PMID:No evidence for the JAK2 (V617F) or JAK2 exon 12 mutations in primary mediastinal large B-cell lymphoma. 1970 59

Mantle cell lymphomas (MCLs) are associated with a characteristic t(11;14)(q13;q32) chromosomal translocation. This causes the CCND1 gene on chromosome 11 to be co-localized with the immunoglobulin heavy chain gene on chromosome 14, resulting in increased expression of cyclin D1. The cyclin D1/D3 expression ratio, as an approach to segregate MCLs from other small B-cell lymphomas, has not previously been evaluated in formalin-fixed, paraffin-embedded tissue. We found that mean cyclin D3 expression was lower in MCLs (P < 0.05) than in chronic lymphocytic leukemias (CLLs), follicular lymphomas (FLs), marginal zone/mucosa-associated lymphoid tissue lymphomas (MALTs), multiple myelomas (MMs), and reactive lymph nodes. As expected, mean cyclin D1 expression was increased in MCL (P < 0.05), but in several cases the expression of cyclin D1 did overlap with the level observed in CLLs, FLs, MALTs, MMs, and reactive lymph nodes. The cyclin D1/D3 expression ratio, however, did fully separate MCLs from FLs, CLLs, and reactive lymph nodes. The mean expression ratio was also significantly different between MCL and MALT (P < 0.05), but 3 MCL cases had values overlapping those of some MALTs. The expression ratio was not significantly different between MCL and MM. In conclusion, the cyclin D1/D3 expression ratio gave an improved segregation of MCLs from CLLs, FLs, MALTs, and reactive lymph nodes, as compared with determination of cyclin D1 alone in formalin-fixed, paraffin-embedded tissue.
Diagn Mol Pathol 2009 Sep
PMID:Improved diagnostic segregation of mantle cell lymphoma by determination of cyclin D1/D3 expression ratio in formalin-fixed tissue. 1970 60

Normalization of quantitative reverse transcription-PCR (Q-RT-PCR) data to appropriate tissue-specific reference genes is an essential part of interpreting the results. This study aimed to determine the most appropriate reference genes for normalizing gene expressions in lymphatic tissue, represented by non-neoplastic lymph nodes and diffuse large B-cell lymphomas, by using 2 statistical software applications, geNorm and NormFinder. In addition, we wanted to validate the usefulness of paraffin-embedded samples for Q-RT-PCR studies by investigating gene expressions of relevant target genes in paired frozen and paraffin-embedded samples. Moreover, we studied the impact of amplicon sizes on the efficiency of Q-RT-PCR in paraffin-embedded tissues. Six putative reference genes were tested for stability of expression in 21 pairs of snap-frozen and formalin-fixed, paraffin-embedded lymph nodes and lymphomas. The genes were ranked according to their suitability as reference genes. According to both statistical approaches, beta-glucoronidase was the single most appropriate reference gene in both snap-frozen and paraffin-embedded samples. TATA box-binding protein gene and Abelson murine leukemia viral oncogene homolog 1 gene were also highly ranked by both programs. In addition, we measured the relative expressions of 7 target genes by Q-RT-PCR, using PCR primer-probes with amplicon sizes up to 105 bases. The correlation coefficient for expression measured in matched frozen and paraffin-embedded samples was 0.93 (P<0.01) after normalization with the appropriate reference genes. Thus, we show that formalin-fixed, paraffin-embedded lymphoid samples are suitable for Q-RT-PCR when using thoroughly validated reference genes.
Diagn Mol Pathol 2009 Dec
PMID:Validation of putative reference genes for normalization of Q-RT-PCR data from paraffin-embedded lymphoid tissue. 1986 91

The CD22 antigen is a viable target for therapeutic intervention for B-cell lymphomas. Several therapeutic anti-CD22 antibodies as well as an anti-CD22-based immunotoxin (HA22) are currently under investigation in clinical settings. Coupling of anti-CD22 reagents with a nano-drug delivery vehicle is projected to significantly improve treatment efficacies. Therefore, we generated a mutant of the targeting segment of HA22 (a CD22 scFv) to increase its soluble expression (mut-HA22), and conjugated it to the surface of sonicated liposomes to generate immunoliposomes (mut-HA22-liposomes). We examined liposome binding and uptake by CD22(+) B-lymphocytes (BJAB) by using calcein and/or rhodamine PE-labeled liposomes. We also tested the effect of targeting on cellular toxicity with doxorubicin-loaded liposomes. We report that: (i) Binding of mut-HA22-liposomes to BJAB cells was significantly greater than liposomes not conjugated with mut-HA22 (control liposomes), and mut-HA22-liposomes bind to and are taken in by BJAB cells in a dose and temperature-dependent manner, respectively; (ii) This binding occurred via the interaction with the cellular CD22 as pre-incubation of the cells with mut-HA22 blocked subsequent liposome binding; (iii) Intracellular localization of mut-HA22-liposomes at 37 degrees C but not at 4 degrees C indicated that our targeted liposomes were taken up through an energy dependent process via receptor-mediated endocytosis; and (iv) Mut-HA22-liposomes loaded with doxorubicin exhibited at least 2-3 fold more accumulation of doxorubicin in BJAB cells as compared to control liposomes. Moreover, these liposomes showed at least a 2-4 fold enhanced killing of BJAB or Raji cells (CD22(+)), but not SUP-T1 cells (CD22(-)). Taken together these data suggest that these 2nd-generation liposomes may serve as promising carriers for targeted drug delivery to treat patients suffering from B-cell lymphoma.
Exp Mol Pathol 2010 Apr
PMID:Specific targeting to B cells by lipid-based nanoparticles conjugated with a novel CD22-ScFv. 2012 24

CD20 is an important target for monoclonal antibody therapy of B-cell malignancies and for some autoimmune disorders. Though there is interest in evaluating the induction of active immunity to CD20 in the mouse model, the CD20 extracellular domain (ECD) has significant secondary and tertiary structure which make it difficult to target using peptide immunogens. We constructed, expressed, and purified a recombinant immunogen, CD20ECD-6, which displays six tandemly repeated copies of the C-terminus of the murine CD20 ECD covalently linked to maltose-binding protein. Analysis of the purified protein suggested a complex conformation as the protein migrated in significantly retarded fashion by SDS-PAGE analysis. Immunization of mice and rabbits with the CD20ECD-6 led to the induction of antibodies reactive with the C-terminal ECD peptide sequence by ELISA and more importantly, with native cell surface CD20 on the murine B-cell lymphomas, 38C13 and A20. Immunoprecipitation using the rabbit antisera and non-denaturing detergent confirmed the identity of the bound cell surface protein as murine CD20 and suggested that the cell-binding antibodies were specific for the native, folded conformation. Finally, immunization of mice with the CD20ECD-6 using Freund's or QS-21 adjuvants was shown to exert significant biological effects in vivo with the pronounced depletion of splenic B cells. The tandem-epitope immunogen represents a promising tool for eliciting and studying active autoimmunity to CD20, as a basis for potential development of new immunotherapeutics for cancer and autoimmune diseases.
Mol Immunol 2010 Apr
PMID:A CD20 tandem-epitope immunogen elicits antibody in mice that binds murine cell surface CD20 and depletes splenic B cells in vivo. 2018 50

Cutaneous lymphomas (CLs) are a heterogeneous group of lymphoproliferative disorders that are manageable by immunotherapy. Twenty-one patients were enrolled in a prospective open-label, dose-escalation multicenter study evaluating the effects of repeated TG1042 [adenovirus-interferon (IFN)-gamma] intralesional injections in patients with primary CLs, of which 18 were of T-cell and 3 of B-cell type. Repeated intralesional therapy using TG1042 consistently results in local tumor regressions in about half of treated patients and one-third of patients also in regressions in noninjected distant lesions, likely reflecting the systemic immune activation after intralesional therapy. Treatment was well tolerated with few adverse events including injection site reactions, chills, lymphopenia, and fever. Immune monitoring in the peripheral blood demonstrated systemic immune activation and the induction of antibodies against tumor antigens in some patients without clear association with clinical responses. CLs, in particular B-cell lymphomas with high objective response rates, seem to be excellent targets for this type of immunotherapy.
Mol Ther 2010 Jun
PMID:Phase II clinical trial of intratumoral application of TG1042 (adenovirus-interferon-gamma) in patients with advanced cutaneous T-cell lymphomas and multilesional cutaneous B-cell lymphomas. 2037 4

Composite lymphoma is a rarely reported entity, defined as two or more morphologically distinct types of lymphoma at the same anatomic site, occurring either synchronously or metachronously. Since 1978, about 100 case reports of composite lymphoma have been cited, many involving combinations of low-grade B-cell lymphomas. To our knowledge, no cases of large-cell transformation of composite lymphoma have yet been described. We report the case of a patient who presented with diffuse large B-cell lymphoma (DLBCL) fifteen years after successful treatment for a mature B-cell lymphoma. Reassessment of the patient's lymph node from 1995, using techniques not previously available, resulted in a revised diagnosis of composite lymphoma, comprising both follicular lymphoma (FL) and small lymphocytic lymphoma (SLL). Analysis of B-cell gene rearrangement studies using BIOMED-2-based PCR, and of t(14;18) rearrangements by both FISH and PCR, provided evidence that the DLBCL evolved from transformation of the composite lymphoma, specifically from its FL component. B-cell gene rearrangement studies also supported a clonal relationship between the FL and SLL components of the composite lymphoma.
Exp Mol Pathol 2010 Dec
PMID:Large-cell transformation of a composite lymphoma. 2062 Oct 95

Although classically described as the driving oncogene in Burkitt lymphoma (BL), abnormalities of MYC have been recognized in other non-Hodgkin lymphomas as well. For example, MYC is overexpressed in approximately 10% of diffuse large B-cell lymphomas (DLBCL), conferring an adverse prognosis with chemoresistance and shortened survival; only approximately 30% of patients achieve long-term survival despite modern therapies. In contrast to BL, MYC aberrations in DLBCL are usually associated with multiple cytogenetic abnormalities and other genetic lesions, such as concurrent BCL2 translocations. Patients with so-called "double-hit" lymphomas have a worse outcome with few survivors beyond 6 months. It is unclear why MYC translocations are diagnostic in BL but prognostic in other lymphomas; different mechanisms underlying MYC abnormalities and a unique target set of genes may explain some of the variance. Furthermore, MYC possesses nontranscriptional functions other than transcriptional controls on genes regulating cell growth and may also influence the lymphoma microenvironment. Here we summarize current knowledge regarding MYC in lymphomas other than Burkitt lymphoma, with an emphasis on transcriptional, epigenetic, clinical, and microenvironmental consequences.
Blood Cells Mol Dis 2010 Dec 15
PMID:The impact of MYC expression in lymphoma biology: beyond Burkitt lymphoma. 2081 5

Convergence of observations from different sources is the norm in science. However, when convergence occurs in man for antibodies it is remarkable because the repertoire of possible immunoglobulin products is very large and diverse. Thus, one would not expect to see the same antibody twice from divergent populations unless there is special significance as to why the immune response is constrained. Now, broadly neutralizing antibodies isolated from combinatorial libraries from three separate populations have been shown to all use the same (V(H) 1-69) germ line gene and interact with the influenza virus in very similar ways. Here we discuss the reasons for this convergence in terms of how the immunological repertoire responds to emergency situations where time is short as occurs, for example, in potentially lethal infections. It is suggested that there is a first responder or S.O.S. component of the antibody repertoire that evolved to initiate rapid defense against infectious agents. The discovery of the homologies between these commonly produced antibodies may have significance for the design of novel vaccines. Finally, these convergent results may give much insight into why antibodies encoded by the V(H) 1-69 germ line gene are highly over represented in B-cell lymphomas.
Mol Biosyst 2011 Apr
PMID:Rare antibodies from combinatorial libraries suggests an S.O.S. component of the human immunological repertoire. 2129 33

The characterization of the antigenic and immunologic properties of lymphoid and hematologic neoplasms has dramatically increased our understanding of the biology of these diseases and at the same time greatly enhanced our diagnostic abilities. Immunophenotyping has helped delineate specific lineage aberrancies indicative of malignant transformation, such as monoclonality, in the form of light- and/or heavy-chain immunoglobulin restriction, or loss of pan-B or pan-T cell antigens, or aberrant crosslineage coexpression of antigens. Unique immunophenotypic profiles have now been described for most forms of lymphoma and leukemia. Classic Hodgkin's disease, for example, has the singular combination of CD15 and CD30 positivity, in the absence of CD45 (see Fig. 1 ). Additional examples are mantle cell lymphoma with its unique nuclear expression of cyclin D1, and hairy cell leukemia, characterized by coexpression of CD22 and CD1 1c, a monocytoid marker. Beyond its diagnostic utility, immunohistochemistry (IHC) may have prognostic significance reflecting the biologic behavior of these diseases; a case in point is CD 10 in large B-cell lymphomas, whose absence conveys a worse prognosis. Fig. 1. Classic Hodgkin's disease phenotype. Reed-Sternberg cell (upper left) coexpressing CD 15 (upper right) and CD30 (lower right), in the absence of CD45 (lower left).
Methods Mol Med 2001
PMID:Immunohistochemistry in leukemias and lymphomas. 2131 14


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