bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid, Sustained B Cell Receptor Signaling in Lymphoma B Cells Differs from Normal Signaling in Tumor Infiltrating Nonmalignant B Cells.
Authors: Irish Jonathan M. , Czerwinski Debra K. , Nolan Garry P. , Levy Ronald 
Published: April 2020

Abstract
The B cell receptor (BCR) drives life and death signaling throughout B cell development, and dysregulation of BCR signaling might be expected to play a role in aberrant proliferation of lymphoma B cells. We have previously used flow cytometry based cell signaling profiles to identify patterns of altered signaling in acute myeloid leukemia that were informative of clinical outcome (Irish et al., Cell, 2004). Here we used a similar signaling profiles approach to compare BCR signaling in normal and lymphoma B cells. However, in addition to comparing follicular lymphoma (FL) B cells with peripheral blood B cells from normal donors, we also interrogated signaling within individual non-tumor B cells infiltrating FL tumor biopsies. By staining for CD20 and BCR light chain isotype (κ vs. λ), we could distinguish tumor and normal B cells within each patient biopsy. Following crosslinking of BCR heavy chains (shared by tumor and non-tumor B cells), we measured phosphorylation of Syk and Btk proteins, as markers of early BCR signaling activity, and Erk1/2 and p38, as markers of downstream BCR signaling effector activity. The BCR signaling network in FL tumor B cells was activated more rapidly than infiltrating non-tumor B cells, achieved greater levels of per-cell signaling, and sustained high levels of signaling over a period of hours. In lymphoma B cells, BCR-mediated Btk and Erk1/2 phosphorylation could reach the normal maximum in as little as 4 minutes, which was much more rapid than the 30–60 minutes required for peak signaling in non-tumor B cells. Strikingly, the timing and magnitude of BCR pathway protein phosphorylation we measured in non-tumor B cells within tumor biopsies was the same as that of normal, mature B cells from peripheral blood. These results suggest that the altered BCR signaling we identified in lymphoma is cell-intrinsic and associated with lymphomagenesis, as opposed to being a general change in tumor microenviornment affecting all B cells within a biopsy. FL tumor B cells from different patients were distinguished by the degree and number of changes to BCR signaling, such that variable profiles of lymphoma signaling kinetics distinguished each patient from the consistent signaling of normal B cells. These results identify cell-intrinsic changes to BCR signaling that may contribute to immortalization of lymphoma B cells and suggest that single cell profiles could identify lymphoma specific BCR-mediated signaling responsible for clinical outcomes.
A Human SIL-SCL Fusion Gene Displays a Development Block at the CD4− CD8− to CD4+CD8+ Transition in Transgenic Mice.
Authors: Cheng Yue , Zhang Zhenhua , Slape Chris , Aplan Peter D. 
Published: April 2020

Abstract
Chromosomal rearrangements leading to dysregulation of the SCL gene, located at chromosome 1p32, is a common event in the development of human T-cell acute lymphocytic leukemia (T-ALL). In the most common form of SCL gene rearrangement, an interstitial deletion of approximately 90 kb brings SCL under the control of regulatory elements that normally govern expression of the ubiquitously expressed SIL (SCL interrupting locus) gene, which is located directly upstream of SCL. To investigate the consequences of this event, we reproduced this gene alteration by using cre-mediated recombination. A BAC clone containing both human SIL and SCL genes was isolated and loxP sites were cloned into the intron 1 region of both the SIL and SCL genes, corresponding to the sites at which recombination leading to an interstitial deletion occurs in human T-ALL patients. This BAC clone was used to generate transgenic SILloxloxSCL mice. The SILloxloxSCL mice were bred to mice that express the cre recombinase in the thymus (Lck-cre mice). The BAC transgene was recombined between the two loxP sites in over 50% of the thymocytes from double transgenic Lck-cre/SILloxloxSCL mice, faithfully recapitulating the event seen in human T-ALL patients, and bringing the SCL gene under the direct control of SIL regulatory elements. Aberrant SCL gene expression was verified by RT-PCR. Using FACS analysis, we found that mice carrying both the SILloxloxSCL transgene and the Lck-cre transgene have decreased CD4+/CD8+, CD4+/CD8−, CD4−/CD8+ and increased CD4−/CD8− thymocytes compared to transgene-negative mice or mice that carried the SILloxloxSCL transgene but not the Lck-cre transgene. These findings were detected in mice from 6 to 15 months of age. Interestingly, increased numbers of CD44+ thymocytes can also been identified in SILloxloxSCL/Lck-cre mice. In the spleen, the SILloxloxSCL/Lck-cre mice show a marked reduction in the number of mature CD4+ or CD8+ cells. These results indicate an accumulation of immature T-cells in mice transgenic for both the SILloxloxSCL transgene and the Lck-cre transgene, and demonstrate that conditional activation of SCL under control of SIL regulatory elements can impair normal T-cell development.
Transallelic Effects at the Cyclin D1 Loci in Mantle Cell Lymphoma.
Authors: Epner Elliot M. , Hui Liu , Jin Wang , Jing Huang , Bruce Clurman E. 
Published: April 2020

Abstract
Cyclin D1 is a gene commonly deregulated in B cell malgnancies. Translocation between chromosomes 11 and 14 (t;14) are found in most patients with mantle cell lymphoma (MCL) and 15–20% of patients with multiple myeloma (MM). Gene targeting experiments in cyclin D1 overexpressing MCL and MM were carried out and genetic variants isolated which had lost the IgH translocated or inserted chromosomes. These clones no longer expressed cyclin D1 but expressed high levels of cyclin D3. Analysis of DNA methylation patterns in these clones has demonstrated that the translocated chromosome exerts a long distance trans DNA hypomethylating effect on the normal chromosome (transvection) at the cyclin D1 locus and at least 100 kilobases upstream. Thus, in the absence of the translocated chromosome, the normal cyclin D1 locus is densely DNA methylated. Reintroduction of the translocated chromosome by somatic cell hybrid fusion induced transhypomethylation in trans. This long distance trans hypomethylating effect was also demonstrated in a MM cell line (U266) which contains an insertion rather than a translocation of IgH sequences, suggesting that 3′ Cα IgH sequences are sufficient for this effect. Combined FISH/immunofluorescent antibody labelling studies have shown the presence of both the normal and translocated chromosome 11’s at the outer nucleolar membrane, where they are tethered by the proteins CTCF and nucleophosmin, as demonstrated using chromatin immunoprecipitation assays. Allelic ChIP studies showed the presence of CTCF and nucleophosmin on both the translocated and normal chromosome 11(s). Tethering of the translocated and nontranslocated chromosomes by CTCF/nucleophosmin at the nucleolus provides a mechanism for pairing and long distance DNA transhypomethylation.
Defining Second-Hit Genetic Abnormalities Involved in the t(12; 21) TEL-AML1 Acute Lymphoblastic Leukemia by Array-Based Comparative Genomic Hybridization.
Authors: Tsuzuki Shinobu , Karnan Sivasundaram , Horibe Keizo , Matsumoto Kimikazu , Kato Koji , Sugita Kanji , Nakazawa Shinpei , Seto Masao 
Published: April 2020

Abstract
TEL (ETV6)-AML1 (RUNX1) chimeric gene fusion is the most common genetic abnormality in childhood acute lymphoblastic leukemias (ALL). Evidence suggests that this chimeric gene fusion usually occurs in utero during fetal hematopoiesis and most probably constitutes an initiating or first-hit mutation that is necessary but insufficient for the development of overt, clinical leukemia. In a search for additional secondary and postnatal genetic events that could be linked to leukemia development, we applied a genome- wide array- CGH technique to 24 TEL-AML1 leukemia samples and two cell lines (REH, KOPN41) and found that at least three chromosomal imbalances were involved in all patient samples and cell lines. Recurrent regions of chromosomal imbalances (found in &gt; 10% of clinical samples) were gain of chromosomes 10 (17 %) and 21q (25 %) and loss of chromosomes 2p11 (100 %), 12p13.2 (87 %), 9p21.3 (29 %), 9p13.2 (25 %), 12q21.3, (25 %), 3p21 (21 %), 6q21 (17 %), 4q31.23 (17 %), 11q22-q23 (13 %) and 19q13.11-q13.12 (13 %). The two cell lines showed gain of 21q22.12-qter and loss of 2p11.2, 9p21.3, 12p13.2, and 12q21.3. Among these, six regions of loss (2p11, 3p21, 4q31.23, 9p13.2, 12q21.3 and 19q13.12) have not been identified previously by conventional CGH in TEL-AML1 leukemia. Representative genes involved in the regions of loss were Igkappa (2p11), TEL (12p13.2), p16INK4a/ARF (9p21.3), Pax5 (9p13.2), BTG1 (12q21.3), LIMD1 (3p21), AIM1 and BLIMP1 (6q21), NR3C2 (4q31.23), ATM (11q22-q23), and PDCD5 (19q13.11-q13.12), while the region of gain at 21q contained RUNX1. These findings suggest that, in addition to TEL previously reported as deleted, genes involved in cell cycle regulation, p53 pathways and apoptosis are also often deleted. Our array-CGH obtained data may provide further insights into the molecular basis for the development of TEL-AML1 leukemia.
Characterization of the CATS Protein Which Interacts with the Leukemogenic Fusion Protein CALM/AF10 Using Mono-Clonal Antibodies and Fluroescent Protein Tags.
Authors: Archangelo Leticia Fröhlich , Krause Alexandre , Hölzel Michael , Kremmer Elisabeth , Deshpande Aniruddha , Buske Christian , Bohlander Stefan K. 
Published: April 2020

Abstract
The CATS gene was first identified in a yeast two hybrid screen as CALM interacting protein expressed in thymus and spleen. The CATS interaction region of CALM is contained in the leukemogenic fusion protein CALM/AF10, which is found in acute myeloid leukemia, malignant lymphoma and acute lymphoblastic leukemia. We performed co-immunoprecipitation experiments to confirm CALM-CATS interaction found in the yeast system. RT PCR analysis showed CATS expression in patient cells and cell line carrying the CALM/AF10 rearrangement. Further expression analysis showed CATS expression in different cell subpopulation from the murine thymus (CD4+, CD8+ and CD4+/CD8+) and bone marrow (cKit+, Sca 1+/CKit+, Ter119, Gr1, CD8+, Mac1) but nearly absent in B220 positive cells. Interestingly, there was a high CATS expression in CALM/AF10 expressing B220+ leukemic cells in a CALM/AF10 murine bone marrow transplant model. Several monoclonal antibodies against the C-terminus of human CATS were generated. These antibodies recognize both the human and the murine CATS protein. Using these antibodies we could show a high expression of CATS in different human leukemia, lymphoma and solid tumor cell lines, as well as in normal proliferating cell lines (HEK293 and WI38), but not in T-cell lines (TYRF8 and JB4). Using protein lysates from cell cycle synchronized cells (Hela and U2OS) a clear cell cycle dependent regulation of CATS protein levels was demonstrated. Moreover, Western Blot analysis shows that serum stimulation after serum starvation leads to increased expression of CATS in the glioblastoma cell line T98G. Immunofluorescence shows that CATS is localized mainly to the nucleus. Coexpression of CFP-CATS with YFP tagged CALM or CALM/AF10 was able to markedly increase the nuclear localization of both CALM and the CALM/AF10 fusion protein. This effect of CATS is stronger on the YFP-CALM/AF10 fusion protein than on the CALM protein. When fused to a GAL4 DNA binding domain, CATS acts as a strong repressor of transcription in reporter gene assays. Our results indicate that the subcellular localization of CALM and CALM/AF10 could depend in part on the presence of CATS with a greater fraction of CALM or CALM/AF10 being present in the nucleus in cells with high CATS expression (e.g. lymphoid cells). The CALM-CATS interaction might thus play an important role in CALM/AF10 mediated leukemogenesis.
Identification of CD20 Mutations in Malignant Lymphoma: Can They Be Predictors of Response to Rituximab?.
Authors: Terui Yasuhito , Sakurai Takuma , Mishima Yuji , Mishima Yuko , Sugimura Natsuhiko , Kojima Kiyotsugu , Yokoyama Masahiro , Hatake Kiyohiko 
Published: April 2020

Abstract
Purpose: Although rituximab is commonly used as induction and maintenance therapy for CD20+ malignant lymphoma, some patients become refractory to treatment and the mechanism of resistance is unclear. The aim of this study was to investigate the relationship between CD20 mutations and rituximab resistance.
Methods: To investigate whether CD20 mutations affect the response to rituximab, fresh CD19+ lymphoma cells were isolated from the lymph nodes, peripheral blood or bone marrow of 48 patients with NHL using magnetic activated cell sorting (MACS). CD19+/CD20+ cells were subsequently sorted by flow cytometry. RNA was prepared from the isolated cells and RT-PCR was performed. The resulting PCR products were sequenced, subcloned into the mammalian expression vector pTARGET, transfected into K562 cells and CD20 expression was examined by flow cytometry and laser scanning confocal microscopy.
Results: In all 48 patients, overall response rate (CR+CRu+PR) to rituximab was 93.8% (45/48), but two cases became PD after PR. DNA sequence analysis revealed that point mutations were mostly observed in two CD20 domains - the third transmembrane domain and the C-terminal cytoplasmic domain. One patient had point mutations in the transmembrane domain, three cases showed point mutations in the C-terminal cytoplasmic domain and six cases had non-specific CD20 mutations, which did not affect CD20 expression. Thirty-eight patients showed no mutations of CD20 gene. CD20 expression was very weak in patients with point mutations in the C-terminal cytoplasmic domain, whereas expression was increased in patients with point mutations in the transmembrane domain.
Conclusions: This study suggests that point mutations in CD20 may cause rituximab resistance and identification of CD20 mutations upon diagnosis may help to predict a patient’s response to rituximab.
BCR-ABL Is Not an Immunodominant Antigen in CML.
Authors: Grünebach Frank , Mirakaj Valbona , Müller Martin R. , Brümmendorf Tim , Brossart Peter 
Published: April 2020

Abstract
Chronic myelogenous leukemia (CML) is a myeloproliferative disorder, which originates from pluripotent hematopoietic bone marrow progenitor cells. It is characterized by excessive proliferation of the granulopoiesis in the bone marrow. In approximately 90% of the patients with CML the Philadelphia chromosome (Ph) is the characteristic cytogenetic hallmark. The Ph is a shortened chromosome 22, which arises from a acquired reciprocal translocation between chromosome 9 and 22 (t(9;22) (q34;q11)). This translocation fuses the bcr gene with part of the c-abl gene, which encodes a protein-tyrosine kinase. The chimeric bcr-abl oncogene is translated into a 210-kDa chimeric protein (p210) which exhibits constitutive ABL kinase activity. In the present study, we analysed the involvement of the BCR-ABL protein in the induction of antigen-specific cytotoxic T lymphocytes (CTLs) in order to develop an immunotherapeutic approach targeting this neo-antigen in patients with CML. To accomplish this, we generated dendritic cells (DCs) in vitro and electroporated them with various sources of RNA harbouring the chimeric bcr-abl transcript. These genetically engineered DCs where used as antigen presenting cells (APCs) for the in vitro induction of CTLs.
By applying this approach we found that the CTLs induced by DCs transfected with RNA extracted from bcr-abl-positive K-562 cells or CML blasts do not recognize epitopes derived from the chimeric BCR-ABL fusion protein. In contrast, they were able to lyse autologous DCs electroporated with RNA isolated from patients with acute myeloid leukemia (AML), indicating that antigens shared among these malignant cells are involved and recognized by these CTLs. However, we successfully generated BCR-ABL-specific CTLs by DCs electroporated with in vitro transcribed bcr-abl-RNA. In patients with CML in complete cytogenetic remission during IFN-α treatment there was some reactivity against BCR-ABL in IFN-γ ELISPOT assays, which was weaker as compared to proteinase 3 (PR3)- or Prame-directed responses supporting the observations obtained in healthy donors.
In summary, BCR-ABL is processed and presented by Ph+ cells but is not the immunodominat antigen that induces CD8+ T lymphocytes in competition with other tumor-associated antigens. Nevertheless, APCs transfected with pure bcr-abl-IVT in vitro are capable of inducing BCR-ABL specific CTLs that efficiently lyse Ph+ target cells.
2005 Update on Accelerated FDA Approval of Drugs Used To Treat Hematologic Malignancies from the Research on Adverse Drug-Events and Reports (RADAR): Rate of Regular Approval Conversion Remains Low.
Authors: Bennett Charles L. , Zagory Jessica A. , McKoy June M. , McCaffrey Kathryn R. , Lyons E. Allison , Belknap Steven 
Published: April 2020

Abstract
Background: At ASH 2004 we reported that prior to 2004, eight drugs had received accelerated approval (AA) for ten hematologic oncology indications, only one had converted to full approval, and three serious adverse events associated with two of these drugs were identified post-approval. Following our presentation, Congressman Ed Markey (D-Massachussets) in June 2005 issued a report (“Conspiracy of Silence”) that raised similar concerns about the low rates of conversion from accelerated to regular approval and the failure of the FDA in ensuring that drug companies complete the required post-marketing studies. We update the experience with accelerated FDA approval for hematologic oncology.
Methods: Information was obtained from the FDA on new drug applications and supplements for new uses, package inserts, and medical literature reviews.
Results: Of 11 drug indications that received AA for hematologic oncology between 1995 and 2005, AA was generally granted for 9 based on clinical trials with &lt;100 patients that identified high response rates. In the past year, none have applied for conversion to regular approval. Bortezomib received regular approval for an indication different than that granted for AA. Three serious adverse drug reactions were identified for two indications (gemtuzumab ozogamicin, imatinib for GIST) within 2 years of AA approval.
Conclusion: Since 2004, one new drug received AA for a hematologic oncology indication, one drug received regular approval for an indication different from that indicated under AA, and although 1 more year has elapsed, conversion has yet to occur for nine AA hematologic oncology indications. It is imperative that the FDA establish clear milestones regarding conversion to regular approval at the time AA is granted.
Drug Name (AA Date; Years Lapsed Since AA) AA Indication Years to AA/Regular Approval N in Trial (Overall Response Rate) *Regular approval granted for myeloma failing one treatment Denileukin difitox (2/99; 6.5) T-cell lymphoma 1.17/- 71 (30%) Cytarabine liposomal (4/99; 6.3) Lymphomatous meningitis 0.46/- 14 (71%) Gemtuzumab ozogamicin (5/00; 5.35) CD33 positive AML 0.58/- 142 (30%) Alemtuzumab (5/01; 4.3) CLL 1.375/- 93 (33%) Imatinib mesylate (5/01) CML 0.25/2 864 (80%) Ibritumomab tuixetan (2/02; 3.5) Low-grade NHL 1.3/- 157(68%) Imatinib mesylate (2/02; 3.5) GIST 0.29/- 147 (54%) Imatinib mesylate (12/02; 2.7) CML peds 0.5/- 39 (67%) Bortezomib (5/03) Multiple myeloma w/ 2 prior chemo treatments* 0.46/2 193 (35%) Tositumomab (6/03/2.2) NHL 4.0/- 59 (71%) Clofarabine (12/04; 0.7) Relapsed/refractory ALL peds 0.75/- 49 (20%)
Risk Factors of HLA-Haploidentical Transplantation Using the Combination of Unmodified Marrow and CD6-Depleted G-CSF Mobilized Blood Cells.
Authors: Kolb Hans-Jochem , Bigalke Iris , Tischer Johanna , Hill Wolfgang , Falk Christine , Simoes Belinda , Schmid Christoph , Ledderose Georg 
Published: April 2020

Abstract
Allogeneic stem cell transplantation from HLA-haploidentical family members has been studied in 80 patients for the treatment of hematological malignancies in advanced stages. The protocol involves unmodified marrow on day 0 and CD6-depleted G-CSF-mobilized blood cells on day 6. Engraftment was seen in patients treated with myeloablative (12 Gy) and non-myeloablative (4 Gy) doses of total body irradiation. Graft-versus-host disease (GVHD) was mild or absent in 53% and severe GVHD did not develop after changing to a more effective method of depletion of CD6-positive cells. Acute GVHD resolved more often and chronic GVHD was less severe than in HLA-identical sibling transplantation. Here we evaluated survival and relapse risk. Acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) was the diagnosis in 41 patients, acute lymphoid leukemia (ALL) in 19 patients, chronic myelogenous leukemia (CML) in 2, chronic lymphocytic leukemia (CLL) in 3, high grade lymphoma (NHL) in 14 and severe aplastic anemia (SAA) in one patient. The patient’s age ranged from 17 to 62 years (median 36.5 yrs), for 65 patients a relative of first degree and for 15 patients a second degree relative was the donor. The major cause of death was recurrence of the disease (29 pts.), 7 patients died early and 22 pts. died of complications (infections 12, GVHD 3, pulmonary compl. 2, PTLD 3, cerebr. hemorrhage 1, liver tox. 1). Survival was significantly better in male patients with female donors (2 yr survival 36% vs 13%; p=0.001), patients transplanted with cells from their mother rather than from the father (2 yr survival 55% vs 8%; p=0.02) and patients transplanted in an earlier phase (2yr survival 50% vs 15%; p=0.048). Patients transplanted for ALL (2 yr. survival 31%) fared better than patients with AML/MDS (2yr survival 23%)and patients with NHL (2 yr. survival 12.5%) (p=0.08). Age, number and type of HLA-mismatches, as well as the depletion method had no effect on survival and on relapse risk. The favorable effect of the female gender of the donor on survival was still significant in multivariate analysis after adjustment for the stage of the disease and the diagnosis (p=0.01). The possibility of non-inherited maternal antigens (NIMA) inducing tolerance was tested in siblings sharing the paternal haplotype. There was a weak effect in the host-versus-graft direction (p=0.06), but no effect in the graft-versus-host direction. The risk of relapse was lowest in patients transplanted with stem cells from their mother as compared to those transplanted from their father (p=0.002). Female gender of the donor was favorable even in patients without GVHD. In summary female donors are preferable to male donors for control of leukemia and survival.