Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0023418 (leukemia)
93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mice with severe combined immunodeficiency (SCID) were injected with 1 x 10(7) MOLT-3 human T-lineage acute lymphoblastic leukemia cells to provide a model for the evaluation of anti-CD7-pokeweed antiviral protein (PAP) immunotoxin directed against the human CD7 antigen. Of control SCID mice (treated with phosphate-buffered saline, PBS) challenged intravenously with 1 x 10(7) MOLT-3 cells, 5/5 died at 29 to 35 days after inoculation, with a median event-free survival of 33 days. Similarly, 6/6 anti-CD19-PAP treated control SCID mice died of MOLT-3 leukemia at a median of 36 days. In contrast, treatment with anti-CD7-PAP (15 micrograms total dose in 5 micrograms intraperitoneal injections on days 1-3) significantly improved event-free survival of SCID mice challenged with 1 x 10(7) MOLT-3 cells. Of nine SCID mice treated with anti-CD7-PAP, four died at 54-149 days and five remained alive for > 172 days without clinical evidence of leukemia (median event-free survival > 172 days). When long-term survivors among the anti-CD7-PAP treated SCID mice were electively killed at 173 days to assess their leukemia burden, histopathologic examination and polymerase chain reaction provided evidence of disseminated leukemia in some of these mice. Intriguingly, marked differences in morphology, tissue distribution, and histologic pattern of organ invasion existed between leukemic blasts killing 100% of PBS-treated control mice at a median of 33 days and 'therapy-refractory' leukemic blasts detected in anti-CD7-PAP-treated long-term survivors. This novel SCID mouse model of disseminated human T-lineage ALL provides a unique in vivo system to investigate the therapeutic potential of new treatment strategies and to study possible mechanisms of in vivo immunotoxin resistance.
Leukemia 1993 Feb
PMID:In vivo anti-leukemic efficacy of anti-CD7-pokeweed antiviral protein immunotoxin against human T-lineage acute lymphoblastic leukemia/lymphoma in mice with severe combined immunodeficiency. 767 82

Topotecan [(S)-9-dimethylaminomethyl-10-hydroxycamptothecin hydrochloride; SK&F 104864-A, NSC 609699], a water soluble semisynthetic analogue of the alkaloid camptothecin, is a potent topoisomerase I inhibitor. Here we show that topotecan stabilizes topoisomerase I/DNA cleavable complexes in radiation-resistant human B-lineage acute lymphoblastic leukemia (ALL) cells, causes rapid apoptotic cell death despite high-level expression of bcl-2 protein, and inhibits ALL cell in vitro clonogenic growth in a dose-dependent fashion. Furthermore, topotecan elicited potent antileukemic activity in three different severe combined immunodeficiency (SCID) mouse models of human poor prognosis ALL and markedly improved event-free survival of SCID mice challenged with otherwise fatal doses of human leukemia cells at systemic drug exposure levels that can be easily achieved in children with leukemia.
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PMID:In vitro and in vivo activity of topotecan against human B-lineage acute lymphoblastic leukemia cells. 774 43

Recent development of chemotherapy enabled us to cure patients with malignancies including leukemia, malignant lymphoma, choriocarcinoma, ovarian cancer, breast cancer and so on. In order to obtain the definite effect, the quantities of chemotherapeutic agents should be increased and the major lethal side effect caused by bone marrow failure should be avoided. For this purpose, hematopoietic stem cells derived from either bone marrow or peripheral blood can be used for the rapid recovery of neutropenia and thrombocytopenia. We prepared stem cells both from bone marrow and peripheral blood by anti-CD34 monoclonal antibody bound on magnetic beads column and administered into severe combined immunodeficiency (SCID) mouse. Four and 20 weeks after transplantation, mononuclear cells bearing human hematopoietic antigens and human immunoglobulin G were appeared in the circulation, suggesting that stem cells from peripheral blood also possess long-standing capability of maturation as well as those from bone marrow. We next conducted clinical study of high dose chemotherapy combined with peripheral blood stem cell transplantation for patients with poor risk choriocarcioma. By this treatment, 4 complete response (CR) and 4 partial response (PR) were obtained, whereas 2 progressive disease (PD), 1 no change (NC) and 5 PR were obtained by the previous conventional chemotherapies. The results obtained were promising and this treatment regimen may become a good modality for the complete treatment of chemotherapy curable tumors.
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PMID:[Hematopoietic stem cell transplantation]. 777 76

Mice with severe combined immunodeficiency (SCID) provide a model system to examine the in vivo homing, engraftment, and growth patterns of normal and malignant human hematopoietic cells. The relation between leukemic cell growth in this model and the treatment outcome in patients from whom cells were derived has not been established. Leukemic cells from 42 children with newly diagnosed high-risk B-lineage acute lymphoblastic leukemia were inoculated intravenously into CB.17 SCID mice. Mice were killed at 12 weeks or when they became moribund as a result of disseminated leukemia. All mice were necropsied and subjected to a series of laboratory studies to assess their burden of human leukemic cells. Twenty-three patients whose leukemic cells caused histopathologically detectable leukemia in SCID mice had a significantly higher relapse rate than the 19 patients whose leukemic cells did not (estimated 5-year event-free survival: 29.5% v 94.7%; 95% confidence intervals, 11.2% to 50.7% v 68.1% to 99.2%; P < .0001 by log-rank test). The occurrence of overt leukemia in SCID mice was was a highly significant predictor of patient relapse. The estimated instantaneous risk of relapse for patients whose leukemic cells caused overt leukemia in SCID mice was 21.5-fold greater than that for the remaining patients. Thus, growth of human leukemic cells in SCID mice is a strong and independent predictor of relapse in patients with newly diagnosed high-risk B-lineage acute lymphoblastic leukemia.
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PMID:Leukemic cell growth in SCID mice as a predictor of relapse in high-risk B-lineage acute lymphoblastic leukemia. 784 9

Recurrent abnormalities of the short arm of chromosome 9, including translocations and interstitial deletions, have been reported in both leukemia and lymphoma. The pathologic consequences of these abnormalities remain unknown. The cyclin-dependent kinase 4 inhibitor (CDKN2) gene, which maps to 9p21, has been implicated by the finding of a high frequency of biallelic deletions in leukemic cell lines. We have determined the incidence of structural abnormalities affecting CDKN2 by DNA blot in a panel of 231 cases of leukemia and lymphoma and 66 cell lines derived from patients with lymphoid malignancies with defined cytogenetic abnormalities. Structural alterations of CDKN2 were seen in 20 (8.3%) of all fresh cases and 10 (15.1%) of all cell lines. Biallelic CDKN2 deletions were seen in 11 of 53 (21%) cases of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). There was no association with any particular cytogenetic abnormality. Biallelic deletions were also found in high-grade and transformed non-Hodgkin's lymphoma (NHL) of both B- and T-cell lineages. In two cases of transformed NHL, analysis of sequential samples showed loss of CDKN2 with transformation. Neither deletions nor rearrangements of the CDKN2 gene were seen in any of the 119 leukemias of mature B or T cells analyzed. Biallelic deletions of CDKN2 were observed in 6 of 13 NHL cell lines. Three of the 6 cases had undergone transformation from low- to high-grade disease: in 2 of these cases it was possible to show that the CDKN2 deletions were present in fresh material from the patient and were therefore not an artifact of in vitro culture. Rearrangements of CDKN2 were seen in 2 cases (4%) of BCP-ALL, in 1 case of B-NHL, and in 1 Burkitt's lymphoma cell line and suggest the presence of a "hot spot" for recombination in the vicinity of the CDKN2 gene. These data indicate that the loss of CDKN2 expression may be involved in the pathogenesis of a subset of BCP-ALL, some high-grade NHL, and in the transformation of NHL from low- to high-grade disease. CDKN2 deletions and rearrangements occurred in the absence of detectable cytogenetic changes of chromosome 9p in 25 of 30 (83%) cases. Finally, of 10 cases of BCP-ALL that produced overt, transplantable leukemia in mice with severe combined immunodeficiency (SCID), seven showed biallelic CDKN2 deletions. In contrast, none of 11 cases that failed to engraft showed biallelic CDKN2 deletions. BCP-ALL cases that lack CDKN2 expression may have a particular propensity to grow in SCID mice.
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PMID:Deletions and rearrangement of CDKN2 in lymphoid malignancy. 784 11

The molecular basis of the Philadelphia chromosome (Ph1) is a structurally altered c-abl (bcr-abl) gene which encodes an abnormally large protein with protein tyrosine kinase activity. Herbimycin a, which effectively reduced intracellular phosphorylation by bcr-abl tyrosine kinase, preferentially inhibited the growth of Ph1-positive leukemia cell lines. Injection of Ph1-positive and -negative leukemia cell lines into mice with severe combined immunodeficiency (SCID) resulted in the death of all mice due to leukemia, although the severity of illness varied according to the cell lines used. Administration of herbimycin A significantly enhanced the survival of mice inoculated with the Ph1-positive leukemia cell lines tested but barely affected the survival of mice inoculated with the Ph1-negative leukemia cell lines tested. These results suggest that herbimycin A and related compounds may be useful for the treatment of Ph1-positive leukemia. The disease that developed using the Ph1-positive leukemia cell line NALM-20 resembled human Ph1-positive acute lymphoid leukemia. There was an inverse relationship between the survival time of mice and the number of cells inoculated. The SCID mouse-NALM-20 human leukemia chimera would be a good experimental model for screening tyrosine kinase inhibitors as therapeutic agents against Ph1-positive leukemia.
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PMID:Treatment of Philadelphia-chromosome-positive human leukemia in SCID mouse model with herbimycin A, bcr-abl tyrosine kinase activity inhibitor. 786 Jan 43

Viral vectors and protein carriers utilizing asialoglycoprotein receptor (ASGR)-mediated endocytosis are being developed to transfer genes for the correction of bilirubin-UDP-glucuronosyltransferase (bilirubin-UGT) deficiency. Ex vivo evaluation of these gene transfer vectors would be facilitated by a cell system that lacks bilirubin-UGT, but expresses differentiated liver functions, including ASGR. We immortalized primary Gunn rat hepatocytes by transduction with a recombinant Moloney murine leukemia virus expressing a thermolabile mutant SV40 large T antigen (tsA58). At 33 degrees C, the immortalized hepatocyte clones expressed SV40 large T antigen, synthesized DNA, and doubled in number every 2 to 3 days. At this temperature, differentiated hepatocyte markers, e.g., albumin, ASGR, and androsterone-UGT, were expressed at 5% to 10% of the levels found in primary hepatocytes maintained in culture for 24 hours. Glutathione-S-transferase Yp (GST-Yp), an oncofetal protein, was expressed in these cells at 33 degrees C, but was undetectable in primary hepatocytes. In contrast, when the cells were cultured at 39 degrees C or 37 degrees C, the large T antigen was degraded, DNA synthesis and cell growth stopped, and morphologic characteristics of differentiated hepatocytes were observed. The expression of albumin, ASGR, and androsterone-UGT, and their corresponding mRNAs, increased to 25% to 40% of the level in primary hepatocytes, whereas GST-Yp expression decreased. Functionality of ASGR was demonstrated by internalization of Texas red-labeled asialoorosomucoid, and binding and degradation of 125I-asialoorosomucoid. After liposome-mediated transfer of a plasmid containing the coding region of human bilirubin-UGT1, driven by the SV40 large T promoter, active human bilirubin-UGT1 was expressed in these cells. The immortalized cells were not tumorigenic after transplantation into severe combined immunodeficiency mice. These conditionally immortalized cells will be useful for ex vivo evaluation of bilirubin-UGT gene transfer vectors.
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PMID:Conditional immortalization of Gunn rat hepatocytes: an ex vivo model for evaluating methods for bilirubin-UDP-glucuronosyltransferase gene transfer. 787 82

Retroviral vectors were constructed in which the U3 promoter/enhancer of Moloney murine leukemia (Mo-MLV) was replaced by the corresponding region from five related murine retroviruses--AKR murine leukemia virus (AKV), Harvey murine sarcoma virus (HaMSV), myeloproliferative sarcoma virus (MPSV), SL3-3, and the NZB-xenotropic virus (Xeno). In these vectors the chimeric long terminal repeat (chLTR) drives the expression of the chloramphenicol acetyl transferase (CAT) reporter gene that is followed by an internal SV40 virus early region promoter linked to the neomycin phosphotransferase II (NEO) gene. As an initial measure of the relative promoter/enhancer strength of the chLTR vectors, the murine NIH-3T3 cell line and the human JURKAT cell lines were transfected and assayed for CAT reporter activity. Relative to the MoMLV vector, the HaMSV construct was the most active in NIH-3T3 cells whereas the SL3-3 vector displayed the greatest activity in JURKAT cells. Retroviral vector producer cell populations and cell clones were established for each chLTR vector, and all were capable of yielding high vector titers (> 10(5) G418R cfu/ml on NIH-3T3). Supernatant from these cells was used to transduce both mouse and human cell lines and primary cells. In NIH-3T3 cells and two murine fibrosarcoma cell lines, the HaMSV chLTR vector was slightly more active than the MoMLV chLTR vector. In the human HepG2 and HeLa cell lines, the MPSV chLTR vector was the most active. Data from the human JURKAT T-cell line and a T cell line derived from an ADA-deficient severe combined immunodeficiency (SCID) patient demonstrate that the SL3-3 chLTR is the most active in these lymphoid cell lines. The greatest difference in the comparison of the different chLTR vectors was observed in primary human umbilical vein endothelial cells, where the MoMLV vector produced up to 100 times more CAT activity than the SL3-3 vector. These data suggest that the use of specific promoter/enhancer elements may lead to higher levels of gene expression following retroviral-mediated gene transfer into specific cell types and these observations may be useful in the design of human gene therapy experiments.
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PMID:Retroviral vectors containing chimeric promoter/enhancer elements exhibit cell-type-specific gene expression. 794 29

Primary bone marrow blasts from 4 children with t(8;21) acute myeloid leukemia (AML), 6 children with inv(16) AML, and 2 children with t(9;11) AML were injected intravenously or transplanted under the kidney capsule of sublethally irradiated mice with severe combined immunodeficiency (SCID). Leukemic cells from all AML patients infiltrated the SCID mouse thymus, suggesting that the thymic microenvironment supports the survival and growth of human AML blasts. Blasts from 1 of 4 t(8;21) AML patients and 4 of 6 inv(16) AML patients caused histopathologically detectable disseminated leukemia. Blasts from the remaining patients produced disseminated occult leukemia that was only detected by polymerase chain reaction. Occurrence of histopathologically detectable disseminated leukemia was dependent on intravenous injection of leukemic cells; none of the mice challenged with an inoculum transplanted under the kidney capsule developed overt leukemia. No obvious association was noted between occurrence of leukemia in SCID mice and clinical or laboratory features presented by patients, including age, sex, or leukocyte count at diagnosis. To our knowledge, this study is the first to show that leukemic blasts from children with newly diagnosed AML, especially inv(16) AML, can cause disseminated human leukemia in SCID mice without exogenous cytokine support. The SCID mouse model system may prove particularly useful for designing more effective treatment strategies against childhood AML.
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PMID:Childhood acute myeloid leukemia in mice with severe combined immunodeficiency. 801 18

Mice with severe combined immunodeficiency (SCID) were injected intravenously with primary bone marrow blasts from 12 children with newly diagnosed t(4;11)(q21;q23) acute lymphoblastic leukemia (ALL). Blasts from eight patients caused overt disseminated leukemia, whereas blasts from the other four patients produced occult leukemia that was detectable only by the polymerase chain reaction (PCR) technique. Only one patient among eight whose blasts caused disseminated leukemia in SCID mice remains alive and disease-free at 48.4 months postdiagnosis. In contrast, three of the other four patients whose blasts did not cause overt leukemia in SCID mice remain alive and disease-free at 6.1, 23.6, and 35.9 months, respectively. Thus, the occurrence of overt leukemia in SCID mice may be a predictor of patients' disease-free survival. The described SCID mouse model system may prove useful for designing more effective treatment strategies against therapy-refractory t(4;11) ALL.
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PMID:Human t(4;11)(q21;q23) acute lymphoblastic leukemia in mice with severe combined immunodeficiency. 804 67


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