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A B Deisseroth

Publications and source records attributed to A B Deisseroth.

At least 37 records · Page 2Linked to original sources
PubMed1998

Low and maximally phosphorylated levels of the retinoblastoma protein confer poor prognosis in newly diagnosed acute myelogenous leukemia: a prospective study.

A prior retrospective study suggested that the level of retinoblastoma protein (RB) expression was prognostic for survival in acute myelogenous leukemia (AML). Individuals with no/low RB protein expression were considered to have loss of RB function, and those with maximally phosphorylated (maxphos) RB were also felt to have nonfunctional RB. To confirm this, we prospectively investigated whether the level of RB expression was prognostic in AML in a larger cohort of patients. RB level was measured by Western blot and immunohistochemical analysis on peripheral blood samples from 210 newly diagnosed AML patients. Patients were divided into three groups based on the level of RB protein expression (i.e., no or low, elevated, and maxphos) or into two groups on the basis of presumed RB function, altered function (AF-RB, low and maxphos RB), versus normal function (NF-RB, elevated RB). By combined results of Western blot and immunohistochemical analysis, 20%, 65%, and 15% of patients had low, elevated, and maxphos RB, respectively. Most patients with acute promyelocytic leukemia (APL) with a French-American-British classification of M3 were in the low RB group, likely reflecting a lower proliferative rate of promyelocytes. Analysis was performed with and without these APL patients. The median survival was significantly shorter for both patients with low RB expression (48 weeks, P = 0.05, including APL patients; 34 weeks, corrected P = 0.008, with APL patients excluded) and maxphos RB expression (51 weeks, P = 0.007) compared to those with elevated RB expression (122 weeks including and 98 weeks excluding APL patients). Differences were greatest among patients with nonfavorable prognosis cytogenetics (median survival, 34 weeks versus 85 weeks; corrected P = 0.001 for AF-RB versus NF-RB). Remission duration was also significantly shorter for non-APL patients with AF-RB versus NF-RB (median survival, 36 weeks versus not reached; corrected P = 0.02). In multivariate analyses, including cytogenetics, performance status, age, antecedent hematological disorder, and RB status, with and without APL patients included, no/low and maxphos-RB protein expression were independent predictors for poorer survival. This prospective study confirms that the level of expression of RB is a strong prognostic factor in AML, with an inferior survival experience being associated with no/low RB and maxphos RB expression. Therefore, therapeutic decisions based on the level of RB expression may be indicated, and protocols to incorporate this are currently under development.

Adolescent↗
PubMed1997

Expression of epidermal growth factor receptor and human papillomavirus E6/E7 proteins in cervical carcinoma cells.

BACKGROUND: Epidermal growth factor receptor (EGF-R) proteins are highly expressed in many tumors, including those of the cervix. We have observed previously that the introduction of a transcription unit containing an antisense sequence for the E6/E7 genes of human papillomavirus (HPV) 18, along with a transcription unit containing a sense complementary DNA sequence for the wild-type retinoblastoma (Rb) gene, decreased the growth of human cervical carcinoma HeLa cells (HPV 18 positive) both in vitro and in vivo. To clarify the regulatory mechanisms by which this reduction in cell proliferation occurred, we studied the expression of EGF-R proteins in these cells. METHODS: Western blot and northern blot techniques were used to measure EGF-R expression, and a pulse-chase immunoprecipitation assay was used to measure the stability of EGF-R protein in HeLa cells and HeLa cells that had been transfected with the antisense E6/E7 or sense Rb sequences. Cell proliferation was measured by use of a tetrazolium-based colorimetric assay for numbers of viable cells. RESULTS: The introduction of sense Rb or antisense E6/E7 transcription units or a combination of these two transcription units into HeLa cells dramatically decreased the level of EGF-R proteins in these cells; EGF-R levels were not affected at the transcriptional level but at the post-transcriptional level. Addition of the anti-EGF-R-specific monoclonal antibody 225mAb to HeLa cells caused 53% (95% confidence interval = 44%-62%) growth inhibition. CONCLUSIONS: These results suggest that HeLa cervical carcinoma cells are dependent on EGF-R for proliferation and that changes in functional levels of the E6/E7 HPV proteins and endogenous Rb proteins may alter the growth rate of cervical cancer cell lines by reducing the stability of EGF-R at the post-transcriptional level.

Blotting, Northern↗
PubMed1997

Use of the cosmid adenoviral vector cloning system for the in vitro construction of recombinant adenoviral vectors.

The large size of the adenoviral genome unfortunately precludes there being many unique, useful restriction sites available for in vitro manipulation. Two methods have been developed for the construction of recombinant adenoviral vectors to date: in vivo homologous recombination or direct ligation in vitro. The efficiency of either the direct ligation method or the homologous recombination method is low because of the large size of the recombinant adenoviral vectors. To circumvent these problems, we have chosen to use the cosmid vector system to facilitate the assembly of recombinant adenoviral vectors. In this paper, we demonstrate for the first time that recombinant adenoviral vectors can be efficiently constructed in vitro by the cosmid vector system. With this method, it is possible to amplify the recombinant adenoviral vector DNA sufficiently to transfect 293 cells. The cosmid adenoviral vector cloning method for in vitro construction of the full-length recombinant adenoviral vectors represented here is simple and efficient and should facilitate the development of recombinant adenoviral vectors for human gene therapy.

Adenoviridae↗
PubMed1997

Allogeneic blood stem cell transplantation in advanced hematologic cancers.

Allogeneic bone marrow transplantation for advanced hematologic cancer is associated with a high risk of early treatment-related morbidity and mortality. To determine the short-term benefits of allogeneic blood stem cell transplants when compared to bone marrow transplants, we reviewed outcomes of 74 adults with advanced hematologic cancer transplanted from HLA-matched related donors after conditioning with thiotepa, busulfan and cyclophosphamide. There were three cohorts: group 1 received bone marrow transplants with cyclosporine (CsA) and methotrexate (MTX) for GVHD prophylaxis; group 2 received bone marrow transplants with CsA and methylprednisolone (MP); and group 3 received blood stem cells with CsA and MP. All patients received filgrastim post-transplant. Median times (range) to neutrophils > or = 0.5 x 10(9)/l were 17 (8-30), 9 (8-16) and 10 (8-13) days post-transplant, and to platelets > or = 20 x 10(9)/l were 28 (14-100+), 19 (13-100+) and 14 (9-86) days post-transplant for groups 1, 2 and 3, respectively (P < 0.05 only for group 1 vs group 3 for both outcomes). Blood stem cell recipients had the least regimen-related toxicity, fewest early deaths and earliest discharge. There was no significant difference in acute GVHD between the three groups. One hundred and eighty-day survivals (95% CI) were 53% (35-72%), 32% (10-53%), and 68% (49-87%) for groups 1, 2 and 3, respectively (P < 0.05 only for group 2 vs group 3). For allogeneic transplantation, use of blood stem cell grafts has substantial advantages over marrow grafts.

Adolescent↗
PubMed1997

Interferon regulatory factor 1 induces the expression of the interferon-stimulated genes.

The interferon regulatory factor 1 (IRF-1) is a positive transcriptional regulatory protein which acts in the interferon signal transduction pathway to activate the transcription of the type I interferon genes by binding to the PRDI response element. The aim of this study was to explore the role of IRF-1 in regulating the expression of other interferon-stimulated genes in the interferon signal transduction pathway. A transient transfection assay was used to show that IRF-1 induced the expression of interferon-stimulated genes. The induction was a direct result of IRF-1 binding to the promoters of the interferon-stimulated response element (ISRE). The levels of endogenous mRNA of two interferon-stimulated genes, 6-16 and 9-27, were increased in cells containing increased levels of IRF-1. In addition, IRF-1 activates the expression of IRF-2, a negative regulator of the type I interferon genes themselves. Two sequences were found in the IRF-2 promoter which were the binding sites for IRF-1. Mutations in the oligonucleotide sequences of these sites could abolish the binding of the IRF-1. These data suggested that IRF-1 not only plays an important role in the induction of type I interferon genes, but also in the activation of interferon-stimulated genes.

Base Sequence↗
PubMed1997

Potential role of bcr-abl in the activation of JAK1 kinase.

To study the oncogenic role of the p210(bcr-abl) fusion protein in chronic myelogenous leukemia cells, we generated a mouse cell line that was stably transfected with and overexpressed the human p210(bcr-abl) fusion protein. We then looked for phosphorylation activation of the Janus-activated kinase (JAK) family of tyrosine-specific protein kinases by the p210(bcr-abl) fusion protein. We found that JAK1, which has been shown by others to be associated with the IFN-alpha and -gamma plasma membrane receptors, was phosphorylated to a much greater degree in cells containing the p210(bcr-abl) fusion protein than was the case in the original, untransfected cell line. In contrast, no phosphorylation of the JAK2 kinase, which is associated with the IFN-gamma but not IFN-alpha receptor, was observed either with or without p210(bcr-abl) protein. A substrate of JAK1, STAT1 (signal transducers and activators of transcription 1), was found to be phosphorylated in cells containing overexpressed p210(bcr-abl) fusion protein. These results indicate that the presence of the p210(bcr-abl) protein kinase within a cell is associated with phosphorylation of the JAK1 kinase and its substrate STAT1.

Cells, Cultured↗
PubMed1997

Interferon-inducible protein 10 as a possible factor in the pathogenesis of cutaneous T-cell lymphomas.

Human IFN-gamma-inducible protein 10 (IP-10), a C-X-C chemokine secreted by IFN-gamma-stimulated keratinocytes, is chemotactic for normal CD4-positive lymphocytes and inhibits the proliferation of early subsets of normal and of leukemic hemopoietic progenitors. Cutaneous T-cell lymphoma (CTCL) is an indolent lymphoproliferative disorder of CD4-positive lymphocytes that remain confined to the skin for many years before visceral dissemination. Because IFN-gamma mRNA was detected in the epidermis of CTCL lesions, we decided to investigate the role of IP-10 in the epidermotropism of CTCL by determining its expression in normal skin and in CTCL lesions. Using purified recombinant IP-10 (rIP-10) or a recombinant fusion protein between IP-10 and the straight phi10 protein of phage T7, we generated rabbit antisera that recognized and neutralized rIP-10. Immunoperoxidase staining of normal epidermis demonstrated that IP-10 was expressed by basal keratinocytes but not by the more differentiated cells. In the often hyperplastic epidermis overlying CTCL lesions, IP-10 immunostaining was enhanced compared to normal skin and extended to the suprabasal keratinocytes in 28 of 29 patients for a frequency of 97% and a 95% confidence interval of 82-100%. However, IP-10 was detectable in the dermal or epidermal lymphoid infiltrates in only 3 of 29 patients (10%; 95% confidence interval, 2-29%). Skin clinically free of CTCL demonstrated normal IP-10 immunostaining. In one patient who had matching biopsies performed before and after treatment, IP-10 was overexpressed before treatment but was normally expressed at remission. The in vitro proliferation of primary normal human keratinocytes was inhibited in a dose-dependent manner by rIP-10. These results suggest that IP-10 plays a role in the epidermotropism of CTCL. Additional work is needed to determine whether IP-10 stimulates or inhibits CTCL proliferation. A better understanding of the growth controls operating in CTCL may be useful in the development of curative strategies for this disorder.

Adult↗
PubMed1997

Simultaneous genetic chemoprotection of normal marrow cells and genetic chemosensitization of breast cancer cells in a mouse cancer gene therapy model.

Repeated exposures to high doses of chemotherapy are often required to eradicate solid tumors. The success of such high-dose therapy is often limited by the myelosuppressive and toxic effects of these drugs on bone marrow cells and by the intrinsic resistance of the cancer cells to chemotherapy. To test ways of using genetic modification of somatic cells to circumvent both of these problems, we first genetically modified normal bone marrow cells with multidrug resistance-1 (MDR-1) cDNA retroviral vectors to render these cells more resistant to p-glycoprotein-transported agents. Experiments conducted previously in a mouse model in our laboratory (E. G. Hanania et al., Cancer Gene Ther., 2: 251-261, 1995; E. G. Hanania and A. B. Deisseroth, Cancer Gene Ther., 1: 21-25, 1994), which involve transplantation of mouse marrow cells modified with the human MDR-1 cDNA, showed that the majority of the marrow cells of these animals were resistant to repetitive administration of myelotoxic doses of Taxol, a MDR-1-transported drug. Next, to test the effects of genetically modifying marrow cells to make them resistant to chemotherapy, and genetically modifying tumor cells to make them more sensitive to chemotherapy, a mouse breast cancer cell line was transfected with a plasmid expression vector that contained a wild-type p53 chemosensitization transcription unit. Others have shown that restoration of the p53 gene can lead to decreased proliferation, reduced tumorigenicity, and increased sensitivity to chemotherapy-induced apoptosis. In this animal model, the simultaneous use of both chemoprotection and chemosensitization vectors, which provided protection of the normal cells to the chemotherapy and at the same time sensitized the tumor cells to the toxic effects of the chemotherapy, resulted in levels of in vivo tumor reduction that were not possible when either genetic chemoprotection of marrow cells or chemosensitization of tumor cells was used alone. These data should be of interest to those who are studying ways of using genetic modification to improve the outcome of established chemotherapy treatment programs for solid tumors.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Allogeneic transplantation for advanced leukemia: improved short-term outcome with blood stem cell grafts and tacrolimus.

We have evaluated the use of blood stem cell grafts for rapid hematopoietic recovery and tacrolimus (FK506) as GVHD prophylaxis to reduce early mortality after allogeneic transplantation. Eighty-five adults with advanced leukemia received high-dose thiotepa, busulfan, and cyclophosphamide as a preparative regimen in a prospective Phase II study. All donors were HLA-matched and related. Marrow (BMT) was used for 44 patients and filgrastim-mobilized blood stem cells (SCT) for 41 patients. GVHD prophylaxis consisted of cyclosporine (CsA) or FK506 with methotrexate (MTX) or methylprednisolone (MP). The median time to neutrophil recovery was earlier after SCT than after BMT (day 10 vs. 17, P<0.001), but this was due to the selective use of MTX only in the BMT patients. The risk of grades 2-4 GVHD was lower with FK506 than with CsA (16% vs. 45%, P=0.02) and was the same for SCT recipients as for BMT recipients (33% vs. 34%). Regimen-related toxicity was significantly lower after SCT than after BMT but did not differ between the FK506 and CsA patients. In comparison with those receiving the standard transplant (BMT with CsA and MTX), only the SCT recipients using FK506 and MP had a significantly higher survival at day 180 posttransplant (84% vs. 53%, P=0.014). In multivariate analyses, use of FK506 was associated with a lower risk of treatment-related mortality and a higher survival at day 180, while the diagnosis of acute lymphoblastic leukemia was associated with a higher risk of treatment-related mortality. These data suggest that the use of blood stem cell grafts and FK506 can reduce the early mortality after allogeneic transplantation for advanced leukemia.

Adolescent↗
PubMed1996

Results of MDR-1 vector modification trial indicate that granulocyte/macrophage colony-forming unit cells do not contribute to posttransplant hematopoietic recovery following intensive systemic therapy.

To formally test the hypothesis that the granulocyte/macrophage colony-forming unit (GM-CFU) cells can contribute to early hematopoietic reconstitution immediately after transplant, the frequency of genetically modified GM-CFU after retroviral vector transduction was measured by a quantitative in situ polymerase chain reaction (PCR), which is specific for the multidrug resistance-1 (MDR-1) vector, and by a quantitative GM-CFU methylcellulose plating assay. The results of this analysis showed no difference between the transduction frequency in the products of two different transduction protocols: "suspension transduction" and "stromal growth factor transduction." However, when an analysis of the frequency of cells positive for the retroviral MDR-1 vector posttransplantation was carried out, 0 of 10 patients transplanted with cells transduced by the suspension method were positive for the vector MDR-1 posttransplant, whereas 5 of 8 patients transplanted with the cells transduced by the stromal growth factor method were positive for the MDR-1 vector transcription unit by in situ or in solution PCR assay (a difference that is significant at the P = 0.0065 level by the Fisher exact test). These data suggest that only very small subsets of the GM-CFU fraction of myeloid cells, if any, contribute to the repopulation of the hematopoietic tissues that occurs following intensive systemic therapy and transplantation of autologous hematopoietic cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Tacrolimus and minidose methotrexate for prevention of acute graft-versus-host disease after matched unrelated donor marrow transplantation.

Thirty adults with leukemia or lymphoma undergoing marrow transplantation from HLA-compatible unrelated donors received tacrolimus (FK506), a new immunosuppressive macrolide lactone, and minidose methotrexate to prevent acute graft-versus-host disease (GVHD). The group had a median age of 36 years (range 21 to 49 years). Twenty-four patients had advanced disease, and 11 were resistant to conventional therapy. Tacrolimus was administered at 0.03 mg/kg/d intravenously (i.v.) by continuous infusion from day -2, converted to oral at four times the i.v. dose following engraftment, and continued through day 180 posttransplant. Methotrexate 5 mg/m2 was given i.v. on days 1, 3, 6, and 11. All patients engrafted. Grades 2-4 GVHD occurred in 34% (95% CI, 17% to 52%), and grades 3-4 GVHD in 17% (95% CI, 3% to 31%). Mild renal toxicity was common before day 100; 63% of patients had a doubling of creatinine, and 52% had a peak creatinine greater than 2 mg/dL, but only one patient was dialyzed. The median last i.v. dose of tacrolimus was 53% of the scheduled dose, and the median oral dose on day 100 was 41% of that scheduled. Overall survival at 1 year was 47% (95% CI, 27% to 66%). We conclude that tacrolimus can be combined safely with minidose methotrexate, and the combination has substantial activity in preventing acute GVHD after unrelated donor marrow transplantation.

Actuarial Analysis↗
PubMed1996

Oncology.

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Antineoplastic Agents↗