Showing papers by "Arnon Nagler published in 2002"

Human mast cells stimulate fibroblast proliferation, collagen synthesis and lattice contraction: a direct role for mast cells in skin fibrosis.

Abstract: Background Mast cells, the key cells of immediate hypersensitivity type reactions, have also been postulated to have a central role in influencing tissue remodelling and fibrosis occurring in the skin. Objective Our aim was to investigate the direct role of human mast cells (HMC) in skin fibrotic processes, by assessing the effects of the addition of the human mast cell line HMC-1 to human skin fibroblasts, and to identify the responsible mediators. Methods HMC-1 sonicates were added to human skin fibroblasts and the following parameters were evaluated: proliferation ([3H]-thymidine), collagen synthesis ([3H] proline), activity of matrix metalloproteinases (MMPs) (zymography) and tissue inhibitors of metalloproteinases (TIMPs) (reverse zymography), and collagen gel contraction. Results HMC-1 sonicate increased significantly both proliferation and collagen production in the human skin fibroblasts and these properties were not affected by heating of the sonicate (56 degrees C, 30 min, or 100 degrees C, 3 min). Two main mast cell mediators, histamine and tryptase, were found to be responsible for the increase in fibroblast proliferation and collagen production. HMC-1 sonicate did not display any pre-formed gelatinase activity, and its addition to the fibroblasts did not change their pro-MMP-2 and MMP-2 activity. On the other hand, HMC-1 were found to possess TIMP-1 and TIMP-2. Addition of HMC-1 had no effect on fibroblasts TIMP-1 but induced a dose-dependent increase of TIMP-2 activity. In addition, HMC-1 sonicate seeded together with the fibroblasts in tri-dimensional collagen gel significantly enhanced their contraction. Conclusion We have shown that human mast cells, by granule-stored and therefore quickly releasable mediators, increase human skin fibroblast proliferation, collagen synthesis, TIMP-2 and collagen gel contraction. Therefore, mast cells have a direct and potentiating role in skin remodelling and fibrosis.

Growth inhibition of prostate cancer xenografts by halofuginone.

Abstract: BACKGROUND Halofuginone, an inhibitor of collagen type I synthesis, is an anti-angiogenic agent. Here we evaluated the efficacy of halofuginone to inhibit prostate cancer (PC) xenografts representing various phenotypes of the disease. METHODS An androgen-dependent (CWR22), an androgen-independent (PC3), and a neuroendocrine (WISH-PC2) PC xenograft were used. Halofuginone was given orally or injected intraperitoneally. Tumor size, collagen α1(I) gene expression (in situ hybridization), collagen content (sirius red staining), angiogenesis (immunohistochemistry with factor VIII antibodies), and apoptosis/necrosis (DNA fragmentation) were evaluated. RESULTS Halofuginone inhibited the growth of all subcutaneously implanted xenografts and of WISH-PC2 when transplanted orthotopically. The effect was dose-dependent (WISH-PC2) and accompanied by decrease in plasma PSA levels (CWR22). In all xenografts, halofuginone inhibited collagen α1(I) gene expression, reduced collagen content, and endothelial cell number resulting in an increase in apoptosis/necrotsis. CONCLUSIONS Oral administration of halofuginone slowed the progression of PC xenografts representing a broad range of phenotypes. Halofuginone may become a new modality for PC prevention. Prostate 51: 73–83, 2002. © 2002 Wiley-Liss, Inc.

Chimerism testing and detection of minimal residual disease after allogeneic hematopoietic transplantation using the bioView (Duet™) combined morphological and cytogenetical analysis

Abstract: Recurrent disease remains a major obstacle to cure after allogeneic transplantation. Various methods have been developed to detect minimal residual disease (MRD) after transplantation to identify patients at risk for relapse. Chimerism tests differentiate recipient and donor cells and are used to identify MRD when there are no other disease-specific markers. The detection of MRD does not always correlate with relapse risk. Chimerism testing may also identify normal hematopoietic cells or other cells not contributing to relapse. In this study we report our initial experience with a novel system that provides combined morphological and cytogenetical analysis on the same cells. This system allows rapid automatic scanning of a large number of cells, thus increasing the sensitivity of detection of small recipient population. The clinical significance of MRD detection is improved by identifying the morphology of recipient cells. Identification of recipient characteristics within blasts predicts overt relapse in leukemia patients and precedes it by a few weeks to months. Identification within mature hematopoietic cells may not be closely associated with relapse. The system also allows chimerism testing after sex-mismatched transplants, within cellular subsets, with no need for sorting of cells. The system merits further study in larger scale trials.

Treatment of leukemia by alloreactive lymphocytes and nonmyeloablative stem cell transplantation.

Abstract: Allogeneic bone marrow or blood stem cell transplantation (BMT) represents an important therapeutic tool for treatment of otherwise incurable malignant and nonmalignant diseases, especially acute and chronic leukemias. Until recently, myeloablative regimens were considered mandatory for effective eradication of all malignant cells of host origin. Our preclinical and ongoing clinical studies indicated that eradication of host immunohematopoietic cells, including chemoradiotherapy-resistant leukemia, could be achieved by adoptive allogeneic cell therapy with donor lymphocyte infusion following induction of host-versus-graft transplantation tolerance mediated by engraftment of donor stem cells in the course of BMT. Thus, eradication of blood cancer cells, especially in patients with chronic myeloid leukemia and less frequently in patients with other hematologic malignancies, could be frequently accomplished despite complete resistance of such tumor cells to maximally tolerated doses of chemoradiotherapy. Our cumulative experience suggested that graft-versus-leukemia (GVL) effects might be a useful tool for both treatment and prevention of relapse. Based on the aforementioned rationale, we speculated that the therapeutic benefit of BMT may be improved by using a safer conditioning as part of the transplant procedure, with the goal in mind to induce host-versus-graft tolerance to enable subsequent induction of GVL effects rather than attempt to eliminate host cells with hazardous myeloablative chemoradiotherapy. The latter hypothesis suggested that effective BMT procedure may be accomplished without lethal conditioning of the host, using a new well-tolerated nonmyeloablative regimen, thus possibly minimizing immediate and late side effects related to myeloablative procedures considered until recently mandatory for conditioning of BMT recipients. Recent clinical observations suggest that effective treatment of leukemia may be accomplished with a well-tolerated nonmyeloablative stem cell transplantation (NST) regimen, while avoiding immediate and late toxicity and minimizing procedure-related mortality. Taken together, our cumulative data suggest that high-dose chemotherapy and radiation therapy may be successively replaced by a more effective biological tool-alloreactive donor lymphocytes-thus setting the stage for innovative immunotherapeutic procedures for more selective and effective treatment of patients in need of BMT, including those resistant to conventional chemoradiotherapy.

Intra-arterial catheter directed therapy for severe graft-versus-host disease

Abstract: Summary. Graft-versus-host disease (GVHD) is a major complication of allogeneic bone marrow transplantation (BMT), resulting in death in the majority of steroid-resistant patients. We assessed the efficacy of regional intra-arterial treatment in patients with resistant hepatic and/or gastrointestinal (GI) GVHD. In total, 15 patients with steroid resistant grade 3–4 hepatic (n = 4), gastrointestinal (GI) (n = 8) GVHD or both (n = 3) were given intra-arterial treatment. Patients with hepatic GVHD received methotrexate and methylprednisolone into the hepatic artery. Patients with GI GVHD were treated with infusions of methylprednisolone into the superior and inferior mesenteric arteries. Two patients with pronounced upper GI symptoms also received upper GI treatment. In total, 25 procedures were carried out (range 1–3 per patient). Hepatic response was observed in four out of seven (57%) patients with hepatic GVHD, three (43%) featuring good response. Complete responses were observed in nine (82%) GI GVHD patients, with median time to initial and complete response of 3 d (range 1–7) and 15·8 d (range 4–33) respectively. Regional treatment of severe GVHD with intra-arterial treatment appears to be effective and safe. GI treatment maybe more effective than intrahepatic treatment. Early administration of isolated intra-arterial therapy in high-risk patients may further improve the outcome and reduce untoward effects of systemic immunosuppressive treatment.

High-dose chemotherapy with autologous stem cell transplantation is an effective treatment of primary refractory Hodgkin's disease. Retrospective study of the Polish Lymphoma Research Group.

Abstract: We analysed the treatment outcome of primary refractory HD patients managed with high-dose chemotherapy and haematopoietic cell transplantation. Data of 65 adult patients who underwent HDC/ASCT in nine Polish centres for primary resistant Hodgkin's disease between June 1991 and July 2000 were collected retrospectively. Response rate to HDC/ASC: CR, 54%; PR, 20%; less than PR, 15%; early deaths, 11%. Actuarial 3-year OS and PFS were 55% and 36%, respectively. In multivariate analysis, lack of bulky lymph nodes and use of immunotherapy were favourable factors for both OS and PFS. IPF <3 at the time of transplantation was predictive for PFS. However, the prognostic impact of immunotherapy should be interpreted with caution since this group included more patients who achieved CR after HDC/ASCT. The results of HDC/ASCT are encouraging and confirm earlier findings. The role of immunotherapy should be further investigated in prospective trials.

Non-myeloablative hematopoietic stem cell transplantation (NST) in the treatment of human malignancies: from animal models to clinical practice.

Abstract: NST is becoming a widely accepted method for allogeneic HSCT. Much experience has been gained, and the biology, indications and limitations are becoming clearer. N onmyeloablative conditioning allows consistent engraftment of allografts from matched related, unrelated, and even partially matched donors. NST has been able to reduce the toxicity of allogeneic HSCT. The better immediate outcome produces better overall DFS. NST was feasible in elderly patients with almost no upper age limit56, and in patients with organ dysfunction or other comorbidities precluding standard ablative conditioning. NST has also reduced the regimen-related toxicity of allogeneic HSCT in high-risk setting such as HSCT in heavily pretreated patients or following failure of a prior transplant procedure and in the unrelated setting. 49,51 NST is rapidly becoming the treatment of choice in these indications where toxicity of standard ablative therapy is unacceptable. In certain malignancies such as in NHL, Hodgkin’s disease and mUltiple myeloma, standard ablative NST has been reported to result in exceptionally high treatment related mortality, and NST is being investigated as a more reasonable alternative. NST may reduce the toxicity of the procedure even in younger patients who are eligible for ablative HSCT as well, however the long-term impact on patient outcome in this group is not yet established, and NST merits further investigation in prospective comparative trials. As described above, the known susceptibility of the underlying malignancy to GVT, the response to prior chemotherapy and bulk of residual disease, and the type of donor are other factors to consider when considering NST, and when selecting a regimen. The optimal preparative regimen needs to be defined. Ultimately less chemotherapy will be used and more specific immune-modulation, rather than intense nonspecific immunosuppression, will be used to achieve HVG tolerance. Preliminary animal models using costimulation blockade for specific induction of tolerance are promising steps towards achievement of this goa1.36

Successful major surgical recovery of a patient following haploidentical stem cell transplantation for chronic myeloid leukemia in blast crisis and aspergillosis.

Abstract: A 44-year-old woman who underwent haploidentical stem cell transplantation (haplo SCT) for chronic myeloid leukemia in blast crisis and aspergillosis was admitted to the emergency room 7 months later because of severe right upper quadrant abdominal pain, fever, leukocytosis and peritoneal signs. Computer tomography disclosed cholecystitis and gallbladder perforation. Within hours, she underwent urgent open laparatomy and cholecystectomy. The postoperative period was uneventful and she was discharged 10 days later without any complications. Currently, she is 2(1/2) years posttransplantation in full hematological, cytogenetic and molecular remission with 100% Karnofsky performance status. Most notably, normal and fast recovery was observed following major surgery 7 months post-haplo SCT which is usually considered to result in long-lasting immunosuppression and malfunction of the immune system.

Human colon adenocarcinoma in the SCID/CB6 radiation chimera is susceptible to adoptive transfer of allogeneic human peripheral blood mononuclear cells

Abstract: The aim of this study was to develop a murine model of human colon carcinoma (hCC) and to ascertain the potential of cellular immunotherapy in this model. Fragments of hCC obtained at surgery from ...