Publications by authors named "Antti Ropponen"

Autologous stem cell transplantation (auto-SCT) is an established treatment option in patients with non-Hodgkin lymphoma (NHL). In this prospective multicenter study, the effect of infused blood graft cellular composition on post-transplant outcome was analyzed in 129 NHL patients. Higher graft CD34 cell content (>2.

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Background: Autologous stem cell transplantation is an established treatment option for patients with multiple myeloma (MM) or non-Hodgkin's lymphoma (NHL).

Study Design And Methods: In this prospective multicenter study, 147 patients with MM were compared with 136 patients with NHL regarding the mobilization and apheresis of blood CD34+ cells, cellular composition of infused blood grafts, posttransplant recovery, and outcome.

Results: Multiple myeloma patients mobilized CD34+ cells more effectively (6.

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The composition of autologous blood grafts after cryopreservation, post-transplant hematological recovery up to 1 year and immune recovery up to 6 months as well as outcome was analyzed in 87 patients with multiple myeloma (MM). The patients receiving added plerixafor due to poor mobilization (11%) were compared to those mobilized with G-CSF or cyclophosphamide (CY) plus G-CSF. The use of plerixafor was found to significantly affect the graft composition as there was a significantly higher proportion of the more primitive CD34 cells, higher number of T and B lymphocytes as well as NK cells in the grafts of patients who received also plerixafor.

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Background: Lenalidomide is an immunomodulatory drug that is also currently used in transplant-eligible patients with multiple myeloma. Previous studies have suggested a negative impact of lenalidomide on the mobilization of CD34 cells. No data are available regarding the more detailed composition of blood grafts after lenalidomide.

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Background: Autologous stem cell transplantation is a standard treatment in multiple myeloma (MM). Blood grafts are usually collected after mobilization with granulocyte-colony-stimulating factor (G-CSF) alone or in a combination with cyclophosphamide (CY). There is limited knowledge of the possible effects of different mobilization regimens on blood graft characteristics and posttransplant outcomes.

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Limited data is available about the factors affecting early immune recovery or its clinical significance after autologous stem cell transplantation (auto-SCT). We prospectively analyzed factors affecting early immune recovery and outcome among 72 non-Hodgkin lymphoma (NHL) patients. Absolute lymphocyte count 15 d after auto-SCT (ALC-15) ≥ 0.

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Bcl-2 family comprises proapoptotic and antiapoptotic proteins. The balance between these proteins is critical for the survival of the cells. Overexpression of the antiapoptotic protein, Bcl-2, is the hallmark of follicular lymphoma (FL).

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Malignant skin melanoma is one of the most deadly human cancers. Extracellular matrix (ECM) influences the growth of malignant tumors by modulating tumor cells adhesion and migration. Hyaluronan is an essential component of the ECM, and its amount is altered in many tumors, suggesting an important role for hyaluronan in tumorigenesis.

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Germinal center (GC) B cells undergo apoptosis after B cell receptor (BCR) ligation, unless they receive CD40-mediated survival signal from helper T cells. In the present study, we used a human follicular lymphoma cell line HF1A3, as an in vitro model to study the selection process in germinal centers. We show here that BCR ligation led to immediate ERK1/2 activation and phosphorylations of its downstream targets, Bim EL/L and Bcl-2 (at Ser70) which resulted in short-term survival.

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Background: Autologous stem cell transplantation is commonly used to treat non-Hodgkin's lymphomas (NHLs). Cellular composition of the blood grafts apparently has a role in the posttransplant hematologic and immune recovery. Plerixafor increases the mobilization of CD34+ cells and higher amounts of various lymphocyte subsets have been reported in the grafts.

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The addition of rituximab (RTX) to standard chemotherapy has improved the treatment of B-cell malignancies. We show here that RTX and dexamethasone (Dex) induced synergistic apoptosis in follicular lymphoma cell lines. However, apoptosis was delayed by RTX-induced early protective signaling.

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Hyaluronan synthases (HAS1-3) are unique in that they are active only when located in the plasma membrane, where they extrude the growing hyaluronan (HA) directly into cell surface and extracellular space. Therefore, traffic of HAS to/from the plasma membrane is crucial for the synthesis of HA. In this study, we have identified Rab10 GTPase as the first protein known to be involved in the control of this traffic.

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As a partner of cyclin-dependent kinase (CDK) 3, Cyclin C controls cellular proliferation and, together with CDK8, represses gene transcription. In this study, we showed that the highly expressed Cyclin C gene is a direct target of the nuclear hormone all-trans retinoic acid (RA) in HEK293 human embryonal kidney cells. The RA receptor (RAR) gamma associates with a Cyclin C promoter region containing two RAR binding sites.

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Glucocorticoids are commonly used in the treatment of lymphoid malignancies. In this study, we show that apoptosis induced by dexamethasone (Dex), a synthetic glucocorticoid, was dependent on mitochondria, since overexpression of Bcl-X(L) prevented Dex-induced apoptotic changes. Dominant negative (DN) caspase-9 also prevented Dex-induced apoptotic changes including the loss of mitochondrial membrane potential indicating that caspase-9 controls mitochondrial changes.

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Despite the wide use of anti-CD20 antibody rituximab in the cancer treatment of B cell malignancies, the signalling pathways of CD20-induced apoptosis are still not understood. By using dominant negative (DN)-caspase-9 overexpressing follicular lymphoma cells we demonstrated that the activation of caspase-9 was essential for rituximab-mediated apoptosis. The death receptor pathway mediated by caspase-8 activation was not involved in rituximab-mediated apoptosis since overexpression of FLIP(short) or FLIP(long) proteins, inhibitors of caspase-8 activation, could not inhibit rituximab-induced apoptosis.

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Based on Bcl-X(L) overexpression studies we identified type I and type II follicular lymphoma cell lines in response to TRAIL. We demonstrate here that either amount of caspase-8 activation or Bid cleavage could not define the dependence on mitochondria. Furthermore, an inhibitor of NF-kappaB, PDTC, enabled TRAIL to activate type I apoptotic pathway in type II cells.

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The anti-proliferative effects of histone deacetylase (HDAC) inhibitors and 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] converge via the interaction of un-liganded vitamin D receptor (VDR) with co-repressors recruiting multiprotein complexes containing HDACs and via the induction of cyclin-dependent kinase inhibitor (CDKI) genes of the INK4 and Cip/Kip family. We investigated the effects of the HDAC inhibitor Trichostatin A (TSA) and 1alpha,25(OH)2D3 on the proliferation and CDKI gene expression in malignant and non-malignant mammary epithelial cell lines. TSA induced the INK4-family genes p18 and p19, whereas the Cip/Kip family gene p21 was stimulated by 1alpha,25(OH)2D3.

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CD95/Fas and CD40 receptors are important regulators of cell survival during germinal center reaction. In this study we used a human follicular lymphoma cell line, HF1A3, to study molecular mechanisms of CD95-mediated apoptosis and CD40-induced rescue from apoptosis. CD95 stimulation induced activation of caspase-8 and -3, collapse of mitochondrial membrane potential (DeltaPsim), release of cytochrome c and fragmentation of nuclear DNA.

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Glucocorticoids are commonly used in the treatment of various lymphoid malignancies. In the present study, we show that dexamethasone (Dex) induced depolarization of mitochondrial membrane, release of cytochrome c and DNA fragmentation in a human follicular lymphoma cell line, HF28RA. New protein synthesis was required before Dex-induced mitochondrial changes, and the kinetics of the apoptotic events correlated with the upregulation of the Bim protein.

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In the present study we used a human follicular lymphoma cell line, HF1A3, as an in vitro model for the antigen-driven selection process in germinal centers. Apoptosis can be induced in HF1A3 cells by B cell receptor (BCR) stimulation, but the molecular mechanisms and kinetics of this process are largely unknown. We demonstrate here that there is over 12 h delay between receptor activation and the execution phase of apoptosis, i.

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