isotretinoin has been researched along with Lymphoma--Large-B-Cell--Diffuse* in 3 studies
3 other study(ies) available for isotretinoin and Lymphoma--Large-B-Cell--Diffuse
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T-cell malignant lymphoma with conjunctival involvement.
To report a rare case of T-cell malignant lymphoma involving the conjunctiva.. A 63-year-old woman had rapid onset of bilateral perilimbal congestion and chemosis. Perilimbal thickening with corneal infiltration developed 20 days later. Computed tomography incidentally disclosed a right maxillary sinus mass. Biopsy specimens from the maxillary sinus mass and the left limbus were subjected to histopathologic examination and immunohistochemical study.. T-cell malignant lymphoma of diffuse large cell type, stage IV, was diagnosed. The patient was treated with combination chemotherapy plus 13-cis-retinoic acid and remained in remission 1 1/2 years after diagnosis.. Conjunctival involvement with T-cell lymphoma may present as episcleritis and chemosis. Topics: Antineoplastic Combined Chemotherapy Protocols; Conjunctival Neoplasms; Female; Humans; Immunohistochemistry; Immunophenotyping; Isotretinoin; Leukocyte Common Antigens; Lymphoma, Large B-Cell, Diffuse; Lymphoma, T-Cell; Maxillary Sinus Neoplasms; Middle Aged; Neoplasm Staging; Tomography, X-Ray Computed | 1998 |
Expression of the Zn finger gene, EVI-1, in acute promyelocytic leukemia.
The EVI-1 gene encodes a Zn finger, DNA binding protein previously detected in some acute myelogenous leukemias (AML) and myelodysplasias (MDS), but not in normal marrow or cord blood cells. Experimental studies suggest EVI-1 blocks cellular differentiation by binding to GATA-1 or other specific DNA sequences controlling gene expression, and may be involved in the pathogenesis of some AMLs. To further define potential roles for EVI-1 in leukemia pathogenesis, we studied its regulation in acute promyelocytic leukemias (APL). Seven of 11 APL cases expressed EVI-1 RNA detected by RNA PCR at diagnosis, and expression was detected in two additional cases after treatment with all-trans retinoic acid (ATRA). Two of four cases studied at relapse also expressed EVI-1 RNA. To investigate regulation of EVI-1 expression in APL, we examined its expression in the NB4 APL cell line. NB4 cells did not express EVI-1 under basal conditions, but expressed EVI-1 after ATRA-induced differentiation. When NB4 cells were exposed to ATRA and transferred to cultures with N,N'-hexamethylene-bis-acetamide (HMBA), differentiation occurred but EVI-1 RNA was not detected, indicating that EVI-1 expression was not required for terminal, NB4 differentiation. ATRA-resistant NB4 cells were obtained by continuous culture in gradually increasing concentrations of ATRA. These cells did not express markers of differentiation but continued to express EVI-1 for several weeks even after ATRA withdrawal. To assess whether expression of the APL PML-RAR alpha fusion gene alone was sufficient for ATRA induction of EVI-1, the PML-RAR alpha gene cDNA was expressed in U937 histiocytic lymphoma cells. ATRA treatment of PML-RAR alpha-transfected or control U937 cells did not induce EVI-1 expression. In conclusion, this study demonstrates the EVI-1 gene is consistently expressed in APL cells either constitutively or after ATRA treatment. ATRA represents the first biologically active agent shown to specifically regulate EVI-1 expression in blood cells. In contrast to previous studies in AML and MDS, the pattern of EVI-1 expression suggests it may facilitate rather than inhibit myeloid differentiation during ATRA treatment. However, effects of EVI-1 expression are likely to be complex, and expression in ATRA-resistant APL cells may indicate multiple roles for this gene. Topics: Acetamides; Alitretinoin; Cell Differentiation; DNA-Binding Proteins; Gene Expression Regulation, Leukemic; HL-60 Cells; Humans; Isotretinoin; Leukemia, Promyelocytic, Acute; Lymphoma, Large B-Cell, Diffuse; MDS1 and EVI1 Complex Locus Protein; Neoplasm Proteins; Oncogene Proteins, Fusion; Proto-Oncogenes; Transcription Factors; Tretinoin; Tumor Cells, Cultured; Zinc Fingers | 1997 |
Anticoagulant effects of retinoic acids on leukemia cells.
We have recently found that all-trans retinoic acid (ATRA) upregulates thrombomodulin (TM) and downregulates tissue factor (TF) expression in acute myelogenous leukemia (AML) M3 cells (NB4) and acute monoblastic leukemia cells (U937) (Koyama et al, Blood 84:3001, 1994). We have further investigated the effects of ATRA on leukemic cells freshly isolated from patients at diagnosis. Increase of TM antigen was documented in all AML cells: M0 (n = 1), M2 (n = 5), M3 (n = 3), M4 (n = 3), M5 (n = 3), and M6 (n = 1). Decrease of TF antigen was observed in 4 M2, 1 M4, and all M3 and M5 patients. However, no TM and TF antigens were detected in all chronic lymphocytic leukemia cells (n = 3) with or without ATRA treatment. Changes of TM and TF antigen levels were associated with those of TM and TF cofactor levels on the cell surface. A stereoisomer of RA, 9-cis RA, is a high-affinity ligand for the RA receptors (RARs) and the retinoid X receptors, although ATRA and another isomer, 13-cis RA, solely bind to RARs. We have also studied the effects of 9-cis RA and 13-cis RA on the expressions of TM and TF in NB4 and U937 cells. A relatively wide range of 9-cis RA concentrations (0.01 to 1 mumol/L) compared with ATRA was optimal for prolongation of normal plasma-based recalcification time (reduction of cell surface TF activity), decrease of TF antigen, and increase of TM antigen on the surface and in the lysates of NB4 and U937 cells. Western blot analysis under nonreducing conditions showed that both ATRA and 9-cis RA markedly induced the prominent band at 75 kD of TM and reduced the band at 45 kD of TF. Northern blot analysis has shown similar changes of mRNA levels, which indicates that RAs regulate TM and TF expression in leukemic cells at transcriptional levels. Anticoagulant effects of ATRA, ie, upregulation of TM expression and downregulation of TF expression, are applied not only to established cell lines of specific subtypes (M3 and M5) but also to more universal AML (most cases of M3 and M5 and a part of the other types of AML) cells freshly isolated from patients. 9-cis RA may be more effective than ATRA as an inducer of differentiation of AML M3 cells and as an anticoagulant agent for patients with certain types of AML as well. Topics: Anticoagulants; Base Sequence; Cell Separation; Cysteine Endopeptidases; Flow Cytometry; Gene Expression Regulation, Leukemic; Humans; Isotretinoin; Leukemia; Leukemia, Monocytic, Acute; Leukemia, Promyelocytic, Acute; Lymphoma, Large B-Cell, Diffuse; Molecular Sequence Data; Neoplasm Proteins; Neoplastic Stem Cells; Receptors, Retinoic Acid; Thrombomodulin; Thromboplastin; Tretinoin; Tumor Cells, Cultured | 1996 |