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Biomedical subjects

R Ueda

Publications and source records attributed to R Ueda.

At least 37 records · Page 2Linked to original sources

Selective apoptosis of tandemly duplicated FLT3-transformed leukemia cells by Hsp90 inhibitors.

An internal tandem duplication of the juxtamembrane (JM) domain of FLT3, a family of ligand-activated receptor tyrosine kinases, has been found in 20% of cases of acute myeloid leukemia (AML), and this mutation is correlated with leukocytosis and a poor prognosis. As a therapeutic approach, we previously reported that herbimycin A (HA) inhibited the growth of tandemly duplicated FLT3 (TDFLT3)-transformed cells (Leukemia 2000; 14: 374). Here, we have investigated the mechanism behind the cytotoxicity of HA, an ansamycin derivative which is now known to target Hsp90. The treatment with HA or another Hsp90 inhibitor, radicicol, induced selective apoptosis in TDFLT3-transformed 32D cells (TDFLT3/32D). The tyrosine-phosphorylation of TDFLT3 was inhibited by HA, whereas FLT3 ligand-induced phosphorylation of wild-type FLT3 (WtFLT3) was not. The downstream signal molecules MAPK, Akt and STAT5a were also dephosphorylated by HA in TDFLT3/32D. Immunoprecipitation analysis showed that TDFLT3 but not WtFLT3 formed a complex with Hsp90, and that the HA treatment dissociated TDFLT3 from the Hsp90 chaperone complex. These findings imply that targeting of Hsp90 will facilitate the development of anti-TDFLT3 therapy, and that Hsp90 is closely involved in the oncogenic activation of FLT3.

Animals↗

The appearance of S-100 protein-positive dendritic cells and the distribution of lymphocyte subsets in idiopathic nonspecific interstitial pneumonia.

Idiopathic interstitial pneumonia (IIP) is a progressive interstitial lung disease of unknown etiology. We investigated dendritic cells in idiopathic nonspecific interstitial pneumonia (NSIP) immunohistochemically, using anti-S-100 protein antibody and anti-HLA-DR antibody and also evaluated the relationship between the distribution of S-100 protein-positive dendritic cells (S- 100 DCs) and the lymphocytic subsets in the lung tissue of NSIP. Fifteen patients with the pathological diagnosis of idiopathic NSIP and six patients with usual interstitial pneumonia (UIP) were recruited into this study. Many S-100 DCs were observed in all the cases of idiopathic NSIP but S-100 DCs were not recognized in UIP cases invariably. In the mirror section method, most S-100 DCs showed a positive reaction of anti-HLA-DR antibody but a negative reaction for anti-CD1a antibody. CD8 and CD4 positive lymphocytes were infiltrated diffusely around S-100 DCs. It was demonstrated that the infiltration of CD8 positive lymphocytes predominated in the fibrosing areas and lymphoid follicles around S-100 DCs more so than CD4 positive lymphocytes.We speculate that the pathogenesis of NSIP is different from UIP and that DC and T cell-mediated immune mechanisms may play a role in the development and perpetuation of NSIP.

Aged↗

Transforming growth factor beta1 gene polymorphism in rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic inflammatory disease and synovial cells, antigen presenting cells, lymphocytes, and their cytokines might be associated with the disease. Transforming growth factor beta1 (TGFbeta1) has been reported to have important roles in unresolved inflammation, immune suppression, fibrosing processes, and angiogenesis. TGFbeta1 is highly expressed in joints in RA and is considered to be a regulator of anti-inflammation in RA. Polymorphisms of TGFbeta1 have been reported to be associated with the production of TGFbeta1 protein, and to increase the risk of acquiring several diseases. It was speculated that these polymorphisms might also be involved in RA, and therefore the TGFbeta1 codon 10 T869C polymorphism in a series of patients and controls was investigated. METHOD: A total of 155 patients with RA and 110 healthy subjects were studied. DNA was extracted from peripheral leucocytes and TGFbeta1 codon 10 T869C polymorphism was determined by polymerase chain reaction restriction fragment polymorphism. RESULTS: A significantly higher proportion of patients with RA with the T allele (CT type or TT type) was found compared with the CC type (p=0.039). CONCLUSION: The T allele, previously reported to be linked with production of TGFbeta1, may be associated with an increased risk of RA.

Adult↗

Transforming growth factor-beta gene polymorphism in sarcoidosis and tuberculosis patients.

SETTING: Transforming growth factor-beta (TGF-beta) plays an important role in many diseases, influencing as it does such processes as immune responses, fibrosing processes, and angiogenesis. Recently, polymorphisms have been described for TGF-beta that are associated with the risk of several diseases. In this study, we investigated whether TGF-beta 1 polymorphism has an effect on sarcoidosis and tuberculosis. OBJECTIVE: TGF-beta 1 Codon 10 T869C polymorphism was investigated in 110 healthy control subjects, 104 sarcoidosis patients, and 101 tuberculosis patients. DESIGN: The TGF-beta genotype was determined using polymerase chain reaction restriction fragment length polymorphism. RESULTS: We found no significant differences in TGF-beta genotypes between sarcoidosis patients and healthy controls or tuberculosis patients and controls. The long axis of the tuberculin skin test was larger in the CC type compared with the CT type. However, there was no association between the TGF-beta genotype and the roentgenographic stage, the disappearance of shadows, or organ involvement in sarcoidosis, nor any association between genotype, the extent or type of roentgenographic shadow, or detected volume of tubercle bacilli in tuberculosis. CONCLUSION: From the results, we believe that TGF-beta polymorphisms on the whole do not have a strong influence on disease onset or clinical progression in sarcoidosis and tuberculosis, although this polymorphism might have an effect on the immune response in a tuberculosis host.

Adult↗

Ganglioside G(D2) in small cell lung cancer cell lines: enhancement of cell proliferation and mediation of apoptosis.

Expression levels of gangliosides and glycosyltransferase genes responsible for their syntheses in human lung cancer cell lines and a normal bronchial epithelial cell line were analyzed. Both non-small cell lung cancers and small cell lung cancers (SCLCs) mainly expressed G(M2) and G(M1), whereas only SCLCs expressed b-series gangliosides, such as G(D2), G(D1b), and G(T1b). Accordingly, many SCLC cell lines showed up-regulation of the G(D3) synthase gene. Consequently, we introduced G(D3) synthase cDNA into a SCLC line with low expression of b-series gangliosides and analyzed the effects of newly expressed gangliosides on tumor phenotypes. The transfectant cells expressing high levels of G(D2) and G(D3) exhibited markedly increased growth rates and strongly enhanced invasion activities. Addition of anti-G(D2) monoclonal antibodies into the culture medium of these cells resulted in the marked growth suppression of G(D2)-expressing cell lines with reduced activation levels of mitogen-activated protein kinases but not of nonexpressants, suggesting that G(D2) plays important roles in cell proliferation. Moreover, G(D2)-expressing cells treated with anti-G(D2) antibodies showed features of apoptotic cell death at 30 min after addition of antibodies, i.e., shrinkage of cytoplasm, binding of Annexin V, and staining with propidium iodide, followed by DNA fragmentation. This G(D2)-mediated apoptosis was associated with caspase-3 activation and partly inhibited by a caspase inhibitor, z-Val-Ala-Asp-fluoromethyl ketone. The finding that anti-G(D2) antibodies suppressed the cell growth and induced apoptosis of SCLC cells strongly suggested the usefulness of G(D2) as a target for the therapy of disastrous cancer, although the precise mechanisms for apoptosis remain to be clarified.

Antibodies, Monoclonal↗

Activating mutation of D835 within the activation loop of FLT3 in human hematologic malignancies.

Mutations of receptor tyrosine kinases are implicated in the constitutive activation and development of human malignancy. An internal tandem duplication (ITD) of the juxtamembrane (JM) domain-coding sequence of the FLT3 gene (FLT3/ITD) is found in 20% of patients with acute myeloid leukemia (AML) and is strongly associated with leukocytosis and a poor prognosis. On the other hand, mutations of the c-KIT gene, which have been found in mast cell leukemia and AML, are clustered in 2 distinct regions, the JM domain and D816 within the activation loop. This study was designed to analyze the mutation of D835 of FLT3, which corresponds to D816 of c-KIT, in a large series of human hematologic malignancies. Several kinds of missense mutations were found in 30 of the 429 (7.0%) AML cases, 1 of the 29 (3.4%) myelodysplastic syndrome (MDS) cases, and 1 of the 36 (2.8%) acute lymphocytic leukemia patients. The D835Y mutation was most frequently found (22 of the 32 D835 mutations), followed by the D835V (5), and D835H (1), D835E (1), and D835N (1) mutations. Of note is that D835 mutations occurred independently of FLT3/ITD. An analysis in the 201 patients newly diagnosed with AML (excluding M3) revealed that, in contrast to the FLT3/ITD mutation (n = 46), D835 mutations (n = 8) were not significantly related to the leukocytosis, but tended to worsen disease-free survival. All D835-mutant FLT3 were constitutively tyrosine-phosphorylated and transformed 32D cells, suggesting these mutations were constitutively active. These results demonstrate that the FLT3 gene is the target most frequently mutated to become constitutively active in AML.

Acute Disease↗

Mutagenic and nonmutagenic bypass of DNA lesions by Drosophila DNA polymerases dpoleta and dpoliota.

cDNA sequences were identified and isolated that encode Drosophila homologues of human Rad30A and Rad30B called drad30A and drad30B. Here we show that the C-terminal-truncated forms of the drad30A and drad30B gene products, designated dpoletaDeltaC and dpoliotaDeltaC, respectively, exhibit DNA polymerase activity. dpoletaDeltaC and dpoliotaDeltaC efficiently bypass a cis-syn-cyclobutane thymine-thymine (TT) dimer in a mostly error-free manner. dpoletaDeltaC shows limited ability to bypass a 6-4-photoproduct ((6-4)PP) at thymine-thymine (TT-(6-4)PP) or at thymine-cytosine (TC-(6-4)PP) in an error-prone manner. dpoliotaDeltaC scarcely bypasses these lesions. Thus, the fidelity of translesion synthesis depends on the identity of the lesion and on the polymerase. The human XPV gene product, hpoleta, bypasses cis-syn-cyclobutane thymine-thymine dimer efficiently in a mostly error-free manner but does not bypass TT-(6-4)PP, whereas Escherichia coli DNA polymerase V (UmuD'(2)C complex) bypasses both lesions, especially TT-(6-4)PP, in an error-prone manner (Tang, M., Pham, P., Shen, X., Taylor, J. S., O'Donnell, M., Woodgate, R., and Goodman, M. F. (2000) Nature 404, 1014-1018). Both dpoletaDeltaC and DNA polymerase V preferentially incorporate GA opposite TT-(6-4)PP. The chemical structure of the lesions and the similarity in the nucleotides incorporated suggest that structural information in the altered bases contribute to nucleotide selection during incorporation opposite these lesions by these polymerases.

Animals↗

GPHN, a novel partner gene fused to MLL in a leukemia with t(11;14)(q23;q24).

We report a novel MLL-associated chromosome translocation t(11;14)(q23;q24) in a child who showed signs of acute undifferentiated leukemia 3 years after intensive chemotherapy that included the topoisomerase-II inhibitor VP 16. Screening of a cDNA library of the patient's leukemic cells showed a novel fusion transcript between MLL and the Gephyrin (GPHN) gene on 14q24. The resulting MLL-GPHN fusion gene encodes MLL AT hook motifs and a DNA methyltransferase homology domain fused to the C-terminal half of Gephyrin, including a presumed tubulin binding site and a domain homologous to the Escherichia coli molybdenum cofactor biosynthesis protein MoeA. Genomic breakpoint analysis showed potential in vitro topoisomerase-II DNA-binding sites spanning the breakpoints in both MLL and GPHN but no flanking sequences that might mediate homologous recombination. This suggests that MLL-GPHN may have been generated by VP 16/topoisomerase-II-induced DNA double-strand breaks, followed by error-prone DNA repair via non-homologous end joining. Gephyrin was originally identified as a submembraneous scaffold protein that anchors and immobilizes postsynaptic membrane neurotransmitter receptors to underlying cytoskeletal elements. It also is reported to bind to phosphatidylinositol 3,4,5-triphosphate binding proteins involved in actin dynamics and downstream signaling and interacts with ATM-related family member RAFT1. Gephyrin domains in the chimeric protein therefore could contribute novel signal sequences or might modify MLL activity by oligomerization or intracellular redistribution.

Amino Acid Sequence↗

Improvement of splenomegaly and pancytopenia by enzyme replacement therapy against type 1 Gaucher disease: a report of sibling cases.

Gaucher disease is a genetic lipid storage disease and represents a potentially serious health problem. It arises from a deficiency of glucocerebrosidase activity with secondary accumulation of large quantities of glucocerebroside. Symptoms are usually multisystemic, often debilitating or disabling, and sometimes disfiguring, and they can lead to death. We report objective clinical response's to repeated infusion of human placental and recombinant glucocerebrosidase in 2 patients with type 1 Gaucher disease and increased hemoglobin levels and platelet counts. Splenic volume decreased during the period of enzyme administration. Enzyme replacement therapy has improved the treatment of type 1 Gaucher disease by safely and effectively arresting, decreasing, or normalizing many of its major signs and symptoms. Consideration by physicians must be given to Gaucher disease, and appropriate treatments must be given when confronted with cryptogenic pancytopenia or hepatosplenomegaly.

Adult↗

Pregnancy-associated cytotoxic lymphoma: a report of 4 cases.

The clinicopathological and biological significance of Hodgkin's disease and non-Hodgkin's lymphoma, which are infrequently encountered in women of childbearing age, remains to be clarified. We recently reviewed 4 cases of non-Hodgkin's lymphoma of the T/natural killer (T/NK)-cell phenotype, all of which were associated with pregnancy and characterized by the expression of the cytotoxic granule-associated proteins T-cell intracellular antigen-1 and/or granzyme B. The 4 cases selected had presented between November 1993 and May 1999. The criteria for selection were that the onset of clinical manifestations occurred during pregnancy or within 6 months after delivery. The patients comprised 1 patient with p80/anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL), 1 with p80/ALK-negative ALCL, and 2 with peripheral T/NK-cell lymphomas of unspecified type. The diseases followed aggressive clinical courses: 3 patients died within 6.5 months after diagnosis, and only 1 was still alive with the disease 17 months after diagnosis. The diseases appeared to progress rapidly after delivery. Maternal immunity and hormonal changes during pregnancy may be closely related to the biological behavior of these unusual tumors. This study is, to the best of our knowledge, the first to address pregnancy-associated cytotoxic lymphoma.

Adult↗

CD34+-selected autologous peripheral blood stem cell transplantation conditioned with total body irradiation for malignant lymphoma: increased risk of infectious complications.

Although high-dose chemotherapy with autologous peripheral blood stem cell transplantation (autoPBSCT) has been shown or confirmed to be an effective treatment for high-risk and relapsed non-Hodgkin's lymphoma (NHL), relapse after autoPBSCT remains a serious problem. In a clinical trial to overcome relapse, we adopted a treatment plan in which PBSCs purified in vitro to CD34+ cells to deplete tumor cells (CD34+ autoPBSCT), total body irradiation (TBI) of 1200 cGy, and melphalan, 180 mg/m2, were used as a preconditioning regimen. Eighteen patients with relapsed or high-risk NHL participated in the study. This study compared the incidence of complications following CD34+ autoPBSCT preconditioned with the TBI regimen (n = 10): the TBI group; CD34+ autoPBSCT with the non-TBI regimen (n = 8): the non-TBI group; and unselected autoPBSCT with the non-TBI regimen (n = 19): the unselected autoPBSCT control group. After day 30 posttransplantation, 6 of 10 patients treated with the TBI regimen developed 11 infectious complications in total, compared with only 1 of 8 patients treated with the non-TBI regimen and 4 of 19 patients given unselected autoPBSCT. Two fatal complications occurred in the TBI group, but none occurred in the other 2 groups. The CD4+ lymphocyte count at 1 month posttransplantation was significantly lower in the TBI group than in the unselected autoPBSCT group. These findings suggest that the addition of TBI to the preconditioning regimen for CD34+ autoPBSCT is associated with an increased incidence of severe infectious complications after transplantation.

Adult↗

FLT3 tyrosine kinase as a target molecule for selective antileukemia therapy.

Fusion gene products such as PML-RARalpha and BCR-ABL generated by leukemia-specific chromosomal translocations have been identified as target molecules for the treatment of leukemia. Here we describe one possibility for extending the frontier of mechanism-based medicine for acute myeloid leukemia (AML). FLT3, a receptor tyrosine kinase (RTK) preferentially expressed in hematopoietic progenitor cells, frequently has a gain-of-function mutation in AML. To search for FLT3-targeted compounds, we screened the growth-inhibitory effects of several tyrosine kinase inhibitors (TKIs) on mutant FLT3-transformed 32D cells. Herbimycin A at a concentration of 0.1 microM markedly inhibited the growth of the transfectants but at that concentration was ineffective in parental 32D cells. It suppressed the constitutive tyrosine phosphorylation of the mutant FLT3, but not the phosphorylation of the ligand-stimulated wild-type FLT3. In mice transplanted with transformed 32D cells, the administration of herbimycin A completely prevented leukemia progression. Recent studies have indicated that herbimycin A binds directly with HSP90, a molecular chaperone, and destabilizes HSP90-associated proteins. Another HSP90 inhibitor, radicicol, also induced apoptosis selectively in transformed 32D cells. HSP90 is a promising target for the treatment of AML with mutant FLT3.

Acute Disease↗

API2-MALT1 fusion transcripts involved in mucosa-associated lymphoid tissue lymphoma: multiplex RT-PCR detection using formalin-fixed paraffin-embedded specimens.

Malignant lymphoma of mucosa-associated lymphoid tissue (MALT) type is a distinct clinicopathological disease entity in the category of extranodal marginal zone B-cell lymphoma. Recently, we and others have shown that the API2 gene on chromosome 11 and the MALT1 gene on chromosome 18 are fused as a result of t(11;18)(q21;q21) in MALT lymphomas. Here we report a detection assay that can be used for formalin-fixed, paraffin-embedded specimens. It consists of a multiplex one-tube reverse transcriptase-polymerase chain reaction (RT-PCR) followed by three parallel multiplex nested polymerase chain reactions. Eight variants of the fusion transcripts have been reported to date. When these variants were used as positive controls, all were successfully detected. The subsequent direct sequencing confirmed the results. Using this rapid and simple method, we could detect API2-MALT1 fusion transcripts in 5 of 15 (33%) archival cases of MALT lymphoma for a frequency comparable with those of RT-PCR assays using frozen materials. The lung was the preferential anatomical site of origin of MALT lymphomas harboring API2-MALT1 fusion. No fusion transcript was detected in any of 20 high-grade B-cell lymphomas. Our multiplex RT-PCR assay, which can be used for routinely-processed paraffin samples, should serve as a useful molecular tool for clarifying the clinicopathological significance of API2-MALT1 fusion in MALT lymphoma.

Adult↗

Interphase detection of immunoglobulin heavy chain gene translocations with specific oncogene loci in 173 patients with B-cell lymphoma.

To detect immunoglobulin heavy chain (IGH) gene translocations with specific oncogene loci, we established an interphase cytogenetic approach using double-color fluorescence in situ hybridization (DC-FISH), which we used to analyze 173 patients with B-cell lymphoma. DC-FISH using the IGH gene (14q32.3) in combination with c-MYC (8q24.1), BCL1 (11q13.3), BCL2 (18q21.3), BCL6 (3q27), and PAX-5 (9p13) gene probes detected IGH translocations in 70 (40.5%) of 173 patients. The partner genes involved in IGH translocations were identified in 56 (80%) of 70 patients, and fusion of the IGH gene with specific oncogenes was detected in 53 of 56 patients, particularly in interphase nuclei of 28 patients for whom cytogenetic analysis was not informative. The most common partner gene was BCL2 (19 patients; 27% of IGH translocation-positive patients), followed by BCL6 (16; 23%), BCL1 (11; 16%), c-MYC (7; 10%), and PAX-5 (2; 3%). These oncogenes were closely associated with subtypes of B-cell lymphoma. The other partners were 19q13 (BCL3), 6p25 (MUM1/IRF4), 1q36, and chromosome 8 identified in one patient each. Six of the nine patients with add(14)(q32) showed a BCL6/IGH translocation. Double translocations of the IGH gene were found in three patients; c-MYC+BCL1, c-MYC+BCL2, and c-MYC+BCL6 in each one. Interphase FISH using specific IGH-translocation probes is valuable for defining clinically meaningful subgroups of B-cell lymphoma.

Adolescent↗

Determination of hepatitis B virus genotype G by polymerase chain reaction with hemi-nested primers.

Hepatitis B virus (HBV) has been classified into six genotypes designated A-F by sequence divergence in the entire genome exceeding 8%. Very recently, the seventh genotype was reported and named genotype G. HBV genotype G is distinct from genomes of the other six genotypes in that it possesses an insertion of 36 nucleotides in the core gene, and has been found so far in France and the United States. A method for determining HBV genotype G was developed by polymerase chain reaction (PCR) with primers deduced from the 36-nucleotide (nt) insertion in five isolates of HBV genotype G the sequences of which have been deposited in DNA databases. The validity of this method, for specifically detecting HBV genotype G, was verified on a panel consisting of 142 HBV isolates of six major genotypes and four of genotype G. A total of 540 sera containing HBV in Japan covering symptom free carriers and patients with a spectrum of chronic liver disease were tested by this method, but not a single HBV genotype G sample was found. A possible method for serological determination of hepatitis B surface antigen of genotype G is suggested, without amplification or sequencing nucleotides, which would expand epidemiological and clinical researches on HBV genotype G.

Amino Acid Sequence↗

Muscarinic cholinergic and glutamatergic reciprocal regulation of expression of hippocampal cholinergic neurostimulating peptide precursor protein gene in rat hippocampus.

Hippocampal cholinergic neurostimulating peptide, an undecapeptide originally isolated from the hippocampus of young rats, enhances acetylcholine synthesis in rat medial septal nucleus in vitro. Hippocampal cholinergic neurostimulating peptide is derived from the N-terminal region of its 21-kmol.wt precursor protein. The highest expression of the hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA is in hippocampal pyramidal neurons. In an in vitro rat hippocampal slice, preparation in which electrical stimulation could be delivered to the Schaffer collateral-CA1 pyramidal cell synapse, semi-quantitative non-radioisotopic in situ hybridization, demonstrated that expression of the hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA is regulated by neuronal activity. Selective inhibition with pharmacological agents revealed that the constitutive hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA level can be up-regulated by D-(-)-2-amino-5-phosphono-valeric acid, and that activity-dependent transcription can be inhibited by tetrodotoxin, nifedipine, 6-cyano-7-nitroquinoxaline-2,3-dione, and scopolamine, but not by mecamylamine. These results indicate that septal cholinergic neurons and hippocampal glutamatergic neurons exert a reciprocal influence over the expression of hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA in the hippocampus, and that the activity-dependent and constitutive expressions of hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA may be regulated by different routes, involving calcium influx via L-type Ca(2+) channels and N-methyl-D-aspartate receptors.

Androgen-Binding Protein↗

Effect of interferon therapy on Japanese chronic hepatitis C virus patients with anti-liver/kidney microsome autoantibody type 1.

AIM: The aim of this study was to determine the prevalence of anti-liver/kidney microsome autoantibody type 1 (anti-LKM-1) among hepatitis C virus (HCV)-infected Japanese patients at various stages (chronic hepatitis, liver cirrhosis and hepatocellular carcinoma), and to assess the influence of anti-LKM-1 on interferon therapy. METHODS: A total of 390 serum samples from 215 HCV-infected patients with chronic hepatitis (HCV-CH), 81 HCV-infected patients with liver cirrhosis (HCV-LC), and 94 HCV-HCC infected patients were subjected to examination. Ninety-one HBsAg-positive patients and 137 healthy subjects served as controls. Anti-liver/kidney microsome autoantibody type 1 was determined by using a newly developed ELISA using recombinant cytochrome P450 IID6 as the antigen. RESULTS: Anti-liver/kidney microsome autoantibody type 1 was detected in six of the 390 (1.5%) chronic HCV-infected patients (four were HCV-CH and two were HCV-LC); in contrast, it was not detected in control groups. Among the 110 HCV-CH patients treated with interferon (IFN), four were positive for anti-LKM-1. No change in anti-LKM-1 immunoreactivity from negative to positive during interferon therapy was observed. Moreover, no increase in the serum alanine aminotransferase level was observed in these four patients with anti-LKM-1. CONCLUSION: Our study indicates that: (i) anti-LKM-1 does not aggravate the liver disease associated with HCV infection; and (ii) no change in anti-LKM-1 immunoreactivity from negative to positive or no aggravations of liver dysfunction were observed among HCV-CH patients during the IFN therapy for Japanese patients with liver disease.

Autoantibodies↗

In vivo effects of a histone deacetylase inhibitor, FK228, on human acute promyelocytic leukemia in NOD / Shi-scid/scid mice.

Histone acetylation and deacetylation are closely linked to transcriptional activation and repression, respectively. In acute promyelocytic leukemia (APL), histone deacetylase inhibitors (HDACIs) have a synergistic effect with all-trans retinoic acid (ATRA) in vitro to induce differentiation. Here we report in vitro and in vivo effects of a HDACI, FK228 (formerly FR901228 or depsipeptide), on the human APL cell line NB4. FK228 had a strong and irreversible cytotoxicity compared with another HDACI, trichostatin A. In vivo administration of ATRA or FK228 alone partly inhibited the growth of established tumors of NB4 subcutaneously transplanted in NOD / Shi-scid / scid mice, and the combination was synergistically effective. Histopathological examination revealed that the combination induced apoptosis and differentiation as well as histone acetylation. Intravenous injection of NB4 in NOD / Shi-scid / scid mice followed by combination treatment significantly prevented leukemia death, whereas single administration did not. These findings suggest that FK228 is a promising agent to enhance ATRA-sensitivity in the treatment of APL.

Animals↗