Frataxin deficiency enhances apoptosis in cells differentiating into neuroectoderm

Deficiency of the mitochondrial matrix protein frataxin causes Friedreich ataxia. Frataxin function is believed to be related to mitochondrial iron metabolism and free radical production. In Friedreich ataxia, loss of dorsal root ganglia neurons occurs early in life, suggesting a developmental process. In addition, frataxin knockout mice die during embryonic life, further suggesting that frataxin is necessary for normal development. In this study we examine the role of frataxin in neuronal differentiation by using the P19 embryonic carcinoma cell line as a model system. We produced stably transfected clones with antisense or sense frataxin constructs. During retinoic acid-induced neurogenesis of frataxin-deficient cells there was a striking rise in cell death, while cell division remained unaffected. However, frataxin deficiency does not affect cell survival in cells induced to differentiate into cardiomyocytes. Frataxin deficiency enhances apoptosis of retinoic acid-stimulated cells, and the number of neuronal-like cells expressing MAP2 was dramatically reduced in these clones. In addition, we found that antisense clones induced to differentiate into neuroectoderm with retinoic acid have increased production of reactive oxygen species, and that only cells non-committed to the neuronal lineages could be rescued by the addition of the antioxidant N-acetyl-cysteine (NAC). However, NAC treatment had no effect in increasing the number of terminally differentiated neuronal-like cells in frataxin-deficient clones. Our results suggest that frataxin deficiency may render cells susceptible to apoptosis after exposure to appropriate stimuli.

Changes in pattern of immunoglobulin heavy chain gene rearrangement and MIB-1 staining before and after eradication of Helicobacter pylori in gastric mucosa-associated lymphoid tissue (MALT) lymphoma

Gastric low-grade mucosa-associated lymphoid tissue (MALT) lymphomas are strongly associated with infection by Helicobacter pylori (H. pylori). Antibiotic treatment for H. pylori induces a sustained remission in a significant number of patients. We report here the outcome in 13 patients with gastric low-grade MALT lymphomas or suspected gastric lesions, treated for eradication of H. pylori. Patients were followed closely with sequential histological studies, polymerase chain reaction (PCR) amplification of the immunoglobulin heavy chain (IgH) gene and immunohistochemistry for MIB-1. Antibiotic therapy resulted in eradication of H. pylori in all but one case, as assessed histologically. In 12 cases with successful eradication, complete regression was observed histologically in 9 cases (75%) and no regression in 3 (25%). In 7 of 9 (78%) patients who had a complete remission, clonal bands of IgH gene detected on PCR before therapy disappeared after therapy. All 9 patients with complete regression showed a reduced number of MIB-1 positive cells, while 4 cases with no change or disease progression showed no change or increased number of MIB-1 positive cells. There was a strong relationship between density of MIB-1-positive cells and histological score. These results indicate that combination analysis of PCR of IgH and MIB-1 seems to represent a very good current approach for the diagnosis of gastric low-grade MALT lymphoma and to assess the effects of chemotherapy, especially in problematic cases.

Evidence for local immunosuppression and demonstration of c-myc amplification in pyothorax-associated lymphoma

AIMS

Pyothorax-associated lymphoma (PAL) develops in the pleural cavity of patients with a long history of pyothorax. Epstein-Barr virus (EBV) is also involved in PAL, similar to lymphomas in immunodeficient patients. Here we examined T-lymphocyte subsets as well as c-myc and REL gene amplification in PAL tissues.

METHODS AND RESULTS

We determined the number and distribution of CD4+ and CD8+ T-lymphocytes, to evaluate T-cells in the host immune reaction in seven cases of PAL. As controls, we also studied 10 cases of extranodal diffuse large B-cell lymphoma (DLBL) and 10 cases of nodal DLBL. Chromosomal imbalances in PAL were determined by using comparative genomic hybridization (CGH) analysis. The mean numbers of CD4+ and CD8+ and their ratio were significantly lower in PAL than in nodal DLBL. CGH analysis of PAL showed amplification of the 8q24 chromosomal region. In addition, c-myc amplification was found in four cases of PAL by Southern blot analysis.

CONCLUSIONS

Our results suggest that the development of PAL may involve a local immunosuppressive environment and that amplification of c-myc might promote tumour progression, as has been described in the development of Burkitt's lymphoma.

Bcl10 expression, rearrangement and mutation in MALT lymphoma: correlation with expression of nuclear factor-kappaB

Mucosa-associated lymphoid tissue (MALT) lymphomas usually involve extranodal sites, especially the stomach, lung and salivary glands. The Bcl10 gene was recently isolated from the breakpoint region of t(1;14) (p22;q32) in MALT lymphomas, and considered to be an apoptosis-associated gene, and involves a caspase recruitment domain (CARD)-containing protein that activates NF-kappaB. We investigated the role of Bcl10 in MALT lymphoma by analyzing its expression, rearrangement and somatic mutation, by immunostaining, reverse transcriptase-polymerase chain reaction (RT-PCR), Southern blot and PCR in 20 cases of MALT lymphoma. Expression of NF-kappaB was studied by immunostaining. Five cases of reactive lymphadenitis (RLA) were used as the control. Bcl10 rearrangement was detected in 8 of 20 (40%) MALT lymphomas, but in none of RLA. Significant Bcl10 mutation was detected only in 1 case (5%) with MALT, but not in RLA. RT-PCR showed higher density bands of Bcl10 in MALT lymphomas than in RLA. Immunostaining showed a weak Bcl10 expression in the germinal center and very weak expression in the marginal zone B-cells in RLA, which was limited to the cytoplasm. In contrast, Bcl10 was strongly expressed in MALT lymphomas, and was mainly detected in the cytoplasm, as well as in the nuclei. Bcl10 expression did not correlate with Bcl10 mutation and re-arrangements. NF-kappaB was expressed in nuclei of MALT lymphoma cells, but not in RLA. Bcl10 expression in MALT lymphoma correlated closely with NF-kappaB expression. Our results suggest that activation of Bcl10 and NF-kappaB may be important in MALT lymphomagenesis, and that nuclear localization of Bcl10 may be important in the progression of MALT.

Interleukin-18 in human milk

We analyzed IL-18 levels of human milk. Colostrum contained significantly higher levels of IL-18 compared with early milk and mature milk. By stepwise multiple linear regression analysis, preterm delivery and pregnancy complications of mothers significantly correlated with high levels of IL-18 in human milk (p = 0.0007 and 0.0018, respectively). There was a significant correlation between the levels of IL-18 and soluble Fas ligand in colostrum (p = 0.0003). IL-18 was detected in actively secreting epithelial cells in lactating mammary gland by immunohistochemical staining. These results suggest that IL-18 in colostrum plays an important role in host defense of high-risk neonates.

Long-term ingestion of a fermented soybean-derived Touchi-extract with alpha-glucosidase inhibitory activity is safe and effective in humans with borderline and mild type-2 diabetes

Water-extracted Touchi, a traditional Chinese food, exerts a strong inhibitory activity against rat intestinal alpha-glucosidase in foodstuffs, and Touchi-extract (TE) has been shown to have an antihyperglycemic effect in rats and humans after a single oral administration. In the present complementary study, the effects of powdered Houji-tea with or without (placebo) TE, a formula designed to enhance good compliance, were monitored in a 3-mo double-blind randomized group comparison study with placebo controls in humans with borderline and mild type-2 diabetes (n = 36). All subjects ingested Houji-tea with or without 0.3 g of TE before each of three meals per day for 3 mo. In the TE group, initial fasting blood glucose (6.9 +/- 0.1 mmol/L) and glycated hemoglobin (HbA(1c); 6.1 +/- 0.1%) levels gradually decreased; fasting blood glucose decreased significantly after 3 mo (6.4 +/- 0.3 mmol/L; P < 0.05) as did HbA(1c) (5.6 +/- 0.2%; P < 0.01) levels at 2 mo postingestion of TE and thereafter. In contrast, fasting blood glucose and HbA(1c) levels did not change in the placebo group. In this study, other biochemical variables were not affected in any of the subjects, and no one complained of any side effects or abdominal distension. Moreover, there was no deterioration as assessed by fasting blood glucose and HbA(1c) levels after withdrawal of TE ingestion. Thus, the alpha-glucosidase inhibitory TE demonstrated an antihyperglycemic effect and may prove useful for improving glycemic control in subjects suffering from borderline and type-2 diabetes mellitus.

CD10 and Bcl10 expression in diffuse large B-cell lymphoma: CD10 is a marker of improved prognosis

AIMS

Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphoma, is clinically and pathologically heterogeneous. The Bcl10 gene was recently isolated from the breakpoint region of t(1;14)(p22;q32) in mucosa-associated lymphoid tissue (MALT) lymphomas, and is considered to be an apoptosis-associated gene. CD10 is considered to be a marker of follicular centre B-cell differentiation. To assess the clinical significance and roles of CD10 and Bcl10 in DLBCL, we analysed 138 cases, using immunohistochemical methods.

METHODS AND RESULTS

CD10 expression was limited to the cytoplasm, whereas Bcl10 expression was detected in the cytoplasm and/or nuclei. CD10 expression was detected in 39 of 138 cases (28.2%), cytoplasmic Bcl10 in 68 cases (49.2%), and nuclear Bcl10 in 34 cases (24.6%). Nuclear Bcl10 was detected in 14 of 28 cases (50%) of extranodal DLBCL, but only 20 of 110 cases (18.2%) of nodal DLBCL. Cytoplasmic Bcl10 was detected in 19 of 28 cases (67.8%) of extranodal DLBCL and 49 of 110 cases (44.5%) of nodal DLBCL. CD10 expression closely correlated with improved survival (68% overall survival (OS) vs. 48% OS), but not with site of disease. A high International Prognostic Index (IPI) was considered to be a poor prognostic factor associated with a shorter OS. CD10 expression was detected in 27 of 84 cases (32.1%) with low-risk IPIs, and in 12 of 54 cases (22.2%) with high-risk IPIs. In the low-risk group, cases expressing CD10 carried a better prognosis than CD10- cases (93% OS vs. 71% OS), whereas this was not the case in the high-risk group (25% vs. 20%).

CONCLUSIONS

Bcl10 expression was associated with extranodal DLBCL, but not with prognosis. CD10 expression was closely associated with improved survival, but not with risk as predicted by IPI. Overall, our results suggest that CD10 expression may be useful, in combination with clinical parameters, for determining the prognosis of DLBCL.

Sticky DNA, a self-associated complex formed at long GAA*TTC repeats in intron 1 of the frataxin gene, inhibits transcription

Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by the expansion of GAA.TTC repeats in the first intron of the frataxin (X25) gene. FRDA patients carrying two expanded GAA.TTC repeats show very low levels of mature frataxin mRNA and protein. A novel type of unusual DNA structure, sticky DNA, was previously found in the expanded GAA.TTC repeats from FRDA patients. To evaluate the effect of sticky DNA on transcription, in vitro transcription studies of (GAA.TTC)(n) repeats (where n = 9-150) were carried out using T7 or SP6 RNA polymerase. When a gel-isolated sticky DNA template was transcribed, the amount of full-length RNA synthesized was significantly reduced compared with the transcription of the linear template. Surprisingly, transcriptional inhibition was observed not only for the sticky DNA template but also another DNA molecule used as an internal control in an orientation-independent manner. The molecular mechanism of transcriptional inhibition by sticky DNA was a sequestration of the RNA polymerases by direct binding to the complex DNA structure. Moreover, plasmids containing the (GAAGGA.TCCTTC)(65) repeat, which does not form sticky DNA, did not inhibit in vitro transcription, as expected. These results suggest that the role of sticky DNA in FRDA may be the sequestration of transcription factors.

[An elderly case of idiopathic dilatation of the right atrium in which right-sided heart failure was exacerbated by drug-induced bradyarrhythmia]

We describe an elderly case of idiopathic dilatation of the right atrium in which right-sided heart failure was exacerbated by drug-induced bradyarrhythmia. An 84-year-old man, who had a 10-year history of episodic edema, was treated with proscillaridin and verapamil hydrochloride at another hospital. He had experienced a poor appetite and general malaise 2 months previously, and exertional dyspnea 10 days previously. On admission, he had jugular venous dilatation, systemic edema, and hepatomegaly. On auscultation, a third heart sound originating from the right ventricle and systolic murmur of tricuspid regurgitation were heard. An admission electrocardiogram showed an atrial standstill and junctional escape rhythm with a QRS rate of 31 beats/minute. Chest roentgenogram revealed a bilateral pleural effusion and cardiomegaly with a cardiothoracic ratio of 76%, but no pulmonary congestion. Echocardiogram disclosed idiopathic dilatation of the right atrium and secondary tricuspid regurgitation. He was given a diagnosis of right-sided heart failure due to idiopathic dilatation of the right atrium exacerbated by bradyarrhythmia, which was suspected to derive from the side effects of proscillaridin and verapamil hydrochloride. Thus, these agents were withheld. In addition, the patient reduced sodium intake and was treated with diuretics and beta-adrenergic agonist. Thereafter, right-sided heart failure markedly improved. At the time of the last follow-up 16 months after discharge, he felt well.

Expression of human tumor-associated antigen RCAS1 in Reed-Sternberg cells in association with Epstein-Barr virus infection: a potential mechanism of immune evasion

RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is present in neoplastic cells, induces apoptosis of natural killer (NK)/T cells and plays a role in immune evasion. Fas ligand (FasL) is considered to have similar roles. The Epstein-Barr virus (EBV)-encoded latent membrane protein is expressed by malignant Hodgkin and Reed-Sternberg (H&RS) cells of EBV-associated Hodgkin's disease (HD) and considered to be a target of cytotoxic T lymphocytes (CTLs). However, CTL response is inadequate in HD. To determine whether RCAS1 and FasL are expressed in EBV-associated HD and participate in immune evasion, tissues of 20 EBV(-) and 15 EBV(+) HD cases were immunohistochemically stained for RCAS1, FasL and HLA classes I and II, whose deficiencies could explain CTL escape. Lymphocytes surrounding H&RS cells tended to be CD4(+) cells and rarely CD8(+), TIA-1(+) (cytotoxic marker) or NK cells. HLA class I and/or II were expressed in all EBV(+) HD cases, and RCAS1-expressing H&RS cells were found in 14/15 (93%) EBV(+) HD cases but only 8/20 (40%) EBV(-) HD cases (p < 0.05). FasL was detected in 9/15 (60%) and 7/20 (35%) EBV(+) and EBV(-) HD cases, respectively. ssDNA-positive (apoptotic) lymphocytes, surrounding H&RS cells, were rarely seen but were present in RCAS1(+) cases (20/22 cases, 91%) rather than negative cases (0/13 cases, 0%) (p < 0.005). Our findings suggest that EBV(+) H&RS cells might evade the host immune response by expressing RCAS1 rather than FasL.

Chromosome 16q deletion and loss of E-cadherin expression in Hodgkin and Reed-Sternberg cells

Hodgkin and Reed-Sternberg (H&RS) cells are generally considered to be the neoplastic cells of Hodgkin's disease (HD); however, such H&RS cells are a few in number due to the numerous reactive cells. Very few data have so far been published on the cytogenetic abnormalities in HD. We have previously used the analysis of comparative genomic hybridization (CGH), employing sorted H&RS cells. The most commonly observed genetic aberrations were a loss on 16q11/21, a gain on 1p13 and a gain on 7q35/36. To confirm the loss of 16q, we analyzed the loss of heterozygosity (LOH) using the regions D16S3075 (16p13), D16S3068 (16q11), D16S3136 (16q12), D16S503 (16q13), D16S515 (16q21), D16S3091 (16q23) and D16S520 (16q24). A total of 100 sorted H&RS cells were compared with a similar number of sorted reactive T cells in 15 cases with HD, including 5 cases with nodular sclerosis (NS) type and 10 cases with mixed cellularity (MC) type. LOHs of 16q, especially 16q21-23, were frequently detected, but 16p deletions were infrequent. Analysis of 16q21 showed LOH in 12 of 15 cases with HD (80%), including 9 cases with MC type (90%) and 3 cases with NS type (60%). 16q23 showed LOH in 9 of 15 cases with HD (60%), including 5 cases with MC type (50%) and 4 cases with NS (80%). On the other hand, 16p13 showed LOH in 3 of 15 cases with HD (20%). Immunohistochemical staining showed that H&RS cells rarely expressed E-cadherin, which is located on 16q. Our findings suggest that 16q deletion, especially 16q21-23, is probably involved in H&RS giant cell formation and tumorigenesis.

Cytogenetic analysis and clinical significance in adult T-cell leukemia/lymphoma: a study of 50 cases from the human T-cell leukemia virus type-1 endemic area, Nagasaki

Identification of cytogenetic abnormalities is an important clue for the elucidation of carcinogenesis. However, the cytogenetic and clinical significance of adult T-cell leukemia/lymphoma (ATLL) is still unclear. To address this point, cytogenetic findings in 50 cases of ATLL were correlated with clinical characteristics. Karyotypes showed a high degree of diversity and complexity. Aneuploidy and multiple breaks (at least 6) were observed frequently in acute and lymphoma subtypes of ATLL. Breakpoints tended to cluster at specific chromosomal regions, although characteristic cytogenetic subgroups of abnormalities were not found. Of these, aberrations of chromosomes 1p, 1q, 1q10-21, 10p, 10p13, 12q, 14q, and 14q32 correlated with one or more of the following clinical features: hepatosplenomegaly, elevated lactate dehydrogenase, hypercalcemia, and unusual immunophenotype, all indicators of clinical severity of ATLL. Multiple breaks (at least 6); abnormalities of chromosomes 1p, 1p22, 1q, 1q10-21, 2q, 3q, 3q10-12, 3q21, 14q, 14q32, and 17q; and partial loss of chromosomes 2q, 9p, 14p, 14q, and 17q regions correlated with shorter survival. These cytogenetic findings are relevant in predicting clinical outcome and provide useful information to identify chromosomal regions responsible for leukemogenesis. This study also indicates that one model of an oncogenic mechanism, activation of a proto-oncogene by translocation of a T-cell–receptor gene, may not be applicable to the main pathway of development of ATLL and that a multistep process of leukemogenesis is required for the development of ATLL.

Splenic lymphoproliferative disorders in human T lymphotropic virus type-I endemic area of japan: clinicopathological, immunohistochemical and genetic analysis of 27 cases

Primary splenic involvement in lymphoid neoplasms is rare and the clinicopathologic features of splenic lymphoma are not well described compared to nodal non-Hodgkin's lymphoma (NHL). Here we characterized splenic lymphomas in an human T lymphotropic virus type-I (HTLV-I) endemic area of Japan. To assess the pattern of splenic involvement and evaluate prognosis, we reviewed 27 specimens consisting of 26 splenectomies and one necropsy, which were classified using REAL classification. Cases were divided into primary splenic lymphoma in 11 patients and secondary in 16 patients. The incidence of primary splenic lymphoma was 0.3% (11 of approximately 4,000 malignant lymphomas). Primary splenic lymphomas included 7 diffuse large B cell lymphoma (DLBL), 2 follicular lymphomas (FL), and 1 each of splenic marginal zone lymphoma (SMZL) and anaplastic large cell lymphoma (ALCL). Secondary splenic lymphomas included 6 DLBL, 4 mantle cell lymphoma (MCL), 2 FL, 2 Hodgkin's disease (HD), 1 each of hairy cell leukemia and ALCL. Gross examination showed two patterns of splenic involvement; solid type (formation of large nodular mass, n=16) and disseminated type (multiple nodules with diffuse infiltration but no large nodular formation, n=10). The type could not be determined in one case. Most solid types were DLBL or FL, while MCL was of the disseminated type. Immunohistochemistry showed all but each 2 cases of ALCL and HD were of B lineage. Follow-up of 26 patients indicated that all but one patient with primary lymphoma were still alive (range, 1-89 months) and 8 of 15 patients with secondary lymphomas died due to the progression of malignant lymphoma; the survival rate at 2 years was 50% in these patients. No elevation of anti-HTLV-I antibody was found. In situ hybridization for Epstein-Barr virus (EBV) showed no reactivity of lymphoma cells, although a few small lymphocytes were positive for EBV. Hepatitis C virus was observed in 6 of 20 (30%) patients examined and 4 of 11 (36%) cases of primary splenic lymphoma. Our findings indicate that patients with primary splenic lymphoma have a favorable prognosis after splenectomy.

Possible immortalization of Hodgkin and Reed-Sternberg cells: telomerase expression, lengthening of telomere, and inhibition of apoptosis by NF-kappaB expression

Telomerase, an enzyme associated with cellular immortality, is expressed on malignant tumor cells. Deregulation of telomerase is thought to facilitate tumorigenesis and cellular immortality by providing cancer cells with unlimited proliferation capacity. Hodgkin and Reed-Sternberg (H&RS) cells are generally considered as neoplastic cells in Hodgkin's disease (HD), however, such cells are only found in a minority of HD lesions. In addition, H&RS cells with mitotic features are rare and mummified forms are occasionally encountered. There are no available data on the relationship between telomerase activity and apoptosis in HD. We studied 14 cases with Hodgkin's disease (mixed cellularity type, nine cases; nodular sclerosis type, five cases) to clarify the relationship between telomerase activity and apoptosis using in situ hybridization of human telomerase reverse transcriptase (hTERT), reverse transcriptase-polymerase chain reaction (RT-PCR) of hTERT, using extracted RNA and immunohistochemistry of nuclear factor-?B (NF-?B), and TdT-mediated dUTP-digoxigenin nick end-labeling (TUNEL) technique for apoptosis. We also analyzed the telomere length, using sorted H&RS cells. TUNEL showed a few apoptotic H&RS cells, but the cells frequently expressed hTERT, as confirmed by ISH and RT-PCR. Lengthening of the telomere of H&RS cells was noted in ten cases. In addition, H&RS cells frequently expressed NF-?B, which is known as an inducible transcription factor and inhibitor of apoptosis. Our findings of telomerase activity in H&RS cells indicate that these cells are neoplastic and are potentially immortal. In addition, NF-?B expression on H&RS cells suggests its possibility in inhibition of apoptosis of these cells.

Interleukin-13 and interleukin-13 receptor in Hodgkin's disease: possible autocrine mechanism and involvement in fibrosis

AIMS

Hodgkin's disease (HD) is characterized by the presence of Hodgkin and Reed-Sternberg (H-RS) cells against a hyperplastic background of reactive cells such as lymphocytes, histiocytes, plasma cells, eosinophils, neutrophils, and stromal cells. There is ample evidence to suggest that proliferation and survival of HD-derived cells is due to cytokine signalling. Recently, high expression of interleukin (IL)-13 was described in HD-derived cell lines. Here we investigated the possible involvement of IL-13 in the pathophysiology, especially autocrine pathways of H-RS cells.

METHODS AND RESULTS

The expression of IL-13 and IL-13 receptor (IL-13R) was determined by immunostaining and reverse transcriptase-polymerase chain reaction in 39 cases of HD, including 17 cases with nodular sclerosis (NS) type, 19 cases with mixed cellularity (MC), and three cases with lymphocyte predominance (LP) type. Expression of IL-13 was confined to H-RS cells and a few lymphocytes. IL-13R was expressed in H-RS cells, lymphocytes, histiocytes, fibroblasts, and endothelial cells. H-RS cells of MC and NS types frequently expressed both IL-13 and IL-13R. However, the number of IL-13-positive H-RS cells was statistically higher in NS-type than in MC-type, but the number of IL-13R was similar. IL-13R-positive fibroblasts were frequently encountered in NS-type. H-RS cells of LP type rarely expressed IL-13.

CONCLUSIONS

Our results suggest that IL-13 might be involved in autocrine pathways of H-RS cells and fibrosis at least in NS-type. Our results also indicated that in addition to the morphological and phenotypic differences, the neoplastic cells of LP type might be functionally different from H-RS cells of MC- and NS-types.

Expression of nuclear factor-kappa B, tumor necrosis factor receptor type 1, and c-Myc in human astrocytomas

Tumor necrosis factor receptor type 1 (TNFR1) and c-Myc are important in signal transduction in tumor necrosis factor-alpha (TNF-alpha)-induced cytotoxicity, whereas activation of nuclear factor-kappa B (NF-kappa B) protects against TNF-alpha-induced apoptosis. This study investigated the expression of NF-kappa B, TNFR1, and c-Myc in human astrocytoma tissues by reverse transcriptase-polymerase chain reaction (PCR) and immunohistochemical analysis. TNFR1 messenger ribonucleic acid (mRNA) and c-Myc mRNA were frequently expressed in malignant astrocytomas, especially in glioblastomas, compared with low-grade astrocytomas by PCR analysis. TNFR1 and c-Myc mRNAs were barely detectable in normal brain tissues. NF-kappa B p50 and p65 subunit mRNAs were detected in various grades of astrocytomas, with frequent expression in malignant astrocytomas. The presence of activated NF-kappa B was confirmed by nuclear localization in neoplastic astrocytes as determined by immunohistochemistry. Both p50 and p65 subunits were inhomogeneously expressed in neoplastic astrocytes of glioblastoma, but only in a few scattered tumor cells in low-grade astrocytoma, and almost undetectable in normal brain tissues. These results indicate that TNFR1 and c-Myc are overexpressed in malignant astrocytomas, and this may increase the cellular sensitivity to the cytotoxic action of TNF-alpha. NF-kappa B p50 and p65 were simultaneously induced and activated in malignant astrocytomas. Our results suggest that the constitutive activation of NF-kappa B subunits in malignant astrocytoma, especially in glioblastoma, could be associated with the resistance to TNF-alpha immunotherapy, and indicates new therapeutic strategies for malignant astrocytomas.

Fermented soybean-derived water-soluble Touchi extract inhibits alpha-glucosidase and is antiglycemic in rats and humans after single oral treatments

A water-soluble extract of Touchi, a traditional Chinese food, was found to exert a strong inhibitory activity against rat intestinal alpha-glucosidase. We orally administered sucrose (2 g/kg) with or without Touchi extract (TE) to normal rats at 100 and 500 mg/kg. Postprandial increases in blood glucose levels at 30 and 60 min after the administration of TE were significantly depressed compared with controls. In humans, eight borderline diabetic subjects were administered 0.1-10.0 g TE before sucrose loading (75 g). TE decreased the glycemic response dose dependently after sucrose loading. Compared with the area under the curve of the postprandial rise in blood glucose with various doses, TE elicited a significant antiglycemic effect at a minimum effective dose of 0.3 g. In addition, when four diabetics were administered 0.3 g TE before eating 200 g of cooked rice, the postprandial increases in blood glucose and mean insulin levels were significantly depressed at 60 and 120 min, respectively, after ingestion compared with levels when no TE was administered. TE, which exhibits alpha-glucosidase inhibitory activity, demonstrated an antihyperglycemic effect and may have potential use in the management of patients with non-insulin-dependent diabetic mellitus.

Nasal CD56 positive small round cell tumors. Differential diagnosis of hematological, neurogenic, and myogenic neoplasms

CD56-positive nasal and nasal-type natural killer (NK)/T-cell lymphoma is now a well-defined disease entity. Rare cases of blastic NK-cell lymphoma positive for CD56 have been recently reported. However, CD56 expression is also identified in several types of non-hematopoietic small round cell tumors in which lymphoma is included as a differential consideration. Here, we present nine cases of CD56+ small round cell tumors of histological origin unrelated to nasal NK/T-cell lymphoma. Eight of the nine cases presented as solid tumors of the sinonasal region. Clinical, histological, ultrastructural, and immunohistochemical examination and gene analysis for T-cell receptor (TcR) and immunoglobulin heavy chain (IgH) genes and in situ hybridization (ISH) for Epstein-Barr virus (EBV) were performed. Two cases presented with features consistent with blastic NK-cell lymphoma or lymphoblastic lymphoma of NK-cell phenotype. These cases showed features of lymphoblastic lymphoma, phenotypes of sCD3-, cCD3+, CD45+, CD56+, TdT+, and human leukocyte antigen (HLA)-DR+, germline of IgH and TcR genes, and EBV negative reactivity. One case had myeloid/NK-precursor acute leukemia/lymphoma with a phenotype of CD13+, CD33+, CD34+, CD56+, and MPO-. Three cases were neurogenic, including one case of olfactory neuroblastoma and two of primitive neuroectodermal tumors (PNET). It was difficult to differentiate CD56+ PNET from blastic NK-cell lymphoma, especially when only paraffin-embedded sections were available. Myogenic markers, such as HHF35, alpha-sarcomeric actin, and desmin, were positive in three cases of rhabdomyosarcomas. Our findings suggest that as CD56 is used more routinely as a marker in immunohistochemical staining, the differential diagnosis of extranodal lymphohematological malignancies and small round cell tumors will become more complicated.

High expression of MDR-1 gene and P-glycoprotein in initial and re-biopsy specimens of relapsed B-cell lymphoma

AIMS

Multidrug resistance (MDR) is a major obstacle in the treatment of lymphoma. The expression of MDR-1 mRNA and P-glycoprotein (MDR-1/P-gp) has been linked to MDR. We aimed to investigate the expression of MDR-1/P-gp in B-cell lymphoma.

METHODS AND RESULTS

Samples at diagnosis and relapse from 10 patients with B-cell lymphoma were obtained. We also obtained 14 unselected control cases of B-cell lymphoma at diagnosis. The expression of mRNA and protein were determined semiquantitatively by RT-PCR and immunohistochemistry. High MDR-1 and P-gp expressions were found in seven and seven of 10 samples obtained at diagnosis, eight and eight of 10 samples obtained at relapse, and three and four of 14 control cases at diagnosis, respectively. The results of RT-PCR paralleled those of immunohistochemistry. Concordance of high MDR-1/P-gp expression was noted in 27 of 34 samples (r = 0.73, P = 0.001). There were no significant changes in MDR-1/P-gp expression in all cases at relapse and during the clinical course following chemotherapy. In the 14 control cases, the average survival time was 12.7 months in MDR-1/P-gp positive cases and 29.0 months in the MDR-1/P-gp negative cases (P = 0.20).

CONCLUSIONS

Our results showed that at least some B-cell lymphomas express MDR-1/P-gp, which could be detected by different methods, and suggested that high MDR-1/P-gp expression in tumour cells may be associated with a high probability of relapse and poor prognosis.

Expression of RCAS1 and FasL in human trophoblasts and uterine glands during pregnancy: the possible role in immune privilege

Pregnancy is an immunological balancing act. Trophoblasts do not express MHC class I or II, except HLA-C and G, but express Fas ligand (FasL), which confers immune privilege. RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) has recently been recognized to play a role in immune evasion of the tumour cells. We therefore studied the involvement of RCAS1 and FasL in the infiltration of NK cells by examining the curettaged uterine contents of 20 cases of early stage of pregnancy. The cases were clinically divided into two groups; curettage was performed (A) due to the absence of foetal heart beats, and (B) due to spontaneous uterine bleeding and abortion. In group A, RCAS1 was expressed in the uterine glands and extravillous cytotrophoblasts, as was FasL. Infiltration of NK cells around the uterine glands was scarcely detected. In contrast, in group B, expression of both RCAS1 and FasL was strikingly decreased in both the level of expression and the numbers of RCAS1/FasL-positive cells and massive infiltration of NK cells was frequently detected around the uterine glands. These findings suggest that a reduction in RCAS1 and FasL expression seems to be closely associated with activation and infiltration of maternal NK cells and destruction of uterine glands, resulting in rejection of the foetus. Thus, expression of RCAS1 and FasL in the uterine glands and cytotrophoblasts may play a role in the downregulation of the maternal immune response, thereby maintaining pregnancy at early stage.

Antinociceptive effect produced by intracerebroventricularly administered dynorphin A is potentiated by p-hydroxymercuribenzoate or phosphoramidon in the mouse formalin test

The antinociceptive effects of intracerebroventricularly (i.c.v.) administered dynorphin A, an endogenous agonist for kappa-opioid receptors, in combination with various protease inhibitors were examined using the mouse formalin test in order to clarify the nature of the proteases involved in the degradation of dynorphin A in the mouse brain. When administered i.c.v. 15 min before the injection of 2% formalin solution into the dorsal surface of a hindpaw, 1-4 nmol dynorphin A produced a dose-dependent reduction of the nociceptive behavioral response consisting of licking and biting of the injected paw during both the first (0-5 min) and second (10-30 min) phases. When co-administered with p-hydroxymercuribenzoate (PHMB), a cysteine protease inhibitor, dynorphin A at the subthreshold dose of 0.5 nmol significantly produced an antinociceptive effect during the second phase. This effect was significantly antagonized by nor-binaltorphimine, a selective kappa-opioid receptor antagonist, but not by naltrindole, a selective delta-opioid receptor antagonist. At the same dose of 0.5 nmol, dynorphin A in combination with phosphoramidon, an endopeptidase 24.11 inhibitor, produced a significant antinociceptive effect during both phases. The antinociceptive effect was significantly antagonized by naltrindole, but not by nor-binaltorphimine. Phenylmethanesulfonyl fluoride (PMSF), a serine protease inhibitor, bestatin, a general aminopeptidase inhibitor, and captopril, an angiotensin-converting enzyme inhibitor, were all inactive. The degradation of dynorphin A by mouse brain extracts in vitro was significantly inhibited only by the cysteine protease inhibitors PHMB and N-ethylmaleimide, but not by PMSF, phosphoramidon, bestatin or captopril. The present results indicate that cysteine proteases as well as endopeptidase 24.11 are involved in two steps in the degradation of dynorphin A in the mouse brain, and that phosphoramidon inhibits the degradation of intermediary delta-opioid receptor active fragments enkephalins which are formed from dynorphin A.

Retrovirus insertion and transcriptional activation of the multidrug-resistance gene in leukemias treated by a chemotherapeutic agent in vivo

To understand the molecular basis for multidrug-resistant (MDR) cancer cells in vivo, this study analyzed molecular changes of the mdr1a gene region in leukemia cells in mice during continuous treatment with vincristine. An inverse insertion of murine leukemia retrovirus (MuLV) into the 5'-flanking region of the mdr1a gene was found. This insertion was concomitantly accompanied by up-regulation of the mdr1a gene and the loss of chemosensitivity. Deletion of long-terminal repeat (LTR) sequences dramatically decreased the mdr1a promoter-driven reporter activity. The MuLV LTR insertion appears to exert its enhancer activity on mdr1a transcription during the appearance of MDR leukemia cells. Two mechanisms were postulated to explain the mdr1a gene activation by retrovirus insertion during in vivo chemotreatment: de novo insertion of MuLV induced by vincristine treatment and selection of a small fraction of pre-existing cells carrying MuLV insertion during vincristine treatment. No rearranged sequence was detected by polymerase chain reaction in parental cells. This result argued for the first mechanism. The randomly altered distribution of MuLV during repetitive chemotreatment might also be consistent with this hypothesis. On the other hand, the retrovirus insertion was detected at the same site of the mdr1a promoter region in 2 independent experiments, which suggests the second mechanism. It should be noted that in vivo chemotreatment using vincristine could generate the mdr1a-overexpressing cells through retrovirus insertion and the enhancer effect of the LTR.

Localization of human interleukin 13 receptor in non-haematopoietic cells

Although the functional roles of interleukin (IL-)13 in haematopoietic cells are well investigated, those in non-haematopoietic cells remain to be addressed. IL-13 exerts its actions by binding to the IL-13 receptor (IL-13R) on target cells, which is composed of IL-13Ralpha1 and the IL-4 receptor alpha chain (IL-4Ralpha). However, there has been no study of localization of IL-13R in each tissue. To address this question, we generated monoclonal anti-IL-13Ralpha1 antibody, and performed immunohistochemistry using this antibody and anti-IL-4Ralpha antibody. Distribution of these two components was the same in all examined tissues. Staining was positive in keratinocytes, hair follicles, and sebaceous and sweat glands in skin; in ciliated respiratory epithelial cells in nasal tissue; in heart muscle cells; in foveola cells, gastric glands, and the smooth muscle layer in stomach; and in hepatocytes in liver. However, staining was undetectable in brain and bone marrow. Fibroblasts and endothelial cells were stained in some tissues. These results provide clues to elucidate the known pathological roles of IL-13 in atopic dermatitis and allergic rhinitis, as well as its unknown physiological roles.

Expression of nuclear factor kappaB and tumor necrosis factor alpha in the mouse brain after experimental thermal ablation injury

OBJECTIVE

Nuclear factor kappa B (NFkappaB) participates in the regulation of a diverse range of genes involved in inflammation and acute phase responses. We investigated the expression of the activated form of NFkappaB and tumor necrosis factor alpha (TNFalpha), an inflammatory cytokine, in experimental brain injury.

METHODS

We generated focal brain injury in mice using radiofrequency thermal ablation at the caudate putamen in mice. Intracerebral expression of TNFalpha and the p50 and p65 subunits of NFkappaB were studied using immunohistochemistry at 1, 4, and 8 hours and at 1, 2, 4, 8, 14, and 28 days postinjury.

RESULTS

Coagulative necrosis approximately 2 mm in diameter was produced at the site of injury. No immunoreactivity for TNFalpha, NFkappaB p50, or NFkappaB p65 was detected in the injured area in the early phase postinjury. On posttrauma Day 2, however, weak expression of TNFalpha, NFkappaB p50, and NFkappaB p65 was detected in mononuclear cells that infiltrated edematous tissue surrounding the lesion. On posttrauma Days 4 to 8, the expression of TNFalpha, NFkappaB p50, and NFkappaB p65 was prominently increased in infiltrating and proliferating mononuclear cells (macrophages and microglia) and in proliferating reactive astrocytes surrounding the lesion. Nuclear subcellular localization of the expression of NFkappaB p50 and p65 was observed, which indicated that these subunits might be activated in these cells. On posttrauma Day 14, the expression of TNFalpha, NFkappaB p50, and NFkappaB p65 decreased and was limited to mononuclear cells, and it finally disappeared on Day 28. The temporal profiles of TNFalpha, NFkappaB p50, and NFkappaB p65 were closely associated with the occurrence of secondary insults and the tissue-remodeling process in wound healing.

CONCLUSION

These results suggest that TNFalpha, NFkappaB p50, and NFkappaB p65 may play a central role in the injury-induced immune response that leads to secondary insults or wound healing after brain injury. Inappropriate and deregulated activation of NFkappaB in injured brain tissue may be implicated in the development of secondary brain damage.