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Biomedical subjects

Masaaki Higashihara

Publications and source records attributed to Masaaki Higashihara.

At least 37 records · Page 2Linked to original sources

Hodgkin's lymphoma and CD30 signal transduction.

Advances in molecular biology have shed light on the biological basis of Hodgkin's lymphoma (HL). Knowledge of the biological basis has enabled us to understand that most Hodgkin and Reed-Sternberg (H-RS) cells are derived from germinal center B-cells and constitutive nuclear factor kappaB (NF-kappaB) activation is a common molecular feature. Molecular mechanisms responsible for constitutive NF-kappaB activation, Epstein Barr virus latent membrane protein 1, and defective IkappaBalpha and IkappaB kinase activation have been clarified in the past several years. A recent study revealed the biological link between 2 characteristic features of H-RS cells: CD30 overexpression and constitutive NF-kappaB activation. Ligand-independent signaling by overexpressed CD3O was shown to be a common mechanism that induced constitutive NF-kappaB activation in these cells. These results suggest the self-growth-promoting potential of H-RS cells and redefine the biology of HL composed of H-RS cells and lymphocytes.

Hodgkin Disease↗

AP-1 mediated relief of repressive activity of the CD30 promoter microsatellite in Hodgkin and Reed-Sternberg cells.

Overexpression of CD30 is the hallmark of Hodgkin and Reed-Sternberg (H-RS) cells and drives constitutive nuclear factor-kappaB activation that is the molecular basis for the pathophysiology of Hodgkin's lymphoma. Transcription of the CD30 gene is controlled by the core promoter that is driven by Sp-1 and the microsatellite sequences (MSs) that represses core promoter activity. To understand the mechanism(s) of CD30 overexpression in H-RS cells, we structurally and functionally characterized the CD30 MSs. Although the CD30 MS of H-RS cell lines was polymorphic, it was not truncated compared with that of control cells. A strong core promoter activity and constitutive Sp-1 binding were revealed in all cell lines examined irrespective of the levels of CD30 expression. In transient reporter gene assays, all MS clones derived from H-RS cell lines repressed the core promoter activity in unrelated cell lines, but not in the H-RS cell lines. An AP-1-binding site was found in the MS at nucleotide position of -377 to -371, the presence of which was found to relieve repression of the core promoter in H-RS cell lines but not in other tumor cell lines. H-RS cell lines showed constitutive and strong AP-1-binding activity, but other cell lines did not. The AP-1 complex contained JunB, whose overexpression activated reporter constructs driven by the CD30 promoter including the MSs, and was dependent on the AP-1 site. JunB expression was detected in H-RS cells in vitro and in vivo, but not in reactive cells or tumor cells of non-Hodgkin's lymphoma of diffuse large B-cell type. Transduction of JunB small interfering RNAs suppressed CD30 promoter activity in L428 cells but not in control cells. Taken together, overexpression and binding of JunB to the AP-1 site appear to relieve the repression of the core promoter by the CD30 MS in H-RS cells, which provide one basis for the constitutive overexpression of CD30 in Hodgkin's lymphoma.

Binding Sites↗

Expression of nm23-H1 is associated with poor prognosis in peripheral T-cell lymphoma.

We have reported previously that the serum nm23-H1 level is a prognostic factor for non-Hodgkin's lymphoma. In this study, we examined nm23-H1 expression in T- and natural killer (NK)-cell lymphoma in order to evaluate whether lymphoma cells produce the protein. The clinical significance of the cytotoxic molecules, T-cell intracellular antigen-1 (TIA-1) and granzyme B and nm23-H1 expression were also examined. Expression of nm23-H1, TIA-1, or granzyme B was examined by immunohistochemistry in 137 previously untreated lymphoma patients. The relationship between the results and clinical outcome was examined in 81 patients with angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphoma, or peripheral T-cell lymphoma, unspecified. The neoplastic cells of some lymphomas produced nm23-H1 and the expression rates of nm-23-H1, TIA-1 and granzyme B were 36.5%, 78.8% and 32.8% respectively. The nm23-H1-positive or TIA-1-positive groups had significantly shorter overall and disease-free survivals. Multivariate analysis confirmed nm23-H1 expression to be an independent prognostic factor. The nm23-H1 protein can be an important prognostic factor in the lymphomas studied here. New treatments that target nm23 overexpression could be developed as a result of nm23-HI production by lymphoma cells.

Adult↗

[Successful treatment of MRSA-associated glomerulonephritis with antibiotic therapy].

We report a case of methicillin-resistant Staphylococcus aureus (MRSA)-associated glomerulonephritis treated with antibiotic therapy. A 67-year-old man was admitted to our hospital because of proteinuria, hematuria, purpura, and high fever one month after a graft replacement of an abdominal aortic aneurysm. MRSA was detected in specimens of his blood, sputum, and joint fluid. Before his operation, he had shown no renal abnormalities. He presented with a rapid deterioration of renal function following MRSA infection. Maximum level of proteinuria was 1.5 g/day, serum creatinine (Cr) was 3.5 mg/dl, and blood urea nitrogen was 57 mg/dl. Renal biopsy revealed necrotizing crescentic glomerulonephritis. Immunofluorescence examination showed IgA and C3 deposits. Clinical and pathological examinations showed the typical features of MRSA-associated glomerulonephritis. Vancomycin and fosfomycin were administered intravenously. The serum level of C-reactive protein fell from 22.0 mg/dl to 0.1 mg/dl. Proteinuria also decreased and the patient's renal function improved in parallel with the decreased activity of MRSA infection. After three months of antibiotic treatment, proteinuria was negative and the level of serum Cr had dropped to 0.9 mg/dl. These findings suggest that antibiotic treatment can lead to complete remission of MRSA-associated glomerulonephritis.

Aged↗

[Outline of treatment--strategy of initial therapy].

Immune thrombocytopenic purpura(ITP) is an autoimmune disorder characterized by a low platelet count and mucocutaneous bleeding. ITP is classified as acute or chronic ITP. In acute ITP, more than 70 percent of affected patients resolves within six months, irrespective of whether they receive therapy. By contrast, in chronic ITP, they receive the initial therapy including corticosteroids, followed by splenectomy when corticosteroid therapy is proved to be ineffective. Long-term remission is observed in 5-30% patients with corticosteroid therapy. Splenectomy produces remissions in 50-70% of patients evaluated 6-12 months after operation. Chronic refractory ITP, they receive immunosuppresants or a number of different treatment regimens. No single treatment algorysm is suitable for all patients.

Adrenal Cortex Hormones↗

[Successful radiotherapy for the thoracic cord infiltration of adult T-cell leukemia/lymphoma].

A-51-year-old woman with a sixteen-year history of mixed connective tissue disease was admitted to the Kitasato University Hospital because of hypogastric pain in September 1999. Colonofiberscopy and computed tomography in the abdomen demonstrated thickening of the intestinal wall with a hemorrhagic ulcer in the terminal ileum. The histopathologic findings of the lesion revealed diffuse infiltration of atypical T-lymphocytes. The titers of anti-HTLV-I antibody and serum soluble IL-2 receptor were elevated. The diagnosis of adult T-cell leukemia/lymphoma (ATLL) infiltrating the terminal ileum was made. Combination chemotherapy including VEPA-M was undertaken, and resulted in a partial response. ATLL became refractory about June 2000. Flaccid paralysis, dysesthesia in the left lower limb and bladder-bowel disturbance emerged in a few days, July 2000. T2-weighed MRCT images demonstrated that a lesion with a high intensity signal was present in the spinal cord around Th 7. Flower-like cells were detected in the cerebrospinal fluid. Infiltration of ATLL into the thoracic cord was diagnosed. Administration of intrathecal methotrexate and prednisolone, systemic dexamethasone and local irradiation of 30 Gy improved the paralysis and the abnormal MRCT findings. Rehabilitation restored the patient's ability to walk.

Antineoplastic Combined Chemotherapy Protocols↗

Ovarian follicular lymphoma: a case report and review of the literature.

Primary ovarian lymphoma is extremely rare, and such a case is reported here. The patient was a 54-year-old Japanese female with abnormal genital bleeding. Pelvic CT and MRI showed a right ovarian tumor with a diameter of 7 cm and an irregular border. With the diagnosis of a right ovarian tumor, the patient underwent a simple hysterectomy and bilateral salpingo-oophorectomy. Microscopic examination of the right ovarian tumor revealed vaguely nodular growth of small lymphoid cells. They were CD10+, Bcl-2+, Cyclin D1- and CD21-, although CD21+ follicular dendritic cell clusters were present as a background component in each vague nodule. A conventional cytogenetic analysis revealed t(14;18)(q32;q21), and somatic hypermutation of the variable region of the immunoglobulin heavy chain gene (IgH) was confirmed by direct sequencing of subcloned DNA samples derived from PCR amplicons. These findings led us to characterize the lesion as follicular lymphoma, grade 1. The patient was free of detectable disease 9 months after initiation of post-surgical chemotherapy. Since the prognosis for primary ovarian lymphoma is relatively favorable in many cases, it is important to establish therapeutic methods for the cure of this disease using chemotherapy and radiotherapy without radical surgery.

Antineoplastic Combined Chemotherapy Protocols↗

Ligand-independent signaling by overexpressed CD30 drives NF-kappaB activation in Hodgkin-Reed-Sternberg cells.

Overexpression of CD30 and constitutive NF-kappaB activation characterizes tumor cells of Hodgkin's disease (HD), Hodgkin and Reed-Sternberg (H-RS) cells. We report that in H-RS cells overexpression of CD30 leads to self-aggregation, recruitment of TRAF2 and TRAF5, and NF-kappaB activation, independent of CD30 ligand. CD30 and TRAF proteins co-localized in H-RS cell lines and in lymph nodes of HD. An adenovirus-vector carrying a decoy CD30 lacking the cytoplasmic region or a dominant negative IkappaBalpha mutant blocks NF-kappaB activation, down regulates IL-13 expression and induces apoptosis. Thus, in H-RS cells, ligand-independent activation of CD30 signaling drives NF-kappaB activation and this leads to constitutive cytokine expression, which provides a molecular basis for HD. Inhibition of NF-kappaB activation by adenovirus vector-mediated gene transfer may provide a novel strategy of cell- and target molecule-specific therapy for patients with HD.

Adenoviridae↗

Cytoplasmic aggregation of TRAF2 and TRAF5 proteins in the Hodgkin-Reed-Sternberg cells.

We previously reported that ligand-independent signaling by highly expressed CD30 in Hodgkin-Reed-Sternberg (H-RS) cells is responsible for constitutive activation of NF-kappa B. In the present study, we characterize the intracellular localization of tumor necrosis factor (TNF) receptor associated factor (TRAF) proteins in H-RS cells. Confocal immunofluorescence microscopy of cell lines derived from H-RS cells and HEK293 transformants highly expressing CD30 revealed aggregation of TRAF2 and TRAF5 in the cytoplasm as well as clustering near the cell membrane. In contrast, TRAF proteins were diffusely distributed in the cytoplasm in cell lines unrelated to Hodgkin's disease (HD) and control HEK293 cells. Furthermore, the same intracellular distribution of TRAF proteins was demonstrated in H-RS cells of lymph nodes of HD, but not in lymphoma cells in lymph nodes of non-Hodgkin's lymphoma. Dominant-negative TRAF2 and TRAF5 suppressed cytoplasmic aggregation along with constitutive NF-kappa B activation in H-RS cell lines. Confocal immunofluorescence microscopy also revealed co-localization of IKK alpha, NIK, and I kappa B alpha with aggregated TRAF proteins in H-RS cell lines. These results suggest involvement of TRAF protein aggregation in the signaling process of highly expressed CD30 and suggest they function as scaffolding proteins. Thus, cytoplasmic aggregation of TRAF proteins appears to reflect constitutive CD30 signaling which is characteristic of H-RS cells.

Cell Line↗

Human B-cell lymphoma cell lines are highly sensitive to apoptosis induced by all-trans retinoic acid and interferon-gamma.

When cells were incubated in the presence of both interferon-gamma (IFN-gamma) and all-trans retinoic acid (ATRA), the concentration of IFN-gamma required to induce apoptosis of B-cell lymphoma cells was much lower than that required for myeloid or erythroid cell lines. The concentration of IFN-gamma that effectively inhibited the proliferation of BALM-3 cells was 1/40 of that required for BALM-1 cells. STAT-1 phosphorylation, IRF-1 mRNA and protein expression and RAR-beta expression were enhanced to a greater degree in BALM-3 cells treated with IFN-gamma and ATRA than in BALM-1 cells treated with IFN-gamma and ATRA, suggesting that these IFN-gamma related genes were involved in the induction of apoptosis of BALM-3 cells.

Apoptosis↗

DNA methylation dominates transcriptional silencing of Pax5 in terminally differentiated B cell lines.

Pax5 plays a key role in the progression of B cell development. Its expression is observed in a wide range of cell types from early lineage-committed precursors up to mature B cells, but is silenced in terminal differentiated plasma cells. In this report, we show that DNA methylation is involved in the silencing of Pax5. In the Pax5-expressing cell lines 38B9 (pre-B) and 2PK-3 (mature B), all CpG sites in TATA-containing upstream promoter were unmethylated, whereas these sites were completely methylated in myeloma cell lines FO and Sp-2/0, which do not express Pax5. Demethylation of FO and Sp-2/0 with 5-aza-2'-deoxycytidine (5-aza-dC) resulted in Pax5 re-expression with the concomitant expression of CD19 and mb-1 genes, which are known to be the target genes of Pax5. Re-expression of Pax5 was also induced by trichostatin A (TSA), which was a specific inhibitor of histone deacetylase. This re-expression was, however, transcribed only from the TATA-less downstream promoter. Taken together, we concluded that the upstream promoter was predominantly inactivated by DNA methylation, while the downstream promoter was repressed by the histone deacetylation. This synergetic inactivation of two promoters results in the final silencing of Pax5 expression in terminally differentiated B cell lines.

Animals↗

The catalytic DNA topoisomerase II inhibitor ICRF-193 and all-trans retinoic acid cooperatively induce granulocytic differentiation of acute promyelocytic leukemia cells: candidate drugs for chemo-differentiation therapy against acute promyelocytic leukemia.

OBJECTIVE: Although all-trans retinoic acid (ATRA) can bring about complete remission of acute promyelocytic leukemia (APL), the incidence of early recurrence is considerably high. Thus, chemotherapeutic agents, such as anthracycline agents or cytosine arabinoside (AraC), are generally co-administered with ATRA. The therapeutic outcome of APL patients has significantly improved by chemo-differentiation therapy. Late-phase toxicities, such as cardiotoxicity and secondary carcinogenesis, are becoming clinically important. Therefore, we must identify the most suitable chemotherapeutic agents for the treatment of APL. METHODS: We examined the effects of ICRF-193 and several other anticancer drugs on the growth and differentiation of APL cell lines (NB4 and HT-93) and other myeloid leukemia cell lines (HL-60 and U937). RESULTS: If anticancer agents were available that not only inhibited the proliferation of APL cells but also induced their differentiation, they would be very useful for the treatment of APL. DNR slightly induced the differentiation of APL cells. On the other hand, other DNA topoisomerase II inhibitors, such as ICRF-154 and ICRF-193, significantly induced the differentiation of APL cell lines and leukemia cells freshly isolated from APL patients. These drugs effectively cooperated with ATRA in inhibiting the growth and inducing the differentiation of APL cells, whereas DNR did not. The incidence of cardiotoxicity and secondary carcinogenesis associated with ICRF-193 are much lower than that with DNR. CONCLUSION: These results suggest that ICRF-193 may be useful in the treatment of patients with APL.

Antineoplastic Agents↗

Potassium-induced increase in renal kallikrein secretion is attenuated in dissected renal connecting tubules of young spontaneously hypertensive rats.

It is suggested that attenuation of the renal kallikrein-kinin system (KKS) involved the development of hypertension in young spontaneously hypertensive rats (SHR). In the present study, a comparison was made between young SHR and Wistar Kyoto rats (WKY) to examine the ability to secrete renal kallikrein from the microdissected connecting tubules (CNT) by potassium or an ATP-sensitive potassium channel blocker, 4-morpholinecarboximidine-N-1-adamantyl-N'-cyclohexylhydrochloride (PNU-37883A), both of which are renal kallikrein secretagogues. Maximum effect of potassium on kallikrein secretion was observed 10 min after placing the tubules at concentration of 20 mM. Kallikrein secretion was also increased concentration-dependently by PNU-37883A (0.1, 1, 10, and 100 microM). In the presence of EDTA, NiCl2, verapamil, xestspongin C (an inositol 1,4,5-trisphosphate (IP3) receptor-selective antagonist), or ruthenium red (a ryanodine-sensitive receptor blocker), potassium-induced increase in renal kallikrein secretion was inhibited. Augmentation of renal kallikrein secretion by potassium or PNU-37883A was diminished in SHR compared to WKY. These results indicate that the ability to secrete renal kallikrein by potassium was attenuated in young SHR compared with WKY. Furthermore, it is suggested that the potassium-induced renal kallikrein secretion requires an extracellular Ca2+ entry through Ca2+ channels including L-type Ca2+ channels and Ca2+ release from intracellular Ca2+ stores through IP3 receptor and ryanodine receptor.

Adamantane↗

Effective antibiotic treatment of methicillin-resistant Staphylococcus aureus-associated glomerulonephritis.

BACKGROUND: A new type of glomerulonephritis following a methicillin-resistant Staphylococcus aureus (MRSA) infection has been reported. The purpose of this study is to elucidate the clinicopathological features and the responsiveness to treatment of the disease. METHODS: We studied the treatment of 8 patients with glomerulonephritis related to MRSA infection. We observed the eight cases and analyzed clinical features, laboratory findings and histopathological data. RESULTS: On admission, all patients had no renal abnormalities. One to four months after suffering from MRSA infection, severe proteinuria and hematuria developed. Renal biopsy specimens revealed moderate to severe mesangial proliferative glomerulonephritis with various degrees of crescent formation. Immunofluorescence studies showed IgA and C3. Antibiotic therapy was performed in six cases, resulting in successfully reducing the proteinuria in parallel with the decreased activity of MRSA infection in five cases. The other 2 cases received corticosteroid treatment after complete cessation of MRSA infection, but they had a relapse of MRSA infection and later died from sepsis. CONCLUSIONS: These results suggested that MRSA-associated glomerulonephritis might respond to antibiotic treatment in most cases. This also indicated that special care must be taken in the application of steroid therapy for the glomerulonephritis with crescents, even though the MRSA infection has gone into an inactive state.

Adrenal Cortex Hormones↗

MPO-ANCA-positive slowly progressive glomerulonephritis with focal tuft necrosis and crescents.

A 37-year-old woman had been found to have proteinuria in October 1996. About 8 months later, the first renal biopsy was performed, revealing focal segmental necrotizing and crescentic glomerulonephritis. At that time, serum creatinine was 1.0 mg/dl and urinary protein 3+. In October 1999, laboratory tests revealed positivity for MPO-ANCA and a serum creatinine level of 1.42 mg/dl, anemia and proteinuria of 2+. A second renal biopsy showed almost the same histological findings. Accordingly, a diagnosis of MPO-ANCA positive glomerulonephritis was made. This patient was thought to be a rare case of MPO-ANCA-positive slowly progressive glomerulonephritis presenting focal segmental tuft necrosis and crescents.

Adult↗

[Granulocytic sarcoma of the colon in chronic myelomonocytic leukemia].

A 59-year-old man with a six-month history of chronic myelomonocytic leukemia (CMML) was admitted to the Kitasato University Hospital because of melena in September 2000. Colonofiberscopy and barium enema demonstrated an ulcerated tumorous lesion in the transverse colon. The histopathologic findings of the ulcer bed revealed diffuse infiltration of granulocytes at each stage of differentiation. The diagnosis of granulocytic sarcoma (GS) was made. Surgical resection was not indicated, because thrombocytopenia was hardly improved enough to allow surgery despite repetitive transfusion of platelet concentrates. CMML developed to refractory anemia with excess of blast in transformation in February 2001. Two courses of low dose cytarabine plus aclarubicin were ineffective on the GS in spite of a decrease in the peripheral blood blasts. Progression to acute myeloid leukemia eventually broke out, in July 2001. The patient died of leukemia complicated with pneumonia and intestinal obstruction. At present, nine cases of GS in the colon have been reported. However, these cases did not include CMML. This is the first report describing GS in the colon associated with CMML.

Colonic Neoplasms↗