Takamitsu Matsushima

Eradication of virus-infected T-cells in a case of adult T-cell leukemia/lymphoma by nonmyeloablative peripheral blood stem cell transplantation with conditioning consisting of low-dose total body irradiation and pentostatin

We describe the case of a 55-year-old man with adult T-cell leukemia/lymphoma (ATL) in first remission who underwent nonmyeloablative allogeneic peripheral blood stem cell transplantation with conditioning consisting of 4 courses of pentostatin and low-dose total body irradiation. Complete chimerism in peripheral blood was achieved on day 42 without severe myelosuppression. Concomitantly, the proviral DNA load for human T-cell leukemia virus I (HTLV-I) in peripheral blood mononuclear cells decreased below detectable limits and was still undetectable on day 270.This fact indicates that eradication of ATL cells is feasible by induction of an alloimmune response without high-dose chemoradiotherapy.

Selective cyclooxygenase 2 inhibitor NS-398 induces apoptosis in myeloma cells via a Bcl-2 independent pathway.

NS-398, a selective inhibitor of cyclooxygenase 2 (COX-2), has been reported to inhibit growth and induce apoptosis in several cancer cell lines that overexpress COX-2. However it has not been extensively studied in multiple myeloma (MM). Here, we studied the effects of COX-2 inhibitors on MM cell lines and primary myeloma patient cells. We investigated the effects of NS-398 on proliferation and apoptosis in three myeloma cell lines (PCM6, U266 and RPMI8226) and isolated CD138-positive cells from MM patients. Furthermore, the combined effects of NS-398 plus dexamethasone (Dex) or thalidomide (Thal) were investigated. All myeloma cell lines express COX-2. NS-398 inhibited growth and induced apoptosis in PCM6, RPMI8226 and CD138-positive MM cells in a time- and dose-dependent manner. At low concentrations (10 μM), NS-398 primarily induced growth arrest without affecting cell viability, but at higher concentrations (over 25 μM), apoptosis was induced. During the process of apoptosis, the number of Fas-positive cells increased. Downstream signals of Fas, such as caspase 8, 3 and 9, were also activated. On the other hand, protein levels of the Bcl-2 family did not change, although mitochondrial transmembrane potential (Δψm) was decreased. Combined incubation with Dex or Thal enhanced NS-398-induced growth inhibition and apoptosis in RPMI8226 cells. The combined effect of Dex was more potent than that of Thal. Our findings suggests that COX-2 plays an important role in regulation of apoptosis in myeloma cells, and COX-2 inhibitors might serve as an effective tool for future chemoprevention and/or treatment of myeloma.

Role of NF-kappa B in regulation of apoptosis of erythroid progenitor cells.

Abstract:  Erythropoietin (EPO) and interferon‐γ (IFN‐γ) added to human erythroid progenitor cells purified from peripheral blood (erythroid colony‐forming cells; ECFC) significantly reduces apoptosis as assessed by flow cytometry (FCM) using annexin V. To clarify the role of NF‐κB in the regulation of the apoptosis of erythroid progenitor cells, cyclosporin A (CsA), which blocks dissociation of the NF‐κB complex, was added to serum‐free cultures of ECFC. CsA induced the apoptosis of ECFCs in the presence of EPO or IFN‐γ, but at different magnitudes. In the presence of a relatively low concentration of CsA (10 μm), apoptosis was induced only in cultures with EPO. The direct involvement of NF‐κB was then assessed by Western blotting and confocal microscopy. In the presence of EPO, NF‐κB was abundant both in the cytoplasm and in the nucleus, and nuclear expression was diminished after adding CsA. In contrast, NF‐κB was undetectable in the nucleus in the presence of IFN‐γ. The effect of CsA on mitochondrial function was investigated by determining the ΔΨm and reactive oxygen species production. CsA disturbed the transmembrane potential in the presence of either EPO or IFN‐γ, although the viability of the cells was maintained in the presence of IFN‐γ plus CsA. These results indicate that IFN‐γ reduced the apoptosis of erythroid progenitor cells through a unique signaling pathway that is independent of NF‐κB translocation, and which is not mediated by modulating mitochondrial function, whereas EPO reduced apoptosis through NF‐κB translocation to the nucleus.

Expression of Apoptosis-Associated Protein RCAS1 in Macrophages of Histiocytic Necrotizing Lymphadenitis

Receptor-binding cancer antigen expressed on SiSo cells (RCAS1), which is recognized by the 22–1–1 monoclonal antibody (MoAb) against human uterine adenocarcinoma cell line SiSo, has been identified on various kinds of cancer cells. RCAS1 appears to be an apoptosis-associated protein that induces apoptosis in activated T-cells and erythroid progenitor cells.We previously demonstrated that monocytes/macrophages express RCAS1. In the present study, we investigated RCAS1 expression by 22–1–1 MoAb in histiocytic necrotizing lymphadenitis (HNL), which is characterized by necrotic lesions consisting of T-cells undergoing apoptosis and macrophages in proliferation. Expression of RCAS1 was analyzed by immunohistochemical staining in 9 cases of HNL and in 9 cases of reactive lymphadenitis used as a control. The ratio of RCAS1+ cells to CD68+ cells (monocytes/macrophages) was significantly higher in the patients with HNL than in the patients with reactive lymphadenitis (P = .0002; paired t test). Our findings suggest that RCAS1 expressed on macrophages may play an important role in the induction of activated T-cell apoptosis in cases of HNL.

Pivotal role of Notch signaling in regulation of erythroid maturation and proliferation

Abstract:  Notch signaling plays an important role in cell fate decisions in developmental systems. To clarify its role in committed hematopoietic progenitor cells, we investigated the effects of Notch signaling in erythroid colony forming cells (ECFCs) generated from peripheral blood. ECFCs express Notch receptors, Notch1 and Notch2, and Notch ligands Delta1, Delta4, and Jagged1. When we assayed the effects of Notch ligands on erythroid maturation by flow cytometry, we found that immobilized Delta1 and immobilized Delta4 in particular inhibited maturation, whereas Jagged1 had no effect. In addition, Delta4 inhibited proliferation without reducing cell viability. Increases in expression levels of the Notch target gene hairy enhancer of split (HES) ‐1 were evident by real‐time PCR after stimulation with immobilized Delta4. The effect of soluble Delta4 on expression of HES‐1 was less pronounced than that seen with the immobilized form, indicating that all surface‐bound ligands are important for effective signal transduction. When ECFCs were cultured in the presence of soluble Delta4 at a low cell concentration, erythroid maturation was slightly inhibited, but at a high concentration, maturation was promoted via competition of soluble Delta4 with endogenous ligands. These results indicate a pivotal role of Notch signaling in regulating erythroid maturation and proliferation, and further suggest that cell–cell interactions modulate growth of erythroid progenitor cells via Notch system.

Isolated ACTH deficiency probably induced by autoimmune-related mechanism evoked with nivolumab

Nivolumab, an anti-programmed death-1 antibody, is a breakthrough treatment for several malignancies. Its specific adverse effects caused by autoimmunity are termed immune-related adverse events, which involve several endocrine dysfunctions. Herein, we report two cases of isolated adrenocorticotropic hormone (ACTH) deficiency induced by nivolumab for the treatment of metastatic malignant melanoma. Case 1 was a 39-year-old man and Case 2 was a 50-year-old woman, both of whom presented with progressive melanoma. After 13 courses of nivolumab administration, both cases were diagnosed with adrenal insufficiency. Despite their basal serum ACTH and cortisol levels being low with little response to corticotropin-releasing hormone loading, other anterior pituitary hormone levels were preserved. Based on these endocrinological data, isolated ACTH deficiency was diagnosed. Magnetic resonance imaging showed normal pituitary glands, excluding hypophysitis. Finally, hydrocortisone replacement enabled the patients to continue nivolumab treatment. Therefore, it is important to consider isolated ACTH syndrome as a possible and potentially severe immune-related adverse event of nivolumab, even when head magnetic resonance imaging of affected cases does not show enlargement. We should not misdiagnose hidden immune-related adverse events behind general complaints of malignancies such as general malaise and appetite loss, to allow successful treatment using this beneficial immune checkpoint inhibitor.

Comparative analysis of pulmonary hypertension in patients treated with imatinib, nilotinib and dasatinib

Pulmonary hypertension (PH) is a rare, but life‐threatening, adverse event in patients treated with tyrosine kinase inhibitors (TKIs), such as dasatinib, but has not been fully evaluated in patients treated with imatinib or nilotinib. We used echocardiography to noninvasively assess the incidence of PH in 105 patients with chronic myeloid leukaemia (CML) treated with imatinib (n = 37), nilotinib (n = 30) or dasatinib (n = 38). The mean triscupid regurgitation peak gradient (TRPG), which reflects pulmonary arterial pressure, was 22·7 mmHg in the imatinib group, 23·1 mmHg in the nilotinib group and 23·4 mmHg for dasatinib group. These values were not significantly different, but higher than those (19·0 mmHg) in newly diagnosed CML patients. A TRPG > 31 mmHg, marking possible PH onset, was detected in 9 of 105 patients: one (2·7%) treated with imatinib, three (10·0%) with nilotinib and five (13·2%) with dasatinib. Only three patients complained of dyspnoea, whereas the other six were asymptomatic. In addition, there was a tendency toward correlation of TRPG value and age or TKI treatment duration. These results suggested that treatment with not only dasatinib, but also imatinib and nilotinib, can be associated with subclinical PH. Noninvasive echocardiography is useful for screening, especially in older patients with long‐term TKI treatment.

Pituitary and adrenal involvement in diffuse large B-cell lymphoma, with recovery of their function after chemotherapy

BackgroundDiffuse large B-cell lymphoma sometimes involves the endocrine organs, but involvement of both the pituitary and adrenal glands is extremely rare. Involvement of these structures can lead to hypopituitarism and adrenal insufficiency, and subsequent recovery of their function is rarely seen. The present report describes an extremely rare case of pituitary and adrenal diffuse large B-cell lymphoma presenting with hypopituitarism and adrenal insufficiency with subsequent recovery of pituitary and adrenal function after successful treatment of the lymphoma.Case presentationA 63-year-old Japanese man was referred to our hospital due to miosis, ptosis, hypohidrosis of his left face, polydipsia and polyuria. 18F-fluorodeoxy glucose positron emission tomography / computed tomography revealed hotspots in the pituitary gland, bilateral adrenal glands and the apex of his left lung. Surgical biopsy from the pituitary lesion confirmed the diagnosis of diffuse large B-cell lymphoma, with lymphoma cells replacing normal pituitary tissue. Endocrine function tests revealed adrenal insufficiency and panhypopituitarism, including a possible affection of the posterior pituitary. Hormone replacement therapy with desmopressin and hydrocortisone was started. Chemotherapy consisted of six courses of R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin and prednisolone) and two courses of high-dose methotrexate followed by autologous hematopoietic stem cell transplantation. Subsequently, his pituitary and bilateral adrenal lesions resolved, and serial endocrine function tests showed gradual improvement in pituitary and adrenal function.ConclusionsThe present report describes an extremely rare case of diffuse large B-cell lymphoma with involvement of both the pituitary and bilateral adrenal glands. R-CHOP and high-dose methotrexate therapy followed by autologous hematopoietic stem cell transplantation was quite effective, and panhypopituitarism and adrenal insufficiency improved to almost normal values after successful treatment of the lymphoma with chemotherapy.

Expression of Human Tumor-Associated Antigen RCAS1 in Adult T-Cell Leukemia/Lymphoma

In human cancer, RCAS1 (the receptor-binding cancer antigen expressed on SiSo cells) on the surface of various kinds of tumor cells reportedly induces the apoptosis of T-cells and natural killer cells, resulting in evasion of the immune system. In the present study, an immunohistochemical analysis of RCAS1 expression was performed with lymph node specimens obtained from patients with adult T-cell leukemia/lymphoma (ATLL). Positive staining was seen in 15 (75%) of 20 cases and in all cases of patients with short survival times. In the cases of B-cell lymphomas, positive staining was seen in only 1 (13%) of 8 cases. These findings indicate that expression of RCAS1 may be associated with the evasion from immune surveillance of cells infected with human T-lymphotropic virus type I, resulting in the development of overt leukemia/lymphoma. Determination of RCAS1 expression may be useful for predicting the prognosis of patients with ATLL.

Intravascular Large B-Cell Lymphoma Complicated by Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis that was Successfully Treated with Rituximab-Containing Chemotherapy

A 64-year-old woman had suffered from painful livedo reticularis for 2 years and was referred to us due to fever, anasarca and paresthesia of the lower limbs. Serum proteinase-3-anti-neutrophil cytoplasmic antibody (ANCA) was positive. Abnormal lymphocytes were found in the cerebrospinal fluid and bone marrow. Skin biopsy revealed large atypical lymphoid cells with CD20 positivity lodged in the small vessels and neutrophilic infiltration into the arterial vascular wall with fibrinoid degeneration. A diagnosis of intravascular large B-cell lymphoma complicated by ANCA-associated vasculitis was made, and rituximab-containing chemotherapy followed by prednisolone was quite effective for both lymphoma and ANCA-associated vasculitis.