Hidenori Imai

Frequent STAT3 activation is associated with Mcl-1 expression in nasal NK-cell lymphoma.

Nasal natural killer (NK)‐cell lymphoma was resistant to various antitumor agents. Although high expression of p‐glycoprotein has been reported, other molecular mechanism of the chemo‐resistance is largely unknown. Activation of STAT3 and expression of major apoptosis‐related proteins Bcl‐2, Bcl‐x, and Mcl‐1 were analyzed by immunohistochemistry. Effects of STAT3 inhibitor AG490 on NK‐YS cell line were analyzed by Western blotting and flow cytometric apoptosis assay. STAT3 was activated in six of the nine nasal NK‐cell lymphomas (67%). In contrast, STAT3 activation was detected in 35% of diffuse large B‐cell lymphoma (DLBCL) and in 10% of follicular lymphoma (FL). Frequent activation of STAT3 was significantly correlated with Mcl‐1 expression in nasal NK‐cell lymphoma, i.e., Mcl‐1 was positive in five of six STAT3‐active cases and negative in all three STAT3‐inactive ones. In DLBCL, not only six out of seven STAT3‐active cases (86%) but also eight out of thirteen STAT3‐inactive cases (62%) were positive for Mcl‐1 expression. Latent membrane protein‐1 was positive in four nasal NK‐cell lymphomas, among which three cases showed intermediate STAT3 activation. Inhibition of STAT3 activation by JAK inhibitor AG490 decreased Mcl‐1 expression and induced apoptosis in STAT3‐active NK‐YS cells. Serum starvation rather increased the Mcl‐1 level in NK‐YS cells, and this effect was also canceled by AG490. These results suggest that activation of STAT3‐Mcl‐1 axis may play a role in the chemotherapy resistance of nasal NK‐cell lymphoma. The pathway may be one of the future therapeutic targets of this intractable disease.

Expression levels of apoptosis-related proteins and Ki-67 in nasal NK / T-cell lymphoma

Objectives:  Nasal natural killer (NK)/T‐cell lymphoma is characterized by chemo‐resistance, angiodestruction, and aggressive tumor progression. Few studies exist on molecular characteristics of this disease entity.

Antithrombin deficiency in three Japanese families: one novel and two reported point mutations in the antithrombin gene.

INTRODUCTION Inherited antithrombin (AT) deficiency is associated with a predisposition to familial venous thromboembolic disease. We analyzed the AT gene in three unrelated patients with an AT deficiency who developed thrombosis. MATERIALS AND METHODS We analyzed the SERPINC1 gene in three patients. Additionally, we expressed the three mutants in the COS-1 cells and compared their secretion rates and levels of AT activity with those of the wild-type (WT). RESULTS We identified three distinct heterozygous mutations of c.2534C>T: p.56Arginine → Cysteine (R56C), c.13398C>A: p.459Alanine → Aspartic acid (A459D) and c.2703C>G: p.112 Proline → Arginine (P112R). In the in vitro expression experiments, the AT antigen levels in the conditioned media (CM) of the R56C mutant were nearly equal to those of WT. In contrast, the AT antigen levels in the CM of the A459D and P112R mutants were significantly decreased. The AT activity of R56C was decreased in association with a shorter incubation time in a FXa inhibition assay and a thrombin inhibition-based activity test. However, the AT activity of R56C was comparable to that of WT when the incubation time was increased. CONCLUSIONS We concluded that the R56C mutant is responsible for type II HBS deficiency. We considered that the A459D and P112R mutants can be classified as belonging to the type I AT deficiency.

Suppression of eIF4E expression by L-Asparaginase.

L -Asparaginase ( L -ASP) is an important anti-tumor agent used in the treatment of childhood acute lymphocytic leukemia and some kinds of non-Hodgkin’s lymphoma [9] . Extranodal NK-cell lymphoma clinically shows high sensitivity to L -ASP [10–12] , and we have previously reported a specifically high anti-tumor effect of L -ASP against NK-cell tumor cell lines and samples [13] . L -ASP causes rapid depletion of asparagine and glutamine and thus suppresses growth of malignant cells [14] . However, the antitumor mechanism of L -asparaginase and the determinants of its sensitivity are not fully understood [15] . High expression of asparagine synthetase, which opposes the action of L -ASP, only partially explains the resistance to L -ASP in pediatric acute lymphocytic leukemia [16] . Iiboshi et al. [17] showed that L -ASP inhibits the rapamycin-targeted pathway, including p70 S6K and 4E-BP1 in Jurkat cells. In this study, we confirmed the result and further revealed rather specific depletion of eIF4E by L ASP. A much lower concentration of L -ASP depleted eIF4E and its down-stream effector Mcl-1 and induced apoptosis in NK-tumor cell lines. We first confirmed the effect of 1 IU/ml of L -ASP on the phosphorylation states of p70 S6K and S6 ribosomal Eukaryotic translation initiation factor 4E (eIF4E) is considered oncogenic because external expression of eIF4E in the primary fibroblast leads to deregulated proliferation and malignant transformation [1] . Over-expression of eIF4E generates lymphoma in vivo, and its cooperation with c-myc markedly accelerates B-cell lymphomagenesis [2] . Indeed, eIF4E is over-expressed in a wide variety of human tumors, including carcinomas of the colon, breast, and some non-Hodgkin lymphomas [3–5] . The protein plays a key regulatory role in cap-dependent mRNA translation by binding to the 7-methylguanosine cap structure of mRNAs and delivering them to the eIF4F translation initiation complex [6] . The translation of a subset of mRNAs with a complex 5 -UTR is more sensitive to the availability of eIF4E than most cellular RNAs with a short, unstructured UTR [7] . The eIF4E-sensitive mRNAs typically encode growth and survival factors like c-myc, cyclin D1, vascular endothelial growth factor and ornithine decarboxylase [8] . The Akt/mammalian target of rapamycin (mTOR) signal inactivates eIF4E-binding protein 1 (4E-BP1), which binds to and prevents the function of eIF4E. The pathway thus facilitates translation of eIF4E-sensitive growth-promoting mRNAs. Received: November 11, 2009 Accepted after revision: February 16, 2010 Published online: April 27, 2010

Severe thrombocytopenia caused by littoral cell angioma

In September 2002, a 54-year-old man, who had been on hemodialysis because of chronic renal failure due to polycystic kidney disease, referred to our department because of progressing thrombocytopenia with platelet count of 27 9 10/L. Abdominal ultrasonography showed significant splenomegaly with numerous hyperechoic lesions of various sizes which might cause the thrombocytopenia. Computed tomographic (CT) scan revealed that multiple hypoenhanced lesions at the early portal venous phase became isoattenuating during the late portal venous Fig. 1 CT scans, microscopic and immunohistochemical images of littoral cell angioma

Patient with Refractory Multiple Myeloma Developing Eosinophilia after Lenalidomide Treatment and Lung Cancer 9 Months Later: Case Report and Review of the Literature

Abstract A 78-year-old man was diagnosed as having advanced symptomatic IgG multiple myeloma in June 2008. Melphalan-prednisolone therapy was effective, however, relapse occurred in January 2011 after 21 courses of melphalan-prednisolone therapy. Addition of bortezomib and dexamethasone led to partial remission, but the treatment needed to be discontinued due to autonomic dysfunction. Combined therapy with lenalidomide and dexamethasone was started in May 2012, which resulted in partial remission. The patient had a persistently elevated eosinophil count (2,350/μL) and increased serum IL-6 level. Pleuritis carcinomatosa developed in January 2013. Lenalidomide was discontinued, which was followed by rapid improvement of the eosinophilia. The patient died of respiratory failure in March 2013. There have been only five reported cases of eosinophilia caused by lenalidomide used for the treatment of multiple myeloma. In these cases, lenalidomide has been speculated to activate cytotoxic T cells to control the plasmacytoma. It would be of interest, therefore, that eosinophilia could serve as a new indicator.

Angioimmunoblastic T-cell lymphoma with intramedullary production of platelet-derived growth factor and possibly complicating myelofibrosis: report of a case with review of the literature

A 65-year-old man was diagnosed with angioimmunoblastic T-cell lymphoma (AITL) with bone marrow (BM) infiltration and myelofibrosis (MF). The BM infiltration and the condition of the MF improved following CHOP therapy (cyclophosphamide hydrate, doxorubicin hydrochloride, vincristine sulfate, and prednisolone). After complete remission was achieved, early central nervous system recurrence was noted, with no evidence of BM infiltration or MF. The lymph nodes and BM were examined for cytokines by immunohistochemical staining with monoclonal murine antibodies. The lymphoma cells were positive only for platelet-derived growth factor (PDGF) and negative for basic fibroblast growth factor, fibronectin, vascular endothelial growth factor, transforming growth factor-β (TGF-β), tumor necrosis factor α, interleukin-1β, and interleukin-6. It was thus inferred that the lymphoma cells producing PDGF caused the MF, and that the absence of MF at relapse may have been attributable to the absence of BM infiltration. There have been seven reported cases of AITL with intercurrent MF, although cytokine data (elevations of blood PDGF and TGFβ levels) are available for only one case. The present report is to our knowledge the only report of a case of AITL complicated by MF for which the results of immunohistostaining with anticytokine antibodies are available.

A case of T cell prolymphocytic leukemia involving blast transformation

We report a case of T cell prolymphocytic leukemia (T-PLL) involving blast transformation. At the initial diagnosis, most peripheral blood cells demonstrated proliferation of indolent T cell small cell variants, i.e., small to medium prolymphocytes with inconspicuous nucleoli and a normal karyotype. These cells were positive for surface CD4, CD5, and CD7, and cytoplasmic CD3, but negative for surface CD3 and CD8 and cytoplasmic terminal deoxynucleotidyl transferase (TdT). The T cell receptor (TCR) Cβ1 gene was rearranged in the cells. Large prolymphocytes with prominent nucleoli, irregular nuclei, and cytoplasmic vacuoles that exhibited chromosome 8 trisomy were observed about 1.5 years later. The CD4+CD8− single positive effector memory T cells transformed into surface CD4+CD8+ double positive precursor T cells. The clonal TCR gene rearrangement patterns of these cells were identical throughout the clinical course, suggesting clonal blast transformation. The CD4+CD8+ cells demonstrated increased chromosome 8 trisomy combined with complex chromosome abnormalities with t(14;14)(q11.2;q32) containing a 14q32 chromosome after transformation. T cell leukemia 1a (TCL1a) (14q32.1) may be implicated in this case. The TCL1a oncoprotein is expressed in approximately 70% of T-PLL cases. The disease gradually developed resistance to chemotherapy, and the patient died of the disease. It is known that indolent T-PLL can become aggressive. Therefore, similar transformations may occur in other aggressive T-PLL cases, particularly those involving trisomy 8 and TCL1a.

A Case of Advanced Primary Thyroid Double-Hit B Cell Lymphoma in Which Complete Remission has been Maintained After High-Dose Chemotherapy and Autologous Peripheral Blood Stem Cell Transplantation Performed During the Second Remission, with a Review of the Literature.

A 50-year-old woman who presented with a mass in the thyroid gland was diagnosed as having diffuse large B-cell lymphoma (DLBCL) by biopsy in August 2011. The tumor had a complex chromosomal karyotype, including 8q24 (C-MYC) and 18q21(BCL-2), and fluorescence in situ hybridization confirmed split signals of C-MYC and BCL-2. BCL-2/IgH and C-MYC/IgH fusion signals were also observed. Three courses of rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone (R-CHOP) therapy were given, followed by thyroid gland irradiation. She was achieved complete remission (CR). In January 2012, a mass appeared in the right breast, which was diagnosed as relapse by biopsy. CR was achieved again after the 4th course of R-CHOP therapy, and one course of rituximab, etoposide, methylprednisolone, cytarabine, cisplatin (R-ESHAP) therapy was given. Thereafter, CR has been maintained after high-dose chemotherapy and autologous peripheral blood stem cell transplantation. There have been only 3 reported cases of primary thyroid C-MYC and BCL-2 double-hit lymphoma, including the present case; 2 of the cases were cases of DLBCL. R-CHOP therapy, irradiation and autologous peripheral blood stem cell transplantation are expected to be effective for such patients.

Occurrence of Carcinoma of the Pancreas Following Nilotinib Therapy for Chronic Myeloid Leukemia: Report of a Case with Review of the Literature

The patient, a 79-year-old Japanese man, was diagnosed with the chronic phase of chronic myeloid leukemia and begun on nilotinib therapy in April 2011. The therapeutic response was major molecular response in August. About 19 months after the start of nilotinib therapy at 400 mg/day (November 2012), an adenocarcinoma (24x20 mm) confined to the head of the pancreas developed. In February 2013, a pancreaticoduodenectomy was performed. The therapy regimen was switched to dasatinib at 100 mg/day, beginning in April. The response was still major molecular response with no recurrence of pancreatic carcinoma in July 2013. There have been 29 reported cases of secondary neoplasms associated with nilotinib therapy. These secondary neoplasms were characterized by relatively frequent occurrence of papilloma (6 cases), gastric cancer (3 cases), fibroma (3 cases), and thyroid neoplasms (2 cases). The present case, however, is the first to be reported as carcinoma of the pancreas. This report describes the case.