Keiki Nagaharu

Tenascin C Induces Epithelial-Mesenchymal Transition–Like Change Accompanied by SRC Activation and Focal Adhesion Kinase Phosphorylation in Human Breast Cancer Cells

Tenascin C (TNC) is an extracellular matrix glycoprotein up-regulated in solid tumors. Higher TNC expression is shown in invading fronts of breast cancer, which correlates with poorer patient outcome. We examined whether TNC induces epithelial-mesenchymal transition (EMT) in breast cancer. Immunohistochemical analysis of invasive ductal carcinomas showed that TNC deposition was frequent in stroma with scattered cancer cells in peripheral margins of tumors. The addition of TNC to the medium of the MCF-7 breast cancer cells caused EMT-like change and delocalization of E-cadherin and β-catenin from cell-cell contact. Although amounts of E-cadherin and β-catenin were not changed after EMT in total lysates, they were increased in the Triton X-100-soluble fractions, indicating movement from the membrane into the cytosol. In wound healing assay, cells were scattered from wound edges and showed faster migration after TNC treatment. The EMT phenotype was correlated with SRC activation through phosphorylation at Y418 and phosphorylation of focal adhesion kinase (FAK) at Y861 and Y925 of SRC substrate sites. These phosphorylated proteins colocalized with αv integrin-positive adhesion plaques. A neutralizing antibody against αv or a SRC kinase inhibitor blocked EMT. TNC could induce EMT-like change showing loss of intercellular adhesion and enhanced migration in breast cancer cells, associated with FAK phosphorylation by SRC; this may be responsible for the observed promotion of TNC in breast cancer invasion.

Binding of αvβ1 and αvβ6 integrins to tenascin-C induces epithelial–mesenchymal transition-like change of breast cancer cells

Tenascin-C (TNC), a large hexameric extracellular glycoprotein, is a pleiotropic molecule with multiple domains binding to a variety of receptors mediating a wide range of cellular functions. We earlier reported that TNC induces epithelial–mesenchymal transition (EMT)-like change in breast cancer cells. In the present study, we clarified TNC receptor involvement in this process. Among integrins previously reported as TNC receptors, substantial expression of αv, α2, β1 and β6 subunits was detected by quantitative PCR and immunoblotting in MCF-7 cells. Integrin β6 mRNA was remarkably upregulated by transforming growth factor (TGF)-β1 treatment, and protein expression was prominently increased by additional exposure to TNC. Immunofluorescent labeling demonstrated integrin αvβ6 accumulation in focal adhesions after TNC treatment, especially in combination with TGF-β1. The α2 and β1 subunits were mainly localized at cell–cell contacts, αv being found near cell cluster surfaces. Immunoprecipitation showed increase in αvβ1 heterodimers, but not α2β1, after TNC treatment. Activated β1 subunits detected by an antibody against the Ca2+-dependent epitope colocalized with αv in focal adhesion complexes, associated with FAK phosphorylation at tyrosine 925. Neutralizing antibodies against αv and β1 blocked EMT-like change caused by TNC alone. In addition, anti-αv and combined treatment with anti-β1 and anti-αvβ6 inhibited TGF-β1/TNC-induced EMT, whereas either of these alone did not. Integrin subunits αv, β1 and β6, but not α2, bound to TNC immobilized on agarose beads in a divalent cation-dependent manner. Treatments with neutralizing antibodies against β1 and αvβ6 reduced αv subunit bound to the beads. Immunohistochemistry of these receptors in human breast cancer tissues demonstrated frequent expression of β6 subunits in cancer cells forming scattered nests localized in TNC-rich stroma. These findings provide direct evidence that binding of αvβ6 and αvβ1 integrins to TNC as their essential ligand induces EMT-like change in breast cancer cells.

Persistent symptomatic parvovirus B19 infection with severe thrombocytopenia transmitted by red blood cell transfusion containing low parvovirus B19 DNA levels

Transfusion‐mediated human parvovirus B19 (PVB19) infection is rare but often causes severe hematologic disorders. In Japan, routine blood donor screening for PVB19 antigen (detection sensitivity, 106.4 IU/mL) using a chemiluminescent enzyme immunoassay (CLEIA) was introduced in 2008. However, there is no consensus on the minimal infectious dose of PVB19 permissible for red blood cells (RBCs).

CXCL12–CXCR4 Axis Is Required for Contact-Mediated Human B Lymphoid and Plasmacytoid Dendritic Cell Differentiation but Not T Lymphoid Generation

We investigated the involvement of CXCL12–CXCR4 interactions in human lymphohematopoiesis by coculture with telomerized human stromal cells. CXCR4 expression was low in CD34+CD38−CD45RA−CD10−CD7−CD19− immature hematopoietic stem/precursor cells (HSPCs) but higher in CD34+CD38−CD45RA+CD10+CD7+/−CD19− early lymphoid precursors and even higher in CD34+CD38+CD45RA+CD10+CD7−CD19+ pro-B cells. Inhibition of the effect of stromal cell–produced CXCL12 by an anti-CXCR4–blocking Ab suppressed the generation of CD45RA+CD10−CD7+CD19− early T lymphoid precursors (ETPs) and CD45RA+CD10+CD7−CD19+/− B lymphoid precursors on stromal cells, but it did not affect the generation of ETPs in conditioned medium of stromal cell cultures. Replating assays showed that contact with stromal cells was critical for HSPC-derived CD45RA+CD10+CD7−CD19− B lineage–biased precursors to differentiate into CD19+ pro-B cells, which was suppressed by the anti-CXCR4 Ab. Conversely, HSPC-derived ETPs possessed T and B lymphoid and monocytic differentiation potential; stromal cell contact was not required for their growth but rather promoted B lymphoid differentiation. The anti-CXCR4 Ab did not affect the growth of ETPs in conditioned medium, but it suppressed their B lymphoid differentiation on stromal cells. CD14−CD11c−HLA-DR+CD123highCD303+ plasmacytoid dendritic cells developed from HSPCs and ETPs exclusively in contact with stromal cells, which was suppressed by the anti-CXCR4 Ab. These data indicate that CXCL12 plays an essential role in stromal cell contact–mediated B lymphoid and plasmacytoid dendritic cell differentiation from immature hematopoietic and early T lymphoid precursors with a multilineage differentiation potential, but it does not participate in contact-independent generation of early T lymphoid precursors.

Spontaneous Tumor Lysis Syndrome in a Patient with a Dedifferentiated Endometrial Adenocarcinoma

Tumor lysis syndrome (TLS) is an oncological emergency caused by massive cytolysis of malignant cells. This syndrome eventually induces metabolic abnormalities. TLS is observed mainly among tumors with rapid cell proliferation or high sensitivity to antineoplastic treatment. In rare cases, TLS occurs without any cytotoxic treatment. Previous reports have shown that alternative stress including proceeding infection or an operation might play a role in TLS. However, exact mechanism of spontaneous TLS remains unknown. Here, we describe a case of a 59-year-old woman who presented with dedifferentiated endometrial adenocarcinoma and developed TLS without any cytotoxic chemotherapy. Although spontaneous TLS in solid malignancies are extremely rare, clinicians should consider the possibilities of TLS especially in aggressive solid tumors.

A Case of Hyperammonemia Associated with High Dihydropyrimidine Dehydrogenase Activity

Over the past decades, 5-Fluorouracil (5-FU) has been widely used to treat several types of carcinoma, including esophageal squamous cell carcinoma. In addition to its common side effects, including diarrhea, mucositis, neutropenia, and anemia, 5-FU treatment has also been reported to cause hyperammonemia. However, the exact mechanism responsible for 5-FU-induced hyperammonemia remains unknown. We encountered an esophageal carcinoma patient who developed hyperammonemia when receiving 5-FU-containing chemotherapy but did not exhibit any of the other common adverse effects of 5-FU treatment. At the onset of hyperammonemia, laboratory tests revealed high dihydropyrimidine dehydrogenase (DPD) activity and rapid 5-FU clearance. Our findings suggested that 5-FU hypermetabolism may be one of the key mechanisms responsible for hyperammonemia during 5-FU treatment.

フルダラビン・リツキシマブ併用療法が奏効したBing-Neel症候群

Bing-Neel syndrome is known as Waldenströms macroglobulinemia with central nervous system infiltration by neoplastic lymphoplasmacytoid and plasma cells. A 74-year-old man was admitted because of progressive cognitive impairment. Serum immunoelectrophoresis showed a monoclonal IgM-kappa component. Bone marrow aspiration revealed 59% small lymphocytes showing plasmacytoid differentiation. Bone marrow flow cytometry disclosed a population of kappa light-chain positive lymphoid cells expressing CD19, CD20, CD38, and CD138. Magnetic resonance imaging of the brain demonstrated gadolinium-enhancement in the right temporo-parieto-occipital meninges with sulcal enhancement. Cerebrospinal fluid cytology showed a population of lymphoplasmacytoid cells, positive for CD19, CD20, CD25, and kappa light-chain. Based on these findings, Bing-Neel syndrome was diagnosed. Although combination chemotherapy consisting of intrathecal methotrexate and oral cyclophosphamide was started, his symptoms continued to worsen. Then, we initiated treatment with a regimen consisting of fludarabine/rituximab (FR). After 6 courses of this FR regimen, a complete remission was achieved. Our case suggests the FR regimen to potentially be an effective treatment option for Bing-Neel syndrome of the scattered type.

Successful treatment of primary bone marrow Hodgkin lymphoma with brentuximab vedotin: a case report and review of the literature

BackgroundHodgkin lymphoma usually presents with sequential enlargement of peripheral lymph nodes, and bone marrow invasion rarely occurs (approximately 3–5%). However, several cases have been reported as “primary” bone marrow Hodgkin lymphoma, especially among patients with human immunodeficiency virus and the elderly. This type of Hodgkin lymphoma is characterized by no peripheral lymphadenopathies and has been reported to have poorer prognosis.Case presentationA 38-year-old Japanese man was admitted to our hospital because of fever of unknown origin and pancytopenia without lymphadenopathies. Bone marrow examination revealed Hodgkin cells mimicking abnormal cells. These were positive for CD30, EBER-1, CD15, PAX-5, and Bob-1 and negative for Oct-2, CD3, CD20, surface immunoglobulin, CD56. On the basis of systemic evaluation and bone marrow examination, he was diagnosed with primary bone marrow Hodgkin lymphoma. We initiated therapy with DeVIC (dexamethasone, etoposide, ifosfamide, and carboplatin) therapy, but remission was not achieved. Then, the patient was treated with brentuximab vedotin combined with systemic chemotherapy (Adriamycin, vinblastine and dacarbazine), which was effective.ConclusionsThere is no established treatment strategy for Hodgkin lymphoma, and therapeutic outcomes using ABVD (Adriamycin, bleomycin, vinblastine and dacarbazine)-like or CHOP (cyclophosphamide, Adriamycin, vincristine, and prednisone)-like regimens are reportedly poor. Only a few patients have been reported to achieve long-term remission. Through this case report, we suggest an alternative therapeutic option for primary bone marrow Hodgkin lymphoma.

髄注と大量シタラビン療法後に上矢状静脈洞血栓症を併発したt(8;21)(q22;q22)急性骨髄性白血病

Superior sagittal sinus thrombosis (SSST) is a very rare but life-threatening complication in leukemia patients. SSST is very rare in acute myeloid leukemia (AML). In leukemia patients, several risk factors for SSST have been reported such as administration of L-asparaginase, disseminated intravascular coagulation, congenital thrombophilia, meningeal leukemia, and intrathecal chemotherapy (IT). Lumbar puncture itself and corticosteroid administration have also been acknowledged as risk factors. We describe herein our clinical experience with SSST in a 29-year-old Japanese man suffering from AML with t(8;21)(q22;q22), who presented with abrupt onset of loss of consciousness, left hemiplegia, and seizure soon after IT and high-dose cytarabine (HD-AraC) with dexamethasone for post remission consolidation. Despite the presence of intracranial hemorrhage (ICH) due to SSST rupture, we conducted anticoagulant therapy with heparin. Although ICH worsened temporarily, his clinical condition gradually improved with resolution of the SSST, and he eventually became fully ambulatory. There were no deficiencies of natural anticoagulants. Three additional cycles of HD-AraC without IT therapy were conducted, but no neurological complications recurred with the concomitant use of warfarin. He was discharged free of neurological deficits. In our case, there is a possibility that IT and the administration of corticosteroids along with HD-AraC triggered SSST.