Ryuko Nakayama

Galectin-3 (Gal-3) induced by leukemia microenvironment promotes drug resistance and bone marrow lodgment in chronic myelogenous leukemia

Bone marrow (BM) microenvironment (BMME) constitutes the sanctuary for leukemic cells. In this study, we investigated the molecular mechanisms for BMME-mediated drug resistance and BM lodgment in chronic myelogenous leukemia (CML). Gene-expression profile as well as signal pathway and protein analyses revealed that galectin-3 (Gal-3), a member of the β-gal–binding galectin family of proteins, was specifically induced by coculture with HS-5 cells, a BM stroma cell-derived cell line, in all five CML cell lines examined. It was also found that primary CML cells expressed high levels of Gal-3 in BM. Enforced expression of Gal-3 activated Akt and Erk, induced accumulation of Mcl-1, and promoted in vitro cell proliferation, multidrug resistance to tyrosine kinase inhibitors for Bcr-Abl and genotoxic agents as a result of impaired apoptosis induction, and chemotactic cell migration to HS-5–derived soluble factors in CML cell lines independently of Bcr-Abl tyrosine kinase. The conditioned medium from Gal-3–overexpressing CML cells promoted in vitro cell proliferation of CML cells and HS-5 cells more than did the conditioned medium from parental cells. Moreover, the in vivo study in a mice transplantation model showed that Gal-3 overexpression promoted the long-term BM lodgment of CML cells. These results demonstrate that leukemia microenvironment-specific Gal-3 expression supports molecular signaling pathways for disease maintenance in BM and resistance to therapy in CML. They also suggest that Gal-3 may be a candidate therapeutic target to help overcome BMME-mediated therapeutic resistance.

Cyclosporine A for Chemotherapy-Resistant Subcutaneous Panniculitis-Like T Cell Lymphoma with Hemophagocytic Syndrome

Subcutaneous panniculitis-like T cell lymphoma (SPTL) is a rare subtype of non-Hodgkin lymphoma for which a definitive therapeutic strategy has not been established yet. We report a case of chemotherapy-resistant SPTL with hemophagocytic syndrome (HPS) which was successfully treated with cyclosporine A (CsA) plus methylprednisolone (mPSL), and also reviewed 11 SPTL cases treated with CsA, previously reported in the literature. Our patient was a 38-year-old female with SPTL. The disease progressed despite conventional chemotherapy using cytotoxic agents including alkylators, anthracyclins or purine analogues, and, after 2 months of chemotherapy, was eventually complicated by HPS and disseminated intravascular coagulation (DIC). CsA (4 mg/kg/day) plus mPSL treatment dramatically improved HPS with DIC, reduced subcutaneous tumors within 2 weeks, and finally induced complete remission (CR) after 3 months. Currently, the patient has maintained CR while being treated with CsA for 12 months. In addition to our case, 9 of 11 SPTL cases were successfully treated with CsA, and 8 were induced to CR. Time to first response to CsA was within 2 weeks in most cases, regardless of prior treatment or the co-occurrence of HPS. Our case and this first comprehensive review on CsA for SPTL suggest that CsA may constitute a candidate treatment strategy for SPTL.

FTY720 induces apoptosis of chronic myelogenous leukemia cells via dual activation of BIM and BID and overcomes various types of resistance to tyrosine kinase inhibitors

PP2A activator FTY720 has been shown to possess the anti-leukemic activity for chronic myelogenous leukemia (CML), however, the cell killing mechanism underlying its anti-leukemic activity has remained to be verified. We investigated the precise mechanisms underlying the apoptosis induction by FTY720, especially focusing on the roles of BH3-only proteins, and the therapeutic potency of FTY720 for CML. Enforced expression of either BCL2 or the dominant-negative protein of FADD (FADD.DN) partly protected CML cells from apoptosis by FTY720, indicating the involvement of both cell extrinsic and intrinsic apoptosis pathways. FTY720 activates pro-apoptotic BH3-only proteins: BIM, which is essential for apoptosis by BCR-ABL1 tyrosine kinase inhibitors (TKIs), and BID, which accelerates the extrinsic apoptosis pathway. Gene knockdown of either BIM or BID partly protected K562 cells from apoptosis by FTY720, but the extent of cell protection was not as much as that by overexpression of either BCL2 or FADD.DN. Moreover, knockdown of both BIM and BID did not provide additional protection compared with knockdown of only BIM or BID, indicating that BIM and BID complement each other in apoptosis by FTY720, especially when either is functionally impaired. FTY720 can overcome TKI resistance caused by ABL kinase domain mutations, dysfunction of BIM resulting from gene deletion polymorphism, and galectin-3 overexpression. In addition, ABT-263, a BH3-mimetic, significantly augmented cell death induction by FTY720 both in TKI-sensitive and -resistant leukemic cells. These results provide the rationale that FTY720, with its unique effects on BIM and BID, could lead to new therapeutic strategies for CML.

RSK2 Ser227 at N-Terminal Kinase Domain Is a Potential Therapeutic Target for Multiple Myeloma

Multiple myeloma is an entity of cytogenetically and genetically heterogenous plasma cell neoplasms. Despite recent improvement in the treatment outcome of multiple myeloma by novel molecular-targeted chemotherapeutics, multiple myeloma remains incurable. The identification of a therapeutic target molecule in which various signaling for cell-survival converge is a core component for the development of new therapeutic strategies against multiple myeloma. RSK2 is an essential mediator of the ERK1/2 signaling pathway for cell survival and proliferation. In this study, we discovered that RSK2Ser227, which is located at the N-terminal kinase domain and is one site responsible for substrate phosphorylation, is activated through phosphorylation regardless of the type of cytogenetic abnormalities or upstream molecular signaling in all 12 multiple myeloma–derived cell lines examined and 6 of 9 patient-derived CD138-positive primary myeloma cells. The chemical inhibition of RSK2Ser227 by BI-D1870 or gene knockdown of RSK2 inhibits myeloma cell proliferation through apoptosis induction, and this anti-myeloma effect was accompanied by downregulation of c-MYC, cyclin D, p21WAF1/CIP1, and MCL1. RSK2Ser227 inhibition resulting from BI-D1870 treatment restored lenalidomide-induced direct cytotoxicity of myeloma cells from interleukin-6–mediated cell protection, showed no cross-resistance to bortezomib, and exerted additive/synergistic antiproliferative effects in conjunction with the mTOR, histone deacetylase, and BH3-mimicking BCL2/BCLXL inhibitors. These results suggest that RSK2Ser227 is a potential therapeutic target not only for newly diagnosed but also for patients with later phase multiple myeloma who are resistant or refractory to currently available anti-myeloma therapies. Mol Cancer Ther; 11(12); 2600–9. ©2012 AACR.

Suppression of SERPINA1-albumin complex formation by galectin-3 overexpression leads to paracrine growth promotion of chronic myelogenous leukemia cells

Galectin-3 is induced in chronic myelogenous leukemia (CML) cells by co-culture with bone marrow stromal cells, making paracrine growth promotion of CML cells in conditioned medium (CM) from galectin-3 overexpressing CML cells more potent. We used gel filtration chromatography to demonstrate that the bovine SERPINA1-fetal bovine serum albumin (BSA) complex was specifically suppressed in CM from galectin-3 overexpressing cells. The SERPINA1-BSA complex as well as human plasma SERPINA1 inhibited the growth of CML cells, while exogenous galectin-3 partly offset this effect. These findings suggest that galectin-3 overexpression promotes paracrine growth of CML cells by interfering with the action of the growth inhibitory SERPINA1-albumin complex.

Clinical manifestation of angioimmunoblastic T-cell lymphoma with exuberant plasmacytosis.

Angioimmunoblastic T-cell lymphoma (AITL) is a rare subtype of non-Hodgkin lymphoma characterized by aggressive symptoms and various abnormal laboratory test results. One of the rare immunologic abnormalities in AITL is exuberant polyclonal plasmacytosis, but its clinical significance has not been evaluated. This report concerns three AITL cases with exuberant polyclonal plasmacytosis and investigates its clinical impact by comparison with 12 patients without plasmacytosis. Our study found that the performance status (PS) of the former was significantly worse and their serum immunoglobulin levels were significantly higher. All other parameters, including B symptoms, various prognostic scores, blood cell counts other than plasmacyte, and serum levels of lactate dehydrogenase, C-reactive protein and soluble interleukin-2 receptor, showed no significant differences. More importantly, although the diagnosis of AITL with plasmacytosis was not straightforward in our series, outcomes of treatment with conventional chemotherapy or immunosuppressive therapy with cyclosporine A were favorable. To conclude, AITL should be considered a candidate underlying disease of exuberant polyclonal plasmacytosis. Provided a correct diagnosis is made early and is followed by adequate treatment, the prognosis for AITL with plasmacytosis may not be worse than that for those without plasmacytosis despite the severe exhaustion at first presentation.

Close pathogenetic relationship between ocular immunoglobulin G4-related disease (IgG4-RD) and ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma

Immmunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a chronic sclerosing inflammatory disease characterized by mass-forming lesions such as swelling, nodules or hypertrophy in one or more organs...

Comprehensive cytogenetic study of primary cutaneous gamma-delta T-cell lymphoma by means of spectral karyotyping and genome-wide single nucleotide polymorphism array.

Primary cutaneous gamma-delta T-cell lymphoma (PCGD-TCL), which originates from activated mature gamma-delta T cells with a cytotoxic phenotype is a rare T-cell lymphoproliferative disease. The prognosis of PCGD-TCL has been rather unfavorable due to poor response to conventional chemotherapy, and its molecular features and pathophysiology underlying disease development remain unknown. We report here a case with primarily treatment-resistant PCGD-TCL featuring highly complex cytogenetic and genetic aberrations detected by spectral karyotyping and genome-wide single nucleotide polymorphism (SNP) array. Chromosomal aberrations included several chromosomal translocations involving breakpoints at 9p21, 14q11.2, 14q32.1, or 16q23.1, suggesting the involvement of WWOX, TCL gene cluster, and BCL11B, which are crucial for tumorigenesis in T-cell lymphomas. SNP analysis also identified genome copy number gains and losses in various regions, which can potently deregulate expression of various pro- and anti-oncogenic genes involved in RAS-related protein pathways, PI3K/AKT/MTOR-related pathways, MYC-related signaling, or TP53-related signaling. Thus, this case report may shed some light on the complex molecular abnormalities involved in the development of PCGD-TCL and on information that can aid the search for druggable target molecules in this disease.

Clinical Studies of Molecular Targeted Therapy for Multiple Myeloma

Multiple myeloma (MM) is the second most common hematological malignancy of plasma cells which still remains incurable despite conventional and high-dose chemotherapies. With the introduction of new agents, such as bortezomib, thalidomide, and lenalidomide, there has been significant improvement in treatment outcomes for MM during the last decade. Furthermore, several new novel agents those offer further possibilities for MM patients have become available clinical trials. Nevertheless, it is unclear the appropriate usage of these agents to obtain optimal survivals, for example, whether sequencing of drugs or multi-agent combinations offer the superiority. In this review we will describe the various classes of novel agents being used for MM treatment, including proteasome inhibitors, immunomodulatory drugs, histone deacetylase inhibitors, monoclonal antibodies, and other novel agents, with particularly focus on their mechanisms and clinical efficacy.

Bortezomib for post-allogeneic hematopoietic stem transplantation relapse and GVHD in multiple myeloma: a single institute experience.

Allogeneic hematopoietic stem cell transplantation (alloSCT) can result in remission and long-term survival for multiple myeloma (MM), but its effect has been often hampered by high rates of therapy-related death by graftversus-host diseases (GVHD), disease progression, or infection [1]. We retrospectively investigated the efficacy and safety of Bortezomib (Bor) alone or with dexamethasone (Dex) (BD) for MM patients with disease progression following allo-SCT. Six MM patients were treated with Bor alone or with BD as the salvage treatment for disease progression following allo-SCT, while 32 patients with relapsed/refractory MM without allo-SCT were also treated with BD at our institute between October 2003 and July 2009. The median age was 39.5 years old for the allo-SCT cohort and 67.5 for the non-allo-SCT cohort. None had prior exposure to Bor. In six post-allo-SCT patients, two underwent a conditioning regimen with high-dose cyclophosphamide (60 mg/kg) plus total body irradiation (10 Gy), while four were treated with a reduced intensity-conditioning regimen using fludarabine (90–125 mg/m) plus melphalan (140–200 mg/m) (Table 1). According to the International Myeloma Working Group response criteria, the best response for alloSCT was complete remission (CR) in one, very good partial response (VGPR) in two and stable disease (SD) in three patients. Bor (1.3, 1.0, or 0.7 mg/m/day) was administered on days 1, 4, 8 and 11, and Dex on days 1, 2, 4, 5, 8, 9, 11 and 12, every 21 days. The dosage of either agent was adjusted by the attending physician in the light of the patient’s condition. Among the six post-allo-SCT patients, one received Bor alone and five received BD, while all patients in the non-allo-SCT cohort received BD. The median number of cycles of Bor alone or BD was 3 (1–7 cycles) for the post-allo-SCT cohort and 2 for the non-allo-SCT cohort. The median interval between allo-SCT to Bor or BD was 12.5 months (6–22 months). All presented acute and chronic GVHD. Three patients received thalidomidecontaining therapy for post-allo-SCT disease progression prior to Bor (Table 2). For the six post-allo-SCT patients, the overall response rate (ORR) was 50.0%, including two VGPR and one PR, while two died of MM progression and one of bacterial pneumonia complicated with bronchiolitis obliterans, a late complication of allo-SCT. Although ORR for the allo-SCT cohort was inferior to that of the non-alloSCT cohort (68.8%), the median overall survival (OS) (912 days) and median progression-free survival (PFS) (71 days), 2-year OS (66.7%) and 2-year PFS (33.3%) from the start of Bor-containing treatment for the allo-SCT cohort did not seem significantly different from those for the non-allo-SCT cohort, although the statistical analysis was not applicable due to the small number of patients (Supplementary Fig. 1). Our findings thus seem to provide further supportive evidence that Bor or BD constitutes a promising salvage treatment even for heavily treated Electronic supplementary material The online version of this article (doi:10.1007/s12185-010-0709-3) contains supplementary material, which is available to authorized users.