[Intravascular large B-cell lymphoma with pontine involvement successfully treated with R-hyper-CVAD/R-MTX-Ara-C regimen]

A 47-year-old woman was admitted to our hospital complaining of persistent fever and dry cough in June 2007. CT scan showed hepatosplenomegaly. Laboratory data revealed pancytopenia and increased levels of LDH and soluble interleukin-2 receptor. Malignant lymphoma was suspected, but histological diagnosis was difficult because superficial lymph nodes could not be palpated. Histological examination of the bone marrow biopsy specimen demonstrated the proliferation of large atypical lymphoid cells positive for CD20 and CD79a in the small capillaries, leading to the diagnosis of intravascular large B-cell lymphoma (IVLBCL). Although the results of neurological examination and CSF analysis were normal, head MRI showed a T2-hyperintense lesion in the pons. We chose R-hyper-CVAD/R-MTX-Ara-C alternating therapy with MTX intrathecal injection because CNS involvement in IVLBCL was highly suspected, and she responded well. Head MRI showed the disappearance of the abnormal signal in the pons after one cycle of R-hyper-CVAD. Five cycles of R-hyper-CVAD/R-MTX-Ara-C were performed and complete remission was obtained. R-hyper-CVAD/R-MTX-Ara-C alternating therapy was effective in an IVLBCL patient with CNS involvement.

Non-tuberculous mycobacterial infection localized in small intestine developing after allogeneic bone marrow transplantation

A 33-year-old man with myelodysplastic/myeloproliferative disease underwent allogeneic bone marrow transplantation. Around day 80 post-transplant, he complained of abdominal pain and diarrhea. Colonoscopy and esophagogastroduodenoscopy findings were unremarkable. Double-balloon enteroscopy revealed atrophic villi and mild erosions localized in the small intestine. Histological examination revealed marked proliferation of histiocytes with numerous acid-fast bacilli in their cytoplasm. The specific polymerase chain reaction for Mycobacterium tuberculosis was negative, and a diagnosis of intestinal non-tuberculous mycobacteria (NTM) was made. Physicians should recognize that NTM infection is one of the gastrointestinal infectious complications in immunocompromised patients such as bone marrow transplant recipients, and could localize in the small intestine.

Haplotype-based case-control study of receptor (calcitonin) activity-modifying protein-1 gene in cerebral infarction

Calcitonin gene-related peptide (CGRP) receptor is a complex molecule that consists of calcitonin receptor-like receptor and receptor activity-modifying protein-1 (RAMP1). It was recently reported that RAMP1-deficient mice (RAMP1(-/-)) showed inflammatory responses with a transiently significant increase in serum CGRP levels and proinflammatory cytokines when compared with RAMP1(+/+) mice. The aim of this study was to investigate the relationship between the human RAMP1 gene and cerebral infarction (CI) using single-nucleotide polymorphisms (SNPs) in a Japanese population. We selected six SNPs in the human RAMP1 gene (rs3754701, rs3769048, rs7557078, rs1584243, rs10199956 and rs7590387) and performed a case-control study using each SNP and haplotype in 171 CI patients and 234 controls. There were no significant differences in overall distribution of genotype and allele frequencies of the SNPs between the CI and control groups. However, there was a significant difference in overall distribution between the CI and control groups (P<0.001) in the haplotype-based case-control study with the combinations of rs3754701-rs3769048-rs7590387. The T-A-C susceptibility haplotype for CI was significantly more frequent than in the control group (P=0.0024). The results suggest that the T-A-C haplotype is a genetic marker for CI, and that RAMP1 or neighbouring genes are associated with increased susceptibility to CI.

[CD4-positive diffuse large B-cell lymphoma]

An 82-year-old man received right upper lobectomy for lung cancer in April 2006. In August, 2006, he was readmitted to our hospital due to left cervical and left inguinal lymph node swelling. A pathologic diagnosis of diffuse large B-cell lymphoma (DLBCL) was made from a biopsy specimen of the left cervical lymph node. The immunophenotype of the lymphoma cells was CD2-, sCD3-, cCD3-, CD4+, CD5+, CD7-, CD8-, CD10-, CD19+, CD20+, CD23+, CD25+, kappa+, lambda-, CD56-, and dual staining confirmed that the cells were positive for both CD4 and CD19. From these findings, he was diagnosed with CD4-positive DLBCL. Five cycles of R-CHOP were performed and complete remission was achieved. To our knowledge, this is the first report of CD4-positive DLBCL.

Refractory plasmablastic type myeloma with multiple extramedullary plasmacytomas and massive myelomatous effusion: remarkable response with a combination of thalidomide and dexamethasone

A 74-year-old man with multiple myeloma was refractory to melphalan/prednisolone (MP), high-dose dexamethasone and VAD chemotherapy. He had the following poor prognostic factors: 1) multiple extramedullary plasmacytomas, 2) massive myelomatous effusion, 3) increasing immature myeloma cells with plasmablastic morphology, and 4) predominance of MPC1-CD49e-CD45+ phenotype immature myeloma cells. Combination therapy with thalidomide and dexamethasone resulted in a rapid response and a partial remission despite his multiple poor prognostic factors. The present case suggests that combination therapy with thalidomide and dexamethasone is still an alternative treatment regimen for resistant extramedullary plasmacytoma with a plasmablastic morphology.

[Sideroblastic anemia after prolonged linezolid therapy]

Linezolid is an effective and well-tolerated antibiotic for the treatment of infections caused by Gram-positive pathogens. Some reports have shown that linezolid treatment for more than 2 weeks has been associated with reversible bone marrow suppression, especially thrombocytopenia and anemia. We encountered a case of sideroblastic anemia following prolonged linezolid therapy in a laryngeal cancer patient. He received linezolid therapy for multiple abscesses due to MRSA. Before treatment, the Hb level was 12.5 g/dl and then slowly decreased to 5.9 g/dl for 2 months during treatment. Ringed sideroblasts were detected in the bone marrow. Linezolid was discontinued and the Hb level was slowly increased. This case was considered to reflect a rare complication of linezolid therapy.

Cantharidin induces apoptosis of human multiple myeloma cells via inhibition of the JAK/STAT pathway

Multiple myeloma is an incurable B-cell malignancy requiring new therapeutic strategies in clinical settings. Interleukin (IL)-6 signaling pathways play a critical role in the pathogenesis of multiple myeloma. The traditional Chinese medicine cantharidin (CTD) has been shown to inhibit cellular proliferation and induce apoptosis of various cancer cells. The aim of this study was to investigate the possibility of CTD as a novel therapeutic agent for the patients with multiple myeloma. We investigated the in vitro effects of CTD for its antimyeloma activity, and further examined the molecular mechanisms of CTD-induced apoptosis. CTD inhibited the cellular growth of human myeloma cell lines as well as freshly isolated myeloma cells in patients. Cultivation with CTD induced apoptosis of myeloma cells in a cell-cycle-independent manner. Treatment with CTD induced caspase-3, -8, and -9 activities, and it was completely blocked by each caspase inhibitor. We further examined the effect of CTD on the IL-6 signaling pathway in myeloma cells, and found that CTD inhibited phosphorylation of STAT3 at tyrosine 705 residue as early as 1 h after treatment and down-regulated the expression of the antiapoptotic bcl-xL protein. STAT3 directly bound and activated the transcription of bcl-xL gene promoter, resulting in the induction of the expression of bcl-xL in myeloma cells. The essential role of STAT3 in CTD effects was confirmed by transfection with the constitutively active and dominant negative form of STAT3 in U266 cells. In conclusion, we have demonstrated that CTD is a promising candidate to be a new therapeutic agent in signal transduction therapy.

Tacrolimus and methotrexate for the prophylaxis of graft-versus-host disease after unrelated donor cord blood transplantation for adult patients with hematologic malignancies

Eighteen patients with hematologic malignancies underwent cord blood transplantation (CBT) from unrelated donors after being conditioned with myeloablative or reduced-intensity regimens, and received tacrolimus and methotrexate (15 mg/m(2) on day 1, 10 mg/m(2) on days 3 and 6) as graft-versus-host disease (GVHD) prophylaxis. The median number of nucleated cells in infused cord blood was 2.66 x 10(7)/kg (range 1.90 to 4.15 x 10(7)/kg). Engraftment was achieved in 16 of 18 patients. The median time to absolute neutrophil count >0.5 x 10(9)/L was 21.5 days (range 17 to 32), and the median time to platelet count >2.0 x 10(9)/L was 36 days (range 26 to 57). Of the 16 evaluable patients, five and eight had grades I and II acute GVHD, respectively, and none had grades III/IV acute GVHD. The cumulative incidence of grade II acute GVHD was 44.4%. Chronic GVHD occurred in 7 of 15 evaluable patients: limited type in three patients, extensive type in four patients. Of the 18 patients, 14 were alive and disease-free between 173 and 1514 days after CBT (median 746 days). The probability of disease-free survival at 2 years was 79.1%. These results, although in a retrospective study, suggested that tacrolimus and short-term methotrexate effectively prevented the occurrence of severe acute GVHD after unrelated CBT, and may contribute to a high survival rate.

Myeloperoxidase Is a Key Regulator of Oxidative Stress–Mediated Apoptosis in Myeloid Leukemic Cells

PURPOSE

We reported previously that reactive oxygen species (ROS) are key mediators of apoptosis induced by a polyphenol, (-)-epigallocatechin-3-gallate (EGCG), in myeloid leukemic cells. This study aimed to further examine the mechanism of ROS-mediated apoptosis induced by EGCG and its relationship to the heme enzyme myeloperoxidase (MPO).

EXPERIMENTAL DESIGN

We established stably transfected K562 cells expressing wild-type and mutant MPO. Then, sensitivity against EGCG and other ROS-inducing agent was examined and further investigated the detailed molecular mechanism of ROS-inducing apoptosis in MPO-positive leukemic cells.

RESULTS

EGCG rapidly induced apoptosis in MPO-positive leukemia cells. Preincubation of myeloid leukemic cells with the MPO-specific inhibitor, 4-aminobenzoic acid hydrazide, and the heme biosynthesis inhibitor, succinylacetone, resulted in inhibition of the intracellular MPO activity, ROS production, and induction of apoptosis following addition of EGCG. Overexpression of MPO sensitized EGCG-resistant K562 cells to apoptosis induced by EGCG. In contrast, an enzymatically inactive MPO mutant-expressing K562 cell could not respond to EGCG, suggesting that MPO is important for determining the sensitivity to EGCG-induced oxidative stress. Hypochlorous acid scavengers and the hydroxyl radical (.OH) scavenger inhibited EGCG-induced apoptosis in myeloid leukemic cells. The fluorescence intensity of both aminophenyl fluorescein- and hydroxyphenyl fluorescein-loaded myeloid leukemic cells significantly increased on stimulation with EGCG, indicating that EGCG generated highly toxic ROS in myeloid leukemic cells.

CONCLUSIONS

These results indicated that highly toxic ROS such as .OH generated via the hydrogen peroxide/MPO/halide system induce apoptosis and that ROS may be the direct mediators of EGCG-induced apoptosis in MPO-positive leukemic cells.

Emodin has a cytotoxic activity against human multiple myeloma as a Janus-activated kinase 2 inhibitor

Emodin is an active component of a traditional Chinese and Japanese medicine isolated from the root and rhizomes of Rheum palmatum L. Here, we show that emodin significantly induces cytotoxicity in the human myeloma cells through the elimination of myeloid cell leukemia 1 (Mcl-1). Emodin inhibited interleukin-6-induced activation of Janus-activated kinase 2 (JAK2) and phosphorylation of signal transducer and activator of transcription 3 (STAT3), followed by the decreased expression of Mcl-1. Activation of caspase-3 and caspase-9 was triggered by emodin, but the expression of other antiapoptotic Bcl-2 family members, except Mcl-1, did not change in the presence of emodin. To clarify the importance of Mcl-1 in emodin-induced apoptosis, the Mcl-1 expression vector was introduced into the human myeloma cells by electroporation. Induction of apoptosis by emodin was almost abrogated in Mcl-1-overexpressing myeloma cells as the same level as in parental cells, which were not treated with emodin. In conclusion, emodin inhibits interleukin-6-induced JAK2/STAT3 pathway selectively and induces apoptosis in myeloma cells via down-regulation of Mcl-1, which is a good target for treating myeloma. Taken together, our results show emodin as a new potent anticancer agent for the treatment of multiple myeloma patients.

Blood eosinophilia as a marker of favorable outcome after allogeneic stem cell transplantation

Eosinophilia is observed in a variety of disorders including acute and chronic graft-versus-host disease (GVHD). The clinical records of 237 patients who underwent allogeneic stem cell transplantation (allo-SCT) were retrospectively reviewed. Eosinophilia, defined as a relative eosinophil count>4% within the first 100 days, was observed in 135 patients (57%). The incidence of grades II-IV acute GVHD was significantly higher in patients without eosinophilia than in those with eosinophilia (68% vs. 43%; P<0.001). The incidence of chronic GVHD was significantly higher in patients without eosinophilia than in those with eosinophilia (73% vs. 56%; P=0.011). Relapse rate was similar between patients with and without eosinophilia (33% vs. 27%; P=0.438). The probability of nonrelapse mortality was 10% in patients with eosinophilia, which was significantly lower than that in patients without eosinophilia (31%; P<0.001), and the overall survival (OS) at 3 years was 67% in patients with eosinophilia, which was significantly higher than that in patients without eosinophilia (51%; P=0.003). Multivariate analysis identified older age, high-risk disease, acute GVHD, sex disparity between patient and donor, and the absence of eosinophilia as significant factors for reduced OS. These data lead us to conclude that eosinophilia after allo-SCT may serve as a favorable prognostic marker.

A natural peptide, dolastatin 15, induces G2/M cell cycle arrest and apoptosis of human multiple myeloma cells

Several anti-cancer agents are derivative from natural products and microorganisms. The dolastatins are natural peptides derived from the marine mollusc Dolabella auricularia, which have recently been reported as an anti-cancer agent. Dolastatin 10 and 15 are small peptides; most preclinical studies have used dolastatin 10. It has been reported that dolastatins have cytotoxic activity by inhibiting microtubule assembly, and several clinical studies have already begun for solid tumors. However, the effects of dolastatin 15 against hematological malignancies such as myeloma cells have never been reported. We demonstrate here for the first time that dolastatin 15 induces cell cycle arrest at the G2/M phase followed by apoptosis in various human myeloma cell lines (RPMI8226, U266, and IM9), suggesting that it has effects on mitotic spindles. In addition, we showed that dolastatin 15 induces apoptosis of myeloma cells via activation of both mitochondrial- and Fas (CD95)/Fas-L (CD95-L)-mediated pathways. Our investigations have identified a novel inhibitor of microtubule assembly that induces mitotic arrest and apoptosis of myeloma cells. Therefore, it is possible that dolastatin 15 might be a novel and safe therapeutic agent for patients with multiple myeloma.

Risk factors for developing human herpesvirus 6 (HHV-6) reactivation after allogeneic hematopoietic stem cell transplantation and its association with central nervous system disorders

We prospectively evaluated the incidence of human herpesvirus 6 (HHV-6) DNAemia after allogeneic hematopoietic stem cell transplantation (HSCT) using quantitative plasma real-time polymerase chain reaction. Of 46 recipients of bone marrow or peripheral blood stem cell transplantation (BMT/PBSCT) from related (n = 11) or unrelated donors (n = 22), and cord blood transplantation (CBT) from unrelated donors (n = 13), 22 (47.8%) developed HHV-6 DNAemia. HHV-6 DNA levels ranged from 200 to 200,000 copies/mL of plasma, and HHV-6 DNAemia was observed significantly more frequently after CBT than after BMT/PBSCT (92.3% vs 30.3%; P < .001). Multivariate analyses identified CBT (vs BMT/PBSCT), HLA mismatches between recipient and donor, and low anti-HHV-6 IgG titer before transplantation as the only risk factors for developing HHV-6 DNAemia. Three patients developed central nervous system (CNS) disorders with detectable HHV-6 DNA in the cerebrospinal fluid; all of these patients simultaneously developed HHV-6 DNAemia. These results suggest that HHV-6 DNAemia is frequently observed after allogeneic HSCT, especially in patients with the aforementioned risk factors. Thus, together with the assessment of risk factors, monitoring of HHV-6 DNAemia could be a useful asset in diagnosing HHV-6-associated CNS disorders.

Sperm protein 17 influences the tissue-specific malignancy of clear cell adenocarcinoma in human epithelial ovarian cancer

Clear cell adenocarcinoma of the ovary has a poor prognosis due to chemoresistance and early metastasis to the lymph nodes. It also can result in endometriosis and is the second most frequent type of ovarian cancer in Japan. Serous adenocarcinoma of the ovary is another common epithelial cancer tissue subtype in Japan, and it is highly sensitive to chemotherapy. In the current study, we examined the differential expression of genes in these types of ovarian cancer and tried to analyze their functions, especially as they relate to chemoresistance. We used differential display to compare clear cell carcinoma and serous adenocarcinoma of the ovary. We identified sperm protein 17 (SP17) as a candidate gene related to the chemoresistance of clear cell carcinoma. Its differential expression was confirmed by real-time polymerase chain reaction. Because the function of the SP17 gene in ovarian cancer is not known, we examined the effect of small interfering RNA targeting the SP17 gene on the chemoresistance and proliferation of ES-2 ovarian cancer cells to paclitaxel, currently the most effective treatment for ovarian cancer. We found that this treatment decreased the chemoresistance of these cells to paclitaxel. Our results strongly suggest that SP17 plays a role in the resistance of clear cell carcinoma to chemotherapy without influencing their ability to proliferate

Total body irradiation and granulocyte colony-stimulating factor-combined high-dose cytarabine as a conditioning regimen in allogeneic hematopoietic stem cell transplantation for advanced myelodysplastic syndrome: a single-institute experience

In this study, we retrospectively evaluated the efficacy and safety of total body irradiation (TBI) and granulocyte colony-stimulating factor (G-CSF)-combined high-dose cytarabine as a conditioning regimen for allogeneic hematopoietic stem cell transplantation (HSCT) in patients with advanced myelodysplastic syndrome (MDS). We evaluated 22 patients with advanced MDS, including refractory anemia with excess blasts (RAEB; n=10), RAEB in transformation (n=2), acute myelogenous leukemia transformed from MDS (n=6) and chronic myelomonocytic leukemia (n=4). The conditioning regimen consisted of 12 Gy of TBI and high-dose cytarabine (3 g/m(2)) every 12 h for 4 days, and the cytarabine was combined with continuous administration of G-CSF. The stem cell sources were bone marrow or peripheral blood stem cells from human leukocyte antigen (HLA)-identical siblings (n=12) and bone marrow from HLA serologically matched unrelated donors (n=10). Three patients experienced disease relapse, two of whom died of disease progression. Of 22 patients, 16 are currently alive and disease-free. The 5-year estimated overall survival, disease-free survival, relapse and non-relapse mortality rates are 76.7, 72.2, 16.6 and 14.1%, respectively. These results suggest that G-CSF-combined high-dose cytarabine could be a promising component of the conditioning regimen of allogeneic HSCT for advanced MDS, providing a low incidence of both relapse and treatment-related mortality.