Safety and pharmacokinetics of milademetan, a MDM2 inhibitor, in Japanese patients with solid tumors: A phase I study.

Milademetan (DS-3032, RAIN-32) is an orally available mouse double minute 2 (MDM2) antagonist with potential antineoplastic activity owing to increase in p53 activity through interruption of the MDM2-p53 interaction. This phase I, dose-escalating study assessed the safety, tolerability, efficacy, and pharmacokinetics of milademetan in 18 Japanese patients with solid tumors who relapsed after or were refractory to standard therapy. Patients aged ≥ 20 years received oral milademetan once daily (60 mg, n = 3; 90 mg, n = 11; or 120 mg, n = 4) on days 1 to 21 in a 28-day cycle. Dose-limiting toxicities, safety, tolerability, maximum tolerated dose, pharmacokinetics, and recommended dose for phase II were determined. The most frequent treatment-emergent adverse events included nausea (72.2%), decreased appetite (61.1%), platelet count decreased (61.1%), white blood cell count decreased (50.0%), fatigue (50.0%), and anemia (50.0%). Dose-limiting toxicities (three events of platelet count decreased and one nausea) were observed in the 120-mg cohort. The plasma concentrations of milademetan increased in a dose-dependent manner. Stable disease was observed in seven out of 16 patients (43.8%). Milademetan was well tolerated and showed modest antitumor activity in Japanese patients with solid tumors. The recommended dose for phase II was considered to be 90 mg in the once-daily 21/28-day schedule. Future studies would be needed to further evaluate the potential safety, tolerability, and clinical activity of milademetan in patients with solid tumors and lymphomas. The trial was registered with Clinicaltrials.jp: JapicCTI-142693.

A Case of Primary Myelofibrosis in Which Ruxolitinib Therapy Ameliorated the Fibrosis, but Resulted in Fatty Marrow.

A 63-year-old woman was referred to our department in 2015 because of anemia and thrombocytosis. MPL W515/K was positive, JAK-2V617F and CALR exon 9 were negative. Bone marrow(BM)biopsy led to a diagnosis of primary myelofibrosis (PMF)in the prefibrotic/early stage(Grade 1). BMbiopsy performed in 2016 showed overt fibrotic stage(Grade 2). She was classified according to the Dynamic International Prognostic Scoring System(DIPSS)as intermediate(Int)-Ⅱrisk. Ruxolitinib 10 mg daily was initiated. Ruxolitinib was suspended for hepatic dysfunction after the dose was increased to 15 mg. Subsequently, ruxolitinib was resumed at 10 mg. BM biopsy performed in 2017 showed progression of myelofibrosis(MF)to Grade 3. BM biopsy performed in 2018 showed improved to Grade 0-1, however, BM was fatty. Currently in 2019, she continues to be on ruxolitinib. Results of immunohistochemical staining of BM biopsy specimens for cytokines and CD34 suggested the role of cytokines in the pathogenesis of the PMF. It was speculated that ruxolitinib blocked the production of cytokines to ameliorate the MF and restore the hematopoietic function of the BM. Although the pathogenesis of the fatty marrow remained unclear, the possibility of involvement of ruxolitinib cannot be denied.

Clinical Evaluation of the Efficacy and Safety of Anagrelide Used with or without Hydroxycarbamide in Japanese Patients with Essential Thrombocythemia-A Retrospective Single-Center Study of 35 Cases.

OBJECTIVE: The clinical features(CF), laboratory data, disease transformation pattern and drug metabolism in essential thrombocythemia(ET)differ between Japan and Western countries. The CF of ET in clinical practice(CP)are more diverse than in prospective clinical studies. We should conduct retrospective analyses in CP. The present study was aimed at evaluating the efficacy, safety and tolerability of anagrelide(ANA)monotherapy and combined ANA plus hydroxycarbamide(HC)in Japanese ET. PATIENTS AND METHODS: We have a total of 35 cases. Sixteen patients received ANA monotherapy, 10 received ANA plus HC, and 9 received ANA plus other drugs. RESULTS: Comparison among three groups revealed the absence of differences in response rate(platelet count C60×10 / / 4/mL, platelet count C40×104/mL)(43.8%, 6.3% vs. 50.0%, 10.0% vs. 44.4%, 11.1%), treatment continuation rate(81.3% vs. 40.0% vs. 55.6%), median daily dose of ANA(1.00 mg in all three groups)or median treatment period(days)(259 vs. 198.5 vs. 161.0), the treatment continuation rate tended to be lower in the combined ANA plus HC. The incidence of all adverse events(AEs)was higher in the ANA monotherapy(45.7%)than ANA plus HC(28.6%)or ANA plus other drugs(25.7%), the AEs were mild in all groups. CONCLUSION: The tolerability of ANA monotherapy, ANA plus HC, and ANA plus other drugs were good.

A Case of Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia with Aspergillus Brain Abscess and Invasive Pulmonary Aspergillosis Successfully Treated with Voriconazole Followed by Cord Blood Transplantation.

A 59-year-old female was diagnosed as pulmonary aspergillosis(IPA)while remission induction therapy for Philadelphia chromosome-positive acute lymphoblastic leukemia. Liposomal amphotericin B improved the fungal serodiagnostic markers, however,the IPA worsened. She also developed an Aspergillus brain abscess,which, while being undetectable on CT,was detected as multiple nodular lesions by MRI. A definitive diagnosis was made by polymerase chain reaction(PCR)of brain biopsy specimens. Voriconazole(VRCZ)was effective,and cord blood transplantation was performed. She has received VRCZ for a long time. There are no relapse of either the IPA or the Aspergillus brain abscess.

Retrospective Analysis of 20 Patients with DLBCL Who Received MCVAC Followed by Autologous Peripheral Blood Stem Cell Transplantation.

Autologous peripheral blood stem cell transplantation(auto-PBSCT)combined with high-dose chemotherapy has been considered as the standard therapy for relapsed or induction therapy-refractory aggressive lymphomas sensitive to chemotherapy. While various regimens have been applied as the conditioning,none has yet been established as the standard. We have begun to employ high-dose ranimustine,cytarabine,etoposide and cyclophosphamide(MCVAC)regimen. The present study was undertaken to review the efficacy and safety of MCVAC. Regimen: We carried out a retrospective analysis of 20 patients diagnosed as diffuse large B-cell lymphoma. The median follow-up duration of 20 patients was 13.05 months(range, 0.57-49.5 months). The 4-year OS and PFS were 57.8% and 30.2%,respectively. Relapse was the most frequent cause of treatment failure(n=7). The major toxicities were anorexia/nausea(95%),diarrhea (75%),hypokalemia (70%). One patient died of hepatic veno-occlusive disease(VOD). The serious adverse events included hypokalemia,arrhythmia,cerebral hemorrhage,and heart failure(1 case[5%]each). There was 1 case of a late-onset adverse event: therapy-related myelo- dysplastic syndrome/acute myeloblastic leukemia(MDS/AML). MCVAC regimen was concluded as effective and well-toler- ated. However,we should carefully monitored for the possible development of VOD and MDS/AML. Further follow-up is needed to evaluate the long-term efficacy and safety.

Rapid progression of anemia related to tumor-lysis syndrome associated with bortezomib treatment in myeloma patients.

OBJECTIVE: Tumor-lysis syndrome is a rare complication in patients with multiple myeloma. However, bortezomib treatment for myeloma is often associated with tumor-lysis syndrome. METHODS: We developed an index called the rapid anemia progression index, which represents the duration and progression of anemia, to evaluate risk factors for tumor-lysis syndrome. We retrospectively reviewed 35 relapsed or refractory myeloma patients treated with bortezomib-containing treatment in our institution. We analyzed various parameters, including albumin, lactase dehydrogenase, ß2-microglobulin and creatinine, similar to the rapid anemia progression index, and evaluated the risk factors for tumor-lysis syndrome associated with bortezomib by the Cairo-Bishop definition. RESULTS: Clinical tumor-lysis syndrome occurred in six patients (17.1%). Tumor-lysis syndrome occurred during the first course of bortezomib-containing treatment among all the patients. The result of the area under the receiver operating characteristic curve for the rapid anemia progression index was 0.759 (P = 0.049). The rapid anemia progression index was more accurate than the index of lactate dehydrogenase, ß2-microglobulin, albumin and creatinine according to the receiver operating characteristic curve. For a cut-off point of -1.12 for the rapid anemia progression index, the sensitivity and specificity were 66.7 and 82.8%, respectively. CONCLUSIONS: The rapid anemia progression index is related to clinical tumor-lysis syndrome associated with bortezomib treatment for multiple myeloma patients with a cut-off point of -1.12 g/dl/month.

Prognostic value of C-reactive protein, lactase dehydrogenase and anemia in recurrent or refractory aggressive lymphoma.

OBJECTIVE: Prognostic predictors for newly diagnosed malignant lymphoma are well known. However, they have not been compared for patients with recurrent or refractory malignant lymphoma. METHODS: We retrospectively analyzed biological prognostic predictors for patients with recurrent or refractory aggressive lymphoma, such as serum levels of C-reactive protein, lactate dehydrogenase, hemoglobin, ß2-microglobulin and soluble interleukin-2 receptor before salvage therapy. The primary endpoint was overall survival after salvage treatment. First, univariate and multivariate analyses were performed for each of the parameters, using the log-rank test and Cox regression analysis, respectively. Secondly, we classified the patients into three risk groups on the basis of significant poor predictors. RESULTS: Sixty-three patients, including 41 patients with diffuse large B-cell lymphoma, were included in this study. Overall survival was significantly worse in patients with elevated C-reactive protein level (hazard ratio 3.757; P = 0.017), elevated lactate dehydrogenase level (hazard ratio 3.948; P = 0.010) and anemia (hazard ratio 3.925; P = 0.016) by multivariate analysis. We classified patients into two groups based on these three biological parameters. The median overall survival of the high- and low-risk patients was 5.8 and 60.1 months, respectively (log-rank test; P < 0.001). The overall response rate was significantly higher among the low-risk patients than among the high-risk patients (71.4 versus 28.6%, P = 0.005). Those results were similar among all aggressive lymphoma and diffuse large B-cell lymphoma. CONCLUSIONS: Elevated C-reactive protein level, elevated lactate dehydrogenase level and anemia before salvage treatment predicted poorer outcomes among patients with recurrent or refractory aggressive lymphoma.

A phase I study of oral panobinostat (LBH589) in Japanese patients with advanced solid tumors.

OBJECTIVE: The objective was to determine the maximum tolerated dose and the dose-limiting toxicity of panobinostat (LBH589) when administered as a single agent to adult patients with advanced solid tumors or cutaneous T-cell lymphoma whose disease had progressed despite standard therapy or for whom no standard therapy existed. METHODS: Panobinostat was administered orally once daily on Monday, Wednesday, and Friday of each week. A total of 13 patients were treated with one of three initial doses: 10 mg (n = 3), 15 mg (n = 4), or 20 mg (n = 6). RESULTS: No dose-limiting toxicity was observed in 12 evaluable patients. The most frequently reported adverse events, regardless of whether they were related to the study drug, were diarrhea and nausea in 10 patients (76.9%). Thrombocytopenia was reported in 12 of 13 patients (92.3%). Five of 11 patients (45.4%) had stable disease. CONCLUSION: Panobinostat administered orally once daily on Monday, Wednesday, and Friday of each week was well tolerated at doses up to 20 mg in Japanese patients. Dose escalation did not proceed after exploration of the 20 mg dose due to emerging global clinical data at that time.

Feasibility and efficacy of combined cisplatin and irinotecan chemotherapy for poorly differentiated neuroendocrine carcinomas.

OBJECTIVE: No standard treatment has been established for poorly differentiated neuroendocrine carcinoma; the usual recommended treatment is based on the strategy for small cell lung carcinoma. The aim of this study was to evaluate the response of poorly differentiated neuroendocrine carcinoma to the combination of irinotecan and cisplatin in one institution. METHODS: We retrospectively reviewed 50 poorly differentiated neuroendocrine carcinoma patients treated from September 2005 to April 2011 in our institution. Patients were divided into two stages: limited disease or extensive disease. Forty-four patients received the combination chemotherapy of irinotecan and cisplatin, consisting of 4-week cycles of 60 mg/m(2) irinotecan on days 1, 8, 15 and 60 mg/m(2) cisplatin on day 1. RESULTS AND CONCLUSION: Median age was 60 years. Median follow-up time was 11.4 months. Overall survival did not reach the median, and 1-year overall survival was 67%. The response rate was 50% (64% at first line), and progression-free survival was 4.8 months (7.3 months at first line). Grade 3-4 hematologic adverse events were seen in 29 patients (66%) and Grade 3-4 non-hematologic adverse events were seen in 20 patients (45%), but no patients died of adverse events. Multivariate analysis showed a statistically significant relationship with neuron-specific enolase elevation and poor overall survival (P= 0.016, hazard ratio 6.261, 95% confidence interval). The combination chemotherapy of irinotecan and cisplatin is moderately effective and feasible, and it should be considered as a treatment option for poorly differentiated neuroendocrine carcinoma.

Identification of CD20 C-terminal deletion mutations associated with loss of CD20 expression in non-Hodgkin's lymphoma.

PURPOSE: Rituximab is commonly incorporated into CD20-positive B-cell lymphoma therapy to improve response and prognosis. With increasing use, resistance to rituximab is a continuing concern, but CD20 mutation as a cause of resistance has not previously been reported. EXPERIMENTAL DESIGN: Freshly collected lymphoma cells from 50 patients with previously untreated or relapsed/resistant non-Hodgkin's B-cell lymphomas (diffuse large B cell, n = 22; follicular, n = 7; mucosa associated lymphoid tissue, n = 16; chronic lymphocytic leukemia, n = 2; small lymphocytic lymphoma, n = 1; lymphoplasmacytic, n = 1; mantle cell lymphoma, n = 1) were assessed for CD20 expression by flow cytometry, and CD20 gene sequencing was done on extracted DNA. RESULTS: CD20 mutations were found in 11 (22.0%) of 50 patients and could be grouped as C-terminal deletion (8.0%), early termination (10.0%), and extracellular domain (2.0%) or transmembrane domain (2.0%) mutations. The mean fluorescence intensity of CD20 on fresh lymphoma cells was significantly lower for the C-terminal deletion mutation [3.26; 95% confidence interval (95% CI), 0.09-6.89] compared with wild type (30.8; 95% CI, 22.4-39.2; P < 0.05). In contrast, early termination mutations did not show significant differences in CD20 expression compared with wild type (19.5; 95% CI, 10.7-28.4; P > 0.05). CONCLUSIONS: It is possible that C-terminal deletion mutations of CD20 may be related to relapse/resistance after rituximab therapy. These mutations should be examined in patients showing progression of disease after partial remission.

[Efficacy of CHOP+/-Rituximab-like therapy plus radiation therapy for patients with diffuse large B-cell lymphoma stage I].

Clinically, R-CHOP-like therapy plus radiation therapy is commonly performed for patients with limited stage diffuse large B-cell lymphoma. However, the efficacy and the safety of the management have not been evaluated properly. In particular, we have few definitive reports about patients with stage I DLBCL. This time we evaluated the effect of CHOP+/-R-like therapy plus radiation therapy, by analyzing 28 patients with stage I DLBCL, retrospectively. 15 patients were treated with the RCHOP-like therapy, and 13 received CHOP-like therapy combined with radiation therapy. A complete response was observed in all of the patients. With a median follow-up time of 14 months, 1-year progression-free survival (PFS) was 100%, and the 1-year overall survival (OS) was 100% for the patients receiving the R-CHOP-like therapy. With a median follow-up time of 68 months, 5-year PFS was 84. 6%, and 5-year OS was 100% for patients receiving the CHOP-like therapy. Since the followup time was not enough and the patient numbers were too few, the benefit of the addition of Rituximab to the CHOP therapy could not be clarified. We need to assess the safety and the efficacy of the combined modality therapy for patients with limited-stage DLBCL by a larger prospective study.

Methotrexate-associated Hodgkin Lymphoma in a Patient with Rheumatoid Arthritis Successfully Treated with Brentuximab Vedotin in Combination with Doxorubicin, Vinblastine, and Dacarbazine (BV+AVD).

A 53-year-old woman had been diagnosed with rheumatoid arthritis (RA) in X-6. She was started on methotrexate (MTX) in X-1. She developed a cough, and chest computed tomography showed abnormalities. In X, MTX was discontinued, but the cough persisted. A lung biopsy revealed a diagnosis of nodular sclerosis classic Hodgkin lymphoma (CHL-NS). She was considered to have "other iatrogenic immunodeficiency-associated lymphoproliferative disorders" (OIIA-LPD), MTX-associated Hodgkin lymphoma (MTX-HL). She received six courses of brentuximab vedotin (BV) in addition to AVD (BV+AVD). A complete metabolic response was obtained, and the RA went into remission. This is the fourth reported case of BV+AVD for MTX-HL.

Significant role of magnetic resonance imaging for the diagnosis and evaluation of cardiac amyloidosis in primary light chain amyloidosis.

A 47-year-old male with macroglossia presented with dyspnea on effort and chest pain at rest. Cardiac MRI revealed diffuse global subendocardial late gadolinium enhancement below the left ventricular endocardium and a dark blood pool of intracardiac contrast medium. Tongue biopsy revealed amyloid deposition, which was limited in the myocardium. He was diagnosed with primary light chain amyloidosis. His condition was stage I according to the Mayo Clinic staging system. He underwent autologous peripheral blood stem cell transplantation. On Day 10, he developed chest pain and died suddenly on Day 11. Postmortem examination revealed amyloid deposition throughout the heart.

Efficacy and safety of quizartinib in Japanese patients with FLT3-ITD positive relapsed or refractory acute myeloid leukemia in an open-label, phase 2 study.

FMS-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) mutations in patients with acute myeloid leukemia (AML) are associated with early relapse and poor survival. This multicenter, single-arm, two-stage phase 2 study (NCT02984995) was conducted to evaluate the efficacy and safety of quizartinib hydrochloride (initial dose 20/30 mg/day), an oral, highly potent, selective FLT3 inhibitor in Japanese patients (median age 65 years) with FLT3-ITD positive relapsed/refractory (R/R) AML. The composite complete remission (CRc) rate (primary endpoint) was 53.8% (90% confidence interval 36.2-70.8%) for evaluable patients in the efficacy analysis set. The median duration of CRc and overall survival was 16.1 weeks and 34.1 weeks, respectively. The most frequent treatment-emergent adverse events (TEAEs) were febrile neutropenia (43.2%), platelet count decreased (37.8%), and QT prolonged (35.1%). Two (5.4%) patients experienced TEAEs associated with treatment discontinuation. All serious TEAEs (45.9%), except febrile neutropenia (16.2%), were reported in ≤ 2 patients. The incidence of QTcF 451-480 ms and 481-500 ms was 37.8% and 2.7%, respectively. No QTcF > 500 ms, events of torsade de pointes or arrhythmia with clinical symptoms were reported. Quizartinib monotherapy was well tolerated and resulted in clinically meaningful reductions in blast count in Japanese patients with FLT3-ITD R/R AML.

Safety and pharmacokinetics of quizartinib in Japanese patients with relapsed or refractory acute myeloid leukemia in a phase 1 study.

Expanded therapeutic options are warranted for patients with relapsed or refractory (R/R) acute myeloid leukemia (AML) who have FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutations. The present phase 1, multicenter, open-label, dose-escalation and dose-expansion study was conducted to assess the safety, pharmacokinetics, and efficacy of multiple-dose monotherapy of the FLT3 inhibitor, quizartinib, in Japanese patients with R/R AML. Patients received oral quizartinib, once daily, under fasting conditions in 28-day cycles. Sixteen patients (median age, 68.0 years; male, 56.3%; FLT3-ITD positive, 43.8%) received quizartinib (9, 3, and 4 patients at 20, 30, and 60 mg/day, respectively; median treatment duration, 95.0 days; median relative dose intensity, 100.0%). No dose-limiting toxicities were observed. The most common treatment-emergent adverse events were electrocardiogram QT prolonged (43.8%, grade 1 or 2) followed by nausea and pyrexia (37.5% each). No quizartinib-related deaths were reported. A dose-dependent increase of quizartinib and its active metabolite AC886 levels was observed at the steady state. The composite complete remission rate was 37.5%. Quizartinib was well tolerated in Japanese R/R AML patients at doses up to 60 mg/day; quizartinib 60 mg/day was considered as the recommended dose for the Japanese patient population in a subsequent study.Trial registration ClinicalTrials.gov identifier NCT02675478.

Histone deacetylase inhibitors profoundly decrease proliferation of human lymphoid cancer cell lines.

Methylation of tumor suppressor genes is frequently observed in human cancers. These genes are silenced by histone deacetylase (HDAC) recruited by methylated DNA in their promoter regions. HDAC removes acetyl groups from histones and prevents the basic transcriptional machinary access to the target gene, leading to transcriptional repression. HDAC inhibitors (HDACIs) can restore the expression of the tumor suppressor and/or cell cycle regulatory genes in cancer cells and block the cellular proliferation of these cells. In this study, we investigated the in vitro antiproliferative activities of the HDACIs, suberoylanilide hydroxamic acid (SAHA), and valproic acid against 14 human lymphoid cancer cell lines. All of these cell lines were sensitive to the antiproliferative effects of the HDACI. SAHA induced either G1 or G2-M arrest as well as apoptosis. SAHA downregulated cyclin D1 and D2, and upregulated p53, p21, and p27. Chromatin immunoprecipitation analysis revealed a remarkable increase in the level of acetylated histones associated with the p21 promoter after SAHA treatment. In nude mice, SAHA significantly inhibited growth of a mantle cell lymphoma without major toxic side effects. In summary, HDACIs are promising therapeutic agents for human lymphoid cancers.

A novel chromosomal translocation t(1;14)(q25;q32) in pre-B acute lymphoblastic leukemia involves the LIM homeodomain protein gene, Lhx4.

Chromosome 1q21-25 is one of the hotspots of chromosomal abnormalities including translocations and duplications in hematological malignancies. This would suggest that oncogene(s) reside in this region. We have cloned the junctional sequence of t(1;14)(q25;q32) in pre-B acute lymphoblastic leukemia cells by an inverse PCR method. A novel sequence was fused to the joining region of the immunoglobulin heavy chain gene. We confirmed this rearrangement by Southern blot analysis, genomic PCR and fluorescence in situ hybridization. We found a coding sequence which is homologous to the mouse Lhx4 cDNA sequence 17 kb from the breakpoint. The human Lhx4 gene encodes 390 amino-acids, including one tandem pair of LIM domains and one homeodomain. The human Lhx4 gene consists of six exons. Lhx4 protein is very homologous to human Lhx3 protein except in the N-terminal region. The transcripts of the Lhx4 gene were not detected in adult multiple tissues analysed by Northern blotting, but were detected in the leukemic cells carrying t(1;14)(q25;q32) by reverse-transcription PCR. The protein expression of Lhx4 in these leukemic cells was confirmed by Western blot analysis. Lhx4 activated the reporter gene carrying the mouse alpha-glycoprotein subunit promoter region, which is regulated by Lhx3. LIM protein and homeodomain protein genes are frequently involved in translocations of hematological malignancies. The Lhx4 gene is deregulated in the leukemic cells and Lhx4 protein may play an important role, possibly as an activator, in leukemogenesis.

Mxi1 isoforms are expressed in hematological cell lines and normal bone marrow.

Mxi1 protein is a basic helix-loop-helix, leucine zipper (bHLHZIP) transcriptional factor, which dimerizes with the Max protein. This heterodimer binds a specific DNA sequence (E-box) and suppresses transcription of target genes. On the other hand, c-Myc protein is also a bHLHZIP protein that dimerizes with Max, binds the identical E-box sequence but activates transcription of the target genes. We report that hematopoietic cells have three novel Mxi1 transcripts: Mxi-D lacks exon 3, which encodes the basic region; Mxi-ND lacks the N-terminal mSin3 binding region and the DNA binding region; and Mxi-NF lacks the N-terminal mSin3 binding region. In normal bone marrow and hematological cell lines, the dominantly expressed isoforms are Mxi-D and full-length Mxi1 (Mxi-F). In GST-pull down assays, the Mxi-D protein binds the Max protein and the PHA2 regions of mSin3 proteins. Whereas the Mxi-F/Max heterodimer binds the E-box sequence, Mxi-D/Max heterodimer can not bind this sequence in electrophoretic mobility shift assays. In reporter gene assay, Mxi-D suppresses transcription as strongly as Mxi-F. In colony formation assay using Rat1 fibroblast cells, Mxi-D cannot suppress clonal growth stimulated by c-Myc as strongly as Mxi-F. In summary, Mxi-D may play an important role in the c-Myc family protein network acting as a dominant negative isoform of Mxi-F since: i) Mxi-D can dimerize with Max in vitro; ii) Mxi-D/Max heterodimers cannot bind E-box in vitro, iii) Mxi-D cannot suppress clonal growth stimulated by c-Myc.

B-cell marker negative (CD7+, CD19-) Epstein-Barr virus-related pyothorax-associated lymphoma with rearrangement in the JH gene.

Pyothorax-associated lymphoma (PAL) develops decades after receiving artificial pneumothorax for pulmonary tuberculosis. The lymphomas, develop in tissue affected by long-standing severe inflammatory process. Most cases demonstrate diffuse large B-cell lymphoma. We present a patient with T-cell phenotype-positive and B-cell phenotype-negative (CD7+, CD43+, CD19-, and CD20-) PAL. Southern blot hybridization using immunglobulin heavy chain J region (IgH) gene probe revealed a monoclonal rearrangement, and hybridization using T-cell receptor beta chain (TCR) gene probe revealed a germline configuration. This indicates that the tumor origin was of B-lymphocytes. Chromosomal abnormality of the lymphoma was complicated. It suggested that many transformations occurred. In the transformation process, probably B-cell antigens were lost, and T-cell antigens were aberrantly expressed.