[Spontaneous regression of HIV-associated EBV-positive mucocutaneous ulcer due to immune reconstruction with antiretroviral therapy]

A 24-year-old man was found to have an ileocecal ulcer by colonoscopy. A pathological diagnosis of diffuse large B-cell lymphoma (DLBCL) with diffuse positive reaction of Epstein-Barr encoding region (EBER) by in situ hybridization was made based on analysis of the specimen. Acquired immunodeficiency syndrome (AIDS) complicated by pneumocystis jirovecii pneumonia was also diagnosed. As no other significant lymphomatous lesions were identified by further examination, a clinical diagnosis of EBV-positive mucocutaneous ulcer (EBVMCU) was made. Rather than performing systemic chemotherapy, the lesion was closely monitored and antiretroviral therapy (ART) for AIDS was started with the hope of treating the lesion through immune reconstitution. The lesion had completely disappeared by day 79 after starting ART, and has not recurred for over 3 years. EBVMCU is known to develop secondary to various immunosuppressive states including AIDS. Here we report a rare case of EBVMCU detected at diagnosis of AIDS that entered complete remission after immune reconstitution by ART.

The clinical impact of the ratio of C-reactive protein to albumin (CAR) in patients with acute- and lymphoma-type adult T-cell leukemia-lymphoma (ATL)

Recently, the ratio of C-reactive protein to albumin (CAR) is used as an inflammatory marker that has been demonstrated to be a simple and reliable prognostic factor in solid tumors and hematological malignancy. However, no studies of the CAR have been performed in patients with adult T-cell leukemia-lymphoma (ATL). We retrospectively analyzed the clinical features and outcomes in 68 newly diagnosed acute- and lymphoma-type ATL [(acute-(n=42) or lymphoma-type (n=26)] patients in Miyazaki Prefecture from 2013 to 2017. Furthermore, we investigated correlations between pretreatment CAR levels and clinical features. The median age was 67 years (range, 44 - 87). Patients were initially treated by either palliative therapy (n=14) or chemotherapy [n=54; CHOP therapy (n=37)/ VCAP-AMP-VECP therapy (n=17)], and showed median survival durations of 0.5 months and 7.4 months, respectively. The factors affecting OS by multivariate analysis were age, BUN, and CAR. Importantly, we revealed that the high CAR group (optimal cut-off point; 0.553) was a significant indicator of worse OS by multivariate analysis (p< 0.001, HR; 5.46). The median survival of patients with a CAR< 0.553 was 8.37 months, while patients with a CAR>0.553 had a median survival of 3.94 months. The different clinical features between high CAR and low CAR groups were hypoproteinemia and the implementation of chemotherapy. Furthermore, in the chemotherapy group, but not the palliative therapy group, CAR was a significant prognostic marker. Our study indicated that CAR may be a new simple and significant independent prognostic marker in acute- and lymphoma-type ATL patients.

Adult Nodal Burkitt Lymphoma Forming Nodular Architectures

In this report, we discuss a case of nodal Burkitt lymphoma seen in a 60-year-old Japanese male patient. Microscopic features of the biopsied 30 mm-sized cervical lymph node revealed nodular architectures with starry sky appearance surrounded by small mantle zone B-lymphocytes. Immunohistochemical and molecular studies demonstrated typical features of sporadic Burkitt lymphoma: the atypical cells were positive for CD20, CD79a, CD10, CD23, HLA-DR, bcl-6, PAX5, c-myc, and cytoplasmic IgM, but negative for CD3, CD5, CD15, CD30, CD34, TdT, bcl-2, and MUM1. The mantle zone B-cells were clearly positive for bcl-2 and IgD. In situhybridization (ISH) analysis for immunoglobulin light chains showed kappa-type monoclonality. A few nuclei were labeled for Epstein-Barr virus-encoded small nuclear RNA (EBER). Ki-67 labeling index was nearly 100%. Within the nodule, CD21, CD23, and CD35-positive follicular dendritic cells were scattered with a small number of CD3/CD5-positive small T-lymphocytes, indicating that the nodular architecture represented follicular colonization of Burkitt lymphoma cells. Karyotypic analysis revealed t(8;14)(q24;q32), and IGH-MYC fluorescence in situ hybridization (FISH) demonstrated IGH-MYC fusion signals. The presentation of follicular colonization was quite unique in Burkitt lymphoma in the present case. Differential diagnosis is also discussed.

PEDT-07 RECURRENT MEDULLOBLASTOMA 9 YEARS AFTER THE PRIMARY TUMOR

Medulloblastoma is one of the most common malignant brain tumors in children. Despite multi-disciplinary treatment for medulloblastoma, including surgery, chemotherapy, and radiation, which have resulted in significant improvement of the prognosis, about 30% of patients still experience recurrence. Most recurrences occur within the first 15 months from diagnosis and late relapse of the tumor is quite rare. We report a case of a 15-year-old female patient with recurrent medulloblastoma 9 years after the primary tumor. At the age of 6, this patient developed a posterior fossa tumor without metastasis and underwent near-total resection. The pathological diagnosis was medulloblastoma with focal desmoplasia. After the surgery, she received multi-agent chemotherapy and radiation therapy consisting of 18 Gy craniospinal irradiation and 51.2 Gy local irradiation. She was in complete remission for 9 years after the treatment. However, gait disturbance began to gradually appear, and magnetic resonance imaging (MRI) showed an intradural lesion in her thoracic spine. The lesion was biopsied, and the pathological findings confirmed the recurrence of medulloblastoma. Currently, we plan to administer local radiation therapy concomitantly with temozolomide to the patient. The case reminds us of the importance of long-term careful follow-up of patients with medulloblastoma. Further studies are warranted for the treatment of relapsed medulloblastomas due to the limited information available at present.

MPC-06 LRG1 HAS MULTIPLE POTENTIAL FOR CLINICOPATHOLOGICAL BIOMARKER OF GLIOBLASTOMA

BACKGROUND AND AIM

Leucine-rich α-2 glycoprotein 1 (LRG1) is one of the candidate proteins as a diagnostic marker for glioblastoma. Although association with angiogenesis has been reported, it has been suggested that the role as a biomarker differs depending on the tumor types. The role of LRG1 as a biomarker in glioblastoma was examined clinicopathologically.

METHODS

Tumor tissues of 156 cases diagnosed as diffuse glioma (27 astrocytomas, 15 oligodendrogliomas, 114 glioblastomas) according to WHO 2016 classification at Kurume University from January 2001 to April 2019 were used. The immunohistochemical intensity of LRG1 was scoring as 4 stages and classified into 2 groups; score 0–1 was defined as low expression and score 2–3 was defined as high expression. Mutations of IDH1/2 and TERT promoter were analyzed by Sanger method. In glioblastoma, the relationship between LRG1 expression and clinical parameters such as age, preoperative Karnofsky Performance Scale, tumor location, extent of resection, MGMT promoter, and prognosis were examined.

RESULTS

LRG1 high expression rate was 41.2% (47/114) in glioblastoma, 3.7% (1/27) in astrocytoma, 20% (3/15) in oligodendroglioma, and glioblastoma showed significant higher expression level of LRG1 compared with lower-grade glioma (p = 0.0003). High expression of LRG1 was an independent favorable prognostic factor (HR 0.41, 95% CI 0.18–0.86, p=0.019) in IDH-wildtype glioblastoma, and correlated with gross total resection (p = 0.002) and the tumor location of the non-subventricular zone (SVZ) (p = 0.00007).

CONCLUSION

LRG1 demonstrated multiple potential as diagnostic, prognostic, and regional biomarker for glioblastoma.

Identification of a novel CCDC22 mutation in a patient with severe Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis and aggressive natural killer cell leukemia

Aggressive natural killer cell leukemia (ANKL) is a rare neoplasm characterized by the systemic infiltration of Epstein-Barr virus (EBV)-associated NK cells, and rapidly progressive clinical course. We report the case of a 45-year-old man with intellectual disability who developed ANKL, and describe the identification of a novel genetic mutation of coiled-coil domain-containing 22 (CCDC22). He presented with persistent fever, severe pancytopenia, and hepatosplenomegary. Following bone marrow aspiration, numerous hemophagocytes were identified. High EBV viral load was detected in NK cells fractionation by qPCR. The initial diagnosis was EBV-related hemophagocytic lymphohistiocytosis (EBV-HLH). A combination of immunosuppressive drugs and chemotherapy was administered, but was unsuccessful in controlling the disease. Therefore, he was treated with HLA-matched related allogeneic hematopoietic stem cell transplantation. However, his condition deteriorated within 30 days, resulting in fatal outcome. Autopsy revealed many EBV-infected NK cells infiltrating major organs, consistent with ANKL. Furthermore, whole-exome sequencing identified a novel missense mutation of the CCDC22 gene (c.112G>A, p.V38M), responsible for X-linked intellectual disability (XLID). CCDC22 has been shown to play a role in NF-κB activation. Our case suggests that CCDC22 mutation might be implicated in pathogenesis of EBV-HLH and NK-cell neoplasms as well as XLID via possibly affecting NF-κB signaling.

Methotrexate-associated lymphoproliferative disorders with angioimmunoblastic T-cell lymphoma-like features accompanied by gamma-heavy chain disease in a patient with rheumatoid arthritis

Although gamma heavy chain disease (γ-HCD) lesions occasionally morphologically resemble angioimmunoblastic T-cell lymphoma (AITL), no association has been described in detail due to the rarity of the disease. In this report, we present a rare manifestation of methotrexate (MTX)-associated lymphoproliferative disorders (LPDs) with AITL-like features accompanied by γ-HCD in a 75-year-old man with rheumatoid arthritis (RA). A biopsy specimen was evaluated using immunohistochemistry, clonal analyses of immunoglobulin VH and T-cell receptor γ gene rearrangements by polymerase chain reaction, and Sanger sequencing for confirmation of the structure of deleted γ-HCD clones. The histological features characterized by proliferation of CD4- and PD-1-positive medium-sized T cells and arborizing high endothelial venules together with numbers of small lymphocytes, eosinophils, plasma cells, and histiocytes in the background mimicked those of AITL, but did not completely fulfill the diagnostic criteria. Clonal analysis demonstrated that the specimen contained multiple LPDs of both B-cell and T-cell lineages. Sequence analysis confirmed the co-existence of a clone responsible for production of the abnormal heavy chain. This report provides new insights into the pathology of γ-HCD. Multiple host-derived factors (e.g., RA and/or use of MTX) may be responsible for the occurrence of LPDs of multiple lineages within a single lymph node.

[Splenic diffuse red pulp small B-cell lymphoma diagnosed by splenectomy initially mimicking hairy cell leukemia-Japanese variant]

A 62-year-old man presented to the hospital with thrombocytopenia, and splenomegaly was detected. His blood films prepared by natural air drying revealed medium-sized lymphocytes with unevenly distributed large and small villous projections. The cytoplasm was basophilic, nuclei were oval with clumped chromatin, and nucleoli were absent in most cells. Immune phenotypes CD19+, CD20+, CD11c+, FMC7+, IgM+, and Igκ+ were detected. TRAP stain appeared negative, IgH JH chain genes were monoclonally rearranged, and BRAF V600E mutation was not detected. On the basis of these findings, hairy cell leukemia-Japanese variant (HCL-JV) was strongly suspected. The patient was followed up for >4 years without treatment. However, because thrombocytopenia and splenomegaly gradually progressed, splenectomy was performed. Microscopic examination confirmed that the splenic white pulp was atrophic. Moreover, infiltrates comprising small-to-medium-sized atypical lymphocytes with inconspicuous nucleoli were predominantly detected in the congested red pulp. On the basis of these results and immune histochemical findings, the patient was diagnosed with splenic diffuse red pulp small B-cell lymphoma (SDRPL). Here we discussed whether the aforementioned diseases (HCL-JV and SDRPL) are the same; however, further accumulation of cases is essential to draw a definite conclusion.

Integrating genomic alterations in diffuse large B-cell lymphoma identifies new relevant pathways and potential therapeutic targets

Genome studies of diffuse large B-cell lymphoma (DLBCL) have revealed a large number of somatic mutations and structural alterations. However, the clinical significance of these alterations is still not well defined. In this study, we have integrated the analysis of targeted next-generation sequencing of 106 genes and genomic copy number alterations (CNA) in 150 DLBCL. The clinically significant findings were validated in an independent cohort of 111 patients. Germinal center B-cell and activated B-cell DLBCL had a differential profile of mutations, altered pathogenic pathways and CNA. Mutations in genes of the NOTCH pathway and tumor suppressor genes (TP53/CDKN2A), but not individual genes, conferred an unfavorable prognosis, confirmed in the independent validation cohort. A gene expression profiling analysis showed that tumors with NOTCH pathway mutations had a significant modulation of downstream target genes, emphasizing the relevance of this pathway in DLBCL. An in silico drug discovery analysis recognized 69 (46%) cases carrying at least one genomic alteration considered a potential target of drug response according to early clinical trials or preclinical assays in DLBCL or other lymphomas. In conclusion, this study identifies relevant pathways and mutated genes in DLBCL and recognizes potential targets for new intervention strategies.

Toxic epidermal necrolysis in a child 6 months post-hematopoietic stem cell transplantation

TEN is a rare and critical disease mostly caused by drugs. It is mediated by activated CD8+ T cells that cause keratinocyte apoptosis with the assistance of cytokines/chemokines. We herein report a pediatric case of TEN after allogeneic HSCT with precursor B-cell acute lymphoblastic leukemia (pre-B-ALL) in second complete remission. Although we did not evaluate the T-cell subpopulation in blood or skin lesion of the patient, an imbalanced immune reconstitution after HSCT might additively contribute to the development of TEN.

Splenic marginal zone lymphoma uncovered after a 10-year follow up as anemia of unknown cause

A 75-year-old man was referred to our hospital for evaluation of persistent anemia. Despite repeated diagnostic tests, including bone marrow aspiration, the cause of his anemia remained unknown. On each occasion, computed tomography had revealed neither swollen lymph nodes nor splenomegaly. After a 10-year follow-up period, he was admitted with general fatigue and had developed splenomegaly as well as the anemia. Bone marrow biopsy revealed increased abnormal lymphocytes with short villi that were positive for CD11c, CD19, CD20, and kappa chain, but not for CD5, CD10, CD23, or cyclin D1, according to flow cytometry. The bone marrow biopsy sample showed nodular proliferation of small to medium-sized abnormal lymphocytes. Based on these findings, the patient was diagnosed as having splenic marginal zone lymphoma, a rare indolent B-cell neoplasm. Although his splenomegaly diminished after eight cycles of weekly rituximab monotherapy, the anemia did not improve, and abnormal lymphocytes remained detectable in his bone marrow. The patient was then treated with bendamustine monotherapy for six cycles, after which the anemia resolved, and he has since been in good condition. Although rare, it is important to consider splenic marginal zone lymphoma during the differential diagnosis of patients with a long history of anemia of unknown cause.

An Epstein-Barr virus susceptible immature T-cell line, WILL4, established from a patient with T-lymphoblastic lymphoma bearing CD21 and a clonal EBV genome

We managed a patient with an Epstein-Barr virus-associated T-cell lymphoblastic lymphoma. Mediastinal tumor cells at initial admission were positive for CD4, CD8, and TdT. Interestingly, a lymph node at necropsy was compatible for a CD4-positive peripheral T-cell lymphoma without CD8 and TdT expression, suggesting a different phenotype from the mediastinal tumor. Tumor cells in pleural effusion continued to proliferate in in vitro and were designated as WILL4. WILL4 cells were positive for CD3, CD4, CD8, CD21, T-cell receptor (TcR) αβ, and TdT, indicating a similar phenotype to thymocytes. Southern blot analyses showed that the pleural tumor and WILL4 cells shared a TcR gene rearrangement, and that both contained a clonal EBV genome in an episomal form. RT-PCR showed that EBNA1 and LMP1 were expressed in the fresh tumor and WILL4 cells. Southern blot analyses revealed that WILL4 cells were susceptible to EBV infection in vitro using B95-8 supernatant. Anti-CD21 antibody inhibited in vitro infection of EBV, suggesting that CD21 plays a role in EBV infection into WILL4 cells. In vitro infection of EBV did not affect latent gene expression in WILL4 cells. WILL4 is a useful tool for analyzing the roles of EBV in onocogenesis in immature T-lymphoid malignancies.

Identification of cell-type-specific mutations in nodal T-cell lymphomas

Recent genetic analysis has identified frequent mutations in ten-eleven translocation 2 (TET2), DNA methyltransferase 3A (DNMT3A), isocitrate dehydrogenase 2 (IDH2) and ras homolog family member A (RHOA) in nodal T-cell lymphomas, including angioimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma, not otherwise specified. We examined the distribution of mutations in these subtypes of mature T-/natural killer cell neoplasms to determine their clonal architecture. Targeted sequencing was performed for 71 genes in tumor-derived DNA of 87 cases. The mutations were then analyzed in a programmed death-1 (PD1)-positive population enriched with tumor cells and CD20-positive B cells purified by laser microdissection from 19 cases. TET2 and DNMT3A mutations were identified in both the PD1+ cells and the CD20+ cells in 15/16 and 4/7 cases, respectively. All the RHOA and IDH2 mutations were confined to the PD1+ cells, indicating that some, including RHOA and IDH2 mutations, being specific events in tumor cells. Notably, we found that all NOTCH1 mutations were detected only in the CD20+ cells. In conclusion, we identified both B- as well as T-cell-specific mutations, and mutations common to both T and B cells. These findings indicate the expansion of a clone after multistep and multilineal acquisition of gene mutations.

Influence of splenectomy in patients with liver cirrhosis and hypersplenism

AIM

Splenectomy improves hypersplenic thrombocytopenia in cirrhotic patients with hypersplenism. However, the long-term influence of splenectomy has not been clarified. We examined whether splenectomy improved liver fibrosis and caused immunological changes.

METHODS

We collected liver and spleen specimens and peripheral blood (PB) from 26 patients with hepatitis C virus-related liver cirrhosis. An immunohistochemical examination of CD4, CD8, forkhead box P3, granzyme B and transforming growth factor-β1, and Masson-trichrome stain were performed in spleen and liver tissues and in seven cases of follow-up liver biopsy sections obtained after splenectomy. We obtained PB before and at various intervals after splenectomy. We also examined the ratio of CD4(+) and CD8(+) lymphocytes in PB using flow cytometry.

RESULTS

We observed improvements in liver fibrosis in four biopsy specimens obtained after splenectomy, in which fibrotic areas significantly decreased from 19.5% to 8.2% (P < 0.05). Increases were also observed in the ratio of CD8(+) cells in PB after splenectomy, which resulted in a significant decrease in the CD4(+) /CD8(+) ratio (P < 0.001). The carcinogenic rate in patients with a CD4(+)  : CD8(+) ratio that decreased by more than 0.5 at 1 month after splenectomy was significantly lower than that in patients with a ratio that decreased by less than 0.5 (P < 0.05).

CONCLUSION

Splenectomy may improve liver fibrosis and cause beneficial immunological changes in cirrhotic patients with hepatitis. Improvements in antitumor mechanisms can be also expected.

Pediatric subcutaneous panniculitis-like T-cell lymphoma with favorable result by immunosuppressive therapy: a report of two cases

Subcutaneous panniculitis-like T-cell lymphoma (SPTL) is a rare type of skin lymphoma. Histopathology mimicking a lobular panniculitis makes it difficult to distinguish SPTL from benign autoimmune disease. We present cases of a 10-year-old female and an 11-year-old male with SPTL showing recurrent panniculitis and systemic manifestations. Initially, antibiotics and steroids were administered to treat infectious disease and benign panniculitis. However, they experienced recurrent fever and erythema nodosum. Additional immunohistochemistry and T-cell receptor (TCR) gene rearrangement analyses were performed, enabling the establishment of an SPTL diagnosis. The affected patients were given immunosuppressive therapy with favorable results.

Epstein-Barr Viral Load is Associated to Response in AIDS-Related Lymphomas

AIDS-related lymphoma (ARL) development is associated to immunodeficiency state with proliferation of B-cells driven by HIV itself and EBV infection. However, Epstein-Barr DNA is not detected in malignant cells of all ARL subtypes. A prospective and controlled study to analyze EBV viral load (VL) in plasma and peripheral blood mononuclear cells (PBMC) of ARL patients was performed to analyze if Epstein-Barr VL could be related to response in these patients. Fifteen patients with ARL were included in this study with measurement of EBV VL at three different periods of time: at lymphoma diagnosis, upon completion of chemotherapy, and 3 months after. Two control groups composed by HIV-negative and HIV-positive patients were also evaluated for EBV VL comparison. In situ hybridization for EBER was performed on diagnostic samples of all ARL patients. Median EBV VL in PBMC and plasma had a significant decrease (p = 0.022 and p = 0.003, respectively) after ARL treatment. EBER was positive in 7 (46.7 %) cases. Median EBV VL in PBMC before lymphoma treatment in patients positive for EBER was significantly higher compared to EBER negative cases (p = 0.041). Reduction of EBV viral load during treatment of lymphoma could be predictive of response. EBER expression was associated to advanced stages of disease and worse immune status. Our study suggests that measurement of EBV VL during ARL treatment could be used as a marker for response, but further studies are needed to validate this association.

Improved treatment results of children with B-cell non-Hodgkin lymphoma: a report from the Japanese Pediatric Leukemia/Lymphoma Study Group B-NHL03 study

BACKGROUND

Previous Japanese studies of childhood B-cell non-Hodgkin lymphoma (B-NHL) have shown a favorable outcome, though the study size was too small to effectively assess the efficacy and safety of treatment for childhood B-NHL.

PROCEDURE

We performed a nation-wide prospective B-NHL03 study to assess the efficacy and safety of short-pulse intensive chemotherapy for children with B-NHL. They were stratified into four treatment groups according to disease stage, tumor resectability and bone marrow/CNS involvement: Group 1 with all resected stage I/II, Group 2 with non-resected stage I/II, Group 3 with stage III & CNS-negative stage IV, and Group 4 with CNS-positive stage IV & Burkitt leukemia. Treatment duration was 2 courses for Group 1, 4 courses for Group 2, and 6 courses for Groups 3 and 4, respectively. CNS irradiation was omitted in all patients.

RESULTS

The follow-up time ranged from 0.8 to 88 months, with a median of being 45 months. For 321 patients analyzed in this study, overall survival and event-free survival (EFS) at 4 years was 92.7% and 87.4%, respectively. The 4-year EFS according to treatment group were 94% for Group 1 (n = 17), 98% for Group 2 (n = 103), 84% for Group 3 (n = 111), and 78% for Group 4 (n = 90). There was no significant difference in outcome by histology. Therapy-related death occurred in three patients in remission.

CONCLUSIONS

Our nationwide large-scale study resulted in a cure rate above 90% with <1% toxic death in childhood B-NHL.

Multilocus sequence analysis of 'Candidatus Phytoplasma asteris' strain and the genome analysis of Turnip mosaic virus co-infecting oilseed rape

AIM

Molecular characterization of a pathogenic complex infecting winter oilseed rape (Brassica napus ssp. oleifera (DC.) Metzg.) plants showing typical rape phyllody symptoms along with some atypical changes.

METHODS AND RESULTS

Phytoplasma ('Candidatus Phytoplasma') presence was confirmed by PCR-RFLP and 16S rRNA gene sequencing. Phylogenetic analyses of phytoplasma amp, tufB, secY, groEL and ribosomal protein genes confirmed its affiliation to the 'Ca. P. asteris' species. However, in the amp gene encoding a specific protein crucial for insect transmission specificity, significant SNPs were found. Biological and serological tests revealed the co-infection with Turnip mosaic virus (TuMV). The phylogenetic analysis of full TuMV genome sequence, the first reported from the Balkans, classified it into the world-B phylogenetic lineage.

CONCLUSIONS

A pathogenic complex consisting of 'Ca. P. asteris' and TuMV found to co-infect oilseed rape plants for the first time was molecularly characterized.

SIGNIFICANCE AND IMPACT OF THE STUDY

Rape phyllody is a serious problem in rapeseed production. The molecular information from this first multi-gene analysis of 'Ca. P. asteris' strain associated with rape phyllody as well as the first report of the complete sequence of TuMV isolate from the Balkans is a starting point for understanding the disease complexity and management.

Abstract A30: Dysregulation of BMI1 and microRNA-16 collaborate to enhance an anti-apoptotic potential in the side population of refractory mantle cell lymphoma

The proto-oncogene BMI1 and its product, Bmi1, is overexpressed in various types of tumors, particularly in aggressive tumors and tumors resistant to conventional chemotherapy. BMI1/Bmi1 is also crucially involved in cancer-initiating cell maintenance, and is recurrently upregulated in mantle cell lymphoma (MCL), especially aggressive variants. Recently, side population (SP) cells were shown to exhibit tumor-initiating characteristics in various types of tumors. In this study, we show that recurrent MCL cases significantly exhibit upregulation of BMI1/Bmi1. We further demonstrate that clonogenic MCL SP shows such tumor-initiating characteristics as high tumorigenicity and self-renewal capability, and that BMI1 was upregulated in the SP from recurrent MCL cases and MCL cell lines. On screening for upstream regulators of BMI1, we found that expression of microRNA-16 (miR-16) was downregulated in MCL SP cells by regulating Bmi1 in the SPs, leading to reductions in tumor size following lymphoma xenografts. Moreover, to investigate downstream targets of BMI1 in MCL, we performed cross-linking/chromatin immunoprecipitation assay against MCL cell lines and demonstrated that Bmi1 directly regulated pro-apoptotic genes such as BCL2L11/Bim and PMAIP1/Noxa, leading to enhance anti-apoptotic potential of MCL. Finally, we found that a proteasome inhibitor bortezomib, which has been recently used for relapsed MCL, effectively induced apoptosis among MCL cells while reducing expression of Bmi1 and increasing miR-16 in MCL SP. These results suggest that upregulation of BMI1 and downregulation of miR-16 in MCL SP has a key role in the disease's progression by reducing MCL cell apoptosis. Our results provide important new insight into the pathogenesis of MCL and strongly suggest that targeting BMI1/Bmi1 might be an effective approach to treating MCL, particularly refractory and recurrent cases.

Citation Format: Akihiro Kitadate, Kazuaki Teshima, Kouichi Ohshima, Masao Seto, Kenichi Sawada, Hiroyuki Tagawa. Dysregulation of BMI1 and microRNA-16 collaborate to enhance an anti-apoptotic potential in the side population of refractory mantle cell lymphoma. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A30.

Gemcitabine with paclitaxel therapy against mesocolic leiomyosarcoma: a case report

A 65-year-old man complained of lower right abdominal pain, and an intra-abdominal mass was identified. An intra-abdominal hemorrhage was discovered during a thorough examination and emergency surgery was performed. The tumor was ruptured and was fragile, making it difficult to perform extirpation; thus, an ileocecal resection was performed. The histopathological diagnosis of the tumor was leiomyosarcoma, and recurrence was observed during the early postoperative period. The patient underwent surgery twice; each time there was a recurrence, but complete resection could not be obtained, and paclitaxel and gemcitabine chemotherapy was performed. A temporary effect was observed, and control of disease progression lasted approximately five months. Standard chemotherapy for leiomyosarcoma has not been established, but this method could become a therapeutic strategy for leiomyosarcoma.

Elevated 1-h plasma glucose following 75-g oral glucose load is a predictor of arterial stiffness in subjects with normal glucose tolerance

AIMS

The study aimed to investigate arterial stiffness in subjects with normal glucose tolerance.

METHODS

BMI, systolic blood pressure, fasting plasma glucose, lipid variables, ankle-brachial pressure index and brachial-ankle pulse wave velocity were measured in 2059 subjects from Takasaki city, located approximately 100 km north of Tokyo in Japan. Following a 75-g oral glucose tolerance test, only subjects with normal glucose tolerance were selected.

RESULTS

One-hour post-challenge plasma glucose levels were correlated with brachial-ankle pulse wave velocity values (r = 0.340, P < 0.0001). When subjects with normal glucose tolerance were divided into three groups-group 1 (1-h plasma glucose < 8.56 mmol/l, n = 1595), group 2 (1-h plasma glucose ≥ 8.56 and < 10.17 mmol/l, n = 334) and group 3 (1-h plasma glucose ≥ 10.17 mmol/l, n = 130)-the brachial-ankle pulse wave velocity of group 3 (1473 ± 322 cm/s) was significantly higher than that of group 2 (1355 ± 252 cm/s) and brachial-ankle pulse wave velocity of group 2 was also significantly higher than that of group 1 (1275 ± 212 cm/s).

CONCLUSIONS

We have identified that, in normal glucose tolerance, arterial stiffness is advanced in subjects with higher 1-h post-challenge plasma glucose in spite of the normal range for BMI, systolic blood pressure, fasting plasma glucose and lipid variables. Higher 1-h plasma glucose level is a risk factor for arterial stiffness in normal glucose tolerance.

Epstein-Barr virus and methotrexate-related CNS lymphoma in a patient with rheumatoid arthritis

Patients with rheumatoid arthritis (RA), especially those treated with methotrexate (MTX), might have an increased risk of lymphoproliferative disorders that are associated with Epstein-Barr virus (EBV). We describe a case of EBV-associated central nervous system (CNS) lymphoma (diffuse large B-cell lymphoma) in a patient with RA on a short course of MTX treatment. The neoplastic cells express the B-cell surface markers (CD20, Pax-5 and CD30), and EBV-encoded RNA was demonstrated by in situ hybridization. The patient's lymphoma did not recur for the 8-year follow-up period after the tumor resection and cessation of MTX. MTX may promote EBV-positive CNS lymphoma in RA patient due to its immunosuppressive properties as well as reactivating latent EBV infection.

Gene expression analysis of rheumatoid arthritis synovial lining regions by cDNA microarray combined with laser microdissection: up-regulation of inflammation-associated STAT1, IRF1, CXCL9, CXCL10, and CCL5

Objectives

The main histological change in rheumatoid arthritis (RA) is the villous proliferation of synovial lining cells, an important source of cytokines and chemokines, which are associated with inflammation. The aim of this study was to evaluate gene expression in the microdissected synovial lining cells of RA patients, using those of osteoarthritis (OA) patients as the control.

Methods

Samples were obtained during total joint replacement from 11 RA and five OA patients. Total RNA from the synovial lining cells was derived from selected specimens by laser microdissection (LMD) for subsequent cDNA microarray analysis. In addition, the expression of significant genes was confirmed immunohistochemically.

Results

The 14 519 genes detected by cDNA microarray were used to compare gene expression levels in synovial lining cells from RA with those from OA patients. Cluster analysis indicated that RA cells, including low- and high-expression subgroups, and OA cells were stored in two main clusters. The molecular activity of RA was statistically consistent with its clinical and histological activity. Expression levels of signal transducer and activator of transcription 1 (STAT1), interferon regulatory factor 1 (IRF1), and the chemokines CXCL9, CXCL10, and CCL5 were statistically significantly higher in the synovium of RA than in that of OA. Immunohistochemically, the lining synovium of RA, but not that of OA, clearly expressed STAT1, IRF1, and chemokines, as was seen in microarray analysis combined with LMD.

Conclusions

Our findings indicate an important role for lining synovial cells in the inflammatory and proliferative processes of RA. Further understanding of the local signalling in structural components is important in rheumatology.

Treatment of mouse melanoma cells with phorbol 12-myristate 13-acetate counteracts mannosylerythritol lipid-induced growth arrest and apoptosis

Mannosylerythritol lipid (MEL), an extracellularglycolipid from yeast, induces the differentiation ofHL-60 promyelocytic leukemia cells towardsgranulocytes. We show here that MEL is also a potentinhibitor of the proliferation of mouse melanoma B16cells. Flow-cytometric analysis of the cell cycle ofMEL-treated B16 cells revealed the accumulation ofcells in the sub-G(0)/G(1) phase, which is a hallmark ofcells undergoing apoptosis. Treatment of B16 cellsfor 24 h with phorbol 12-myristate 13-acetate (PMA),an activator of protein kinase C (PKC), did notinterfere with the growth and survival of the cells,but it effectively counteracted the MEL-induced growtharrest and apoptosis. The activity of PKC was reducedin B16 cells treated with MEL at a concentration atwhich MEL induced apoptosis. However, incubation withPMA in addition to MEL reversed this reduction in theactivity of PKC. These results suggest thatconverging signaling pathways are triggeredindependently by MEL and PMA and that the signalsmight both be mediated by PKC.

Novel monoclonal antibodies against pancreatic juice from pancreatic cancer patients and their possible application in differential diagnosis

Pancreatic cancer (PC) has a poor clinical prognosis with a <10% 5-year survival rate. Because there are no specific biomarkers of PC, it is difficult to detect small PC tumors and most patients are diagnosed at an advanced stage. Specific biomarkers are useful tools for the early detection of cancer. However, PC-related biomarkers, such as CA19-9 lack specificity and sensitivity. In this study, we took an immunological approach to establish novel monoclonal antibodies (mAbs) specific for the pancreatic juice from PC patients, which would be potentially useful in the diagnosis of PC. Mice were immunized by subtractive immunization using mixed pancreatic juices from chronic pancreatitis and PC patients as the tolerogen and the immunogen, respectively. After screening by Western blotting, four mAbs were obtained: 2P-1-2-1, 2P-1-17-1, 6P-3-2-4 and 7P-9-11-6. The mAb 2P-1-2-1 showed reactivity against the tolerogen at 115 and 120 kDa, but only the 120-kDa antigen was also reactive to the immunogen. The mAb 2P-1-17-1 showed an intense smear reactivity at ~150 kDa against the immunogen. Finally, the mAbs 6P-3-2-4 and 7P-9-11-6 showed PC-specific reactivity to the immunogen at >250 kDa and at ~70 kDa, respectively. We propose that investigation of pancreatic juice samples with these mAbs may enable us to perform reliable differential diagnosis of benign and malignant diseases. Furthermore, we demonstrated that subtractive immunization is a useful method for producing mAbs specific for the pancreatic juice from PC patients.