Comparison of clinicopathological features and treatment outcomes in aggressive primary intestinal B- and T/NK-cell lymphomas.

BACKGROUND: Primary intestinal lymphomas (PILs) are rare, and this study compared the clinical outcomes of aggressive primary intestinal B-cell lymphomas (aB-PILs) and T/natural killer-cell lymphomas (T/NK-PILs). METHODS: The clinical information of patients diagnosed with aggressive PILs at our institution between 1995 and 2015 were retrospectively investigated. Pathological subtypes were confirmed according to the 2016 revision of the World Health Organization classification. The correlation between clinicopathological features and overall survival (OS) was determined using univariate and multivariate analyses. RESULTS: Cases of T/NK-PILs had higher initial bowel perforation incidence (67% vs. 7%, P < 0.001) and lower complete response rate to first-line chemotherapy regimens (22% vs. 69%, P = 0.009) than aB-PILs. Patients with aB-PILs had a better 5-year event-free survival rate (55.8% vs. 13.9%, P = 0.026) and a 5-year OS rate (74.3% vs. 29.6%, P = 0.036) than those with T/NK-cell lymphomas. Multivariate analysis identified that female gender and stage III/IV were unfavorable prognostic factors. Among the 54 patients with diffuse large B-cell lymphoma (DLBCL), those with International Prognostic Index (IPI) scores of 0-2 had a better 5-year OS rate than those with scores of 3-5 (84.2% vs. 46.8%, P = 0.002). IPI scores of 3-5 (P = 0.026) and tumors located in the large intestine (P = 0.015) were poor prognostic factors based on the multivariate analysis. CONCLUSION: The prognosis of T/NK-PILs was less favorable than that of aB-PILs. Female gender, stage III/IV disease, DLBCL with IPI scores of 3-5, or tumors in the large intestine were poor prognostic factors.

Expressions of the CagA protein and CagA-signaling molecules predict Helicobacter pylori dependence of early-stage gastric DLBCL.

We previously reported that early-stage gastric diffuse large B-cell lymphomas (DLBCLs), including DLBCLs with mucosa-associated lymphoid tissue (DLBCL[MALT]) and without ("pure" DLBCL) the features of MALT lymphomas, can achieve long-term complete remission after frontline Helicobacter pylori (HP) eradication (HPE). We recently reported that expression of cytotoxin-associated gene A (CagA) and CagA-signaling molecules (phospho-Src homology-2 domain-containing phosphatase [p-SHP2] and phospho-extracellular signal-regulated kinase [p-ERK]) is associated with HP dependence of gastric MALT lymphoma. However, the significance of CagA and CagA-signaling molecules in gastric DLBCL remains unexplored. The association between expression of CagA, p-SHP-2, and p-ERK in malignant B cells and tumor response to HPE was evaluated in 63 patients with stage IE/IIE1 HP-positive gastric DLBCL who received HPE as frontline treatment. We detected CagA expression in 20 of 42 DLBCL (MALT) cases (47.6%) and in 13 of 21 "pure" DLBCL cases (61.9%). CagA expression was higher in HP-dependent tumors than in HP-independent tumors (74.3% [26 of 35] vs 25.0% [7 of 28]). Patients with CagA expression responded to HPE quicker than those without expression (median time to complete remission, 4.0 months vs 5.0 months). The expression of CagA was closely associated with p-SHP-2 and p-ERK expression. Combined CagA, p-SHP-2, and p-ERK expression showed an increased positive predictive value (81.8% vs 75.9%) and an increased specificity (84.0% vs 75.0%) for HP dependence compared with CagA expression alone. Our results indicated that CagA and its signaling molecules can be detected in the malignant B cells of gastric DLBCL, and the expression of these molecules is clinically and biologically associated with HP dependence.

Regulation of EBV LMP1-triggered EphA4 downregulation in EBV-associated B lymphoma and its impact on patients' survival.

Epstein-Barr virus (EBV), an oncogenic human virus, is associated with several lymphoproliferative disorders, including Burkitt lymphoma, Hodgkin disease, diffuse large B-cell lymphoma (DLBCL), and posttransplant lymphoproliferative disorder (PTLD). In vitro, EBV transforms primary B cells into lymphoblastoid cell lines (LCLs). Recently, several studies have shown that receptor tyrosine kinases (RTKs) play important roles in EBV-associated neoplasia. However, details of the involvement of RTKs in EBV-regulated B-cell neoplasia and malignancies remain largely unclear. Here, we found that erythropoietin-producing hepatocellular receptor A4 (EphA4), which belongs to the largest RTK Eph family, was downregulated in primary B cells post-EBV infection at the transcriptional and translational levels. Overexpression and knockdown experiments confirmed that EBV-encoded latent membrane protein 1 (LMP1) was responsible for this EphA4 suppression. Mechanistically, LMP1 triggered the extracellular signal-regulated kinase (ERK) pathway and promoted Sp1 to suppress EphA4 promoter activity. Functionally, overexpression of EphA4 prevented LCLs from proliferation. Pathologically, the expression of EphA4 was detected in EBV(-) tonsils but not in EBV(+) PTLD. In addition, an inverse correlation of EphA4 expression and EBV presence was verified by immunochemical staining of EBV(+) and EBV(-) DLBCL, suggesting EBV infection was associated with reduced EphA4 expression. Analysis of a public data set showed that lower EphA4 expression was correlated with a poor survival rate of DLBCL patients. Our findings provide a novel mechanism by which EphA4 can be regulated by an oncogenic LMP1 protein and explore its possible function in B cells. The results provide new insights into the role of EphA4 in EBV(+) PTLD and DLBCL.

The B-cell-activating factor signalling pathway is associated with Helicobacter pylori independence in gastric mucosa-associated lymphoid tissue lymphoma without t(11;18)(q21;q21).

We previously reported that activation of the B-cell-activating factor (BAFF) pathway upregulates nuclear factor-κB (NF-κB) and induces BCL3 and BCL10 nuclear translocation in Helicobacter pylori (HP)-independent gastric diffuse large B-cell lymphoma (DLBCL) tumours with evidence of mucosa-associated lymphoid tissue (MALT). However, the significance of BAFF expression in HP independence of gastric low-grade MALT lymphomas without t(11;18)(q21;q21) remains unexplored. Sixty-four patients who underwent successful HP eradication for localized HP-positive gastric MALT lymphomas without t(11;18)(q21;q21) were studied. BAFF expression was significantly higher in the HP-independent group than in the HP-dependent group [22/26 (84.6%) versus 8/38 (21.1%); p < 0.001]. Similarly, BAFF receptor (BAFF-R) expression (p = 0.004) and nuclear BCL3 (p = 0.004), BCL10 (p < 0.001), NF-κB (p65) (p = 0.001) and NF-κB (p52) (p = 0.005) expression were closely correlated with the HP independence of these tumours. Moreover, BAFF overexpression was significantly associated with BAFF-R expression and nuclear BCL3, BCL10, NF-κB (p65) and NF-κB (p52) expression. These findings were further validated in an independent cohort, including 40 HP-dependent cases and 18 HP-independent cases of gastric MALT lymphoma without t(11;18)(q21;q21). The biological significance of BAFF signalling in t(11;18)(q21;q21)-negative lymphoma cells was further studied in two types of lymphoma B cell: OCI-Ly3 [non-germinal centre B-cell origin DLBCL without t(11;18)(q21;q21) cell line] and MA-1 [t(14;18)(q32;q21)/IGH-MALT1-positive DLBCL cell line]. In both cell lines, we found that BAFF activated the canonical NF-κB and AKT pathways, and induced the formation of BCL10-BCL3 complexes, which translocated to the nucleus. BCL10 and BCL3 nuclear translocation and NF-κB (p65) transactivation were inhibited by either LY294002 or by silencing BCL3 or BCL10 with small interfering RNA. BAFF also activated non-canonical NF-κB pathways (p52) through tumour necrosis factor receptor-associated factor 3 degradation, NF-κB-inducing kinase accumulation, inhibitor of κB kinase (IKK) α/ß phosphorylation and NF-κB p100 processing in both cell lines. Our data indicate that the autocrine BAFF signal transduction pathway contributes to HP independence in gastric MALT lymphomas without the t(11;18)(q21;q21) translocation. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Epstein-Barr virus LMP2A suppresses MHC class II expression by regulating the B-cell transcription factors E47 and PU.1.

Oncogenic Epstein-Barr virus (EBV) uses various approaches to escape host immune responses and persist in B cells. Such persistent infections may provide the opportunity for this virus to initiate tumor formation. Using EBV-immortalized lymphoblastoid cell lines (LCLs) as a model, we found that the expression of major histocompatibility complex (MHC) class II and CD74 in B cells is repressed after EBV infection. Class II transactivator (CIITA) is the master regulator of MHC class II-related genes. As expected, CIITA was downregulated in LCLs. We showed that downregulation of CIITA is caused by EBV latent membrane protein 2A (LMP2A) and driven by the CIITA-PIII promoter. Furthermore, we demonstrated that LMP2A-mediated E47 and PU.1 reduction resulted in CIITA suppression. Mechanistically, the LMP2A immunoreceptor tyrosine-based activation motif was critical for the repression of E47 and PU.1 promoter activity via Syk, Src, and the phosphatidylinositol 3-kinase/Akt pathway. Elimination of LMP2A in LCLs using a shLMP2A approach showed that the expression levels of E47, PU.1, CIITA, MHC class II, and CD74 are reversed. These data indicated that the LMP2A may reduce MHC class II expression through interference with the E47/PU.1-CIITA pathway. Finally, we demonstrated that MHC class II may be detected in tonsils and EBV-negative Hodgkin disease but not in EBV-associated posttransplant lymphoproliferative disease and Hodgkin disease.

The PTEN-AKT-mTOR/RICTOR Pathway in Nasal Natural Killer Cell Lymphoma Is Activated by miR-494-3p via PTEN But Inhibited by miR-142-3p via RICTOR.

Nasal natural killer (NK) cell lymphoma (NNL) is an Epstein-Barr virus-associated lymphoma of cytotoxic NK cell origin. The Epstein-Barr virus-encoded miR-BART20-5p inhibits T-bet (TBX21), the master transcription factor of cytotoxic NK cells. To further explore the roles of miRNAs in NNLs, we measured the miRNA expression profiles of 36 NNLs. miR-21, miR-142-3p, miR-126, miR-451, and miR-494-3p were the top five miRNAs with the highest expression levels. By using pathway analysis, we identified associations between all of the five miRNAs with the PTEN-AKT-mTOR pathway, in which PTEN suppresses the oncogenic AKT, and mTOR mediates the oncogenic effects of AKT. YT and NK92 cells derived from NK cell lymphomas were used. miR-494-3p inhibited PTEN with secondary activation of AKT in NK92 cells, and miR-142-3p inhibited RICTOR, a key component of the mTOR complex, with secondary suppression of AKT in YT cells. Significantly, T-bet inhibited the PTEN-AKT-mTOR/RICTOR pathway through induction of PTEN and suppression of RICTOR. Therefore, a molecular circuit of T-bet, PTEN, AKT, and RICTOR is regulated by miR-BART20-5p, miR-494-3p, and miR-142-3p. This circuit is involved in the pathogenesis of NNL. Hence, antagomirs to miR-BART20-5p or miR-494-3p, miR-142-3p mimics, or AKT inhibitors may be useful in NNL therapy.

EBV-encoded miR-BART20-5p and miR-BART8 inhibit the IFN-γ-STAT1 pathway associated with disease progression in nasal NK-cell lymphoma.

Nasal NK-cell lymphoma (NNL) is an Epstein-Barr virus (EBV)-associated lymphoma of cytotoxic natural killer (NK) cell origin. Because normal NK cells secrete the principal cytotoxic cytokine IFN-γ to suppress both tumor growth and viral replication, we investigated how EBV may have used miRNAs of viral origin to inhibit the IFN-γ-STAT1 pathway to facilitate viral replication and tumor growth. In EBV(-) Jurkat cells, transfection of miR-BART20-5p and miR-BART8 inhibited translation of luciferase-IFN-γ-3'-UTR and luciferase-STAT1-3'-UTR, respectively. In EBV(+) IFN-γ(weak)/STAT1(strong) YT leukemic cells and IFN-γ(strong)/STAT1(weak) NK92 cells, relative endogenous levels between miR-BART20-5p and IFN-γ mRNAs or between miR-BART8 and STAT1 mRNAs determined expression of the targets. Chromatin immunoprecipitation studies showed that STAT1 regulates the transcription of the tumor suppressor TP53 (encoding p53) and miR-let7a. Consistent with these findings, overexpression of miR-BART8 in YT cells or of miR-BART20-5p in NK92 cells inhibited p53 and increased resistance to doxorubicin. In 36 NNLs, the levels of miR-BART20-5p or miR-BART8 correlated inversely with the expression of STAT1. Additionally, in 46 NNLs, expression of both miR-BART20-5p and miR-BART8 identified a group of NNLs with decreased p53 mRNAs and evidence of disease progression. We conclude that miR-BART20-5p and miR-BART8 cause progression of nasal NK-cell lymphomas through inhibition of the IFN-γ-STAT1 pathway.

Higher bone marrow LGALS3 expression is an independent unfavorable prognostic factor for overall survival in patients with acute myeloid leukemia.

Alterations of galectin-3 expression are often seen in cancers and may contribute to tumorigenesis, cancer progression, and metastasis. The studies concerning clinical implications of galectin-3 expression in patients with acute myeloid leukemia (AML) are scarce. We investigated the expression of LGALS3, the gene encoding galectin-3, in the bone marrow (BM) mononuclear cells from an original cohort comprising 280 adults with primary non-acute promyelocytic leukemia. Higher LGALS3 expression was closely associated with older age, French-American-British M4/M5 subtypes, CD14 expression on leukemic cells, and PTPN11 mutation, but negatively correlated with CEBPA mutation and FLT3-ITD. Compared with patients with lower LGALS3 expression, those with higher expression had lower complete remission rates, higher primary refractory rates, and shorter overall survival. This result was validated in an independent validation cohort. A scoring system incorporating higher LGALS3 expression and 8 other risk factors, including age, white blood cell count, cytogenetics, and gene mutations, into survival analysis proved to be very useful to stratify patients with AML into different prognostic groups (P < .001). In conclusion, BM LGALS3 expression may serve as a new biomarker to predict clinical outcome in patients with AML, and galectin-3 may serve as a potential therapeutic target in those patients with higher expression of this protein.

Inhibition of ZEB1 by miR-200 characterizes Helicobacter pylori-positive gastric diffuse large B-cell lymphoma with a less aggressive behavior.

Primary gastric diffuse large B-cell lymphomas may or may not have a concurrent component of mucosa-associated lymphoid tissue lymphoma. Diffuse large B-cell lymphoma/mucosa-associated lymphoid tissue lymphomas are often associated with Helicobacter pylori (H. pylori) infection, suggesting that the large cells are transformed from mucosa-associated lymphoid tissue lymphomas. In contrast, only limited data are available on the clinical and molecular features of pure gastric diffuse large B-cell lymphomas. In 102 pure gastric diffuse large B-cell lymphomas, we found H. pylori infection in 53% of the cases. H. pylori-positive gastric diffuse large B-cell lymphomas were more likely to present at an earlier stage (73% vs 52% at stage I/II, P=0.03), to achieve complete remission (75% vs 43%, P=0.001), and had a better 5-year disease-free survival rate (73% vs 29%, P<0.001) than H. pylori-negative gastric diffuse large B-cell lymphomas. Through genome-wide expression profiles of both miRNAs and mRNAs in nine H. pylori-positive and nine H. pylori-negative gastric diffuse large B-cell lymphomas, we identified inhibition of ZEB1 (zinc-finger E-box-binding homeobox 1) by miR-200 in H. pylori-positive gastric diffuse large B-cell lymphomas. ZEB1, a transcription factor for marginal zone B cells, can suppress BCL6, the master transcription factor for germinal center B cells. In 30 H. pylori-positive and 30 H. pylori-negative gastric diffuse large B-cell lymphomas, we confirmed that H. pylori-positive gastric diffuse large B-cell lymphomas had higher levels of miR-200 by qRT-PCR, and lower levels of ZEB1 and higher levels of BCL6 using immunohistochemistry. As BCL6 is a known predictor of a better prognosis in gastric diffuse large B-cell lymphomas, our data demonstrate that inhibition of ZEB1 by miR-200, with secondary increase in BCL6, is a molecular event that characterizes H. pylori-positive gastric diffuse large B-cell lymphomas with a less aggressive behavior.

Epstein-Barr virus-encoded miR-BART20-5p inhibits T-bet translation with secondary suppression of p53 in invasive nasal NK/T-cell lymphoma.

Nasal NK/T-cell lymphoma (NNL) is an Epstein-Barr virus (EBV)-associated lymphoma derived from cytotoxic NK or T cells of the nasal mucosa. NNLs are noninvasive in the earliest stage, and become invasive with disease progression. The EBV encodes at least 44 miRNAs, whose functions in the pathogenesis of NNL are mostly unknown. We evaluated the levels of 39 EBV-encoded miRNAs with quantitative real-time RT-PCR in a series of 20 noninvasive NNLs and 20 invasive NNLs. miR-BART20-5p was associated most strongly with invasion (P ≤ 0.001), and lack of T-bet, the master transcription factor for cytotoxic NK cells. However, we identified T-bet (official symbol, TBX21) transcripts in T-bet-negative NNLs, implying a block in the translation of T-bet by miR-BART20-5p. In co-transfection experiments, miR-BART20-5p inhibited T-bet translation in both non-Hodgkin and Hodgkin lymphoma cell lines. Endogenous mir-BART20-5p also inhibited translation of T-bet in EBV-infected YT lymphoma cells of NK-cell origin. Induction of T-bet in YT cells up-regulated p53, leading to increased sensitivity in response to doxorubicin. Finally, YT cells transplanted into severe combined immunodeficiency mice had an invasive behavior. Taken together, we conclude that EBV-encoded miR-BART20-5p inhibits T-bet translation with secondary suppression of p53 in invasive nasal NK/T-cell lymphoma. An antagomir to miR-BART20-5p might be an effective therapeutic agent through induction of T-bet and p53.

Helicobacter pylori eradication therapy is effective in the treatment of early-stage H pylori-positive gastric diffuse large B-cell lymphomas.

An explorative study evaluates the efficacy of Helicobacter pylori (HP) eradication (HPE) therapy on early-stage gastric diffuse large B-cell lymphomas (DLBCLs) without features of mucosa-associated lymphoid tissue (MALT), the pure (de novo) DLBCLs, in comparison with its efficacy on high-grade transformed gastric MALT lymphomas, the DLBCL(MALT). In total, 50 patients of stage IE/IIE1 HP-positive gastric DLBCLs with frontline HPE treatment were included. HP infection was successfully eradicated in 100% (16/16) of the pure (de novo) DLBCL patients and 94.1% (32/34) of the DLBCL(MALT) patients. In total, 68.8% (11/16) of pure (de novo) DLBCL patients and 56.3% (18/32) of DLBCL(MALT) patients achieved complete pathologic remission (pCR) after HPE therapy. The median time to pCR was 2.1 months (95% confidence interval, 0.6%-3.7%) for pure (de novo) DLBCLs and 5.0 months (95% confidence interval, 2.8%-7.5%; P = .024) for DLBCL(MALT). At a median follow-up of 7.7 years, all patients with pCR after HPE therapy were alive and free of lymphomas, except for one patient with pure (de novo) DLBCL who died of lung cancer. Similar to DLBCL(MALT), a substantial portion of early-stage HP-positive gastric pure (de novo) DLBCLs remains HP-dependent and responds to antibiotic treatment. Prospective studies to validate the findings are warranted.

Expression of cereblon protein assessed by immunohistochemicalstaining in myeloma cells is associated with superior response of thalidomide- and lenalidomide-based treatment, but not bortezomib-based treatment, in patients with multiple myeloma.

Cereblon (CRBN) is essential for the anti-myeloma (MM) activity of immunomodulatory drugs (IMiDs), such as thalidomide and lenalidomide. However, the clinical implications of CRBN in MM patients are unclear. Using immunohistochemical (IHC) staining on paraffin-embedded bone marrow sections, the expression of CRBN protein in myeloma cells (MCs) was assessed in 40 relapsed/refractory MM (RRMM) patients who received lenalidomide/dexamethasone (LD) and 45 and 22 newly diagnosed MM (NDMM) patients who received thalidomide/dexamethasone (TD) and melphalan/bortezomib/prednisolone (MVP), respectively. IHC staining were scored on a scale representing the diffuseness and intensity of positive-staining MCs (range, 0-8) and a score ≥4.5 was used for CRBN positivity (CRBN(+)) on a cut-point analysis of all possible scores and response of TD and LD. Compared to CRBN(+) NDMM patients, CRBN(-) NDMM patients had more international staging system (ISS) III (26 vs. 61 %, respectively; P = 0.006). In the LD and TD cohorts, the response rate (RR) was higher in CRBN(+) patients than CRBN(-) patients (LD 79 vs. 33 %, respectively; P = 0.005) (TD 75 vs. 29 %, respectively; P = 0.005); however, this trend was not observed in the MVP cohort. In the LD and TD cohorts, the positive and negative prediction value of CRBN(+) for treatment response was 79 and 67 % and 75 and 71 %, respectively. Multivariate analysis showed that CRBN(+) was a significant factor associated with superior RR for LD and TD. The data suggest that expression of CRBN protein in MCs assessed using the IHC is a feasible approach to predict the response of IMiDs in MM patients.

First-line antibiotic treatment in patients with localized extragastric mucosa-associated lymphoid tissue lymphoma.

Between January 2010 and December 2015, we enrolled 28 patients with stage IEI/IIE1 extragastric mucosa-associated lymphoid tissue (MALT) lymphoma who received first-line antibiotic treatment, after informing them about the pros and cons of alternative therapies. In addition, during the same period, 64 patients with stage IE/IIE1 disease who received conventional treatment were selected as the control group. The most common primary sites were the ocular adnexal area (17 cases), followed by the salivary glands (four cases), pulmonary (three cases), and thyroid, trachea, larynx, and colon region (one case each). First-line antibiotic treatment resulted in an overall response rate of 57.1%: 12 patients achieved complete remission (CR), while four achieved partial remission (antibiotic-responsive tumors). Monoclonal gammopathy was significantly prevalent in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (50.0% [6/12] vs. 12.5% [2/16], p = 0.044). After a median follow-up of 7 years, all patients with CR remained lymphoma-free, with 7-year event-free survival (EFS) and overall survival (OS) rates of 62.7% and 96.4%, respectively. The 7-year EFS and OS rates of patients who received conventional treatments were 73.1% and 91.1%, respectively. Compared with that noted in patients who received conventional treatment, antibiotic treatment was effective in some patients with localized extragastric MALT lymphoma.

Improved outcomes of localized diffuse large B-cell lymphoma at the Waldeyer ring in comparison to the sinonasal area in the rituximab era.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) of the head-and-neck area primarily involves the Waldeyer ring (WR) and sinonasal area (SN). However, the differential clinical outcomes between patients with WR-DLBCL and those with SN-DLBCL in the rituximab era remain unclear. METHODS: To avoid confounding factors contributed by advanced DLBCL with WR and SN involvement, we assessed the clinical outcomes of patients with stage I/II WR-DLBCL and SN-DLBCL and compared them with those having corresponding stages of DLBCL in the lymph nodes but without other extranodal involvement (LN-DLBCL) in the same period. We compared the patients' clinical characteristics, treatment modalities, event-free survival (EFS), and overall survival (OS) among the three subgroups. RESULTS: We analyzed 67, 15, and 106 patients with WR-DLBCL, SN-DLBCL, and LN-DLBCL, respectively, between January 2000 and December 2019. All patients received front-line rituximab-based regimens, and > 80% received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone-based regimens. More patients with SN-DLBCL had revised International Prognostic Index (R-IPI) score 3 (27%) when compared with those with WR-DLBCL (7%) and those with LN-DLBCL (10%, p = 0.181). Patients with WR-DLBCL, LN-DLBCL, and SN-DLBCL had 5-year EFS and OS rates of 80.7%, 59.5%, and 41.9% (p = 0.021) and 83.7%, 70.8%, and 55.8% (p = 0.032), respectively. Compared to patients with LN-DLBCL, those with WR-DLBCL also had a significantly favorable 5-year EFS rate (p = 0.021) and 5-year OS rate (p = 0.023). Three of the 15 patients with SN-DLBCL experienced lymphoma recurrence in the brain after front-line treatment. In multivariate analyses, R-IPI scores of 1-2 and 3 served as significantly poor prognostic factors for patients with poor EFS and OS. CONCLUSIONS: Compared to patients with LN-DLBCL, patients with WR-DLBCL receiving front-line rituximab-based treatments had favorable clinical outcomes; however, patients with SN-DLBCL had worse clinical outcomes. Further studies on molecular prognostic factors and treatment strategies for SN-DLBCL are warranted.

Intramucosal variant of nasal natural killer (NK)/T cell lymphoma has a better survival than does invasive variant: implication on loss of E26 transformation-specific sequence 1 (ETS-1) and T-box expressed in T cells (T-bet) with invasion.

AIMS: Nasal natural killer/T cell lymphoma (NNKTCL) arises from the nasal mucosa, and spreads to adjacent tissues via local invasion or to regional lymph nodes and distant sites via metastasis. The aims of this study were to determine the impact of invasion on the prognosis of NNKTCL, and correlate invasion with the expression of cytotoxic markers of lymphoma cells. METHODS AND RESULTS: Histopathological evaluations of invasion and immunohistochemistry for cytotoxic markers, including E26 transformation-specific sequence 1 (ETS-1), T-box expressed in T cells (T-bet), signal transducer and activator of transcription (STAT-1), CD56 and granzyme B (GB), were performed in 64 NNKTCLs. There were 17 stage I cases without invasion (stage Ia or intramucosal), 21 stage I cases with invasion (stage Ib), 16 stage II cases and 10 stages III/IV cases. Stage Ia NNKTCLs had a better 5-year overall survival rate than that of stages Ib, II or III/IV NNKTCLs (85%, 38%, 33% and 20%, respectively, P < 0.001 by log-rank test). Loss of ETS-1 was found in 24% (four of 17) stage Ia NNKTCLs and in 65% (28 of 43) stages Ib/II/III/IV NNKTCLs (P = 0.04, Fisher's exact test); loss of T-bet was found in 29% (five of 17) stage Ia NNKTCLs and in 67% (30 of 45) stages Ib/II/III/IV NNKTCLs (P = 0.02, Fisher's exact test). CONCLUSIONS: NNKTCL is classically an aggressive lymphoma, but the intramucosal variant is less aggressive. Loss of ETS-1 or T-bet correlated weakly with invasion, a finding that requires further confirmation.

Establishment of a novel MALT lymphoma cell line, ma-1, from a patient with t(14;18)(q32;q21)-positive Helicobacter pylori-independent gastric MALT lymphoma.

Although t(11;18)(q21;q21), t(1;14)(p22;q32), and a few other genetic mutations are specific markers for the Helicobacter pylori (HP)-independent status of gastric mucosa-associated lymphoid tissue (MALT) lymphoma, the molecular mechanisms responsible for HP-independence of gastric MALT lymphoma without such translocations and mutations remain uncharacterized. In the present study, we describe the establishment and characterization of a novel MALT lymphoma cell line, MA-1, which was derived from a gastric MALT lymphoma which was negative for both t(11;18)(q21;q21) and t(1;14)(p22;q32); the patient had failed HP eradication therapy and chemotherapy. The cell morphology and the immunophenotype of this cell line were similar to that of the original gastric MALT lymphoma. Comparative genomic hybridization analysis showed no significant gene copy number changes. Spectral karyotyping displayed a near-diploid chromosome content (48 < 2n>XY), with at least 13 chromosome structural abnormalities. Furthermore, fluorescence in situ hybridization analyses disclosed the existence of three sub-clones, characterized by t(14;18)(q32;q21)/IGH-BCL2, t(14;18)(q32;q21)/IGH-MALT1, and the presence of both chromosomal translocations in the same cell, respectively; whereas amplification of the genes CRAD9, TRAF2, and BCL10 were not found. In conclusion, we have established the first human gastric MALT lymphoma cell line, which is characterized by unusual and complex chromosome translocations and will be useful to explore further the molecular mechanisms of HP-independence in gastric MALT lymphoma.

miR-155-regulated mTOR and Toll-like receptor 5 in gastric diffuse large B-cell lymphoma.

BACKGROUND: Gastric diffuse large B-cell lymphoma (DLBCL) is often associated with Helicobacter pylori (H. pylori) infection. Those in the early stage could be treated with H. pylori eradication therapy, and are classified into a sensitive group and a resistant group. METHODS: Genome-wide miRNA and miRNA expression profiles were obtained from biopsy specimens of gastric DLBCL. MiRNAs and their targets as predictors of responses to H. pylori eradication therapy were identified through differential expression and pathway enrichment analysis, and further confirmed with transfection experiments in lymphoma cell lines of B-cell origin. RESULTS: Genome-wide miRNA and mRNA profiles showed miR-200 was associated with the sensitive group, and that the resistant group had higher levels of miR-155 and lower levels of DEPTOR (an inhibitor of mTOR) than the sensitive group. BJAB cells transfected with miR-155 also had lower DEPTOR and higher mTOR levels. Therefore, miR-155-mediated inhibition of DEPTOR with secondary activation of mTOR was a potential marker for resistance to H. pylori eradication therapy. In contrast, pathway enrichment analysis showed that Toll-like receptor 5 (TLR5), the receptor for bacterial flagellin, was a potential marker for sensitivity to H. pylori eradication therapy. In an independent series, stronger expression of pS6K1 (a direct target of mTOR) was associated with the resistant group and morphologic evidence of active gastritis was associated with the sensitive group. CONCLUSIONS: These findings showed that activation of the miR-155-DEPTOR pathway is a marker for resistance to H. pylori eradication therapy, and that histological evaluation of active gastritis might be used as a surrogate marker to predict responses to H. pylori eradication therapy in gastric DLBCL.

Current Status of the Spectrum and Therapeutics of Helicobacter pylori-Negative Mucosa-Associated Lymphoid Tissue Lymphoma.

Helicobacter pylori (HP)-unrelated mucosa-associated lymphoid tissue (MALT) lymphoma includes the majority of extragastric MALT lymphomas and a small proportion of gastric MALT lymphomas. Although the role of first-line antibiotics in treating HP-negative gastric MALT lymphomas remains controversial, HP eradication therapy (HPE)-like regimens may result in approximately 20-30% complete remission (CR) for patients with localized HP-negative gastric MALT lymphoma. In these patients, H. heilmannii, H. bizzozeronii, and H. suis were detected in sporadic gastric biopsy specimens. Extragastric MALT lymphoma is conventionally treated with radiotherapy for localized disease and systemic chemotherapy for advanced and metastatic diseases. However, a proportion of extragastric MALT lymphomas, such as ocular adnexal lesions and small intestinal lesions, were reported to be controlled by antibiotics for Chlamydophila psittaci and Campylobacter jejuni, respectively. Some extragastric MALT lymphomas may even respond to first-line HPE. These findings suggest that some antibiotic-responsive tumors may exist in the family of HP-negative MALT lymphomas. Two mechanisms underlying the antibiotic responsiveness of HP-negative MALT lymphoma have been proposed. First, an HPE-like regimen may eradicate the antigens of unknown bacteria. Second, clarithromycin (the main component of HPE) may have direct or indirect antineoplastic effects, thus contributing to the CR of these tumors. For antibiotic-unresponsive HP-negative MALT lymphoma, high-dose macrolides and immunomodulatory drugs, such as thalidomide and lenalidomide, have reported sporadic success. Further investigation of new treatment regimens is warranted.