Prognostic impact of C-REL expression in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) with a germinal center B-cell (GCB) phenotype is believed to confer a better prognosis than DLBCL with an activated B-cell (ABC) phenotype. Previous studies have suggested that nuclear factor-κB (NF-κB) activation plays an important role in the ABC subtype of DLBCL, whereas c-REL amplification is associated with the GCB subtype. Using immunohistochemical techniques, we examined 68 newly diagnosed de novo DLBCL cases (median follow-up 44 months, range 1 to 142 months) for the expression of c-REL, BCL-6, CD10, and MUM1/IRF4. Forty-four (65%) cases demonstrated positive c-REL nuclear expression. In this cohort of patients, the GCB phenotype was associated with a better overall survival (OS) than the non-GCB phenotype (Kaplan–Meier survival (KMS) analysis, p = 0.016, Breslow–Gehan–Wilcoxon test). In general, c-REL nuclear expression did not correlate with GCB vs. non-GCB phenotype, International Prognostic Index score, or OS. However, cases with a GCB phenotype and negative nuclear c-REL demonstrated better OS than cases with a GCB phenotype and positive nuclear c-REL (KMS analysis, p = 0.045, Breslow–Gehan–Wilcoxon test), whereas in cases with non-GCB phenotype, the expression of c-REL did not significantly impact the prognosis. These results suggest that c-REL nuclear expression may be a prognostic factor in DLBCL and it may improve patient risk stratification in combination with GCB/non-GCB phenotyping.     

BCL10 expression is unrelated to clinico-pathological parameters or prognoses for oral squamous cell carcinomas

Abstract

BCL-10 (B-cell lymphoma 10) has been linked to a pro-apoptotic gene in mucosa-associated lymphoid tissue (MALT) lymphomas. We describe the expression of BCL10 in oral squamous cell carcinoma (OSCC) and its relation to clinical, pathological and prognostic parameters. We carried out a retrospective study of 50 patients in Spain who were diagnosed with OSCC. We constructed a tissue microarray of the samples to study the expression of BCL10 using immunohistochemistry. Diffuse and homogeneous staining was observed in the nuclei and cytoplasms of most neoplastic cells of the vast majority of tumors and no significant differences were seen in different areas of the tumors. The expression was unrelated to any clinical or pathological parameters including tumor stage. The intra-class coefficient was 0.97, which indicates the minimal variability among the determinations.     

Commentary on the WHO classification of tumors of lymphoid tissues (2008): ��Gray zone�� lymphomas overlapping with Burkitt lymphoma or classical Hodgkin lymphoma

The 2008 WHO Classification of Tumors of Haematopoietic and Lymphoid Tissues has introduced two new categories of high-grade B-cell lymphomas: entities in which features of diffuse large B-cell lymphoma (DLBCL) overlap with Burkitt lymphoma (DLBCL/BL) or classical Hodgkin lymphoma (DLBCL/HL). The DLBCL/BL category encompasses cases that resemble Burkitt lymphoma morphologically, but have one or more immunophenotypic or molecular genetic deviations that would exclude it from the BL category; conversely, some cases have immunophenotypic and/or genetic features of BL, but display cytologic variability unacceptable for BL. Many of the cases in the DLBCL/BL category contain a translocation of MYC as well as either BCL2 or BCL6 (so-called double-hit lymphomas) and have a very aggressive clinical behavior. The DLBCL/HL category encompasses lymphomas that exhibit the morphology of classical Hodgkin lymphoma but the immunophenotype of DLBCL, or vice versa. Most DLBCL/HL cases described present as mediastinal masses, but this category is not limited to mediastinal lymphomas. These new categories acknowledge the increasing recognition of cases that display mixed features of two well-established diseases. Whether the existence of such cases reflects shortcomings of our current diagnostic armamentarium or a true disease continuum in which such hybrid or intermediate neoplasms actually exist remains to be determined.     

Expression of microRNAs in diffuse large B cell lymphoma is associated with immunophenotype, survival and transformation from follicular lymphoma

MicroRNAs are naturally occurring small RNA species that regulate gene expression and are frequently abnormally expressed in cancers. However, the role of microRNAs in lymphoma is poorly understood. Therefore, we undertook a comprehensive study of microRNA expression in two of the most common lymphomas: diffuse large B-cell lymphoma (DLBCL) ( n = 80) and follicular lymphoma (FCL) ( n = 18) using microarrays containing probes for 464 human microRNAs. Unsupervised cluster analysis revealed distinct expression patterns between these two lymphomas and specific microRNA signatures (including members of the miR-17–92 cluster) were derived that correctly predicted lymphoma type in >95% of cases. Furthermore, we identified microRNAs in de novo DLBCL ( n = 64) associated with germinal centre-like and non-germinal centre-like immunophenotypes, international prognostic index status and event-free survival in CHOP and rituximab (R)-CHOP treated patients. Despite the indolent nature of FCL a significant proportion of cases undergo high-grade transformation to more aggressive DLBCL. In order to see if transformation is associated with changes in microRNA expression we compared transformed DLBCL cases ( n = 16) with de novo DLBCL, as well as FCL cases that underwent subsequent transformation ( n = 7) with FCL cases that had not transformed at a median follow-up of 60 months ( n = 11). Differential expression of 12 microRNAs correctly predicted >85% of transformed versus de novo DLBCL cases; six microRNAs ( miR-223, 217, 222 , 221 and let-7i and 7b) were found which could similarly predict or transformation in FCL ( P < 0.05). These data suggest that microRNAs have potential as diagnostic and prognostic markers in these lymphomas and may be used to identify FCL patients at risk of high-grade transformation.     

Long non-coding RNA as a novel biomarker and therapeutic target in aggressive B-cell non-Hodgkin lymphoma: A systematic review

Cancer initiation and progression have been associated with dysregulated long non-coding RNA (lncRNA) expression. However, the lncRNA expression profile in aggressive B-cell non-Hodgkin lymphoma (NHL) has not been comprehensively characterized. This systematic review aims to evaluate the role of lncRNAs as a biomarker to investigate their future potential in the diagnosis, real-time measurement of response to therapy and prognosis in aggressive B-cell NHL. We searched PubMed, Web of Science, Embase and Scopus databases using the keywords “long non-coding RNA”, “Diffuse large B-cell lymphoma”, “Burkitt's lymphoma” and “Mantle cell lymphoma”. We included studies on human subjects that measured the level of lncRNAs in samples from patients with aggressive B-cell NHL. We screened 608 papers, and 51 papers were included. The most studied aggressive B-cell NHL was diffuse large B-cell lymphoma (DLBCL). At least 79 lncRNAs were involved in the pathogenesis of aggressive B-cell NHL. Targeting lncRNAs could affect cell proliferation, viability, apoptosis, migration and invasion in aggressive B-cell NHL cell lines. Dysregulation of lncRNAs had prognostic (e.g. overall survival) and diagnostic values in patients with DLBCL, Burkitt's lymphoma (BL), or mantle cell lymphoma (MCL). Furthermore, dysregulation of lncRNAs was associated with response to treatments, such as CHOP-like chemotherapy regimens, in these patients. LncRNAs could be promising biomarkers for the diagnosis, prognosis and response to therapy in patients with aggressive B-cell NHL. Additionally, lncRNAs could be potential therapeutic targets for patients with aggressive B-cell NHL like DLBCL, MCL or BL.     

Commentary on the WHO classification of tumors of lymphoid tissues (2008): aggressive B-cell lymphomas

In the novel WHO classification 2008, the classification of aggressive B-cell lymphoma has been revised for several categories with the aim to define “clean” entities. Within large B-cell lymphoma, a few distinct clinico-pathological entities have been recognized with more clinically defined entities than pathologically defined ones. The majority of known morphological variations were not considered to merit more than classification as a variant of DLBCL, not otherwise specified. Specifically, a biological subgrouping of DLBCL on the basis of molecular (activated B-cell versus germinal center B-cell) or immunophenotypic (CD5+) features was felt to be too immature to include at this stage. The role of EBV in aggressive B-cell lymphoma has been explored in more depth with the recognition of several novel and re-defined clinico-pathological entities. Also, in these diseases, clinical definitions play a very dominant role in the WHO classification 2008.     

Genetic immunization: a new monoclonal antibody for the detection of BCL-6 protein in paraffin sections.

Genetic immunization can be combined with hybridoma technology to generate high-affinity monoclonal antibodies (MAbs). A new anti-BCL-6 MAb (GI191E/A8) was produced by cloning full-length BCL-6 cDNA into a eukaryotic vector and delivering this into mouse epidermis using a helium gene gun. A comparative study was made of the specificity and the effects of formalin fixation on immunohistochemistry quality of GI191E/A8 and two other anti-BCL-6 MAbs. To evaluate its possible application to differential diagnosis of lymphomas, two tissue microarrays (89 diffuse large B-cell lymphomas and 24 B-cell chronic lymphocytic leukemia cases) were stained with GI191E/A8 and another anti-BCL-6 MAb produced by conventional means. Using GI191E/A8, the detection of BCL-6 protein was significantly increased, and its specificity was independent of formalin-fixation time. Using automatic quantified analysis, the correlation between the two anti-BCL-6 MAbs tested was identical in cases with overexpression or absence of BCL-6. In cases with intermediate BCL-6 protein expression, detection with GI191E/A8 was more sensitive. A significant association of higher BCL-6 expression and longer median overall survival times in diffuse large B-cell lymphomas was found. Using conventionally produced MAbs in the same patient group, the association was not significant.     

Lymphoma immunophenotyping: "borderline" lymphomas

Immunophenotyping of B-cell lymphoproliferative disorders is indispensable, especially in disorders with CD19(+) CD5(+) B lymphocytes, where we have to make the distinction between low grade neoplasia, such as chronic lymphocytic leukemia with CD23(+) malignant lymphocytes, and aggressive neoplasia such as mantle cell lymphoma with CD23(-) malignant lymphocytes. We found some cases of CD19(+) CD5(+) lymphoproliferative disorders that do not meet all criteria for diagnosis of chronic lymphocytic leukemia or mantle cell lymphoma. For instance, we found cases with a low or no expression of CD23, asociated with absence of expression of FMC7 and surface immunoglobulins. These cases could be classified as "borderline" CD19(+) CD5(+) B cell lymphoproliferative disorders, with an intermediate neoplasic grade.     

抗CD20单克隆抗体治疗B 细胞淋巴瘤的效应机制

B细胞淋巴瘤是一种主要的非霍奇金淋巴瘤(non-Hodgkin’s lymphoma,NHL),95%以上的B细胞淋巴瘤均表达B细胞分化抗原CD20。尽管目前CD20在B细胞分化发育过程中的具体功能尚未阐明,但其特有的表达方式和在细胞膜上的分布特点决定了其成为B细胞淋巴瘤靶向治疗的主要靶点。近十年来,随着抗CD20单克隆抗体的不断发展和进步,联合传统的CHOP化疗方案,在NHL的治疗中显示出良好的效果。虽然,近年来抗CD20单抗逐渐被用于B细胞相关的自身免疫病的治疗,但相关作用机制尚不明确。在针对NHL的临床治疗中,抗CD20单抗的疗效被认为依赖于效应器机制,主要有ADCC、CDC和细胞凋亡。虽然抗CD20在淋巴瘤的治疗中具有显著的免疫疗效,但部分瘤荷较大的病人出现了耐药和复发,循环中大量B细胞由于单抗的结合而被机体的单核巨噬细胞吞噬或NK细胞杀伤,机体出现成熟B细胞空缺期,同时单核巨噬细胞、NK细胞和补体大量消耗,造成机体免疫效应功能饱和和效应器耗竭。本文就抗CD20单克隆抗体在治疗淋巴瘤中的具体作用机制及可能造成的机体效应器耗竭问题做一简要的概述。     

Immunoflow cytometry compared with PCR for the identification of clonality in FNAs of T-cell-rich B-cell lymphomas

OBJECTIVE: The study aimed to compare the utility of immunoflow cytometry (IFC) with two IgH polymerase chain reaction (PCR) methods for the identification of clonality in fine needle aspirations (FNAs) from T-cell-rich B-cell lymphomas (TCRBCLs). METHODS: Ten cases of TCRBCLs were identified in which IFC had been performed according to our previously described method. Seven of these were cases in which the original diagnosis had been made by FNA cytology with IFC and cell block immunohistochemistry (IHC). The remaining three cases only had biopsies with histology, IFC and IHC. Formalin-fixed paraffin-embedded FNA cell block or histology tissue from these specimens had also been submitted for IgH PCR clonality studies using primers FR2a/VLJH and primers FR3a/VLJH. The results were reviewed and compared. RESULTS: All 10 case demonstrated B-cell clonality for at least one of the primer sets on PCR, but none showed light chain restriction on IFC. All TCRBCLs were positive for CD20 and CD79a but negative for CD10 and BCl-2. They were also consistently negative for CD22, CD23, CD5, CD43, ALK-1, cyclin D1 and CD30. CONCLUSIONS: If IgH PCR clonality assays had a turnaround time of 1 or 2 days, there might be a strong case for these studies supporting or even replacing IFC, in the FNA diagnosis of lymphoid lesions.     

Hypergammaglobulinemia in an SIV-infected rhesus macaque with a B-cell neoplasm with plasma cell differentiation

An SIV-infected rhesus macaque presented with anemia, hypercalcemia, and hyperglobulinemia. Neoplastic round cells with plasma cell morphology infiltrated multiple organs and stained immunohistochemically positive for CD45, MUM1/IRF4, CD138, VS38C, and Kappa light chain and variably positive for CD20 and CD79a, consistent with a B-cell neoplasm with plasma cell differentiation.     

Mimotope vaccination for epitope-specific induction of anti-CD20 antibodies

CD20 is expressed strictly by B-cells and is ubiquitously expressed at high surface densities of malignant human B-cells. This suggests that CD20 may be a tumor target for immunotherapy of B-cell lymphomas. Rituximab, a chimeric monoclonal antibody directed against CD20, has been demonstrated to be an effective treatment for non-Hodgkin's lymphoma (NHL) and some autoimmune diseases. In the current study, we used the phage display technique to generate mimotopes that complemented the screening Ab Rituximab. A total of seven candidate mimotopes were isolated from a 12-mer peptide library from which one mimotope was conjugated to keyhole limpet hemocyanin (KLH) or tetanus toxoid (TT). The immunogenicity of the two vaccines generated was examined in BALB/c mice. Sera from the vaccinated mice demonstrated high-titer specific antibodies to the mimotope conjugates. Antibody binding to native CD20 and Ab-mediated cytotoxicity (CDC, complement-dependent cytotoxicity) were also analyzed. Our data suggest that a Rituximab mimotope may be a useful tool for the construction of a functional vaccine to treat B-cell malignancy as well as some CD20 related autoimmune disorders.     

Expression of L-selectin and efficient binding to high endothelial venules do not modulate the dissemination potential of murine B-cell lymphoma

The homing receptor L-selectin is essential for the migration of naive lymphocytes into peripheral lymph nodes. In contrast to naive lymphocytes, activated and memory cells down-regulate L-selectin and enter peripheral lymph nodes by an L-selectin-independent mechanism. In view of the concept that lymphomas present the malignant counterparts of normal lymphocytes at a defined stage of differentiation, it has been suggested that in contrast to lymphomas with a memory/activated cell phenotype, L-selectin is essential for dissemination of lymphomas that represent naive cells. 38C-13 is a murine B-cell lymphoma with an immature naive cell phenotype. 38C-13 cells express high levels of L-selectin and bind to lymph node high endothelial venules in an L-selectin-dependent manner. In this study we demonstrate that treatment of 38C-13 tumor-bearing mice with anti-L-selectin antibodies did not inhibit tumor dissemination to peripheral lymph nodes. Moreover, L-selectin-negative 38C-13 variant cells disseminated as efficiently as wild-type cells. Thus, in spite of its expression, L-selectin is not required and does not affect the metastatic potential of the tumor. L-selectin of the malignant cells and of normal lymphocytes appears to be functionally different. Thus, whereas antibody cross-linking of L-selectin resulted in down-modulation of the receptor in normal lymphocytes, cross-linking had no effect on L-selectin expression in 38C-13 cells, suggesting that, in spite of comparable levels of surface expression in normal and malignant cells, L-selectin may be functionally impaired in some malignant cells. Received: 9 November 2000 / Accepted: 11 January 2001     

Three spontaneous lymphomas in a colony of cotton-top tamarins (Saguinus oedipus)

Cotton-top tamarins are well known for their prevalence to idiopathic colitis and adenocarcinomas. At the same time, information on the incidence of spontaneous lymphomas in this highly endangered species is rare. Records, 212 in total, of cotton-top tamarins (Saguinus oedipus) necropsied at the German Primate Centre between 1979 and 1998 were viewed to establish the prevalence of lymphoid neoplasms. Neoplastic lymphoid cell growth was mentioned in three necropsy records. Immunohistology was performed in all three cases on the remaining formalin-fixed, paraffin-embedded tissue using antibodies against CD20, CD3, lysozyme, Ki-67, IgM, IgG, kappa, lambda and EBNA-2. Combining histological and immunohistological results, the lymphomas could be differentiated into two low-grade T-cell lymphomas and one high-grade multicentric polymorphic B-cell lymphoma. This corresponds to a 1.4% incidence of lymphomas in our cotton-top tamarin population over a period of 19 years. Although frozen material was not available and virological testing could not be carried out, clinical or histological evidence did not support an aetiological role of Herpes (H.) saimiri, H. ateles, simian T-cell leukaemia virus type 1 (STLV-1) or Epstein-Barr-related herpesvirus in any of these cases. The lymphomas were considered to be spontaneous.     

BCL10 expression is unrelated to clinico-pathological parameters or prognoses for oral squamous cell carcinomas

BCL-10 (B-cell lymphoma 10) has been linked to a pro-apoptotic gene in mucosa-associated lymphoid tissue (MALT) lymphomas. We describe the expression of BCL10 in oral squamous cell carcinoma (OSCC) and its relation to clinical, pathological and prognostic parameters. We carried out a retrospective study of 50 patients in Spain who were diagnosed with OSCC. We constructed a tissue microarray of the samples to study the expression of BCL10 using immunohistochemistry. Diffuse and homogeneous staining was observed in the nuclei and cytoplasms of most neoplastic cells of the vast majority of tumors and no significant differences were seen in different areas of the tumors. The expression was unrelated to any clinical or pathological parameters including tumor stage. The intra-class coefficient was 0.97, which indicates the minimal variability among the determinations.