van den Anke Berg

High expression of the CC chemokine TARC in Reed-Sternberg cells : A possible explanation for the characteristic T-cell infiltrate in Hodgkin's lymphoma

Hodgkins lymphoma is characterized by the combination of Reed-Sternberg (R-S) cells and a prominent inflammatory cell infiltrate. One of the intriguing questions regarding this disease is what is causing the influx of T lymphocytes into the involved tissues. We applied the serial analysis of gene expression (SAGE) technique on the Hodgkins lymphoma-derived cell line L428 and on an Epstein-Barr virus (EBV)-transformed lymphoblastoid B-cell line. A frequently expressed tag in L428 corresponded to the T-cell-directed CC chemokine TARC. Reverse transcription polymerase chain reaction analyses demonstrated expression of TARC in nodular sclerosis (NS) and mixed cellularity (MC) classical Hodgkins lymphomas but not in NLP Hodgkins lymphoma, anaplastic large-cell lymphomas, and large-B-cell lymphomas with CD30 positivity. Two of five cases of T-cell-rich B-cell lymphoma (TCRBCL) were TARC positive. RNA in situ hybridization (ISH) showed a strong signal for TARC in the cytoplasm of R-S cells, and immunohistochemical staining confirmed the presence of the TARC protein in the R-S cells of NS and MC Hodgkins lymphomas. The lymphocytic and histiocytic (L&H)-type cells of nodular lymphocyte predominance Hodgkins lymphoma and the neoplastic cells of non-Hodgkins lymphomas with the exception of two cases of TCRBCL did not stain for TARC. TARC is known to bind to the CCR4 receptor, which is expressed on activated Th2 lymphocytes. The immunophenotype of lymphocytes surrounding R-S cells is indeed Th2-like, and by RNA ISH these lymphocytes showed a positive signal for the chemokine receptor CCR4. The findings suggest that production of TARC by the R-S cells may explain the characteristic T-cell infiltrate in classical Hodgkins lymphoma.

Association with HLA class I in Epstein-Barr-virus-positive and with HLA class III in Epstein-Barr-virus-negative Hodgkin's lymphoma.

BACKGROUND Associations of Hodgkins lymphoma with HLA have been reported for many years. In 20-40% of patients with this disorder, Epstein-Barr virus (EBV) is present in the neoplastic cells. Because presentation of EBV antigenic peptides can elicit vigorous immune responses, we investigated associations of the HLA region with EBV-positive and EBV-negative Hodgkins lymphoma. METHODS In a retrospective, population-based study, patients with Hodgkins lymphoma were reclassified according to the WHO classification, and EBV status was assessed by in-situ hybridisation of EBV-encoded small RNAs. Germline DNA was isolated from 200 patients diagnosed between 1987 and 2000 and from their first-degree relatives. Genotyping was done with 33 microsatellite markers spanning the entire HLA region and two single-nucleotide polymorphisms in the genes for tumour necrosis factor alpha and beta. Classic association analysis and the haplotype sharing statistic were used to compare patients with controls. FINDINGS Classic association analysis (but not the haplotype sharing statistic) showed an association of consecutive markers D6S265 and D6S510 (p=0.0002 and 0.0003), located in the HLA class I region, with EBV-positive lymphomas. The haplotype sharing statistic (but not classic association analysis) showed a significant difference in mean haplotype sharing between patients and controls surrounding marker D6S273 (p=0.00003), located in HLA class III. INTERPRETATION Areas within the HLA class I and class III regions are associated with susceptibility to Hodgkins lymphoma, the association with class I being specific for EBV-positive disease. This finding strongly suggests that antigenic presentation of EBV-derived peptides is involved in the pathogenesis of EBV-involved Hodgkins lymphoma. RELEVANCE TO PRACTICE Polymorphisms in the HLA region could explain ethnic variation in the incidence of Hodgkins lymphoma. The association of EBV-positive Hodgkins lymphoma with HLA class I suggests that this polymorphism might affect the proper presentation of EBV antigens to cytotoxic T lymphocytes.

miRNA analysis in B-cell chronic lymphocytic leukaemia: proliferation centres characterized by low miR-150 and high BIC/miR-155 expression.

Several miRNAs have been reported to be associated with immunoglobulin heavy chain (IgH) mutation and ZAP‐70 expression status in blood samples of B‐cell chronic lymphocytic leukaemia/small lymphocytic lymphoma (B‐CLL/SLL). In the bone marrow and lymphoid tissues, proliferation centres (PCs) represent an important site of activation and proliferation of the neoplastic cells, suggesting that these tissues better reflect the biology of CLL than circulating blood cells. We collected 33 lymph nodes and 37 blood CLL samples and analysed IgH mutation status and ZAP‐70 expression status. Expression of 15 miRNAs was analysed by qRT‐PCR and RNA‐ISH. Sixty‐three per cent of the lymph node cases contained mutated IgH genes and 49% of the lymph node cases were ZAP‐70‐positive, and a significant correlation was observed between ZAP‐70 expression and IgH mutation status. Of the blood CLL samples, 49% contained mutated IgH sequences. The miRNA expression pattern in CLL lymph node and blood samples was very similar. Three of 15 miRNAs (miR‐16, miR‐21, and miR‐150) showed a high expression level in both blood and lymph node samples. No difference was observed between ZAP‐70‐positive or ‐negative and between IgH‐mutated or unmutated cases. No correlation was found between miR‐15a and miR‐16 expression levels and 13q14 deletion in the blood CLL samples. RNA in situ hybridization (ISH) revealed strong homogeneous staining of miR‐150 in the tumour cells outside the PCs. In reverse BIC/pri‐miR‐155 expression was observed mainly in individual cells including prolymphocytes of the PCs. This reciprocal pattern likely reflects the different functions and targets of miR‐150 and miR‐155. Copyright

The role of microRNAs in normal hematopoiesis and hematopoietic malignancies.

Over the past few years, it has become evident that microRNAs (miRNAs) play an important regulatory role in various biological processes. Much effort has been put into the elucidation of their biogenesis, and this has led to the general concept that a number of key regulators are shared with the processing machinery of small interfering RNAs. Despite the recognition that several miRNAs play crucial roles in normal development and in diseases, little is known about their exact molecular function and the identity of their target genes. In this review, we report on the biological relevance of miRNAs for the differentiation of normal hematopoietic cells and on the contribution of deregulated miRNA expression in their malignant counterparts.

A meta-analysis of Hodgkin lymphoma reveals 19p13.3 TCF3 as a novel susceptibility locus

Recent genome wide association studies (GWAS) of Hodgkin lymphoma (HL) have identified associations with genetic variation at both HLA and non-HLA loci; however, much of heritable HL susceptibility remains unexplained. Here we perform a meta-analysis of three HL GWAS totaling 1,816 cases and 7,877 controls followed by replication in an independent set of 1,281 cases and 3,218 controls to find novel risk loci. We identify a novel variant at 19p13.3 associated with HL (rs1860661; odds ratio [OR] = 0.81, 95% confidence interval [95% CI] = 0.76–0.86, Pcombined = 3.5 × 10−10), located in intron 2 of TCF3 (also known as E2A), a regulator of B- and T-cell lineage commitment known to be involved in HL pathogenesis. This meta-analysis also notes associations between previously published loci at 2p16.1, 5q31, 6p31.2, 8q24.21 and 10p14 and HL subtypes. We conclude that our data suggest a link between the 19p13.3 locus, including TCF3, and HL risk

The mutational landscape of Hodgkin lymphoma cell lines determined by whole-exome sequencing

The mutational landscape of Hodgkin lymphoma cell lines determined by whole-exome sequencing

Gene expression analysis of dendritic/Langerhans cells and Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a neoplastic disorder that results in clonal proliferation of cells with a Langerhans cell (LC) phenotype. The pathogenesis of LCH is still poorly understood. In the present study, serial analysis of gene expression (SAGE) was applied to LCs generated from umbilical cord blood CD34+ progenitor cells to identify LC‐specific genes and the expression of these genes in LCH was investigated. Besides the expression of several genes known to be highly expressed in LCs and LCH such as CD1a, LYZ, and CD207, high expression of genes not previously reported to be expressed in LCs, such as GSN, MMP12, CCL17, and CCL22, was also identified. Further analysis of these genes by quantitative RT‐PCR revealed high expression of FSCN1 and GSN in all 12 LCH cases analysed; of CD207, MMP12, CCL22, and CD1a in the majority of these cases; and CCL17 in three of the 12 cases. Immunohistochemistry confirmed protein expression in the majority of cases. The expression of MMP12 was most abundant in multi‐system LCH, which is the LCH type with the worst prognosis. This suggests that expression of MMP12 may play a role in the progression of LCH. These data reveal new insight into the pathology of LCH and provide new starting points for further investigation of this clonal proliferative disorder. Copyright

The microenvironment of classical Hodgkin lymphoma: heterogeneity by Epstein-Barr virus presence and location within the tumor

Correction to: Blood Cancer Journal (2016) 6, e417; doi:10.1038/bcj.2016.26 Since the publication of the paper the authors have noticed that R Wu was listed as the sole first author. This is incorrect; R Wu and A Sattarzadeh contributed equally to this paper and are co-first authors. The authors wish to apologize for any inconvenience caused.

Frequent lack of translation of antigen presentation-associated molecules MHC class I, CD1a and Beta(2)-microglobulin in Reed-Sternberg cells

Epstein‐Barr virus (EBV) is present in Reed‐Sternberg (RS) cells of a substantial proportion of Hodgkins lymphoma cases. Most EBV‐positive cases are also MHC class I‐positive, whereas the majority of EBV‐negative cases lack detectable levels of MHC class I expression. Application of the SAGE technique has led to the identification of tags corresponding to MHC class I and β2‐microglobulin genes in the EBV‐ and MHC class I‐negative L428 Hodgkins cell line. Further expression studies indicated that single RS cells that do not express HLA class I also lack β2‐microglobulins but frequently contain mRNA coding for these proteins. Another tag was identified corresponding to CD1a, a thymocyte and Langerhans cell antigen structurally related to the MHC class I genes. CD1a expression studies revealed mRNA in all cell lines and in several of the single cells, whereas immunostaining showed a cytoplasmic signal in only 2 of the 4 cell lines and in none of the Hodgkins lymphoma tissue samples. In conclusion, RS cells frequently lack MHC class I, β2‐microglobulin and CD1a protein expression but contain mRNA coding for these proteins in some of the RS cells, suggesting a common mechanism affecting the translation of these antigen presentation–associated molecules. Int. J. Cancer 86:548–552, 2000.

Embryological signaling pathways in Barrett's metaplasia development and malignant transformation; mechanisms and therapeutic opportunities

Barretts metaplasia of the esophagus (BE) is the precursor lesion of esophageal adenocarcinoma (EAC), a deadly disease with a 5-year overall survival of less than 20%. The molecular mechanisms of BE development and its transformation to EAC are poorly understood and current surveillance and treatment strategies are of limited efficacy. Increasing evidence suggests that aberrant signaling through pathways active in the embryological development of the esophagus contributes to BE development and progression to EAC. We discuss the role that the Bone morphogenetic protein, Hedgehog, Wingless-Type MMTV Integration Site Family (WNT) and Retinoic acid signaling pathways play during embryological development of the esophagus and their contribution to BE development and malignant transformation. Modulation of these pathways provides new therapeutic opportunities. By integrating findings in developmental biology with those from translational research and clinical trials, this review provides a platform for future studies aimed at improving current management of BE and EAC.