Pathobiology of Classical Hodgkin Lymphoma

JAK/STAT blockade reverses the malignant phenotype of Hodgkin and Reed-Sternberg cells

Constitutive activation of the JAK/STAT pathway is a common phenomenon in classic Hodgkin lymphoma (cHL). The clinical potential of anti-JAK/STAT therapy is being explored in early-stage clinical trials. Notwithstanding, very little information is available about the complex biological consequences of this blockade. Here, we investigated the effects of JAK/STAT pharmacological inhibition on cHL cell models using ruxolitinib, a JAK 1/2 inhibitor that induces apoptosis by concentration- and time-dependent mechanisms. An unbiased whole-transcriptome approach identified expression of the anti-GCSF receptor (CSF3R) as a potential surrogate biomarker of JAK/STAT overactivation. In addition, longitudinal gene expression analyses provided further mechanistic information about pertinent biological pathways involved, including 37 gene pathways distributed in 3 main clusters: cluster 1 was characterized by upregulation of the G2/M checkpoint and major histocompatibility complex-related clusters; 2 additional clusters (2 and 3) showed a progressive downregulation of the tumor-promoting inflammation signatures: JAK/STAT and interleukin 1 (IL-1)/IL-4/IL-13/IL-17. Together, our results confirm the therapeutic potential of JAK/STAT inhibitors in cHL, identify CSF3R as a new biomarker, and provide supporting genetic data and mechanistic understanding.

Synthesis and biological evaluation of N-biphenyl-nicotinic based moiety compounds: A new class of antimitotic agents for the treatment of Hodgkin Lymphoma

We previously demonstrated that some N-biphenylanilides caused cell-cycle arrest at G2/M transition in breast cancer cells. Among them we choose three derivatives, namely PTA34, PTA73 and RS35 for experimentation in solid tumor cell lines, classical Hodgkin Lymphoma (cHL) cell lines and bona fide normal cell lines. Almost all tumor cells were sensitive to compounds in the nanomolar range whereas, they were not cytotoxic to normal ones. Interestingly the compounds caused a strong G2/M phase arrest in cHL cell lines, thus, here we investigated whether they affected the integrity of microtubules in such cells. We found that they induced a long prometaphase arrest, followed by induction of apoptosis which involved mitochondria. PTA73 and RS35 induced the mitotic arrest through the fragmentation of microtubules which prevented the kinethocore-mitotic spindle interaction and the exit from mitosis. PTA34 is instead a tubulin-targeting agent because it inhibited the tubulin polymerization as vinblastine. As such, PTA34 maintained the Cyclin B1-CDK1 regulatory complex activated during the G2/M arrest while inducing the inactivation of Bcl-2 through phosphorylation in Ser70, the degradation of Mcl-1 and a strong activation of BIML and BIMS proapoptotic isoforms. In addition PTA34 exerted an antiangiogenic effect by suppressing microvascular formation.

A pattern-based approach to reactive lymphadenopathies

A crucial task in histopathological examination of enlarged lymph nodes is to discriminate malignant form benign processes. The central importance of this issue is reflected by the fact that benign lymphadenopathies mistaken for lymphomas belong to the most commonly misdiagnosed cancers. In addition, recognition of distinct histopathological patterns of reactive lymph node changes narrow down the potential number of causative agents, especially of those that can be specifically identified by means of often very resource-consuming ancillary techniques; thus, the more precise the differential diagnosis established upon histopathological examination is, the more targetable and efficient the application of these techniques will be. This review provides a synopsis on a histopathological pattern-based approach towards reactive lymphadenopathies.

Mulberry cells in the thyroid: warthin-finkeldey-like cells in hashimoto thyroiditis-associated lymphoma

Warthin-Finkeldey type giant cells were first described in autopsies performed on young children who died during the highly lethal measles epidemic in Palermo during the winter of 1908. The cells had 8-15 nuclei without identifiable cytoplasm within the germinal centers of lymphoid organs resembling megakaryocytes. We describe a case of Hashimoto thyroiditis with an enlarging substernal throid mass. The resection specimen contained many Warthin-Finkeldey-Like Cells (WFLC) in an extranodal marginal zone lymphoma (MALT type) with focal transformation to diffuse large B-cell lymphoma. The WFLC showed nuclear features similar to those of neighboring follicular dendritic cells (FDCs), favoring the hypothesis that these cells might be the product of fusion of FDCs. This is supported by immunostaining results and the occurrence of similar cells in follicular dendritic cell sarcomas and in "dysplastic" FDCs in hyaline vascular type Castleman disease, a possible precursor of follicular dendritic cell tumors. Diagn. Cytopathol. 2017;45:212-216. © 2016 Wiley Periodicals, Inc.

Curcuma Contra Cancer? Curcumin and Hodgkin's Lymphoma

Curcumin, a phytochemical isolated from curcuma plants which are used as coloring ingredient for the preparation of curry powder, has several activities which suggest that it might be an interesting drug for the treatment or prevention of cancer. Curcumin targets different pathways which are involved in the malignant phenotype of tumor cells, including the nuclear factor kappa B (NFKB) pathway. This pathway is deregulated in multiple tumor entities, including Hodgkin’s lymphoma (HL). Indeed, curcumin can inhibit growth of HL cell lines and increases the sensitivity of these cells for cisplatin. In this review we summarize curcumin activities with special focus on possible activities against HL cells.

Expression and Regulation of the Endogenous Retrovirus 3 in Hodgkin's Lymphoma Cells

Human endogenous retroviruses (ERV) are an integral part of our genome. Expression of ERV is usually switched off but reactivation of ERV has been observed in varying human diseases including cancer. Recently, reactivation of ERV associated promoters in Hodgkin's lymphoma (HL) cells has been described. Despite relatively good prognosis, not all patients with HL can be cured with the established therapy and this therapy is associated with severe late side effects. Therefore, new targets are required for the development of future treatment strategies. Reactivated ERV might represent such target structures. Therefore, we asked which ERV loci are expressed in HL cells. Using DNA microarray analysis, we found no evidence for a general activation of ERV transcription in HL cells. In contrast, we observed down-regulation of ERV3, an ERV with potential tumor suppressor function, in HL cells in comparison to normal blood cells. Interestingly, ERV3 was also differentially expressed in published DNA microarray data from resting versus cycling B cells. Treatment of HL cells with the histone deacetylase inhibitor vorinostat strongly up-regulated ERV3 expression. In addition, we observed up-regulation in HL cells after treatment with hypoxia-mimetic cobalt(II) chloride. Like vorinostat, cobalt(II) chloride inhibited cell growth of HL cells. Our results suggest that cell cycle inhibition of HL cells is accompanied by up-regulation of ERV3.

Knock-down of PRAME increases retinoic acid signaling and cytotoxic drug sensitivity of Hodgkin lymphoma cells

The prognosis for patients with Hodgkin lymphoma (HL) has improved in recent decades. On the other hand, not all patients can be cured with the currently established therapy regimes and this therapy is associated with several adverse late effects. Therefore it is necessary to develop new therapy strategies. After treatment of L-540 HL cells with 5′-azacytidine (5AC), we observed increased expression of the preferentially expressed antigen in melanoma (PRAME). In addition, we detected an increased resistance of 5AC-treated cells against cytotoxic drugs. We analyzed the influence of PRAME on cell survival of HL cells by knocking down PRAME in the chemotherapy resistant cell line L-428, a cell line that express PRAME at a high level. After knock-down of PRAME using vector based RNA interference we observed increased sensitivity for cisplatin, etoposide and retinoic acid. DNA microarray analysis of HL cells after PRAME knock-down indicated regulation of several genes including down-regulation of known anti-apoptotic factors. Increased retinoic acid signaling in these cells was revealed by increased expression of the retinoic acid metabolizing cytochrome P450 (CYP26B1), a transcriptional target of retinoic acid signaling. Our data suggest that PRAME inhibits retinoic acid signaling in HL cells and that the knock-down of PRAME might be an interesting option for the development of new therapy strategies for patients with chemo-resistant HL.

Molecular functions of metallothionein and its role in hematological malignancies

Metallothionein (MT) was reported to be a potential negative regulator of apoptosis, and various reports have suggested that it may play roles in carcinogenesis and drug resistance, in at least a portion of cancer cells. The author summarizes the current understanding of the molecular functions of MT for tumor cell growth and drug resistance. These activities are regulated through intracellular metal ion modulation and free radical scavenging. Compared with analyses of solid tumors, few studies have analyzed the roles of MT in hematological malignancies. This review mainly describes the functions of MT in hematopoietic cells. Furthermore, through expression analyses of leukemias and lymphomas, the roles of MT in the biology of these diseases are particularly focused upon.

Refined prognostic role of CD68-positive tumor macrophages in the context of the cellular micromilieu of classical Hodgkin lymphoma

OBJECTIVE

Classical Hodgkin lymphoma (HL) consists of neoplastic Hodgkin and Reed-Sternberg cells (HRSC) and a nonneoplastic micromilieu that greatly outnumbers the HRSC. Studies on HRSC-related prognostic biomarkers have been unsuccessful, but the microenvironmental composition is of prognostic importance. Recently, the number of CD68-positive macrophages was correlated with adverse survival in HL, and there was a call to validate these results.

METHODS

We utilized immunohistochemistry to analyze the prognostic importance of the CD68-positive macrophage number compared to other cellular environmental components in an unselected series of 105 HLs in tissue microarrays.

RESULTS

Applying a cutoff score of >0.82% tumor macrophages, cases with increased numbers showed worse overall survival (mean 185 months, median 192) compared to cases with lower numbers (mean 285 months, median not reached). Eleven of 62 patients with ≤0.82% tumor macrophages died, compared to 19 of 43 with >0.82% (p < 0.001). The number of macrophages correlated with a low FOXP3-/high granzyme B-/high PD-1-positive micromilieu and patient age, but did not have independent prognostic significance. A combination background score taking into consideration all negative prognostic microenvironmental components (CD68-, PD-1- and granzyme B-positive cells) was of independent prognostic significance (p = 0.002).

CONCLUSION

Increased numbers of CD68-positive tumor macrophages indicate an adverse overall outcome in HL.

BOB.1, CD79a and cyclin E are the most appropriate markers to discriminate classical Hodgkin's lymphoma from primary mediastinal large B-cell lymphoma

AIMS

To clarify which immunohistochemical markers could be helpful in distinguishing between classical Hodgkin's lymphoma (cHL) and primary mediastinal B-cell lymphoma (PMBCL) to more narrowly define 'B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and cHL'.

METHODS AND RESULTS

Two hundred and 83 cHLs and 51 PMBCLs were analysed on validated tissue microarray platforms with antibodies to BOB.1, CD15, CD20, CD23, CD30, CD79a, cyclin E, LMP-1, MUM1p, p63 and Oct2. The marker cut-off scores were calculated using receiver-operating characteristic curves. Markers with the highest positive predictive value for cHL were: CD15, cyclin E, LMP-1 (all 100%), MUM1p (93%) and CD30 (83%). High sensitivity was achieved only by CD30 (92%) and cyclin E (79%). Nineteen percent of PMBCLs were also positive for CD30, which led to a lower specificity of CD30 as regards cHL (81%) compared with cyclin E (100%). The antibodies with the highest positive predictive value for PMBCL were: CD23 (98%), p63 (96%), BOB.1 (94%) and CD79a (90%), with high sensitivity for BOB.1 (100%), CD79a (89%) and p63 (82%).

CONCLUSIONS

The use of at least three of the most accurate immunohistochemical markers, cyclin E, CD79a and BOB.1, may be helpful in the differential diagnosis of cHL and PMBCL.

Hodgkin lymphoma: an update on its biology with new insights into classification

In the past few years, there has been a greater understanding of the spectrum and biology of Hodgkin lymphoma (HL). In standard texts, HL is classified as 2 distinct entities, namely nodular lymphocyte-predominant HL and classical HL (CHL). However, recent evidence suggests that CHL is not a single disease. Although the mixed cellularity and lymphocyte-depleted subtypes might be part of a biologic continuum, the nodular sclerosis subtype has a distinct epidemiology, clinical presentation, and histology. Nodular sclerosis HL might also be related to primary mediastinal B-cell lymphoma and mediastinal gray-zone lymphomas. We present an update on the pathobiology of HL and discuss these biologic and clinical differences in this review.

Circulating clonotypic B cells in classic Hodgkin lymphoma

Although Hodgkin and Reed-Sternberg (HRS) cells are B lymphoid cells, they are unlike any normal cells of that lineage. Moreover, the limited proliferative potential of HRS cells belies the clinical aggressiveness of Hodgkin lymphoma (HL). More than 20 years ago, the L428 HL cell line was reported to contain a small population of phenotypic B cells that appeared responsible for the continued generation of HRS cells. This observation, however, has never been corroborated, and such clonotypic B cells have never been documented in HL patients. We found that both the L428 and KM-H2 HL cell lines contained rare B-cell subpopulations responsible for the generation and maintenance of the predominant HRS cell population. The B cells within the HL cell lines expressed immunoglobulin light chain, the memory B-cell antigen CD27, and the stem cell marker aldehyde dehydrogenase (ALDH). Clonal CD27(+)ALDH(high) B cells, sharing immunoglobulin gene rearrangements with lymph node HRS cells, were also detected in the blood of most newly diagnosed HL patients regardless of stage. Although the clinical significance of circulating clonotypic B cells in HL remains unclear, these data suggest they may be the initiating cells for HL.

[Hodgkin's lymphoma in adolescents: where to treat it--in an adult or pediatric institution?]

Adolescent patients with Hodgkin's lymphoma (HL) are treated either in pediatric, or in adult oncological wards.

AIM

The aim of our work was to compare the treatment modalities and the survival rates in adolescents with HL treated in adult (A) or pediatric (P) institutes.

METHODS

From January 1990 to December 2004, 138 patients (14-21 years) with HL were treated in two adult institutes (A) and 107 in the 10 centres of the Hungarian Pediatric Oncology Network (P).

RESULTS

Male:female ratio was 1:1.15 (A) and 1:1.38 (P). The mean age was 18.6 (A) and 15.7 (P) years. There was no difference between the distribution of the stages in the two patient groups. The distribution of histological subtypes (A and P): nodular sclerosing 47% and 59%, mixed cellularity 45% and 25%, lymphocyte rich 1.5% and 10%, lymphocyte depleted 4% and 1%, nodular lymphocyte predominant 1.5% and 3% and unknown 1% and 2%. The majority of the patients were treated with ABVD (A) and OPPA/OEPA +/- COPP (P). One hundred and fifteen (A) and 97 (P) adolescents received irradiation therapy. 80% (A) and 91% (A) of the patients got radiotherapy. In group A 14%, in group P 13% of the patients had relapse. In group A 16 patients died and in group P 7. There was no significant difference in the overall survival (OS) rates at 5 and 10 years in the two patient groups. The event-free survival (EFS) was 76.5 +/- 4% and 72.5 +/- 4% at 5 and 10 years in group A, and 85.3 +/- 4% at both times in group P ( p = 0.0452).

CONCLUSION

Survival rates in HL are quite high, 80-90% of the patients can be cured. Event-free survival was higher in pediatric than in adult institutes. In case of patients younger than 18 years, the survival rates were much better in pediatric institutes, so these patients should be treated in pediatric institutes or with protocols used by the pediatricians.

Laboratory Findings, Histopathology, and Immunophenotype of Lymphoma in Domestic Ferrets

Lymphoma is a common tumor in ferrets, but anatomic distribution, histomorphology, immunophenotype, laboratory abnormalities, and response to chemotherapy are incompletely defined. In this study, lymphoma was diagnosed by histopathology of tumor tissue in 29 ferrets ranging in age from 0.8 to 8.5 years, including 12 males and 17 females. Tumors involved the viscera of the abdominal cavity (n = 11), thoracic cavity (n = 1), or abdominal and thoracic cavities (n = 7); the skin (n = 2); or the viscera of both body cavities plus other sites (n = 8). Microscopically, all tumors had diffuse architecture. Assessment by histomorphology and immunophenotype classified tumors as peripheral T-cell lymphoma (n = 17), anaplastic large T-cell lymphoma (n = 5), anaplastic large B-cell lymphoma (n = 4), diffuse large B-cell lymphoma (n = 1), and Hodgkin-like lymphoma (n = 2). Cytologic evaluation of tumor tissue was diagnostic in 11 of 13 cases. Twenty-two of 27 ferrets had anemia, 2 had leukemia, and 5 were neutropenic. Common comorbid disorders were adrenal disease (n = 27) and insulinoma (n = 6). Tumors most frequently involved mesenteric lymph nodes, while enlargement of peripheral lymph nodes was uncommon (n = 3). Ferrets with Hodgkin-like lymphoma had massive enlargement of single lymph nodes. Mean survival of ferrets not immediately euthanized was 5.0 months (T-cell lymphoma) and 8.4 months (B-cell lymphoma). Ferrets treated with chemotherapy survived an average of 4.3 months (T-cell lymphoma, n = 9) or 8.8 months (B-cell lymphoma, n = 4). Results indicate that lymphomas in ferrets most commonly affect abdominal viscera, may be amenable to cytologic diagnosis, are frequently associated with anemia and, in some cases, may be chemosensitive, resulting in relatively long survival times.

Patterns of liver infiltration in lymphoproliferative disease

AIMS

Liver involvement is a common finding in patients suffering from lymphoproliferative disease, and histopathological patterns of infiltration vary according to lymphoma subtype. Data correlating the form of liver involvement with distinct lymphoma subtypes is, however, scarce. The aim was to review 89 liver biopsies diagnosed with lymphoma infiltration and evaluate the infiltration patterns.

METHODS AND RESULTS

In equivocal cases, additional immunohistochemical and molecular pathology analyses were performed to differentiate between neoplastic and reactive cell infiltrates and to classify the lymphoma subtypes. Diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukaemia (CLL), Hodgkin's lymphoma (HL) and Burkitt lymphoma (BL) were the most prevalent subtypes in our series, which included 14 different lymphoma entities in total. Whereas DLBCL and BL predominantly demonstrated tumour nodules deranging the normal hepatic architecture, CLL and HL mostly showed infiltration of the portal fields. Interestingly, distinct lymphoma entities, particularly marginal zone B-cell lymphomas (MZL) and HL, commonly revealed lympho-epithelial lesions of bile ducts, which were observed in 10% of all investigated cases. Four cases, initially interpreted as T-cell lymphomas, proved to be reactive T-cell lesions.

CONCLUSIONS

Distinct lymphoma subtypes show characteristic patterns of liver infiltration. Additional molecular analyses can support diagnosis by verification of clonality or detection of characteristic genetic aberrations.

The association of multiple sclerosis and Hodgkin's disease: the role of Epstein—Barr virus infection

The aetiology of multiple sclerosis (MS) is still an unresolved question. Several recently reported studies are implicating Epstein—Barr virus (EBV) as one of the key players in MS pathogenesis. We present a 21-year-old male patient with a history of EBV-related infectious mononucleosis in puberty and Hodgkin's disease two years previously treated with irradiation and chemotherapy. The patient presented with spastic paraparesis that resolved promptly on corticosteroid treatment. There were no signs of Hodgkin's disease relapse. In the next three years he had three more bouts of the disease and he was diagnosed with relapse—remitting MS. There is evidence of EBV involvement in MS pathogenesis; the association of MS with EBV-related infectious mononucleosis and Hodgkin's disease being just one of them. Although there are many unanswered questions, it is clear that without EBV seropositivity MS in adults is extremely rare. Multiple Sclerosis 2008; 14: 284—287. http://msj.sagepub.com