Diffuse large B-cell lymphoma with overexpression of cyclin e substantiates poor standard treatment response and inferior outcome

ELF3-AS1 contributes to gastric cancer progression by binding to hnRNPK and induces thrombocytosis in peripheral blood

Numerous studies have reported that a variety of long noncoding RNAs (lncRNAs) can promote the proliferation, invasion, and migration of different tumor cells. However, different lncRNAs regulate cell functions in various forms, and the exact mechanisms are not clear. Here, we investigated the effect of the lncRNA ELF3-AS1 on gastric cancer (GC) cell function and explored the exact mechanism. Quantitative real-time polymerase chain reaction was used to detect the expression of ELF3-AS1 in GC tissues and adjacent nontumor tissues. Knockdown and overexpression of ELF3-AS1 was used to detect the effect of ELF3-AS1 on cell function. Potential downstream target genes were identified using RNA transcriptome sequencing, while RNA immunoprecipitation, chromatin immunoprecipitation, and Western blotting were performed to explore the tumor promotion mechanisms of ELF3-AS1. We observed that ELF3-AS1 was highly expressed in GC tissues, and high ELF3-AS1 expression predicted poor prognosis. The knockdown of ELF3-AS1 significantly inhibited cell proliferation, migration, and epithelial-mesenchymal transition and promoted apoptosis. Mechanistic investigations revealed that ELF3-AS1 may regulate the downstream target gene, C-C motif chemokine 20, by binding with the RNA-binding protein hnRNPK. Additionally, we found that high ELF3-AS1 expression was associated with thrombocytosis. Interleukin-6 and thrombopoietin may be involved in ELF3-AS1-induced paraneoplastic thrombocytosis. Together, our results demonstrate that aberrantly expressed ELF3-AS1 in GC may play important roles in oncogenesis and progression and is expected to become a new target for the diagnosis and treatment of GC.

Overexpression of Cyclin E1 or Cdc25A leads to replication stress, mitotic aberrancies, and increased sensitivity to replication checkpoint inhibitors

Oncogene-induced replication stress, for instance as a result of Cyclin E1 overexpression, causes genomic instability and has been linked to tumorigenesis. To survive high levels of replication stress, tumors depend on pathways to deal with these DNA lesions, which represent a therapeutically actionable vulnerability. We aimed to uncover the consequences of Cyclin E1 or Cdc25A overexpression on replication kinetics, mitotic progression, and the sensitivity to inhibitors of the WEE1 and ATR replication checkpoint kinases. We modeled oncogene-induced replication stress using inducible expression of Cyclin E1 or Cdc25A in non-transformed RPE-1 cells, either in a TP53 wild-type or TP53-mutant background. DNA fiber analysis showed Cyclin E1 or Cdc25A overexpression to slow replication speed. The resulting replication-derived DNA lesions were transmitted into mitosis causing chromosome segregation defects. Single cell sequencing revealed that replication stress and mitotic defects upon Cyclin E1 or Cdc25A overexpression resulted in genomic instability. ATR or WEE1 inhibition exacerbated the mitotic aberrancies induced by Cyclin E1 or Cdc25A overexpression, and caused cytotoxicity. Both these phenotypes were exacerbated upon p53 inactivation. Conversely, downregulation of Cyclin E1 rescued both replication kinetics, as well as sensitivity to ATR and WEE1 inhibitors. Taken together, Cyclin E1 or Cdc25A-induced replication stress leads to mitotic segregation defects and genomic instability. These mitotic defects are exacerbated by inhibition of ATR or WEE1 and therefore point to mitotic catastrophe as an underlying mechanism. Importantly, our data suggest that Cyclin E1 overexpression can be used to select patients for treatment with replication checkpoint inhibitors.

Comparative pathologic analysis of mediastinal B-cell lymphomas: selective expression of p63 but no GATA3 optimally differentiates primary mediastinal large B-cell lymphoma from classic Hodgkin lymphoma

Background

Interpretation of mediastinal biopsy is often challenging even for experienced pathologists especially when a hematolymphoid neoplasm is suspected. Primary mediastinal large B-cell lymphoma (PMLBCL) and classic Hodgkin lymphoma (CHL) represent two major types of mature B-cell lymphomas of the mediastinum. Although PMLBCL and mediastinal CHL share many clinicopathologic characteristics, their treatment strategies and responses are remarkably different. We therefore aimed to find distinctive histologic or protein markers to better differentiate these two lesions.

Methods

Search for primary mediastinal B-cell lymphomas found 52 consecutive cases from 3 university hospitals of Korea during 2005 to 2012. Among them, 32 cases that were available for additional immunohistochemistry (IHC) assessment were enrolled in this study. These cases consisted of the following: CHL (N = 13), PMLBCL (N = 16), and B-cell lymphoma unclassifiable, with features intermediate between diffuse large B-cell lymphoma and CHL (gray zone lymphoma, N = 3). Along with the clinicopathologic findings, the expression of p63, GATA3 and cyclin E was investigated by IHC in the three categorized lesions mentioned above.

Results

Most clinical features overlapped between PMLBCL and CHL except for the increased disease progression and mortality found in PMLBCL. In the pathologic review, the presence of epithelioid granuloma favored a diagnosis of CHL, whereas reticulated or alveolar patterns of fibrosis were characteristic of PMLBCL. For protein markers, p63 was predominantly positive in PMLBCL (15/16) compared with CHL (2/13), which indicates that p63 is a marker of the highest diagnostic accuracy when calculated by the area under the ROC curve. GATA3 was expressed in the majority of CHL cases (10/13) compared with PMLBCL (0/16), while the expression of cyclin E was only rarely present in a minor population of PMLBCL.

Conclusions

P63 expression in tumor cells, even focal expression, and no GATA3 is the most helpful feature in distinguishing PMLBCL from mediastinal CHL.

Prognostic Values of CCNE1 Amplification and Overexpression in Cancer Patients: A Systematic Review and Meta-analysis

A number of studies revealed that CCNE1 copy number amplification and overexpression (on mRNA or protein expression level) were associated with prognosis of diverse cancers, however, the results were inconsistent among studies. So we conducted this systematic review and meta-analysis to investigate the prognostic values of CCNE1 amplification and overexpression in cancer patients. PubMed, Cochrane library, Embase, CNKI and WanFang database (last update by February 15, 2018) were searched for literatures. A total of 20 studies were included and 5 survival assessment parameters were measured in this study, which included overall survival (OS), progression free survival (PFS), recurrence free survival (RFS), cancer specific survival (CSS) and distant metastasis free survival (DMFS). Pooled analyses showed that CCNE1 amplification might predict poor OS (HR=1.59, 95% CI: 1.05-2.40, p=0.027) rather than PFS (HR=1.49, 95% CI: 0.83-2.67, p=0.177) and RFS (HR=0.982, 95% CI: 0.2376-4.059, p=0.9801) in various cancers; CCNE1 overexpression significantly correlated with poor OS (HR=1.52, 95% CI: 1.05-2.20, p=0.027), PFS (HR=1.20, 95% CI: 1.07-1.34, p=0.001) and DMFS (HR=1.62, 95% CI: 1.09-2.40, p=0.017) rather than RFS (HR=1.68, 95% CI: 0.81-3.50, p=0.164) and CSS (HR=1.54, 95% CI: 0.74-3.18, p=0.246). On the whole, these results indicated CCNE1 amplification and overexpression were associated with poor survival of patients with cancer, suggesting that CCNE1 might be an effective prognostic signature for cancer patients.

Long non-coding RNA LUCAT1 is associated with poor prognosis in human non-small lung cancer and regulates cell proliferation via epigenetically repressing p21 and p57 expression

Recently, long non-coding RNAs (lncRNAs) have been recognized as playing key roles in regulating cellular processes, such as proliferation, invasion, and metastasis. These lncRNAs have been shown to be abnormally expressed in tumorigenic processes. However, the role and clinical relevance of LUCAT1 in non-small-cell lung cancer (NSCLC) remain unclear. In this study, we found that the expression of LUCAT1 was significantly up-regulated in NSCLC tissues compared to non-tumor tissues, and its expression was associated with tumor size, tumor–node–metastasis (TNM) stage and overall survival (OS). Further experiments showed that LUCAT1 knockdown inhibited cell proliferation both in vitro and in vivo. Mechanistic investigations showed that LUCAT1 plays a key role in G0/G1 arrest. We further demonstrated that LUCAT1 was associated with polycomb repressor complexes (PRC2) and that this association was required for epigenetically repression of p21 and p57, thus contributing to the regulation of NSCLC cell cycle and proliferation. In summary, our results show that LUCAT1 could regulate tumorigenesis of NSCLC and be biomarker for poor prognosis in NSCLC.

Prognostic Significance of in situ Phenotypic Marker Expression in Diffuse Large B-cell Lymphomas

Diffuse large B-cell lymphomas (DLBCL) are the most common lymphoid malignancies, and encompass all malignant lymphomas characterized by large neoplastic cells and B-cell derivation. In the last decade, DLBCL has been subjected to intense clinical, phenotypic and molecular studies, and were found to represent a heterogeneous group of tumors. These studies suggested new disease subtypes and variants with distinct clinical characteristics, morphologies, immunophenotypes, genotypes or gene expression profiles, associated with distinct prognoses or unique sensitivities to particular therapy regimens. Unfortunately, the reliability and reproducibility of the molecular results remains unclear due to contradictory reports in the literature resulting from small sample sizes, referral and selection biases, and variable methodologies and cut-off levels used to determine positivity. Here, we review phenotypic studies on the prognostic significance of protein expression profiles in DLBCL and reconsider our own retrospective data on 301 primary DLBCL cases obtained on a previously validated tissue microarray in light of powerful statistical methods of determining optimal cut-off values of phenotypic factors for prediction of outcome.

CXCL-8/IL8 Produced by Diffuse Large B-cell Lymphomas Recruits Neutrophils Expressing a Proliferation-Inducing Ligand APRIL

Tumor-infiltrating neutrophils have been implicated in malignant development and progression, but mechanisms are ill defined. Neutrophils produce a proliferation-inducing ligand APRIL/TNFSF13, a factor that promotes development of tumors from diverse origins, including diffuse large B-cell lymphoma (DLBCL). High APRIL expression in DLBCL correlates with reduced patient survival, but the pathway(s) dictating APRIL expression are not known. Here, we show that all blood neutrophils constitutively secrete APRIL, and inflammation-associated stimuli, such as TNF, further upregulate APRIL. In a significant fraction of DLBCL patients, tumor cells constitutively produced the ELC-CXC chemokine CXCL-8 (IL8), enabling them to recruit APRIL-producing blood neutrophils. CXCL-8 production in DLBCL was unrelated to the cell of origin, as APRIL-producing neutrophils infiltrated CXCL-8⁺ DLBCL from both germinal center (GC) and non-GC subtypes. Rather, CXCL-8 production implied events affecting DNA methylation and acetylation. Overall, our results showed that chemokine-mediated recruitment of neutrophils secreting the tumor-promoting factor APRIL mediates DLBCL progression. Cancer Res; 77(5); 1097-107. ©2016 AACR.

A comparative study of molecular characteristics of diffuse large B-cell lymphoma from patients with and without human immunodeficiency virus infection

PURPOSE

HIV-related diffuse large B-cell lymphoma (DLBCL) may be biologically different from DLBCL in the general population. We compared, by HIV status, the expression and prognostic significance of selected oncogenic markers in DLBCL diagnosed at Kaiser Permanente in California, between 1996 and 2007.

EXPERIMENTAL DESIGN

Eighty HIV-infected DLBCL patients were 1:1 matched to 80 HIV-uninfected DLBCL patients by age, gender, and race. Twenty-three markers in the following categories were examined using IHC: (i) cell-cycle regulators, (ii) B-cell activators, (iii) antiapoptotic proteins, and (iv) others, such as IgM. Tumor marker expression was compared across HIV infection status by Fisher exact test. For markers differentially expressed in HIV-related DLBCL, logistic regression was used to evaluate the association between tumor marker expression and 2-year overall mortality, adjusting for International Prognostic Index, cell-of-origin phenotype, and DLBCL morphologic variants.

RESULTS

Expression of cMYC (% positive in HIV-related and -unrelated DLBCL: 64% vs. 32%), BCL6 (45% vs. 10%), PKC-β2 (61% vs. 4%), MUM1 (59% vs. 14%), and CD44 (87% vs. 56%) was significantly elevated in HIV-related DLBCLs, whereas expression of p27 (39% vs. 75%) was significantly reduced. Of these, cMYC expression was independently associated with increased 2-year mortality in HIV-infected patients [relative risk = 3.09 (0.90-10.55)] in multivariable logistic regression.

CONCLUSIONS

These results suggest that HIV-related DLBCL pathogenesis more frequently involves cMYC and BCL6 among other factors. In particular, cMYC-mediated pathogenesis may partly explain the more aggressive clinical course of DLBCL in HIV-infected patients.

c-Myc-induced, long, noncoding H19 affects cell proliferation and predicts a poor prognosis in patients with gastric cancer

Gastric cancer (GC) is one of the most frequent cancers worldwide. Recent studies have shown that long noncoding RNAs (lncRNAs) play critical roles in multiple biological processes, including oncogenesis. The present study aimed to evaluate the potential role of lncRNA H19 in GC. qRT-PCR was performed to investigate the expression of H19 in tumor tissues and corresponding non-tumor lung tissues from 80 patients with GC and in GC cell lines. The Kaplan-Meier method and Cox proportional hazards analysis were used to evaluate the association between H19 expression and overall survival time (OS). The biological significance of H19 was evaluated using siRNAs in vitro. We also constructed a c-Myc plasmid to investigate the cause of the altered expression of H19 in the progression of GC. The results show that lncRNA H19 is overexpressed in tumor tissues compared with adjacent normal tissues. An advanced tumor-node-metastasis stage was positively correlated with increased H19 expression (P < 0.001), and a high H19 expression was associated with poor OS and can be regarded as an independent predictor of the OS of GC patients (P = 0.042). MTT and colony formation assays confirmed that H19 expression affects GC cell proliferation in vitro. Furthermore, exogenous c-Myc significantly induces H19 expression, and the expression of H19 was positively correlated with the c-Myc levels in the 80 samples used in our study (Pearson correlation coefficient = -0.687). In conclusion, our study demonstrates that the altered expression of lncRNA H19, which is induced by c-Myc, is involved in the development and progression of GC by regulating cell proliferation and shows that H19 may be a potential diagnostic and prognostic target in patients with GC.

CDK/CCN and CDKI alterations for cancer prognosis and therapeutic predictivity

The regulation of cell growth and division occurs in an accurate sequential manner. It is dictated by the accumulation of cyclins (CCNs) and cyclin-dependent kinases (CDKs) complexes and degradation of CCNs. In human tumors, instead, the cell cycle is deregulated, causing absence of differentiation and aberrant cell growth. Oncogenic alterations of CCNs, CDKs, and CDKIs have been reported in more than 90% of human cancers, and the most frequent are those related to the G1 phase. Several molecular mechanisms, including gene overexpression, chromosomal translocations, point mutations, insertions and deletions, missense and frame shift mutation, splicing, or methylation, may be responsible for these alterations. The cell cycle regulators are involved in tumor progression given their association with cancers characterized by higher incidence of relapses and chemotherapy resistance. In the last decade anticancer drug researches focused on new compounds, able to target molecules related to changes in genes associated with tumor status. Recently, the studies have focused on the restoration of cell cycle control modulating molecular targets involved in cancer-cell alterations. This paper aims to correlate alterations of cell cycle regulators with human cancers and therapeutic responsivity.

RelA and RelB cross-talk and function in Epstein-Barr virus transformed B cells

In this study, we determined the respective roles of RelA and RelB NF-κB subunits in Epstein-Barr virus (EBV)-transformed B cells. Using different EBV-immortalized B-cell models, we showed that only RelA activation increased both survival and cell growth. RelB activity was induced secondarily to RelA activation and repressed RelA DNA binding by trapping the p50 subunit. Reciprocally, RelA activation repressed RelB activity by increasing expression of its inhibitor p100. To search for such reciprocal inhibition at the transcriptional level, we studied gene expression profiles of our RelA and RelB regulatable cellular models. Ten RelA-induced genes and one RelB-regulated gene, ARNTL2, were repressed by RelB and RelA, respectively. Apart from this gene, RelB signature was included in that of RelA Functional groups of RelA-regulated genes were for control of energy metabolism, genetic instability, protection against apoptosis, cell cycle and immune response. Additional functions coregulated by RelA and/or RelB were autophagy and plasma cell differentiation. Altogether, these results demonstrate a cross-inhibition between RelA and RelB and suggest that, in fine, RelB was subordinated to RelA. In the view of future drug development, RelA appeared to be pivotal in both classical and alternative activation pathways, at least in EBV-transformed B cells.

Addition of rituximab to chemotherapy overcomes the negative prognostic impact of cyclin E expression in diffuse large B-cell lymphoma

BACKGROUND

High levels of cyclin E (CCNE) are accompanied by shorter survival in cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone (CHOP)-treated diffuse large B-cell lymphomas (DLBCL), independent of the international prognostic index (IPI). Data on the prognostic role of CCNE in the 'rituximab (R)-era' are lacking.

METHODS

To test reproducibility and applicability of observations from the 'pre-R era' to the 'R era', we examined the prognostic role of CCNE expression by immunohistochemistry in 1579 DLBCL on tissue microarrays (TMA); 339 patients were treated by CHOP and 635 by R-CHOP.

RESULTS

1209 samples (77%) were evaluable; failures were due to missing TMA punches and fixation artefacts. Mean expression of CCNE was 13% (0-85%); applying a cut-off of >16%, 382 DLBCL (31%) were positive. CCNE did not correlate with any of the known variables (IPI, primary site, cell of origin, proliferation, and BCL2- or C-MYC rearrangements). We were able to reproduce data suggesting an IPI- and response to therapy independent, negative prognostic impact of CCNE in CHOP-treated DLBCL patients: CCNE-positive cases had a median survival of 16 months compared with 57 months in negative ones (p=0.012). In R-CHOP-treated patients the prognostic impact of CCNE was abrogated and only IPI, cell of origin and response to therapy had a prognostic significance.

CONCLUSIONS

Addition of R to CHOP overcomes the negative prognostic impact of CCNE in DLBCL. Thus, R not only prolongs survival in DLBCL but also serves a cautionary note that prognostic factors should not be transferred into the 'R era' without proper scientific studies.

Overexpression of long noncoding RNA PCAT-1 is a novel biomarker of poor prognosis in patients with colorectal cancer

Long noncoding RNAs (lncRNA) are emerging as key molecules in human cancer. Prostate cancer-associated ncRNA transcripts 1 (PCAT-1), a lncRNA, has been recently revealed involving in human prostate cancer progression. However, whether PCAT-1 could serve as novel biomarker to predict prognosis in colorectal cancer (CRC) or not is unknown. We therefore carried out the present study to explore the correlation between PCAT-1 expression and the progression of CRC. In this study, the expression of PCAT-1 in 108 cases of CRC tissues and matched 81 adjacent normal tissues were determined by quantitative real-time PCR. Furthermore, the copy number variation of PCAT-1 was also measured in 17 tumor tissues and matched normal tissues. Our results showed that PCAT-1 expression in CRC tissues was significantly upregulated compared with the matched normal tissues (p < 0.001) and the overexpression of PCAT-1(upregulated by more than 50 %) was found in 64 % (62/81) of CRC. Moreover, PCAT-1 gene copy number variation explains only a few percent of observed overexpression. In addition, there was a significant association between PCAT-1 expression and distant metastasis (p = 0.04), but not other clinical characteristics. More important, CRC patients with PCAT-1 higher expression have shown significantly poorer overall survival than those with lower PCAT-1 expression (p < 0.001). Also, multivariable Cox regression analysis identified PCAT-1 overexpression as an independent prognostic factor for CRC (p = 0.007, HR = 3.12 95 %CI = 1.355-7.185). In conclusion, our results suggest that high expression of PCAT-1 is involved in CRC progression and could be a novel biomarker of poor prognosis in patient with colorectal cancer.

The role of the ubiquitin proteasome system in lymphoma

The ubiquitin-proteasome system (UPS) maintains the integrity of cellular processes by controlling protein degradation pathways. The role of the UPS in proliferation, cell cycle, differentiation, DNA repair, protein folding, and apoptosis is well documented, and a wide range of protein activities in these signaling pathways can be manipulated by UPS inhibitors, which include many anti-cancer agents. Naturally occurring and synthetic drugs designed to target the UPS are currently used for hematological cancers, including lymphoma. These drugs largely interfere with the E1 and E2 regions of the 26S proteasome, blocking proteasomal activity and promoting apoptosis by enhancing activities of the extrinsic (death receptors, Trail, Fas) and intrinsic (caspases, Bax, Bcl2, p53, nuclear factor-kappa B, p27) cell death programs. This review focuses on recent clinical developments concerning UPS inhibitors, signaling pathways that are affected by down-regulation of UPS activities, and apoptotic mechanisms promoted by drugs in this class that are used to treat lymphoma.

PIM kinases are progression markers and emerging therapeutic targets in diffuse large B-cell lymphoma

Background:

PIM serine/threonine kinases are often highly expressed in haematological malignancies. We have shown that PIM inhibitors reduced the survival and migration of leukaemic cells. Here, we investigated PIM kinases in diffuse large B-cell lymphoma (DLBCL) biopsy samples and DLBCL cell lines.

Methods:

Immunohistochemical staining for PIM kinases and CXCR4 was performed on tissue microarrays from a cohort of 101 DLBCL cases, and the effects of PIM inhibitors on the survival and migration of DLBCL cell lines were determined.

Results:

PIM1 expression significantly correlated with the activation of signal transducer and activator of transcription (STAT) 3 and 5, P-glycoprotein expression, CXCR4-S339 phosphorylation, and cell proliferation. Whereas most cases exhibited cytoplasmic or cytoplasmic and nuclear PIM1 and PIM2 expression, 12 cases (10 of the non-germinal centre DLBCL type) expressed PIM1 predominately in the nucleus. Interestingly, nuclear expression of PIM1 significantly correlated with disease stage. Exposure of DLBCL cell lines to PIM inhibitors modestly impaired cellular proliferation and CXCR4-mediated migration.

Conclusion:

This work demonstrates that PIM expression in DLBCL is associated with activation of the JAK/STAT signalling pathway and with the proliferative activity. The correlation of nuclear PIM1 expression with disease stage and the modest response to small-molecule inhibitors suggests that PIM kinases are progression markers rather than primary therapeutic targets in DLBCL.

Chromosomal instability substantiates poor prognosis in patients with diffuse large B-cell lymphoma

PURPOSE

The specific role of chromosomal instability (CIN) in tumorigenesis has been a matter of conjecture. In part, this is due to the challenge of directly observing chromosome mis-segregation events as well as the inability to distinguish the role of CIN, which consists of increased rates of chromosome mis-segregation, from that of aneuploidy, which is a state of nondiploid chromosome number.

EXPERIMENTAL DESIGN

Here, we examine the contribution of CIN to the prognosis of patients diagnosed with diffuse large B-cell lymphoma (DLBCL) by directly surveying tumor cells, fixed while undergoing anaphase, for evidence of chromosome mis-segregation. Hematoxylin and eosin-stained samples from a cohort of 54 patients were used to examine the relationship between frequencies of chromosome mis-segregation and patient prognosis, overall survival, and response to treatment.

RESULTS

We show that a two-fold increase in the frequency of chromosome mis-segregation led to a 24% decrease in overall survival and 48% decrease in relapse-free survival after treatment. The HR of death in patients with increased chromosome mis-segregation was 2.31 and these patients were more likely to present with higher tumor stage, exhibit tumor bone marrow involvement, and receive a higher International Prognostic Index score.

CONCLUSIONS

Increased rates of chromosome mis-segregation in DLBCL substantiate inferior outcome and poor prognosis. This is likely due to increased heterogeneity of tumor cells leading to a larger predilection for adaptation in response to external pressures such as metastasis and drug treatments. We propose that targeting CIN would yield superior prognosis and improved response to chemotherapeutic drugs.

Chromosomal instability and cancer: a complex relationship with therapeutic potential

Chromosomal instability (CIN) is a hallmark of human neoplasms. Despite its widespread prevalence, knowledge of the mechanisms and contributions of CIN in cancer has been elusive. It is now evident that the role of CIN in tumor initiation and growth is more complex than previously thought. Furthermore, distinguishing CIN, which consists of elevated rates of chromosome missegregation, from aneuploidy, which is a state of abnormal chromosome number, is crucial to understanding their respective contributions in cancer. Collectively, experimental evidence suggests that CIN enables tumor adaptation by allowing tumors to constantly sample the aneuploid fitness landscape. This complex relationship, together with the potential to pharmacologically influence chromosome missegregation frequencies in cancer cells, offers previously unrecognized means to limit tumor growth and its response to therapy.

Kinetochores and disease: keeping microtubule dynamics in check!

The essential role of microtubules in cell division has long been known. Yet the mechanism by which microtubule attachment to chromosomes at kinetochores is regulated has only been recently revealed. Here, we review the role of kinetochore-microtubule (kMT) attachment dynamics in the cell cycle as well as emerging evidence linking deregulation of kMT attachments to diseases where chromosome mis-segregation and aneuploidy play a central role. Evidence indicates that the dynamic behavior of kMTs must fall within narrow permissible boundaries, which simultaneously allow a level of stability sufficient to establish and maintain chromosome-microtubule attachments and a degree of instability that permits error correction required for accurate chromosome segregation.

Vav-1 expression correlates with NFκB activation and CD40-mediated cell death in diffuse large B-cell lymphoma cell lines

Diffuse large B-cell lymphoma (DLBCL) is an aggressive malignancy with a variable response to therapy. We have previously shown that DLBCL cell lines differ in their susceptibility to CD40-mediated cell death, and that resistance to CD40-targeted antibodies correlated with increased expression of markers of immature B-cell and absence of Vav-1 mRNA. We used gene expression profiling to investigate the mechanism of CD40 resistance in these cell lines, and found that resistance correlated with lack of Vav-1 and inability to activate NFκB upon CD40 ligation. Analysis of tissue microarrays of 213 DLBCL cases revealed that Vav-1 expression correlated with a higher proliferative index and the presence of the post-germinal centre marker Irf-4. Our results suggest that Vav-1 expression may be associated with activated B-cell DLBCL origin and higher proliferative activity, and indicate Vav-1 as a potential marker to identify tumours likely to respond to CD40-targeted therapies.

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.

Prognostic immunophenotypic biomarker studies in diffuse large B cell lymphoma with special emphasis on rational determination of cut-off scores

A number of biomarkers, particularly proteins that contribute to prognosis in diffuse large B cell lymphoma (DLBCL), have been identified. However, translation into accepted standards to predict survival has not yet been accomplished, primarily due to contradictory reports in the literature resulting from, among other factors, arbitrary methodologies used to set cut-off values for determining positivity. Some of these problems might be resolved by application of rational statistical methods for determination of cut-off scores. Herein, we critically address issues on in situ phenotypic prognostic tumor-related biomarkers in DLBCL with a particular and practical emphasis on tools for cut-off level determination, especially receiver operating characteristic curve analysis. Moreover, we candidly illustrate the application of these tools for efficient disease-specific survival prognostication on a tissue microarray collective of 240 primary DLBCL using the common prognostic biomarkers Bcl-2, Bcl-6, CD10, FOXP1, MUM1, and Cyclin E. Comparison of the results relative to disease-specific survival unequivocally showed the superior discriminatory power of the cut-off levels calculated by receiver operating curves and the Youden's index, compared to arbitrary cut-off values from the literature, advocating fundamental application of rational methods for determination of clinically relevant prognostic biomarkers' cut-off scores.

Identification of the gene encoding cyclin E1 (CCNE1) as a novel IGH translocation partner in t(14;19)(q32;q12) in diffuse large B-cell lymphoma

In a subset of B-cell malignancies, the genes encoding members of the cyclin D familiy are juxtaposed to immunoglobulin loci through recurrent chromosomal translocations. Here, we identified the gene encoding cyclin E1 as novel translocation partner of the immunoglobulin heavy chain (IGH) locus involved in a t(14;19)(q32;q12) in a case of t(8;14)(q24;q32) IGH-MYC-positive leukemic diffuse large B-cell lymphoma. The translocation breakpoints were cloned and mapped to the switch region Salpha1 of IGH in 14q32 and approximately 60kb centromeric to CCNE1 in 19q12. Immunohistochemical analysis revealed overexpression of the cyclin E1 protein in this case, which to a comparable extent was observed in 3/41 independent DLBCL. These data indicate that cyclin E1 may act as a novel oncogene in B-cell lymphomagenesis.

Recurrent numerical aberrations of JAK2 and deregulation of the JAK2-STAT cascade in lymphomas

The Janus kinase 2 (JAK2)-signal transducers and activators of transcription (STAT) pathway plays an important role in hematological malignancies. Mutations and translocations of the JAK2 gene, mapped at 9p24, lead to constitutive activation of JAK2 and its downstream targets. The presence of JAK2 mutations in lymphomas has been addressed in larger cohorts, but there are little systemic data on numerical and structural JAK2 aberrations in lymphoid neoplasms. To study the molecular epidemiology of these aberrations and the consecutive activation of the JAK2-STAT pathway in lymphomas, we examined 527 cases, covering the most common entities, in a tissue microarray by fluorescent in situ hybridization with breakable JAK2 probes, and immunohistochemistry for phosphorylated JAK2 (pJAK2) and its preferred downstream pSTAT3 and pSTAT5. 9p24 gains were detected in 6/17 (35%) primary mediastinal B-cell lymphomas (PMBCLs), 25/77 (33%) Hodgkin's lymphomas (HLs), 3/16 (19%) angioimmunoblastic T-cell lymphomas (AILTs) and 1/5 ALK1(+) anaplastic large cell lymphomas (ALCLs); breaks were observed only in three cases. pJAK2 expression was most prevalent in PMBCL, peripheral T-cell lymphomas and HL. pSTAT3 predominated in ALCLs, HLs, AILTs, PMBCLs and peripheral T-cell lymphomas. pSTAT5 expression was detected frequently in follicular lymphomas, diffuse large B-cell lymphomas and AILTs. 9p24 gains correlated with increased proportions of tumor cells expressing pJAK2 (P=0.002) and pSTAT3 (P=0.001). In follicular lymphomas, concomitant expression of pJAK2 and pSTAT5 was linked to better prognosis, whereas expression of pSTAT3 in nongerminal center-like diffuse large B-cell lymphomas could identify a patient group with an inferior outcome. Our findings stress that despite the rarity of activating JAK2 mutations in lymphomas, JAK2 is recurrently targeted by numerical, and rarely by structural, genetic aberrations in distinct lymphoma subtypes and that JAK2-STAT pathway may play a role in lymphomagenesis.

Cytokeratin expression in hematological neoplasms: a tissue microarray study on 866 lymphoma and leukemia cases

Aberrant expression of cytokeratins (CK) is known to occasionally occur in malignant lymphomas. The monoclonal mouse-anti-human CK cocktail CK22 recognizes keratin polypeptides with a wide range of molecular weights and can be applied in diagnostic panels for tumors of unknown origin. Using tissue microarray technology, we tested 1059 lymphoma and acute leukemia cases, covering the most common disease entities, for aberrant CK expression, using CK22. In total, 866 of the arrayed cases were evaluable (80%), and 13 positive cases (1.5%) were found: 1 out of 230 Hodgkin lymphomas (0.4%), 1 plasma cell myeloma, 2 out of 326 diffuse large B-cell lymphomas (0.6%), 5 out of 18 mantle cell lymphomas (26%), 3 out of 70 small cell lymphomas/chronic lymphocytic leukemias (4%) and 1 out of 27 peripheral T-cell lymphomas, not otherwise specified (4%). Immunostaining was finely granular in most cases, and the total amount of positively staining cells exceeded 10% only in the cases of Hodgkin lymphoma and plasmocytoma. All CK22-positive cases, except for one mantle cell lymphoma, expressed the specific simple epithelial CK8 but not the basal/stratified epithelial CK5/6. Aberrant CK expression can be encountered in a small subset of otherwise characteristic B- and T-cell lymphomas, but not in acute leukemias, which should be considered in difficult differential diagnostic settings.

Large-scale analysis of cell cycle regulators in urothelial bladder cancer identifies p16 and p27 as potentially useful prognostic markers

AIMS

We investigated the value of multiple cell cycle markers for their prognostic impact on overall survival and recurrence-free survival in urothelial carcinoma (UC).

METHODS

A tissue microarray consisting of 99 UCs was evaluated for the expression of p53, p16, p21, p27, cyclin D1, cyclin E , Bcl-2, Ki-67 and PCNA. Statistical analysis was performed applying Kaplan-Meier and Cox regression models using receiver operator characteristic curves for determination of markers' cutoffs.

RESULTS

Expression above the cutoffs of Ki-67, p53 and p27, particularly in high-grade and early-stage UC, was associated with worse overall survival, while expression of p16 indicated a better outcome in low-grade and low-stage tumors. Recurrence-free survival was better in patients with high-grade UC expressing PCNA, p16 and cyclin E, and low-grade UC expressing Bcl-2 above the cutoffs, but worse in all tumors with high Ki-67.

CONCLUSION

Cell cycle deregulation in UC is complex and the prognostic value of the various involved proteins should be differentially regarded with respect to this complexity and other tumor characteristics such as grade and stage. Our results point towards the role of p16- and p27-associated pathways in tumor progression and indicate that, by using standardized approaches for tissue antigen expression, evaluation and cutoff determination, single potentially useful prognostic markers could be identified.

Application of Genomics in Clinical Oncology

Genomics is a comprehensive study of the whole genome, genetic products, and their interactions. Human genome project has identified around 25,000-30,000 genes, and prevailing presence in tumor pathogenesis, high number of mutations, epigenetic changes, and other gene disorders have been identified. Microarrays technology is used for the analysis of these changes. Postgenome age has begun, and the initial results ensure the improvement of molecular tumor diagnostics and the making of a new taxonomic tumor classification, as well as the improvement, optimization and individualization of anti-tumor therapy. First genomic classifications have been made of leukemias, non-Hodgkin lymphoma, and many solid tumors. For example, 4 molecular types of breast carcinoma, three types of diffuse B cell lymphoma, two types of chromophobic renal carcinoma have been identified. Also, gene structures for favorable and unfavorable outcome in leukemia, breast cancer, prostate, bronchi, and other tumors have been identified. It is absolutely possible to diagnose the primary outcome of tumors with which standard tumor position may not be proved using standard diagnostic tools. Pharmacogenomic profiles have ensured better definition of interindividual differences during therapy using antineoplastic drugs and the decrease of their toxicity, as well as individual treatment approach and patient selection with which favorable clinical outcome is expected. Pharmacogenomics has impacted the accelerated development of target drugs, which have showed to be useful in practice. New genomic markers mtDNA, meDNA, and miRNA have been identified, which, with great certainty, help the detection and diagnostics of carcinoma. In the future, functional genomics in clinical oncology provides to gain knowledge about tumor pathogenesis; it will improve diagnostics and prognosis, and open up new therapeutic options.

Microarray expression technology in clinical research of non-Hodgkin lymphoma

Nowadays, in genomocentric era accelerated research of the human genome coupled with advances is enabling the comprehensive molecular profiling of human tissue. Particularly, DNA microarrays are powerful tools for obtaining global view of human non-Hodgkin lymphomas gene expression. Complex information from lymphomas "expression profiling" studies can, in turn, be used to create molecular markers that have diagnostic or prognostic implications. The gene "expression profiling" is not of routine clinical oncology practice, but is used in genomic classification of clinically relevant subgroups of non-Hodgkin lymphoma. The genomics biomarkers have been incorporated into current prognostic models which are based on IPI, R-IPI, and FLIPI. Molecular or pharmacogenomic profiling can be used as new therapeutic targets for patients who are refractory to current therapy. We discus the utility of DNA microarray-based lymphoma profiling in clinical oncology research, and identify future of research in lymphoma evolving fields.

Pathobiology of Classical Hodgkin Lymphoma

The World Health Organization has acknowledged the malignant nature of classical Hodgkin lymphoma (cHL), which encompasses four histological subtypes. The diagnosis of cHL is based on the detection of malignant Hodgkin and Reed-Sternberg cells (HRSC) confirmed by immunophenotyping and the detection of growth patterns specific to each histological subtype. The pathologic HRSC arise from germinal center or immediate postgerminal cells that lack detectable immunoglobulin/B-cell antigen receptor expression, with a consequent loss of B-cell identity; very few cHL cases are of T-cell origin. To escape apoptosis, which normally occurs in B cells with nonfunctioning antigen receptor machinery, HRSC develop concurrent antiapoptotic mechanisms by activation of nuclear factor-kappaB or are rescued by Epstein-Barr virus infection. HRSC are characterized by a variable and inconstant immunophenotype, with a remarkable loss of lineage-specific cell antigens and expression of antigens of other cell lineages. The master plan of B-cell identity in HRSC is disturbed not only at the immunoglobulin expression level, but also at the transcriptional factor level. HRSC are further characterized by profound cell cycle deregulation with futile replication, multinucleation and poly- and aneuploidy. Here, we review pathobiological aspects of cHL with respect to lymphomagenesis and routine diagnostics.