Topoisomerase IIα expression in mantle cell lymphoma: a marker of cell proliferation and a prognostic factor for clinical outcome

Identification of tumor-associated antigens of lung cancer: SEREX combined with bioinformatics analysis

The aim of this study is to identify novel tumor-associated antigens (TAAs) of lung cancer by using serological analysis of recombinant cDNA expression library (SEREX) and bioinformatics analysis as well as to explore their humoral immune response. SEREX and pathway enrichment analysis were used to immunoscreen TAAs of lung cancer and elaborate their function in biological pathways, respectively. Subsequently, the sera level of autoantibodies against the selected TAAs (TOP2A, TRIM37, HSP90AB1, EEF1G and TPP1) was detected by immunoserological analysis to explore the immune response of these antigens. The Gene Expression Profiling Interactive Analysis (GEPIA) and Human Protein Atlas (HPA) database were applied to explore the mRNA and protein expression level of TOP2A, TRIM37 and HSP90AB1 in tissues, respectively. Seventy positive clones were identified by SEREX which contain 63 different genes, and 35 genes of them have been reported. These 35 genes were mainly related to regulation of different transcription factor and performed enrichment in legionellosis, RNA transport, IL-17 signaling pathway via enrichment analysis. Additionally, the positive rate of autoantibodies against TOP2A, TRIM37 and HSP90AB1 in lung cancer patients were typically higher than normal control (NC; P < 0.05). Moreover, the combination of the autoantibodies against TOP2A, TRIM37 and HSP90AB1 possessed an excellent diagnostic performance with sensitivity of 84% and specificity of 60%. The mRNA expression level of TOP2A was obviously unregulated in squamous cell carcinoma (SCC) tissues and adenocarcinoma (ADC) tissues compared to normal tissues (P < 0.05). In addition, TRIM37 and HSP90AB1 also showed a significant difference between SCC and NC at the mRNA expression level (P < 0.05). This study combining comprehensive autoantibody and gene expression assays has added to the growing list of lung cancer antigens, which may aid the development of diagnostic and immunotherapeutic targets for lung cancer patients.

Prognostic relevance of topoisomerase II α and minichromosome maintenance protein 6 expression in colorectal cancer

BACKGROUND

Despite rising incidence rates of colorectal malignancies, only a few prognostic tools have been implemented in proven clinical routine. Cell division and proliferation play a significant role in malignancies. In terms of colorectal cancer, the impact of proliferation associated proteins is controversially debated. The aim of our study was to examine the expression of topoisomerase II α and minichromosome maintenance protein 6 and to correlate these findings with the clinical data.

METHODS

Tissue samples of 619 patients in total were stained using the antibodies Ki-S4 and Ki-MCM6 targeting topoisomerase II α as well as minichromosome maintenance protein 6. The median rate of proliferation was correlated with clinical and follow up data.

RESULTS

The expression rate of minichromosome maintenance protein 6 is significantly higher than the proportion of topoisomerase II α in tumour cells (p < 0.001). A high expression of both proteins coincides with a beneficial outcome for the patient, indicating a favourable prognostic marker (p < 0.001 and p = 0.008).

CONCLUSIONS

We have demonstrated that high expression rates of proliferative markers is linked to a beneficial patient outcome. According to the general opinion, a high expression rate correlates with a poor patient outcome. In this study, we were able to refute this assertion.

Gene expression profiling reveals a close relationship between follicular lymphoma grade 3A and 3B, but distinct profiles of follicular lymphoma grade 1 and 2

A linear progression model of follicular lymphomas (FL) FL1, FL2 and FL3A has been favored, since FL3A often co-exist with an FL1/2 component. FL3B, in contrast, is thought to be more closely related to diffuse large B-cell lymphoma (DLBCL), and both are often simultaneously present in one tumor (DLBCL/FL3B). To obtain more detailed insights into follicular lymphoma progression, a comprehensive analysis of a well-defined set of FL1/2 (n=22), FL3A (n=16), FL3B (n=6), DLBCL/FL3B (n=9), and germinal center B-cell-type diffuse large B-cell lymphoma (n=45) was undertaken using gene expression profiling, immunohistochemical stainings and genetic analyses by fluorescence in situ hybridization. While immunohistochemical (CD10, IRF4/MUM1, Ki67, BCL2, BCL6) and genetic profiles (translocations of BCL2, BCL6 and MYC) delineate FL1-3A from FL3B and DLBCL/FL3B, significant differences were observed between FL1/2 and FL3A upon gene expression profiling. Interestingly, FL3B turned out to be closely related to FL3A, not categorizing within a separate gene expression cluster, and both FL3A and FL3B showed overlapping profiles in between FL1/2 and diffuse large B-cell lymphoma. Finally, based upon their gene expression pattern, DLBCL/FL3B represent a composite form of FL3B and DLBCL, with the majority of samples more closely resembling the latter. The fact that gene expression profiling clearly separated FL1/2 from both FL3A and FL3B suggests a closer biological relationship between the latter. This notion, however, is in contrast to immunohistochemical and genetic profiles of the different histological FL subtypes that point to a closer relationship between FL1/2 and FL3A, and separates them from FL3B.

Mantle cell lymphoma in the era of precision medicine-diagnosis, biomarkers and therapeutic agents

Despite advances in the development of clinical agents for treating Mantle Cell Lymphoma (MCL), treatment of MCL remains a challenge due to complexity and frequent relapse associated with MCL. The incorporation of conventional and novel diagnostic approaches such as genomic sequencing have helped improve understanding of the pathogenesis of MCL, and have led to development of specific agents targeting signaling pathways that have recently been shown to be involved in MCL. In this review, we first provide a general overview of MCL and then discuss about the role of biomarkers in the pathogenesis, diagnosis, prognosis, and treatment for MCL. We attempt to discuss major biomarkers for MCL and highlight published and ongoing clinical trials in an effort to evaluate the dominant signaling pathways as drugable targets for treating MCL so as to determine the potential combination of drugs for both untreated and relapse/refractory cases. Our analysis indicates that incorporation of biomarkers is crucial for patient stratification and improve diagnosis and predictability of disease outcome thus help us in designing future precision therapies. The evidence indicates that a combination of conventional chemotherapeutic agents and novel drugs designed to target specific dysregulated signaling pathways can provide the effective therapeutic options for both untreated and relapse/refractory MCL.

Structure-based identification of a NEDD8-activating enzyme inhibitor via drug repurposing

NEDD8-activating enzyme (NAE) is an essential player of the NEDD8 conjugation pathway that regulates protein degradation. Meanwhile, drug repurposing is a cost-efficient strategy to identify new therapeutic uses for existing scaffolds. In this report, mitoxantrone (1) was repurposed as an inhibitor of NAE by virtual screening of an FDA-approved drug database. Compound 1 inhibited NAE activity in cell-free and cell-based systems with high selectivity and was competitive with ATP. Furthermore, compound 1 induced apoptosis of colorectal adenocarcinoma cancer cells through inhibiting the degradation of the neddylation substrate p53.

New paradigms in mantle cell lymphoma: is it time to risk-stratify treatment based on the proliferative signature?

The elucidation of crucial biologic pathways of cell survival and proliferation has led to the development of highly effective drugs, some of which have markedly improved mantle cell lymphoma (MCL) therapeutic opportunities in the past 10 years. Moreover, an undeniable clinical heterogeneity in treatment response and disease behavior has become apparent in this neoplasm. Thus, the need for biologic markers stratifying patients with MCL in risk classes deserving different treatment approaches has recently been fervently expressed. Among several newly discovered biomarkers, the dismal predictive value of a high proliferative signature has been broadly recognized in large studies of patients with MCL. Different techniques have been used to assess tumor cell proliferation, including mitotic index, immunostaining with Ki-67 antibody, and gene expression profiling. Ki-67 proliferative index, in particular, has been extensively investigated, and its negative impact on relapse incidence and overall survival has been validated in large prospective clinical trials. However, one important pitfall limiting its widespread use in clinical practice is the reported interobserver variability, due to the previous lack of a standardized approach for quantification among different laboratories. In the present review, we describe some of the major techniques to assess cell proliferation in MCL, focusing in particular on the Ki-67 index and its need for a standardized approach to be used in multicenter clinical trials. The value of MCL biologic prognostic scores (as MIPI-b) is discussed, along with our proposal on how to integrate these scores in the planning of future trials investigating a tailored therapeutic approach for patients with MCL. See all articles in this CCR Focus section, "Paradigm Shifts in Lymphoma."

Inhibition of topoisomerase IIα sensitizes FaDu cells to ionizing radiation by diminishing DNA repair

Despite the high efficiency of ionizing radiation (IR) to inactivate malignant tumours in general, an appreciable number of individual patients cannot be cured by standard IR. Head and neck tumours are not likely to be cured even by high-dose radiotherapy or chemotherapy. Accordingly, combined therapy is one of the most applicable strategies. Topoisomerase IIα is a ubiquitous enzyme that removes knots and tangles from the genetic material by generating and subsequently resealing of transient double-strand breaks. Due to its unique mechanism of action, topoisomerase IIα is the target of many chemotherapeutic agents such as etoposide. The aim of the present study is to examine the effect of inhibiting topoisomerase IIα by etoposide on the response of squamous cell carcinoma to IR. Results of the present study demonstrated a radiosensitizing effect for the topoisomerase IIα inhibitor etoposide on exponentially growing squamous cell carcinoma (FaDu) cell line especially at low radiation doses. This effect was found to be due to inhibition, by etoposide, of the repair of radiation-induced DNA damage. Cell cycle studies showed that the concentration of etoposide that sensitized the cells to radiation had no effect on the distribution of cells at different phases of the cell cycle. Synchronization of FaDu cells in different cell cycle phases revealed that proliferating G1 and G2 cells are responsible for sensitization of cells at low doses of ionizing radiation. It might, therefore, be concluded that topoisomerase II enzyme may be involved in the repair of radiation-induced DNA damage and consequently its inhibition constitute a strategy for sensitizing tumour cells to ionizing radiation.

Cytotoxic activity of octahydropyrazin[2,1-a:5,4-a']diisoquinoline derivatives in human breast cancer cells

Evaluation of the cytotoxicity of novel octahydropyrazin[2,1-a:5,4-a']diisoquinoline derivatives (1a-2c) employing a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and inhibition of [(3)H]thymidine incorporation into DNA demonstrated that these compounds were more active than etoposide and camptothecin in both MDA-MB-231 and MCF-7 human breast cancer cells. Flow cytometric analysis after Annexin V-FITC and propidium iodide staining also confirmed that apoptosis was the main response of human breast cancer cells to 1a-2c treatment. Our results suggest that apoptosis of human breast cancer cells in the presence of 1a-2c follows the mitochondrial pathway, with the decrease in mitochondrial membrane potential and activation of caspase 9, as well as by the external pathway with the significant increase in caspase 8 expression. Cytotoxic properties of compounds 1a-2c in cultured human breast cancer cells correlate to their ability to inhibit topoisomerase I/II.

The NF-κB pathway is rarely spontaneously activated in mantle cell lymphoma (MCL) cell lines and patient's samples

In this study, we investigated the role of NF-κB (canonical and alternative pathways) in the survival or proliferation of mantle cell lymphoma (MCL) cell lines. P50/p65 complexes were detectable by EMSA assays in 4/5 cell lines. Stable expression of a dominant-negative form of IkBa had no effect on proliferation nor on apoptosis in EBV-negative cell lines. Three out of 4 of the cell lines tested exhibited Phospho-p65 (Ser(536)). The alternative NF-κB pathway was not activated in 4/5 cell lines tested. Patient samples were also studied by Western blot, EMSA and Immunohistochemistry (IHC). No p50/p65 complexes were detected in cells freshly collected from 7 patients, but 1/7 cells exhibited Phospho-p65 (Ser(536)). We investigated immunohistochemically, the expression of NF-κB in 86 patients enrolled in two multicentre prospective trials. Patients with MCL exhibiting negative or positive cytoplasmic expression of NF-κB had a median overall survival of 35.7months compared to 22.4months for patients with nuclear NF-κB expression (p=0.0193). All these data suggest that NF-κB does not play a key role in proliferation and apoptotic processes in MCL cell lines. In patient samples, the presence of p65 in the nucleus reflecting NF-κB activation is rare but associated with a poor outcome.

MicroRNA signature obtained from the comparison of aggressive with indolent non-Hodgkin lymphomas: potential prognostic value in mantle-cell lymphoma

PURPOSE

Mantle-cell lymphoma (MCL) has a variable natural history but is incurable with current therapies. MicroRNAs (miRs) are useful in prognostic assessment of cancer. We determined an miR signature defining aggressiveness in B-cell non-Hodgkin lymphomas (NHL) and assessed whether this signature aids in MCL prognosis.

METHODS

We assessed miR expression in a training set of 43 NHL cases. The miR signature was validated in 44 additional cases and examined on a training set of 119 MCL cases from four institutions in Canada. miRs significantly associated with overall survival were examined in an independent cohort of 114 MCL cases to determine association with patient outcome. miR expression was combined with current clinical prognostic factors to develop an enhanced prognostic model in patients with MCL.

RESULTS

Fourteen miRs were differentially expressed between aggressive and indolent NHL; 11 of 14 were validated in an independent set of NHL (excluding MCL). miR-127-3p and miR-615-3p were significantly associated with overall survival in the MCL training set. Their expression was validated in an independent MCL patient set. In comparison with Ki-67, expression of these miRs was more significantly associated with overall survival among patients with MCL. miR-127-3p was combined with Ki-67 to create a new prognostic model for MCL. A similar model was created with miR-615-3p and Mantle Cell Lymphoma International Prognostic Index scores.

CONCLUSION

Eleven miRs are differentially expressed between aggressive and indolent NHL. Two novel miRs were associated with overall survival in MCL and were combined with clinical prognostic models to generate novel prognostic data for patients with MCL.

Topo IIα gene alterations correlated with survival in patients with diffuse large B-cell lymphoma

BACKGROUND

Topoisomerase IIα (topo IIα) protein expression has prognostic significance in many cancers. However, it is still unclear whether topo IIα protein expression and gene alterations play roles as prognostic factors in diffuse large B-cell lymphoma (DLBCL).

MATERIALS AND METHODS

We selected 102 patients with DLBCL who were homogeneously treated with CHOP chemotherapy and followed up. Using tissue microarray technology, all of the cases, consisting of 25 germinal centre B-cell-like (GCB) and 77 nongerminal centre B-cell-like (non-GCB) types, were studied. Topo IIα protein expression was detected by immunohistochemistry. Gene copy number of topo IIα was analysed by chromogenic in situ hybridization. Cox regression, chi-square test and Kaplan-Meier statistics were performed using SPSS 15·0.

RESULTS

Topo IIα protein overexpression was found in 91 (91/102, 89·2%) cases, while topo IIα gene amplification was absent in all cases. Chromosome 17 deletion was identified in 3 (3/102, 2·9%) cases, diploid in 66 (66/102, 64·7%) cases and aneuploidy in 33 (33/102, 32·4%) cases. By multivariate analysis, no significant differences in progression-free survival (PFS) and overall survival (OS) were observed in patients with topo IIα protein overexpression (P > 0·05), while chromosome 17 aneuploidy predicted worse PFS and OS (P < 0·001).

CONCLUSIONS

These results suggested that chromosome 17 aneuploidy, but not topo IIα protein expression, could predict worse survival in patients with DLBCL.

Candidate genes contributing to the aggressive phenotype of mantle cell lymphoma

Mantle cell lymphoma and small lymphocytic lymphoma are lymphocyte cancers that have similar morphologies and a common age of onset. Mantle cell lymphoma is generally an aggressive B cell lymphoma with a short median survival time, whereas small lymphocytic lymphoma is typically an indolent B cell lymphoma with a prolonged median survival time. Using primary tumor samples in bi-directional suppression subtractive hybridization, we identified genes with differential expression in an aggressive mantle cell lymphoma versus an indolent small lymphocytic lymphoma. "Virtual" Northern blot analyses of multiple lymphoma samples confirmed that a set of genes was preferentially expressed in aggressive mantle cell lymphoma compared to indolent small lymphocytic lymphoma. These analyses identified mantle cell lymphoma-specific genes that may be involved in the aggressive behavior of mantle cell lymphoma and possibly other aggressive human lymphomas. Interestingly, most of these differentially expressed genes have not been identified using other techniques, highlighting the unique ability of suppression subtractive hybridization to identify potentially rare or low expression genes.

High levels of topoisomerase IIalpha protein expression in diffuse large B-cell lymphoma are associated with high proliferation, germinal center immunophenotype, and response to treatment

Gene copy number and protein expression of topoisomerase IIalpha were correlated to benefit from anthracyclines in various tumors. A retrospective series of 69 patients with DLBCL managed with CHOP chemotherapy were studied for immunohistochemical TopoIIalpha expression and numerical gene abnormalities by fluorescent in situ hybridization (FISH). The results were analyzed in relation to the expression of cell cycle proteins (Ki67, p53, HDM2, p21, p14, pRb, p16, and cyclins A, B1, D1, D2, D3, and E) and BCL6/CD10/MUM1/CD138 B-cell differentiation immunophenotype and outcome. High levels of TopoIIalpha protein were found in 91% of DLBCL cases. No evidence of TopoIIalpha gene amplification or deletion was found. The TopoIIalpha expression showed significant positive correlations with the proliferation index Ki67 (p = 0.002), cell cycle proteins pRb and cyclin D2 (p = 0.018 and p = 0.028, respectively), and the germinal center proteins bcl6 and CD10 (p = 0.010 and p < 0.0001, respectively). TopoIIalpha expression was significantly higher in germinal center B-cell like (GCB) DLBCL than in non-germinal center B-cell like (non-GCB) DLBCL (p = 0.048). TopoIIalpha protein was significantly associated with response to chemotherapy (chi(2), p = 0.024), but not with relapse-free or overall survival (p = 0.5). On multivariate analysis, only stage of disease retained independent prognostic significance (HR 0.33 for early stage, p = 0.008). Although TopoIIa gene copy number abnormalities were not found in DLBCL, high levels of protein expression are associated with GCB-cell differentiation immunophenotype, high proliferation, and response to treatment.

Validation, revision and extension of the Mantle Cell Lymphoma International Prognostic Index in a population-based setting

BACKGROUND

The aim of this study was to validate the Mantle Cell Lymphoma International Prognostic Index in a population-based cohort and to study the relevance of its revisions.

DESIGN AND METHODS

We analyzed data from 178 unselected patients with stage III or IV mantle cell lymphoma, registered between 1994 and 2006 in the Eindhoven Cancer Registry. Follow-up was completed up to January 1(st), 2008. Multiple imputations for missing covariates were used. Validity was assessed by comparing observed survival in our cohort with predicted survival according to the original Mantle cell lymphoma International Prognostic Index. A revised model was constructed with Cox regression analysis. Discrimination was assessed by a concordance statistic ('c').

RESULTS

The original Mantle cell lymphoma International Prognostic Index could stratify our cohort into three distinct risk groups based on Eastern Cooperative Group performance status, white blood cell count, lactate dehydrogenase level, and age, with the discrimination being nearly as good as in the original cohort (c 0.65 versus 0.63). A modified model including performance status in five categories (0/1/2/3/4) instead of two (0-1/2-4), the presence of B-symptoms (yes/no) and sex (male/female) in addition to the original variables resulted in a better prognostic index (c 0.75).

CONCLUSIONS

The Mantle cell lymphoma International Prognostic Index is a valid tool for risk stratification, comparison of prognosis, and treatment decisions in an unselected Dutch population-based setting. Although the index can be significantly improved, external validation on an independent data set is warranted before broad application of the modified instrument could be recommended.

Topoisomerase II alpha as a universal tumor antigen: antitumor immunity in murine tumor models and H-2K(b)-restricted T cell epitope

Topoisomerase II alpha (Top2alpha) is an attractive candidate to be used as a tumor antigen for cancer immunotherapy, because it is abundantly expressed in various tumors and serves as a target for a number of chemotherapeutic agents. In this study, we demonstrated the immunogenicity of Top2alpha, using dendritic cells (DC) electroporated with RNA encoding the Top2alpha C-terminus (Top2alphaCRNA/DC). Top2alphaCRNA/DC were able to demonstrate in vitro stimulation of T cells from mice that were previously vaccinated with Top2alpha-expressing tumor lysate-pulsed DC. Vaccination with Top2alphaCRNA/DC induced Top2alpha-specific T cell responses in vivo as well as antitumor effects in various murine tumor models including MC-38, B16F10, and GL26. DC pulsed with p1327 (DSDEDFSGL), defined as an epitope presented by H-2K(b), also induced Top2alpha-specific immune responses and antitumor effects. Based on these data, Top2alpha is suggested to be a universal target for cancer immunotherapy.

A novel quantitative PCR of proliferation markers (Ki-67, topoisomerase IIalpha, and TPX2): an immunohistochemical correlation, testing, and optimizing for mantle cell lymphoma

A clinical course of patients with mantle cell lymphoma (MCL) is aggressive, and the disease is rarely curable. Proliferation rate is the most important prognostic factor. We developed a novel, reliable, rapid, and routinely applicable approach allowing a precise quantitative assessment of three proliferation markers, Ki-67, topoisomerase IIalpha, and TPX2. A total of 95 lymphoma specimens were measured in the study by real-time reverse transcription PCR (RQ-RT-PCR). We tested the reproducibility and accuracy of the assay and correlated the results with the immunohistochemical staining of the corresponding proteins. The results obtained indicated individual variability of the mRNA expression levels, reflecting heterogeneity of the proliferation rate in individual patients. In general, we observed the highest mRNA expression in the group of Burkitt lymphomas and the lowest in patients with reactive lymphadenopathies. We found increased proliferation rate in MCLs with high cyclin D1 mRNA, indicating a quantitative control of the cell cycle. We observed a correlation between mRNA expression level and the immunohistochemical staining of corresponding proteins, which significantly argues for the prognostic significance of the mRNA expression measuring. We confirmed the accuracy of the current assay for a precise quantitative examination of the proliferation activity. Real-time RT-PCR provides a novel approach applicable for clinical trials, and it represents a potent approach allowing to stratify MCL patients for entry into clinical trials according to the expression of the proliferation signature genes in their tumors. This approach may contribute to improved and individualized therapeutic options respecting the individual progression risk of patients with MCL.

Expression of eukaryotic initiation factor 4E predicts clinical outcome in patients with mantle cell lymphoma treated with hyper-CVAD and rituximab, alternating with rituximab, high-dose methotrexate, and cytarabine

BACKGROUND

Oncogenic AKT/mammalian target of rapamycin (mTOR) signaling has recently been shown to contribute to tumor survival and proliferation in mantle cell lymphoma (MCL) through its downstream effector eukaryotic initiation factor 4E (eIF4E), which may control cyclin D1 protein levels. However, the clinical significance of eIF4E expression in MCL is unknown.

METHODS

The authors investigated the prognostic significance of eIF4E expression in 70 MCL patients uniformly treated with hyper-CVAD and rituximab, alternating with the rituximab, high-dose methotrexate, and cytarabine regimen (R-hyper-CVAD). eIF4E expression was assessed using tissue biopsy specimens obtained before treatment, immunohistochemical methods, and a highly specific monoclonal antibody. Failure-free (FFS) and overall (OS) survival were used as endpoints in univariate and multivariate survival analysis.

RESULTS

High eIF4E expression was found in 28 (40%) MCL tumors. After a median follow-up of 51 months for survivors, the 5-year FFS was 20.6% for patients with high eIF4E expression, compared with 63.5% for patients with low or no eIF4E expression (P=.01, log-rank). Similarly, the 5-year OS was 40.1% for patients with high eIF4E expression, compared with 73.8% for patients with low or no eIF4E expression (P=.018, log-rank). In multivariate analysis, eIF4E expression was associated with poorer FFS and OS, along with age>60 years and high beta2-microglobulin in the final prognostic model.

CONCLUSIONS

In summary, eIF4E, which seems to recapitulate most of the biologic effects of mTOR signaling in MCL, is an independent predictor of clinical outcome in MCL patients uniformly treated with the R-hyper-CVAD regimen.

Ki-67 as a prognostic marker in mantle cell lymphoma-consensus guidelines of the pathology panel of the European MCL Network

Mantle cell lymphoma (MCL) has a heterogeneous clinical course and is mainly an aggressive B cell non-Hodgkin lymphoma; however, there are some indolent cases The Ki-67 index, defined by the percentage of Ki-67-positive lymphoma cells on histopathological slides, has been shown to be a very powerful prognostic biomarker. The pathology panel of the European MCL Network evaluated methods to assess the Ki-67 index including stringent counting, digital image analysis, and estimation by eyeballing. Counting of 2 × 500 lymphoma cells is the gold standard to assess the Ki-67 index since this value has been shown to predict survival in prospective randomized trials of the European MCL Network. Estimation by eyeballing and digital image analysis showed a poor concordance with the gold standard (concordance correlation coefficients [CCC] between 0.29 and 0.61 for eyeballing and CCC of 0.24 and 0.37 for two methods of digital image analysis, respectively). Counting a reduced number of lymphoma cells (2 × 100 cells) showed high interobserver agreement (CCC = 0.74). Pitfalls of the Ki-67 index are discussed and guidelines and recommendations for assessing the Ki-67 index in MCL are given.

Molecular outcome prediction in mantle cell lymphoma

Mantle cell lymphoma (MCL), a subtype of B-cell non-Hodgkin lymphoma, is usually incurable with current therapeutic approaches and the clinical course displays considerable variability. Objective assessment of the efficacy of new and more tailored treatment strategies requires deeper molecular insights into the disease and more individual risk assessment. The molecular feature of tumor cell proliferation as measured by Ki-67 immunohistochemistry or, more precisely, by microarray-based gene-expression profiling, has been shown to be of strong predictive value in MCL. The recently proposed quantitative reverse transcription-PCR based five-gene model survival predictor is applicable to fresh-frozen and routinely obtained formalin-fixed and paraffin-embedded tumor tissues, and provides the potential to investigate its prognostic value in prospective clinical trials of MCL patients.

Prognostic significance of beta-catenin and topoisomerase IIalpha in de novo acute myeloid leukemia

The Wnt/beta-catenin signaling is important for controlling self-renewal of hematopoietic stem cells and its constitutive activation has recently been documented in a significant proportion of acute myeloid leukemia (AML) cases. Topoisomerase IIalpha (Topo IIalpha) is a marker of cell proliferation and a crucial target for anthracycline cytotoxicity, the mainstay of management employed in AML. We retrospectively investigated the prognostic roles of beta-catenin and topo IIalpha in a cohort of 59 patients with newly diagnosed AML by immunohistochemistry. Aberrant beta-catenin expression was demonstrated in 13 patients (22%), and it was more likely to occur in those with unfavorable karyotypes. Advanced age and poor performance status adversely influenced the achievement of complete remission, while neither aberrant beta-catenin expression nor enhanced topo IIalpha activity did. On multivariate survival analysis, four factors independently predicted a shortened overall survival: aberrant beta-catenin expression, high topo IIalpha activity, poor-risk cytogenetics, and presence of at least one comorbidity factor. Our results suggest that both beta-catenin and topo IIalpha independently predicted an adverse prognosis and might serve as new markers for risk stratification in AML patients.

Massive swelling of the cervical region: an uncommon manifestation of B cell chronic lymphocytic leukemia

CASE REPORT

We report about a 61-year-old woman who attended our Department of Oral and Maxillofacial Surgery complaining about an increasing swelling of her neck over a period of several years and asking for possible plastic surgery options. Further examinations lead us to the diagnosis of an uncommon manifestation of chronic B cell lymphoma. We suggest that plastic surgeons may refer to magnetic resonance tomography imaging and blood cell counts prior to liposuction of a massive swelling of the neck.

DISCUSSION

Accurate reduction of adipose tissue in the obese patient is a common field for plastic surgeons. Thus, liposuction has become a standard regimen to treat adipose swelling. But there may be exceptions to the rule. In this case report, we present an uncommon manifestation of a chronic lymphocytic leukemia which showed a massive soft swelling of the whole neck, mimicking Madelung's disease.

Ki67 and PIM1 expression predict outcome in mantle cell lymphoma treated with high dose therapy, stem cell transplantation and rituximab: a Cancer and Leukemia Group B 59909 correlative science study

The proliferation index in mantle cell lymphoma (MCL) has not been validated in the context of aggressive therapy regimens in the rituximab era. We assessed Ki67 and PIM1 (a cell cycle-related gene upregulated in blastoid MCL) expression by immunohistochemistry in a phase II study Cancer and Leukemia Group B 59909 of aggressive chemotherapy and rituximab followed by autologous stem cell transplantation plus rituximab in untreated MCL patients <70 years of age. As a continuous variable or using a cutoff of 35%, higher image analysis (IA Ki67, n = 52) was associated with shorter progression free survival (PFS) (P < or = 0.030) and event free survival (EFS) (P < or = 0.017). PIM1 expression (n = 50) was associated with PFS (P = 0.033) and EFS (P = 0.043). Bivariate Cox models showed IA Ki67 and PIM1 were independent of clinical factors. High Ki67 (>35%) is an important independent prognostic marker in aggressively treated MCL in the rituximab era. PIM1 expression predicts poor outcome and, given its potential role as a therapeutic target, deserves further study.

Prognostic role of topoisomerase-IIalpha in advanced ovarian cancer patients

To our knowledge, very few data about the role of Topoisomerase IIalpha (TOPO-IIalpha), an enzyme involved in critical steps of tumour cell proliferation and chemoresistance are currently available in ovarian cancer patients. The aim of this study was to investigate the prognostic value of TOPO-IIalpha expression in a large, single institution series of 96 primary untreated advanced ovarian cancer patients admitted to the Gynecologic Oncology Unit, Catholic University of Campobasso and Rome. Immunohistochemistry was carried out by using the MoAb anti-human TOPO-IIalpha antibody (clone Ki-S1). TOPO-IIalpha immunoreaction was observed in 70 out of 96 cases (72.9%), and the percentages of positively stained cells ranged between 1 and 83% (median=10%). There was no association with clinico-pathological parameters. During the follow up period, progression and death of disease were observed in 76 (79.2%) and 45 (46.9%) cases. A statistically significant direct association between the percentages of positively immunostained tumour cells and the relative risk of death was observed (chi(2)=6.6, P-value=0.0101). In multivariate analysis, only platinum resistance, advanced stage of disease and high levels of TOPO-IIalpha expression retained an independent negative prognostic role for OS. The unfavourable role of high TOPO-IIalpha expression was maintained only in the subgroup of platinum resistant recurrent ovarian cancer patients, be TOPO-IIalpha expression evaluated as continuous variable (chi(2)=5.1, P-value=0.024), or by means of the defined cutoff point. Our study suggests that the assessment of TOPO-IIalpha could be helpful to identify poor prognosis platinum-resistant ovarian cancer patients, potentially candidates to investigational agents.

Topoisomerase IIalpha expression as an independent prognostic factor in Hodgkin's lymphoma

PURPOSE

To correlate the immunohistochemical expression of topoisomerase IIalpha (topoIIalpha) in Hodgkin's lymphoma (HL) with clinicopathological parameters, the expression of Ki-67 and the outcome of patients, who had been homogenously treated with ABVD or equivalent regimens.

EXPERIMENTAL DESIGN

Immunohistochemistry using the monoclonal antibody Ki-S1 (topoIIalpha) was performed in 238 HL patients. MiB1 (Ki-67) expression was evaluated in 211/238.

RESULTS

The mean +/- SD percentage of topoIIalpha- and Ki-67-positive Hodgkin-Reed-Sternberg (HRS) cells was 63 +/- 19% (5%-98%) and 73 +/- 19% (8%-99%), respectively. The median percentage of topoIIalpha-positive HRS cells was 64% (interquartile range, 51-78%). There was no correlation between topoIIalpha expression and patient characteristics. TopoIIalpha and Ki-67 expression were correlated (Spearman's Rho 0.255, P < 0.001). TopoIlalpha expression within the highest quartile of this patient population was predictive of failure free survival (FFS) (10-year rates 82 +/- 3% vs 68 +/- 7%, P = 0.02 for patients falling into the quartiles 1-3 and 4 respectively). In multivariate analysis topoIIalpha expression was independently predictive of FFS.

CONCLUSION

TopoIIalpha was expressed in all cases of HL showing a correlation with Ki-67 expression. Under current standard therapy including drugs inhibiting its activity, topoIIalpha was an independent adverse predictor of FFS with no statistically significant correlation with other established prognostic factors.

Advances in the understanding of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a well-defined lymphoid neoplasm characterized by a proliferation of mature B lymphocytes expressing CD5 that may show a spectrum of morphological and phenotypic features broader than initially described. Although some patients may follow an indolent clinical evolution, in most of them the tumour has an aggressive behaviour with poor response to conventional chemotherapy. The genetic hallmark is the t(11;14)(q13;q32) translocation leading to the overexpression of cyclin D1, which is considered the initial oncogenic event. In addition to this translocation, MCL may carry a high number of secondary chromosomal and molecular alterations that target regulatory elements of the cell cycle machinery and senescence (BMI1/INK4/ARF/CDK4/RB1), DNA damage response pathways (ATM/CHK2/p53), and cell survival signals. The knowledge of these mechanisms and their influence on the behaviour of the tumour are facilitating the development of prognostic models with a more precise prediction of the clinical evolution of the patients. This information coupled with the availability of a new generation of innovative drugs targeting basic molecular process of the tumour cells, should facilitate the design of new therapeutic protocols able to overcome the resistance of this aggressive lymphoma to conventional treatments and improve the life expectancy of the patients.

Ki-67 predicts outcome in advanced-stage mantle cell lymphoma patients treated with anti-CD20 immunochemotherapy: results from randomized trials of the European MCL Network and the German Low Grade Lymphoma Study Group

Clinical outcome of mantle cell lymphoma (MCL) is highly heterogeneous. Tumor cell proliferation as assessed by the Ki-67 index has been shown to yield prognostic information on MCL in many studies using heterogeneously treated patient cohorts. The prognostic value of the Ki-67 index in patients treated with anti-CD20 therapy has not been studied so far. We analyzed the Ki-67 index at primary diagnosis in 249 advanced-stage MCL patients treated within randomized trials. Ki-67 showed high prognostic relevance for overall survival (relative risk 1.27 for 10% higher Ki-67, P < .001), also independently from clinical prognostic factors. The 3 groups with different Ki-67 index of less than 10%, 10% to less than 30%, and 30% or more showed significantly different overall survival in patients treated with CHOP (P = .001) as well as in patients treated with CHOP in combination with anti-CD20 therapy (R-CHOP, P = .013). Thus, the Ki-67 index remains an important prognostic marker in the era of anti-CD20 therapy. The Euro-pean MCL study is registered at www.ClinicalTrials.gov as #NCT00016887.

A new prognostic index (MIPI) for patients with advanced-stage mantle cell lymphoma

There is no generally established prognostic index for patients with mantle cell lymphoma (MCL), because the International Prognostic Index (IPI) and Follicular Lymphoma International Prognostic Index (FLIPI) have been developed for diffuse large cell and follicular lymphoma patients, respectively. Using data of 455 advanced stage MCL patients treated within 3 clinical trials, we examined the prognostic relevance of IPI and FLIPI and derived a new prognostic index (MCL international prognostic index, MIPI) of overall survival (OS). Statistical methods included Kaplan-Meier estimates and the log-rank test for evaluating IPI and FLIPI and multiple Cox regression for developing the MIPI. IPI and FLIPI showed poor separation of survival curves. According to the MIPI, patients were classified into low risk (44% of patients, median OS not reached), intermediate risk (35%, 51 months), and high risk groups (21%, 29 months), based on the 4 independent prognostic factors: age, performance status, lactate dehydrogenase (LDH), and leukocyte count. Cell proliferation (Ki-67) was exploratively analyzed as an important biologic marker and showed strong additional prognostic relevance. The MIPI is the first prognostic index particularly suited for MCL patients and may serve as an important tool to facilitate risk-adapted treatment decisions in patients with advanced stage MCL.

Follikuläre Lymphome und Mantelzelllymphome

Indolent (low-grade) B-cell non-Hodgkin's lymphomas, such as follicular and mantle cell lymphomas, are primarily nodal lymphomas in which lymph node involvement is the dominant clinical feature. The frequency of extranodal manifestations of these primarily nodal lymphomas is often underestimated. The typical growth pattern of nodal lymphomas can be absent or not evaluable because the biopsy specimens are often small in cases with extranodal involvement. Therefore, the immunophenotype of the lymphoma cells is of great importance for the diagnosis of indolent lymphomas with extranodal localizations.

Treatment of mantle cell lymphoma: current approach and future directions

Although mantle cell lymphoma has been described as "moderately aggressive" it has become clear that it carries a worse long-term prognosis than other subtypes of non-Hodgkin's lymphoma. In recent years, this has prompted numerous clinical trials of novel and more aggressive therapies in hopes of impacting these poor outcomes. These include more intensive combination chemotherapy regimens, monoclonal antibody therapy in conjunction with other treatments or conjugated to radioactive isotopes, high-dose chemotherapy followed by autologous or allogeneic stem cell transplantation, and newer targeted therapies based on increasing understanding of the molecular pathways of this malignancy.

Germline variations of the topoisomerase IIα gene as risk factors for primary gastric B-cell lymphoma

We investigated if germline variations of the Topoisomerase II alpha gene could predispose patients with chronic Helicobacter pylori infection to develop gastric lymphoma and conducted a mutation detection of the entire promoter region. Single marker and haplotype analysis did not reveal any associations with development of gastric lymphoma in general, histological grade or stage of disease (P>0.05). No genetic variations in the promotor region were found in 92 chromosomes of lymphoma patients and controls and linkage disequilibrium indicated a highly conserved genomic region. The results of our work exclude genetic variations as predisposing factors of primary gastric B-cell lymphoma development.

Mantle cell lymphoma: prognostic capacity of the Follicular Lymphoma International Prognostic Index

The International Prognostic Index (IPI) is the most commonly used prognostic model for mantle cell lymphoma (MCL). However, the prognostic value of the IPI is limited. The recently published Follicular Lymphoma International Prognostic Index (FLIPI) is built on variables, which are pertinent to MCL. This study was conducted to evaluate the prognostic value of FLIPI in a population-based series of 93 patients with MCL diagnosed in a 7-year period. End points of the study were response to therapy, overall survival, and disease-free survival (DFS) according to the IPI and FLIPI. Applied to the whole series, the FLIPI identified three risk groups with markedly different outcome with 5-year overall survival rates of 65%, 42%, and 8% respectively. Notably, the high-risk group comprised 53% of patients. In contrast, the IPI only allocated 16% of cases to the high-risk group and had a lower overall predictive capacity. When both the FLIPI and IPI were included in a multivariate analysis, only the FLIPI was related to survival. Multivariate analysis of DFS also identified the FLIPI, and not the IPI, as independently significant. Thus, in the present study, the FLIPI was superior as a prognostic model compared with the IPI and can therefore be recommended as a clinical prognostic index for MCL.

Topoisomerase II-alpha expression increases with increasing Gleason score and with hormone insensitivity in prostate carcinoma

AIM

To investigate and compare topoisomerase II-alpha expression in benign prostatic hyperplasia (BPH), prostate cancer of varying Gleason scores and hormone-insensitive prostate cancer.

METHODS

The immunohistochemical expression of topoisomerase II-alpha antibody in the above-mentioned diagnostic categories was investigated and compared.

RESULTS

Increased expression of topoisomerase II-alpha was seen in the prostate cancers of Gleason scores 7 and 8-10 (p = 0.000) compared with prostate cancers of Gleason score 6 and BPH (p = 0.245). Statistically significant differences were found in the topoisomerase II-alpha gene expression between prostate cancers categorised by Gleason Score. Also, increased expression of topoisomerase II-alpha was seen in the known hormone-resistant prostate carcinomas compared with prostate cancers with no hormone treatment in the subgroup with Gleason scores 8-10, which approached statistical significance (p = 0.081). No statistically significant difference was observed in topoisomerase II-alpha expression between the groups with BPH and prostate carcinoma of Gleason score 6 (p = 0.245).

CONCLUSION

Topoisomerase II-alpha expression was found to increase with the known prognostic marker Gleason score and with hormone insensitivity. Objective evidence is provided for clinical trials with drugs targeting topoisomerase II-alpha to be targeted to patients with prostate cancers of Gleason Score >6 and, in particular, prostate cancers of Gleason Scores 8-10.

Immunoglobulin class-switch recombination occurs in mantle cell lymphomas

Mantle cell lymphoma (MCL) is an IgM-expressing B cell lymphoma that originates from naive B cells and responds poorly to chemotherapy. We show here that several MCLs harbour isotype-switched subclones. Similar to the situation in normal B cells, in vitro stimulation of MCL cell lines with CD40 ligand (CD40L) and interleukin-4 induced expression of activation-induced cytidine deaminase (AID) and germline transcription at the immunoglobulin heavy chain gene locus. Additionally, the occurrence of switch-circle transcripts and mature IgG transcripts after stimulation indicated ongoing class-switch recombination in mantle cell lymphoma cell lines. Furthermore, stimulation of primary MCL cells in vitro induced expression of class-switched IgG mRNA in the tumour cells. Our data indicate that mantle cell lymphomas have retained the ability to undergo class-switch recombination if appropriate stimuli, such as the CD40 ligand, are provided.

Repp86: a new prognostic marker in mantle cell lymphoma

OBJECTIVES

Proliferation indices are important prognostic factors for the clinical outcome of patients with mantle cell lymphoma (MCL). We investigated whether the expression of repp86 (restrictedly expressed proliferation-associated protein 86 kDa), a new proliferation specific marker expressed in the cell cycle phases G(2), S and M, but not in G(1), correlates with the clinical course in patients with MCL.

PATIENTS AND METHODS

Biopsy specimens from 94 untreated patients enrolled in two multicenter trials were investigated immunohistochemically with monoclonal antibodies against CD20, CD5, CD3, CD23, cyclin D1, and repp86 (Ki-S2).

RESULTS

Patients with 0-1% repp86 expression had a median overall survival time of 71.0 months, compared with 38.2 months for patients with 1-5% positive cells and 25.4 months for patients with 5-10% positive tumor cells. Patients with repp86 expression of more than 10% showed the shortest survival (median: 15.0 months). Kaplan-Meier analysis revealed a significant difference in the overall survival time between patients with very high (>10%) and very low (0-1%) repp86 expression (P < 0.0001) in the tumor cells. The multivariate analysis revealed repp86 expression to be superior to other clinical characteristics as a prognostic factor (P = 0.0016).

CONCLUSION

Based on these findings, repp86 expression is a new important prognostic factor in MCL.

Minichromosome maintenance protein 6, a proliferation marker superior to Ki-67 and independent predictor of survival in patients with mantle cell lymphoma

Minichromosome maintenance protein 6 (MCM6) is one of six proteins of the MCM family which are involved in the initiation of DNA replication and thus represent a marker of proliferating cells. Since the level of cell proliferation is the most valuable predictor of survival in mantle cell lymphoma (MCL), we investigated lymph node biopsy specimens from 70 patients immunohistochemically with a monoclonal antibody against MCM6. The percentage of MCM6 expressing lymphoma cells ranged from 12.0 to 95.6%, with a mean of 61.0%, and was significantly higher than the percentage of Ki-67-positive cells (P<0.0001). Surprisingly, the ratio of MCM6-positive cells to Ki-67-positive cells was higher than in normal stimulated peripheral blood mononuclear cells, indicating a cell early G1-phase arrest in MCL. A high MCM6 expression level of more than 75% positive cells was associated with a significantly shorter overall survival time (16 months) compared to MCL with a low MCM6 expression level of less than 25% (no median reached, P<0.0001). Multivariate analysis revealed MCM6 to be an independent predictor of survival that is superior to the international prognostic factor and the Ki-67 index. Therefore, aside from gene expression profiling, immunohistochemical detection of MCM6 seems to be the most promising marker for predicting the outcome in MCL.

Mantle cell lymphomas with low levels of cyclin D1 long mRNA transcripts are highly proliferative and can be discriminated by elevated cyclin A2 and cyclin B1

The role of transcript variants of cyclin D1 in cancer biology is unclear. Most tumors with high levels of cyclin D1 express 2 transcripts due to alternative splicing: one full-length transcript of 4.4 kb and one short transcript of approximately 1.7 kb. The short transcript lacks part of the 3'UTR region regulating mRNA stability and has a longer half-life. In our study, the contribution of each of these mRNAs to gene expression and cell proliferation has been investigated in mantle cell lymphoma (MCL), a B cell lymphoma characterized by a specific gene translocation resulting in enhanced expression of cyclin D1. A subset of MCL tumors with low levels of the long cyclin D1 transcript (cyclin D1 3'UTR) was identified by quantitative PCR and by oligonucleotide array hybridization. This tumor-subset had 3.4-fold higher levels of the short form of cyclin D1 mRNA (p < 0.0001) and had higher expression of cyclin D1 protein. Gene expression analysis identified a number of cell-cycle regulatory genes as upregulated. There was a significant difference in frequencies of cyclin B1 (p = 0.0006) and cyclin A2 (p = 0.0006) positive cells that discriminated MCL with low cyclin D1 3'UTR from other highly proliferative MCL. Among differentially expressed genes, there was a highly upregulated gene with homology to the group of cell-cycle promoting E2F transcription partners, E2F_TDP5. Several of the upregulated genes, such as TOP2A, AURORA A and RRM2 may influence a response to therapy. Identification of MCL with low cyclin D1 3'UTR is important because it seems to be associated with shorter overall survival.

Histopathology, cell proliferation indices and clinical outcome in 304 patients with mantle cell lymphoma (MCL): a clinicopathological study from the European MCL Network

Mantle cell lymphoma (MCL) is a distinct lymphoma subtype with a particularly poor clinical outcome. The clinical relevance of the morphological characteristics of these tumours remains uncertain. The European MCL Network reviewed 304 cases of MCL to determine the prognostic significance of histopathological characteristics. Cytomorphological subtypes, growth pattern and markers of proliferation (mitotic and Ki-67 indices) were analysed. In addition to the known cytological subtypes, classical (87.5%), small cell (3.6%), pleomorphic (5.9%) and blastic (2.6%), we identified new pleomorphic subgroups with mixtures of cells (classical + pleomorphic type; 1.6%) or transitions (classical/pleomorphic type; 1.6%), which, however, did not differ significantly in overall survival time. Exactly 80.5% of cases displayed a diffuse growth pattern, whereas 19.5% of cases had a nodular growth pattern, which was associated with a slightly more favourable prognosis. A high proliferation rate (mitotic or Ki-67 indices) was associated with shorter overall survival. Cut-off levels were defined that allowed three subgroups with different proliferation rates to be discriminated, which showed significantly different clinical outcomes (P < 0.0001). Based on this large clinicopathological study of prospective clinical trials, multivariate analysis confirmed the central prognostic role of cell proliferation and its superiority to all other histomorphological and clinical criteria.

Immunohistochemical detection of cdc2 is useful in predicting survival in patients with mantle cell lymphoma

Recent cDNA microarray studies have reported the prognostic value of several genes in mantle cell lymphoma patients. We aimed to validate the prognostic significance of three of these genes: alpha-tubulin, cdc2, and CENP-F. The protein expression of alpha-tubulin, cdc2, and CENP-F was assessed using immunohistochemistry. Their immunoreactivity in 48 formalin-fixed/paraffin-embedded mantle cell lymphoma tumors was determined by estimating the percentage of positive cells. These results were correlated with the expression of proliferation marker Ki67 and survival. Of these 48 mantle cell lymphoma patients, 41 were men and seven were women. The median age at time of diagnosis was 64.5 years, and the overall median survival was 40 months. In benign lymph nodes, the expression of cdc2 and alpha-tubulin was restricted to the germinal centers; mantle zones were negative. Expression of CENP-F was more uniformly distributed. In mantle cell lymphoma, Ki67 significantly correlated with all three markers (P<0.05, Spearman), but only Ki67 (>50%) and cdc2 (>25%) significantly correlated with shorter survival (P<0.0006, Spearman). Of several clinical parameters examined, international prognostic index of >or=2 correlated with worse clinical outcome, and high clinical stage (ie 4 vs <or=3) showed a trend for shorter survival. The prognostic significance of cdc2 and Ki67 was independent of international prognostic index and clinical stage. We have validated the prognostic value of cdc2, and confirmed that of Ki67, in a cohort of mantle cell lymphoma patients. Immunohistochemical detection of cdc2 and Ki67 may be a useful and simple method in evaluating the prognosis of mantle cell lymphoma patients.

Activation of mitochondrial apoptotic pathway in mantle cell lymphoma: high sensitivity to mitoxantrone in cases with functional DNA-damage response genes

Mantle cell lymphoma (MCL) is a mature B-cell proliferation characterized by the presence of translocation t(11;14)(q13;q32), an aggressive clinical course, and poor response to chemotherapy. The majority of drugs currently used in the treatment of lymphoproliferative disorders induce cell death by triggering apoptosis, but few data concerning drug-induced apoptosis in MCL have been reported. We have analysed the mechanisms of drug-induced cell death in four cell lines with the t(11;14) and in primary cells from 10 patients with MCL. Mitoxantrone, a topoisomerase II inhibitor, induced a strong cytotoxic effect in three cell lines (JVM-2, REC-1, and Granta 519), and in primary MCL cells. This cytotoxic effect due to apoptosis induction was observed despite the presence of either p53 or ATM abnormalities. However, no cytotoxic effect was detected after incubation with DNA-damaging agents in the NCEB-1 cell line, carrying p53 and ATM alterations, despite the presence of functional mitochondrial machinery. These results support that mitoxantrone can be effective in the treatment of MCL but that this activity requires the integrity of functional DNA-damage response genes.

High expression of cyclin B1 predicts a favorable outcome in patients with follicular lymphoma

Substantial research has been dedicated to the study of the relationship between genetic mechanisms regulating cell functions in tumors and how those tumors respond to various treatment regimens. Because these mechanisms are still not well understood, we have chosen to study the genetic makeup of 57 tumor samples from patients with follicular lymphoma (FL). Our goal was to develop a prognostic tool, which can be used as an aid in determining FL patients with tumors genetically predisposed to a successful treatment with the CHOP (cyclophosphamide, vincristine, doxorubicin, prednisone) regimen. To select relevant genes, high-density oligonucleotide arrays were used. There were 14 genes highly expressed in FL patients that responded well to CHOP chemotherapy, and 11 of these were involved in G2/M transition of the cell cycle, in mitosis, or in DNA modulation. A high expression of CCNB1 (cyclin B1), CDC2, CDKN3A, CKS1B, ANP32E, and KIAA0101, but not of the proliferation-related antigen Ki-67, was associated with better survival rate in a univariate analysis. CCNB1 expression had an independent prognostic value when included in a multivariate analysis together with the 5 parameters of the follicular lymphoma international prognostic index.

Diffuse aggressive lymphoma

The aggressive non-Hodgkin's lymphomas can be cured in more than half of the cases. However, there has been great variation in the results reported from individual clinical Phase II trials. This variation in result can be attributed to unrecognized heterogeneity in this group of diseases. Recent clinical and molecular studies have enabled us to define more homogenous population in which new therapies can be studied. For patients with advanced stages of diffuse large B cell lymphoma, a new standard of therapy exists. For patients with localized aggressive non-Hodgkin's lymphomas, heterogeneity in patient selection prevents us from defining a new standard of care. Finally, in mantle cell lymphoma, new opportunities in drug discovery may permit advances in the treatment of this uniformly fatal malignancy. In Section I, Dr. Richard Fisher reviews the development of combination chemotherapy for patients with advanced stage diffuse large B cell lymphoma. Because of great heterogeneity in patients enrolled in Phase II studies, large randomized Phase III studies were required in the 1980s to define CHOP has the standard of care. This heterogeneity has now been defined carefully in the international prognostic factor index and more recently by gene array studies. It will now need to be incorporated prospectively into studies or retrospectively analyzed to understand clinical trial results. The addition of rituximab to CHOP has now been demonstrated to improve survival in two large Phase III studies in elderly patients. A recently presented study in younger patients suggests a similar benefit. Thus CHOP/rituximab has become the established standard of care for all patients with advanced stage diffuse large B cell lymphoma. Other concepts being evaluated to further improve on these results include: dose intensification; initial treatment with chemotherapy plus allogeneic stem cell transplantation; and infusional chemotherapy. Finally, the status of the treatment for relapsed patients will be defined. In Section II, Dr. Thomas Miller defines the treatment for limited stage aggressive non-Hodgkin's lymphoma. Randomized trials have demonstrated the critical importance of initial chemotherapy for treatment of these patients. The amount of chemotherapy given needs to be increased for patients with bulky tumors. In most circumstances radiotherapy after the completion of chemotherapy has been shown to be advantageous. A modification of the international prognostic factor index for patients with early stage disease is presented to permit comparisons among different populations. Recently reported early-stage studies need to be analyzed in terms of the heterogeneity of the patients involved to understand the reported results. The addition of monoclonal antibodies, as well as radioimmunotherapy, are being tested in an effort to improve on the results for the poor prognosis patients. In Section III, Dr. Owen O'Connor describes the pathology immunophenotype and natural history of mantle cell lymphoma. Conventional treatment strategies with combination chemotherapy achieved objective responses in approximately half of the patients but no significant impact on survival. The addition to rituximab to CHOP chemotherapy or other treatment strategies appears to improve the remission rate; however, no major changes in survival have also been reported. Excellent single institution results have been reported with HyperCVAD plus rituximab regimen, which is currently being tested in a national cooperative group trial. The most excitement in this field currently relates to the variety of new agents which appear to have significant activity in relapsed patients with mantle cell lymphoma. This includes the proteosome inhibitor, bortezomib, which is shown to have approximately a 50% response rate with some CRs and reasonable durability in early single institution Phase II studies. Larger national multi-center trials are ongoing. In addition, agents such as thalidomide, flavopiridol, and piroxantrone will be reviewed.