K-ras(G12V) transformation leads to mitochondrial dysfunction and a metabolic switch from oxidative phosphorylation to glycolysis

Increased aerobic glycolysis and oxidative stress are important features of cancer cell metabolism, but the underlying biochemical and molecular mechanisms remain elusive. Using a tetracycline inducible model, we show that activation of K-ras(G12V) causes mitochondrial dysfunction, leading to decreased respiration, elevated glycolysis, and increased generation of reactive oxygen species. The K-RAS protein is associated with mitochondria, and induces a rapid suppression of respiratory chain complex-I and a decrease in mitochondrial transmembrane potential by affecting the cyclosporin-sensitive permeability transition pore. Furthermore, pre-induction of K-ras(G12V) expression in vitro to allow metabolic adaptation to high glycolytic metabolism enhances the ability of the transformed cells to form tumor in vivo. Our study suggests that induction of mitochondrial dysfunction is an important mechanism by which K-ras(G12V) causes metabolic changes and ROS stress in cancer cells, and promotes tumor development.

Metabolic alterations in highly tumorigenic glioblastoma cells: preference for hypoxia and high dependency on glycolysis

Recent studies suggest that a small subpopulation of malignant cells with stem-like properties is resistant to chemotherapy and may be responsible for the existence of residual cancer after treatment. We have isolated highly tumorigenic cancer cells with 100-fold increase in tumor initiating capacity from the tumor xenografts of human glioblastoma U87 cells in mice. These cells exhibit stem-like properties and show unique energy metabolic characteristics including low mitochondrial respiration, increased glycolysis for ATP generation, and preference for hypoxia to maintain their stemness and tumor forming capacity. Mechanistically, mitochondrial depression in the highly tumorigenic cells occurs mainly at complex II of the electron transport chain with a down-regulation of the succinate dehydrogenase subunit B, leading to deregulation of hypoxia-inducible factors. Under hypoxia, the stem-like cancer cells are resistant to conventional anticancer agents but are sensitive to glycolytic inhibition. Furthermore, combination of glycolytic inhibition with standard therapeutic agents is effective in killing the tumor-initiating cells in vitro and inhibits tumor formation in vivo. Our study suggests that stem-like cancer cells prefer a low oxygen microenvironment and actively utilize the glycolytic pathway for ATP generation. Inhibition of glycolysis may be an effective strategy to eradicate residual cancer stem cells that are otherwise resistant to chemotherapeutic agents in their hypoxic niches.

The B cell antigen receptor in atypical chronic lymphocytic leukemia with t(14;19)(q32;q13) demonstrates remarkable stereotypy

The t(14;19)(q32;q13) is a recurrent chromosomal translocation reported in a variety of B-cell leukemias and lymphomas, including chronic lymphocytic leukemia (CLL). CLL cases associated with t(14;19) often have atypical morphologic and immunophenotypic features and unmutated immunoglobulin heavy chain (IGH) variable region (V) genes, associated with an aggressive clinical course. We analyzed IGHV somatic mutation status and gene use in 11 patients with t(14;19)-positive CLL. All cases were unmutated, and the IGHV genes in 10 cases showed minimal deviation from germline sequences. In 7 of 11 patients, we found homologous heavy chain rearrangements using IGHV4-39; light chain analysis revealed identical IGKV1-39 use. Corresponding V-(D)-J sequences demonstrated remarkable stereotypy of the immunoglobulin heavy and kappa light chain complementarity determining region 3 (H/K CDR3) genes. These findings raise the possibility that specific antigen drive is involved in the clonal development and/or selection of t(14;19)(q32;q13)-positive CLL cells. Our findings support the hypothesis that stimulatory signals through specific antigen receptors may promote the expansion of either CLL precursor cells or CLL clones that harbor distinct chromosomal abnormalities.

Chronic lymphocytic leukemia with t(14;19)(q32;q13) is characterized by atypical morphologic and immunophenotypic features and distinctive genetic features

The t(14;19)(q32;q13) involving the IGH@ and BCL3 loci is an infrequent cytogenetic abnormality detected in B-cell malignancies. We describe the clinicopathologic, cytogenetic, and molecular genetic characteristics of 14 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) with t(14;19)(q32;q13). All patients (10 men and 4 women) had lymphocytosis; 10 had lymphadenopathy. Blood and bone marrow lymphocytes were predominantly small, but cytologically and immunophenotypically atypical. In all cases, t(14;19) was found in the neoplastic stem line; it was the sole abnormality in 4. Ten cases showed additional cytogenetic abnormalities, including trisomy 12 in 9 and complex karyotypes in 7. Fluorescence in situ hybridization demonstrated IGH@/BCL3 fusion gene in all cases. In all cases, the IGHV genes were unmutated, but only 7 expressed ZAP70. Seven cases preferentially used IGHV4-39. Our results indicate that t(14;19)(q32;q13) identifies a subset of CLL/SLL with distinctive clinicopathologic and genetic features. Furthermore, t(14;19) may represent an early, possibly primary, genetic event.

Abstract 1191: Role of histone deacetylases in silencing functionally relevant microRNAs in CLL

Chronic lymphocytic leukemia (CLL) is characterized by the selective down-regulation of a class of gene regulators, the microRNA (miRs) in comparison to healthy B- lymphocytes. Low levels of miRs are associated with multiple aspects of CLL pathology such as the genesis of disease, apoptotic resistance, progression, and overall survival, suggesting that miRs may function as tumor suppressors in this disease. However, despite the central role of miRs in regulating CLL pathobiology, the mechanisms by which they become under-expressed in CLL are not well known. We hypothesized that the gene repressive action of the histone deacetylases (HDACs) may lead to the silencing of functionally relevant miRs in CLL. HDACs lead to the deacetylation of histones at gene promoters, an action that triggers a loss in the levels of the transcriptionally required histone modification, H3K4me3, which leads to gene silencing. Therefore, we used chromatin immunoprecipitation directed at the H3K4me3 mark to conduct a genome wide analysis of the levels of this transcriptionally activating modification at all miR promoters in normal CD19+ B-cells and in CLL cells before and following HDAC inhibition. Our data demonstrates that normal B-cells displayed the H3K4me3 mark at miR promoters. In contrast, primary CLL samples lacked the H3K4me3 mark at miR promoters but accumulated this activating modification at multiple promoters upon HDAC inhibition. Correspondingly, accumulation of H3K4me3 was associated with an increase in the expression levels of the cognate miRNAs in CLL samples. To determine whether the epigenetically re-expressed miR genes had functional relevance in CLL we first performed a pathway analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. This analysis indicated that the targets of the epigenetically repressed miRs had roles in regulating apoptosis, proliferation, or as transcription factors indicating that the miRs that underwent HDAC-mediated silencing in CLL had important functional roles in regulating multiple, critical cellular processes in CLL. In addition, a detailed functional evaluation of a panel of representative miRs that underwent HDAC-mediated silencing identified both Mcl-1 and E3 ligases that negatively regulate p73-dependent apoptotic signaling among their cellular targets. Finally, our data also identified the presence of HDAC1 at epigenetically silenced miR promoters in CLL suggesting that HDAC1 is an integral component of the repressor complex that silences miR promoters in CLL. Thus our data delineates the complement of miR that is silenced by HDACs in CLL, identifies that such silencing may have functional consequences in facilitating apoptotic resistance or progression in CLL and may identify a new target for therapeutic manipulation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1191. doi:10.1158/1538-7445.AM2011-1191

CD28 costimulation improves expansion and persistence of chimeric antigen receptor-modified T cells in lymphoma patients

Targeted T cell immunotherapies using engineered T lymphocytes expressing tumor-directed chimeric antigen receptors (CARs) are designed to benefit patients with cancer. Although incorporation of costimulatory endodomains within these CARs increases the proliferation of CAR-redirected T lymphocytes, it has proven difficult to draw definitive conclusions about the specific effects of costimulatory endodomains on the expansion, persistence, and antitumor effectiveness of CAR-redirected T cells in human subjects, owing to the lack of side-by-side comparisons with T cells bearing only a single signaling domain. We therefore designed a study that allowed us to directly measure the consequences of adding a costimulatory endodomain to CAR-redirected T cells. Patients with B cell lymphomas were simultaneously infused with 2 autologous T cell products expressing CARs with the same specificity for the CD19 antigen, present on most B cell malignancies. One CAR encoded both the costimulatory CD28 and the ζ-endodomains, while the other encoded only the ζ-endodomain. CAR+ T cells containing the CD28 endodomain showed strikingly enhanced expansion and persistence compared with CAR+ T cells lacking this endodomain. These results demonstrate the superiority of CARs with dual signal domains and confirm a method of comparing CAR-modified T cells within individual patients, thereby avoiding patient-to-patient variability and accelerating the development of optimal T cell immunotherapies.

Nonmyeloablative allogeneic stem cell transplantation in relapsed/refractory chronic lymphocytic leukemia: long-term follow-up, prognostic factors, and effect of human leukocyte histocompatibility antigen subtype on outcome

BACKGROUND

The role of nonmyeloablative allogeneic stem cell transplantation (NST) in the treatment of chronic lymphocytic leukemia (CLL) is not well established. The authors report on long-term experience with NST in relapsed/refractory CLL and define prognostic factors associated with outcome.

METHODS

The authors reviewed the outcome of 86 patients with relapsed/relapsed CLL enrolled in sequential NST protocols.

RESULTS

The median patient age was 58 years. Patients were heavily pretreated before transplantation, and 43 required immunomanipulation after NST for persistent or recurrent disease. Immunomanipulation included withdrawal of immunosuppression, rituximab, and step-wise donor lymphocyte infusions. Of 43 patients receiving immunomanipulation, 20 (47%) experienced a complete remission. Patients with human leukocyte antigen (HLA) genotype A1(+) /A2(-) /B44(-) were more likely to experience a complete remission (P = .0009), with rates of 9%, 36%, 50%, and 91%, respectively, for 0, 1, 2, and 3 of these HLA factors. This resulted in significant improvement in progression-free-survival rates of 68.2% at 5 years for patients with all 3 HLA factors. Overall, the estimated 5-year survival rate was 51%. In a multivariate model, a CD4 count of <100/mm(3) and a below normal serum immunoglobulin G level at study entry were associated with a short survival duration (P < .0001).

CONCLUSIONS

These results confirm the potential cure of relapsed/refractory CLL with NST and provide the first evidence that immunoglobulin G and CD4 levels are predictive of overall survival after NST in CLL and that human leukocyte antigen alleles predict response to immunomanipulation.

STAT-3 activates NF-kappaB in chronic lymphocytic leukemia cells

NF-κB plays a major role in the pathogenesis of B-cell neoplasms. A broad array of mostly extracellular stimuli has been reported to activate NF-κB, to various degrees, in chronic lymphocytic leukemia (CLL) cells. Because CLL cells harbor high levels of unphosphorylated STAT-3 (USTAT-3) and USTAT-3 was reported to activate NF-κB, we sought to determine whether USTAT-3 activates NF-κB in CLL. Using the electrophoretic mobility shift assay (EMSA), we studied peripheral blood low-density cells from 15 patients with CLL and found that CLL cell nuclear extracts from all the samples bound to an NF-κB DNA probe, suggesting that NF-κB is constitutively activated in CLL. Immunoprecipitation studies showed that STAT-3 bound NF-κB p65, and confocal microscopy studies detected USTAT-3/NF-κB complexes in the nuclei of CLL cells, thereby confirming these findings. Furthermore, infection of CLL cells with retroviral STAT-3-short hairpin RNA attenuated the binding of NF-κB to DNA, as assessed by EMSA, and downregulated mRNA levels of NF-κB-regulated genes, as assessed by quantitative PCR. Taken together, our data suggest that USTAT-3 binds to the NF-κB p50/p65 dimers and that the USTAT-3/NF-κB complexes bind to DNA and activate NF-κB-regulated genes in CLL cells.

Treatment with lenalidomide modulates T-cell immunophenotype and cytokine production in patients with chronic lymphocytic leukemia

BACKGROUND

Lenalidomide, an immunomodulatory agent, has activity in lymphoproliferative disorders. The authors, therefore, evaluated its effects on T-cell immunophenotype and cytokine production in patients with chronic lymphocytic leukemia (CLL).

METHODS

To study the immunomodulatory effects of lenalidomide in CLL, the authors recruited 24 patients with untreated CLL enrolled in a phase 2 clinical trial of lenalidomide and obtained peripheral blood specimens for immunologic studies consisting of enumeration of T cells and assessing their ability to synthesize cytokines after activation through T-cell receptor (TCR).

RESULTS

After 3 cycles of therapy, patients had a significant reduction in percentage (%) and absolute lymphocyte count (ALC) and an increase in percentage of T cells, percentage of activated CD8(+) T cells producing IFN-γ, and percentage of regulatory T (T(R) ) cells when compared with their respective levels before treatment. After 15 cycles of treatment, responder patients had significant reduction in percentage of lymphocytes and ALC, percentage of activated CD4(+) T cells producing IL-2, IFN-γ, or TNF-α, and percentage of T(R) cells when compared with their perspective levels after 3 cycles of treatment. Furthermore, the numbers of activated CD4(+) T cells producing IL-2, IFN-γ, or TNF-α, activated CD8(+) T cells producing IFN-γ, and T(R) cells normalized to the range of healthy subjects.

CONCLUSIONS

Treatment with lenalidomide resulted in the normalization of functional T-cell subsets in responders, suggesting that lenalidomide may modulate cell-mediated immunity in patients with CLL.

CCL3 (MIP-1α) plasma levels and the risk for disease progression in chronic lymphocytic leukemia

B-cell receptor (BCR) signaling has been inferred as an important mechanism for disease progression in chronic lymphocytic leukemia (CLL) and other B-cell malignancies. In response to BCR activation, CLL cells secrete the chemokine CCL3, which fosters interactions between CLL cells and the leukemia microenvironment. CCL3 secretion correlates with expression of the 70-kDa ζ-associated protein (ZAP-70) and responsiveness of the CLL clone to BCR stimulation. Here, we measured CCL3 plasma levels by enzyme-linked immunosorbent assay (ELISA) in 351 CLL patients and examined CCL3 levels for associations with established prognostic markers and time from diagnosis to initial therapy. We found that CCL3 plasma concentrations were strongly associated with established prognostic markers. In a Cox proportional hazards regression model, CCL3 as well as established prognostic markers (immunoglobulin heavy chain variable-region mutation status, CD38 or ZAP-70 cytogenetics, clinical stage) were significantly associated with time to treatment. Multivariable analysis revealed that CCL3 (hazard ratio [HR] = 2.33, P < .0001), advanced clinical stage (HR = 2.75, P = .0025), poor risk cytogenetics (del 17p, HR = 2.38; del11q, HR = 2.36, P = .001), and CD38 expression (HR = 1.43, P = .023) were independent prognostic markers. Collectively, CCL3 is a novel, robust, and independent prognostic marker in CLL that can easily and reliably be measured by ELISA. CCL3 therefore should become useful for risk assessment in patients with CLL.

Experience with rituximab immunotherapy as an early intervention in patients with Rai stage 0 to II chronic lymphocytic leukemia

BACKGROUND

Management of asymptomatic early stage chronic lymphocytic leukemia (CLL) centered on expectant surveillance for active disease warranting chemotherapy. In CLL, elevated serum β-2 microglobulin (β2M) levels were associated with more rapid disease progression and shorter survival (OS).

METHODS

An early intervention trial was designed to assess response, time-to-progression (TTP), and OS after immunotherapy with standard-dose rituximab (375 mg/m² intravenously weekly for 8 consecutive weeks) in 34 asymptomatic untreated early stage CLL with β2M level ≥ 2 mg/dL.

RESULTS

Long-term follow-up and results are reported. The overall response rate in 34 patients was 82% (9% complete [CR]), median TTP in the 28 responders was 23 months, the median time to subsequent treatment was 43 months, and the 8-year OS rate was 74% (median follow-up, 102 months).

CONCLUSIONS

Early treatment with rituximab was well tolerated and safe. Further studies are needed to determine if this intervention can decrease CLL-related morbidity and mortality.

Association of a microRNA/TP53 feedback circuitry with pathogenesis and outcome of B-cell chronic lymphocytic leukemia

CONTEXT

Chromosomal abnormalities (namely 13q, 17p, and 11q deletions) have prognostic implications and are recurrent in chronic lymphocytic leukemia (CLL), suggesting that they are involved in a common pathogenetic pathway; however, the molecular mechanism through which chromosomal abnormalities affect the pathogenesis and outcome of CLL is unknown.

OBJECTIVE

To determine whether the microRNA miR-15a/miR-16-1 cluster (located at 13q), tumor protein p53 (TP53, located at 17p), and miR-34b/miR-34c cluster (located at 11q) are linked in a molecular pathway that explains the pathogenetic and prognostic implications (indolent vs aggressive form) of recurrent 13q, 17p, and 11q deletions in CLL.

DESIGN, SETTING, AND PATIENTS

CLL Research Consortium institutions provided blood samples from untreated patients (n = 206) diagnosed with B-cell CLL between January 2000 and April 2008. All samples were evaluated for the occurrence of cytogenetic abnormalities as well as the expression levels of the miR-15a/miR-16-1 cluster, miR-34b/miR-34c cluster, TP53, and zeta-chain (TCR)-associated protein kinase 70 kDa (ZAP70), a surrogate prognostic marker of CLL. The functional relationship between these genes was studied using in vitro gain- and loss-of-function experiments in cell lines and primary samples and was validated in a separate cohort of primary CLL samples.

MAIN OUTCOME MEASURES

Cytogenetic abnormalities; expression levels of the miR-15a/miR-16-1 cluster, miR-34 family, TP53 gene, downstream effectors cyclin-dependent kinase inhibitor 1A (p21, Cip1) (CDKN1A) and B-cell CLL/lymphoma 2 binding component 3 (BBC3), and ZAP70 gene; genetic interactions detected by chromatin immunoprecipitation.

RESULTS

In CLLs with 13q deletions the miR-15a/miR-16-1 cluster directly targeted TP53 (mean luciferase activity for miR-15a vs scrambled control, 0.68 relative light units (RLU) [95% confidence interval {CI}, 0.63-0.73]; P = .02; mean for miR-16 vs scrambled control, 0.62 RLU [95% CI, 0.59-0.65]; P = .02) and its downstream effectors. In leukemic cell lines and primary CLL cells, TP53 stimulated the transcription of miR-15/miR-16-1 as well as miR-34b/miR-34c clusters, and the miR-34b/miR-34c cluster directly targeted the ZAP70 kinase (mean luciferase activity for miR-34a vs scrambled control, 0.33 RLU [95% CI, 0.30-0.36]; P = .02; mean for miR-34b vs scrambled control, 0.31 RLU [95% CI, 0.30-0.32]; P = .01; and mean for miR-34c vs scrambled control, 0.35 RLU [95% CI, 0.33-0.37]; P = .02).

CONCLUSIONS

A microRNA/TP53 feedback circuitry is associated with CLL pathogenesis and outcome. This mechanism provides a novel pathogenetic model for the association of 13q deletions with the indolent form of CLL that involves microRNAs, TP53, and ZAP70.

High serum thymidine kinase 1 level predicts poorer survival in patients with chronic lymphocytic leukemia

Serum thymidine kinase 1 (TK1) levels have been reported to have prognostic significance in patients with chronic lymphocytic leukemia (CLL). Until recently, serum TK1 levels were assessed using inconvenient radioenzyme assays. In this study, we used a novel chemiluminescence assay to assess serum TK1 levels in patients with CLL at the time of first examination. We show that high serum TK1 levels predict poorer overall survival and correlate with unmutated immunoglobulin variable region genes, CD38 and ZAP-70 expression, and subsequent risk of developing large B-cell lymphoma (Richter syndrome). Similar findings were observed in a subset of patients treated with current fludarabine-based chemotherapy regimens. We suggest that serum TK1 levels analyzed using this convenient chemiluminescence assay may be useful in the risk assessment of patients with CLL.

Self-administered, subcutaneous alemtuzumab to treat residual disease in patients with chronic lymphocytic leukemia

BACKGROUND

Alemtuzumab is highly effective at treating chronic lymphocytic leukemia (CLL) in bone marrow, which is the usual site of residual disease after fludarabine-based treatment. Eliminating residual disease potentially is associated with longer remission and overall survival. The authors of this report evaluated the ability of subcutaneous alemtuzumab to treat residual disease.

METHODS

Patients in partial remission (PR), nodular PR (nPR), or complete remission (CR) who had disease in bone marrow established by 2-color flow cytometry analysis were enrolled and received alemtuzumab 30 mg subcutaneously 3 times weekly for 4 weeks, and patients had the option to self-administer alemtuzumab. Responders were patients in PR who converted to an nPR or a CR, patients in nPR who converted to a CR, and patients in CR who had no evidence of disease on 2-color flow cytometry analysis after treatment.

RESULTS

There were 31 patients enrolled, of whom 29 were evaluable, and there were 23 responders (4 of 4 patients who achieved a CR, 8 of 9 patients who achieved an nPR, and 11 of 16 patients who achieved a PR. Nonresponders had significantly lower plasma alemtuzumab levels at the end of treatment. Furthermore, higher plasma alemtuzumab levels at the end of treatment were correlated with a longer response duration. Compared with the results from an historic group that received intravenous alemtuzumab for residual disease, there was a trend toward a higher response rate but a shorter response duration with subcutaneous alemtuzumab.

CONCLUSIONS

The current results demonstrated that self-administered, subcutaneous alemtuzumab was safe and active for residual disease and that plasma alemtuzumab levels and real-time minimal residual disease evaluation are important endpoints to monitor in future alemtuzumab consolidation trials.

Chemoimmunotherapy with a modified hyper-CVAD and rituximab regimen improves outcome in de novo Philadelphia chromosome-negative precursor B-lineage acute lymphoblastic leukemia

PURPOSE

The adverse prognosis of CD20 expression in adults with de novo precursor B-lineage acute lymphoblastic leukemia (ALL) prompted incorporation of monoclonal antibody therapy with rituximab into the intensive chemotherapy regimen hyper-CVAD (fractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone). Other modifications (irrespective of CD20 expression) included early anthracycline intensification, alterations in number of risk-adapted intrathecal chemotherapy treatments for CNS prophylaxis, additional early and late intensifications, and extension of maintenance phase chemotherapy by 6 months.

PATIENTS AND METHODS

Two hundred eighty-two adolescents and adults with de novo Philadelphia chromosome (Ph)-negative precursor B-lineage ALL were treated with standard or modified hyper-CVAD regimens. The latter incorporated standard-dose rituximab if CD20 expression > or = 20%.

RESULTS

The complete remission (CR) rate was 95% with 3-year rates of CR duration (CRD) and survival (OS) of 60% and 50%, respectively. In the younger (age < 60 years) CD20-positive subset, rates of CRD and OS were superior with the modified hyper-CVAD and rituximab regimens compared with standard hyper-CVAD (70% v 38%; P < .001% and 75% v 47%, P = .003). In contrast, rates of CRD and OS for CD20-negative counterparts treated with modified versus standard hyper-CVAD regimens were similar (72% v 68%, P = not significant [NS] and 64% v 65%, P = NS, respectively). Older patients with CD20-positive ALL did not benefit from rituximab-based chemoimmunotherapy (rates of CRD 45% v 50%, P = NS and OS 28% v 32%, P = NS, respectively), related in part to deaths in CR.

CONCLUSION

The incorporation of rituximab into the hyper-CVAD regimen appears to improve outcome for younger patients with CD20-positive Ph-negative precursor B-lineage ALL.

Genome-wide DNA methylation profiling of chronic lymphocytic leukemia allows identification of epigenetically repressed molecular pathways with clinical impact

We performed a genome-wide analysis of aberrant DNA methylation in chronic lymphocytic leukemia (CLL) using methylated CpG island amplification (MCA) coupled with a promoter microarray. We identified 280 potential targets of aberrant DNA methylation in CLL. These genes were located more frequently in chromosomes 19 (16%, p=0.001), 16 (11%, p=0.001), 17 (10%, p=0.02) and 11 (9%, p=0.02) and could be grouped in several functional networks. Methylation status was confirmed for 22 of these genes (SOX11, DLX1, FAM62C, SOX14, RSPO1, ADCY5, HAND2,SPOCK, MLL, ING1, PRIMA1, BCL11B, LTBP2, BNC1, NR2F2, SALL1, GALGT2, LHX1, DLX4, KLK10, TFAP2 and APP) in 78 CLL patients by pyrosequencing. As a proof of principle, we analyzed the expression of 2 genes, PRIMA1 and APP, in primary cells and of GALGT2, TFAP2C and PRIMA1 in leukemia cells. There was an inverse association between methylation and gene expression. This could be reversed by treatment with 5-aza-2'-deoxycytidine in cell lines. Treatment in a clinical trial with 5-azacitidine resulted in decreased methylation of LINE, DLX4 and SALL1 in the peripheral blood B-cells of patients with CLL. IgVH mutational status or ZAP-70 expression were not associated with specific methylation profiles. By multivariate analysis, methylation of LINE and APP was associated with shorter overall survival (p = 0.045 and 0.0035, respectively). This study demonstrates that aberrant DNA methylation is common and has potential prognostic and therapeutic value in CLL.

Treatment of patients with fludarabine-refractory chronic lymphocytic leukemia: need for new treatment options

Fludarabine-refractory chronic lymphocytic leukemia is associated with poor survival rates. Chemoimmunotherapy combinations that include purine analogs, alkylating agents, and monoclonal antibodies have shown the highest response rates to date. Intensive treatment approaches can be associated with poor tolerability that is often characterized by deteriorating immune functions and high infection rates. Treatment with some monoclonal antibodies is often complicated by infusion-related adverse events and increased risk of infections. Several novel agents are currently being investigated for this difficult-to-treat patient population. Ofatumumab is an anti-CD20 monoclonal antibody that targets a different epitope from the one targeted by rituximab and, it has shown promising antileukemia activity. Lenalidomide is an immunomodulatory agent that has shown promising activity in patients with fludarabine-refractory chronic lymphocytic leukemia, many of whom had poor prognostic features and bulky disease. Encouraging results have been observed with each of these agents individually. However, given the diverse mechanisms governing CLL pathogenesis and disease progression, ongoing clinical trials combinations of these agents may improve clinical outcomes for this patient population.

The synthetic heat shock protein 90 (Hsp90) inhibitor EC141 induces degradation of Bcr-Abl p190 protein and apoptosis of Ph-positive acute lymphoblastic leukemia cells

The prognosis of patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) is poor. Chemotherapy is rarely curative and tyrosine kinase inhibitors (TKIs) induce only transient responses. Heat shock protein 90 (Hsp90) is a chaperone protein that is important in signal transduction, cell cycle control, and transcription regulation in both normal and leukemia cells. In the current study, we tested the growth inhibitory and apoptotic effects of a novel Hsp90 inhibitor, EC141 on the Ph+ ALL lines Z-119, Z-181, and Z-33, as well as primary bone marrow-derived blasts from patients with newly diagnosed Ph+ ALL. We found that EC141 inhibited the growth of Ph+ ALL cells in a concentration-dependent manner with IC(50) ranged from 1 to 10 nM. EC141 also inhibited the proliferation of primary bone marrow-derived blasts using the ALL blast colony assay. EC141 down-regulated Hsp90 and up-regulated Hsp70 protein levels, inhibited CrkL phosphorylation, and induced degradation of Bcr-Abl p190 protein through ubiquitin-dependent proteasomal pathway. Furthermore, exposure of Ph+ ALL cells to EC141 resulted in activation of caspase-3, cleavage of poly (ADP-ribose) polymerase (PARP), and induction of apoptosis. In conclusion, our data suggest that EC141 is a potent Hsp90 inhibitor with activity against Ph+ ALL. Further studies to investigate the anticancer effect of EC141 either as a single agent, or in combination in Ph+ ALL and other hematological malignancies are warranted.

Alemtuzumab by continuous intravenous infusion followed by subcutaneous injection plus rituximab in the treatment of patients with chronic lymphocytic leukemia recurrence

BACKGROUND

Monoclonal antibodies may be used more effectively in combination. A previous study of intravenous (iv) bolus alemtuzumab plus rituximab in patients with chronic lymphocytic leukemia (CLL) recurrence produced a response rate of 54% after a 4-week treatment period.

METHODS

To optimize dose, schedule, and route of alemtuzumab, a study was designed exploring continuous intravenous infusion (civ) followed by subcutaneous (sc) alemtuzumab together with weekly iv rituximab in patients with previously treated CLL.

RESULTS

Data from 40 patients with a median age of 59 years, and a median of 3 prior regimens (range, 1-8 regimens) were evaluable. Approximately 64% of patients were fludarabine-refractory. Seven patients (18%) achieved a complete response (CR), 4 (10%) a nodular partial response (nPR), and 10 (25%) a partial response for an overall response rate of 53%. Of 11 major responses (CR, nPR), 8 occurred after cycle 1. Response rates were highest in blood (94%), followed by liver/spleen (82%), bone marrow (68%), and lymph nodes (51%). The combination did not generate unexpected toxicities. Cytomegalovirus (CMV) reactivations occurred in 6 patients (15%) and responded well to anti-CMV therapy. High titers of anti-idiotype antibodies after sc alemtuzumab were demonstrated in 1 patient, but remained without clinical sequelae.

CONCLUSIONS

The combination of civ/sc alemtuzumab plus rituximab has activity in some patients with recurrent/refractory CLL and maximum response is achieved after 1 cycle (4 weeks) in 73% of patients. Further exploration in other settings of CLL together with accompanying pharmacokinetic studies is recommended.

Abstract 1541: Role of GSH in mediating stromal-leukemia interaction and promoting cell survival and drug resistance in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western countries. The interaction between CLL cells and the bone marrow stromal environment is thought to play a major role in promoting the leukemia cell survival and drug resistance. Here we show a novel biochemical mechanism by which the bone marrow stromal cells exert a profound influence on the redox status of primary CLL cells and enhance their ability to sustain oxidative stress and drug treatment. Fresh leukemia cells isolated from the peripheral blood of CLL patients exhibited two major redox alterations when they were cultured alone: a significant decrease in cellular glutathione (GSH) and an increase in basal ROS levels. However, when cultured in the presence of bone marrow stromal cells, CLL cells restored their redox balance with an increased synthesis of GSH, a decrease in spontaneous apoptosis, and an improved cell survival. Further study showed that CLL cells were under intrinsic ROS stress and highly dependent on GSH for survival, and that the bone marrow stromal cells promoted GSH synthesis in CLL cells through a novel biochemical mechanism. Cysteine is a limiting substrate for GSH synthesis and is chemically unstable. Cells normally obtain cysteine by uptaking the more stable and abundant precursor cystine from the tissue environment and convert it to cysteine intracellularly. We showed that CLL cells had limited ability to take up extracellular cystine for GSH synthesis due to their low expression of the transporter Xc-, but had normal ability to uptake cysteine. In the co-culture system, the bone marrow stromal cells effectively took up cystine and reduced it to cysteine for secretion into the tissue microenvironment to be taken up by CLL cells for GSH synthesis. The elevated GSH in CLL cells in the presence of bone marrow stromal cells significantly protected the leukemia cells from stress-induced apoptosis, and rendered them resistant to standard therapeutic agents such as fludarabine and oxaliplatin. Importantly, disabling of this protective mechanism by depletion of cellular GSH using a pharmacological approach potently sensitized CLL cells to drug treatment, and effectively enhanced the cytotoxic action of fludarabine and oxaliplatin against CLL in the presence of stromal cells. This study reveals a key biochemical mechanism of leukemia-stromal cells interaction, and identifies a new therapeutic strategy to overcome drug resistance in vivo.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1541.

Abstract 4091: Epigenetic silencing of microRNA in the pathobiology of CLL

MicroRNAs (miRs, miRNA) are a class of non-coding RNA that control gene expression at a post-transcriptional level. Specific and aberrant miRNA signatures distinguish indolent and relapsed forms of chronic lymphocytic leukemia (CLL). In this study, we focused on the expression and cellular targets of a set of microRNA (miR15a, miR-16, miR-29b and miR-101) that are differentially expressed in indolent and refractory disease. The tumor suppressor microRNAs, miR-15a and miR-16, are downregulated in 68% of all CLL and associated with an indolent course. These miRNA are located on an intron of the dleu2 gene within a genomic locus (chr13q) that is frequently deleted in leukemia. However, deletions in 13q usually involve only one allele and do not adequately account for the low expression levels of miR-15a and miR-16. We hypothesized that aberrant recruitment of the histone deacetylases could be a novel mechanism that drives the silencing of miR-15a and miR-16 in CLL. Correspondingly, exposure to a variety of small molecule histone deacetylase inhibitors led to the re-expression of miR-15a and miR-16 in 30% of samples that undergo silencing. We then evaluated the cellular targets of miR-15a and miR-16 in CLL. Ectopic expression of miR-15 and miR-16 in primary leukemia cells led to a loss of Bcl-2 and Mcl-1. However, pharmacological re-expression of these miRNA led to decreases in Mcl-1 protein, with no loss in Bcl-2. Losses in the levels of Mcl-1 were associated with induction of cell death in these leukemia cells. In contrast to miR-15a and miR-16, the microRNAs miR-29b and miR-101 are well expressed in indolent disease but become silenced in relapsed/refractory disease by unknown mechanisms. We identified that exposure to a variety of histone deacetylase inhibitors induced the re-expression of miR-29b and miR-101 in 30-50% of the downregulated samples. Chromatin immunoprecipitation experiments demonstrated that deacetylase inhibition led to an increase in permissive chromatin marks at the gene promoters for these miRNA. miR-29b is known to target Mcl-1, Tcl-1 as well as the DNA methyltransferases 3a and 3b. Ectopic expression of miR-29b in CLL cells led to the decrease of Mcl-1 protein. In parallel, expression of miR-101 led to the inhibition of EZH2 expression. Correspondingly, pharmacological re-expression of miR-29b and miR-101 was associated with losses in Mcl-1 and EZH2 in CLL cells and apoptotic death of these leukemia cells. These results identify a role for epigenetic mechanisms in the pathological silencing of miRNA in both indolent and relapsed CLL. They also offer a novel therapeutic strategy by which to reverse epigenetic silencing of miRNA for therapeutic benefit.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4091.

Fludarabine, cyclophosphamide, mitoxantrone plus rituximab (FCM-R) in frontline CLL <70 Years

Randomized trials demonstrated the superiority of chemoimmunotherapy over chemotherapy in the frontline treatment of CLL. Based on favorable experience with the addition of mitoxantrone (M) to fludarabine (F) plus cyclophosphamide (C), we designed a pilot study testing the combination of FCM plus rituximab (R). Thirty patients with previously untreated, symptomatic CLL, <70 years, and beta-2-microglobulin Collapse

Key Words

• chronic lymphocytic leukemia (cll)
• chemoimmunotherapy
• mitoxantroe
• nucleoside analogs

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MESH Headings

• Adult
• Aged
• Antibodies, Monoclonal/administration & dosage
• Antibodies, Monoclonal/adverse effects
• Antibodies, Monoclonal, Murine-Derived
• Antineoplastic Combined Chemotherapy Protocols/therapeutic use
• Cell Separation
• Cyclophosphamide/administration & dosage
• Cyclophosphamide/adverse effects
• Female
• Flow Cytometry
• Humans
• Leukemia, Lymphocytic, Chronic, B-Cell/blood
• Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
• Male
• Middle Aged
• Mitoxantrone/administration & dosage
• Mitoxantrone/adverse effects
• Pilot Projects
• Remission Induction
• Rituximab
• Treatment Outcome
• Vidarabine/administration & dosage
• Vidarabine/adverse effects
• Vidarabine/analogs & derivatives
• beta 2-Microglobulin/blood

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Grants

• P30 CA016672 NCI NIH HHS

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Affiliation(s)

Stefan Faderl Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, United States.
William Wierda
Susan O'Brien
Alessandra Ferrajoli
Susan Lerner
Michael J Keating

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Epstein-Barr virus latent membrane protein 1 mRNA is expressed in a significant proportion of patients with chronic lymphocytic leukemia

BACKGROUND

Epstein-Barr virus (EBV) infection has been associated with Richter transformation in patients with chronic lymphocytic leukemia (CLL).

METHODS

A direct isothermal mRNA amplification method was developed for detection of EBV latent membrane protein 1 (LMP1) mRNA transcriptional activity in the peripheral blood of 135 chronic lymphocytic leukemia patients and 98 hematologically healthy control subjects.

RESULTS

EBV LMP1 mRNA transcripts were found in 19 of 135 (14%) of the CLL cases, but only 1% of the healthy controls (P < .0001). In contrast, 23 solid tumor patients tested negative for EBV LMP1 transcripts. In a later cohort of patients after hematopoietic stem cell transplantation, 4 of 7 patients with Hodgkin lymphoma or Burkitt lymphoma had EBV LMP1 detected. In a preliminary analysis, outcome data were available for 88 of the 135 patients with CLL. EBV LMP1 mRNA positivity was associated with a significantly increased degree of histologically demonstrated bone marrow involvement by CLL (P = .003, Mann-Whitney U test).

CONCLUSIONS

EBV LMP1 mRNA transcriptional activity was observed in a significant proportion of CLL patients. Transcription of the EBV LMP1, a late gene with known transforming potential in vitro, suggests that EBV activation plays a role in CLL disease progression. Thus, EBV LMP1 expression in CLL patients may be a factor involved in the genesis of refractory disease.

Non-codingRNA sequence variations in human chronic lymphocytic leukemia and colorectal cancer

Cancer is a genetic disease in which the interplay between alterations in protein-coding genes and non-coding RNAs (ncRNAs) plays a fundamental role. In recent years, the full coding component of the human genome was sequenced in various cancers, whereas such attempts related to ncRNAs are still fragmentary. We screened genomic DNAs for sequence variations in 148 microRNAs (miRNAs) and ultraconserved regions (UCRs) loci in patients with chronic lymphocytic leukemia (CLL) or colorectal cancer (CRC) by Sanger technique and further tried to elucidate the functional consequences of some of these variations. We found sequence variations in miRNAs in both sporadic and familial CLL cases, mutations of UCRs in CLLs and CRCs and, in certain instances, detected functional effects of these variations. Furthermore, by integrating our data with previously published data on miRNA sequence variations, we have created a catalog of DNA sequence variations in miRNAs/ultraconserved genes in human cancers. These findings argue that ncRNAs are targeted by both germ line and somatic mutations as well as by single-nucleotide polymorphisms with functional significance for human tumorigenesis. Sequence variations in ncRNA loci are frequent and some have functional and biological significance. Such information can be exploited to further investigate on a genome-wide scale the frequency of genetic variations in ncRNAs and their functional meaning, as well as for the development of new diagnostic and prognostic markers for leukemias and carcinomas.

Circulating CD52 and CD20 levels at end of treatment predict for progression and survival in patients with chronic lymphocytic leukaemia treated with fludarabine, cyclophosphamide and rituximab (FCR)

CD52 and CD20 antigens are important therapeutic targets for the monoclonal antibodies (mAbs) alemtuzumab and rituximab respectively. Circulating CD52 (cCD52) and CD20 (cCD20) have prognostic utility in lymphoid malignancies. The efficacy of mAb therapy in patients with chronic lymphocytic leukaemia (CLL) may be adversely affected by cCD52 or cCD20. In this report, blood and bone marrow (BM) cCD52 and cCD20 were measured at response assessment in previously treated (N = 235) patients with CLL who received fludarabine, cyclophosphamide, and rituximab (FCR). Univariate and multivariate statistical models evaluated correlations of pre- and response variables with progression-free (PFS) and overall survival (OS). Response variables included 1996 National Cancer Institute-Working Group (NCI-WG) response, polymerase chain reaction (PCR) for immunoglobulin heavy chain (IGHV) in BM, and cCD52 and cCD20 levels (blood and BM) at response assessment. Using multivariate analysis, response blood and BM cCD52, blood cCD20, and NCI-WG response were significant independent predictors of PFS. At the time of response assessment, BM cCD52 correlated with OS in univariate analysis. cCD52 and cCD20, therefore appear useful in predicting survival and may be important for monitoring patients following salvage FCR (fludarabine, cyclophosphamide, rituximab) therapy. These data further indicate that plasma may be a good target to evaluate for minimal residual disease using cCD52/cCD20 levels.

Dynamic model for predicting death within 12 months in patients with primary or post-polycythemia vera/essential thrombocythemia myelofibrosis

PURPOSE

Current prognostic tools in myelofibrosis (MF) fail to identify patients at the highest risk of death and are limited by their applicability only to the time of diagnosis. We aimed to define an accelerated phase (AP) in MF by characterizing disease features that can identify patients with median overall survival of <or= 12 months at any time in the disease course.

PATIENTS AND METHODS

Baseline characteristics of 370 consecutive patients with MF from a single center were analyzed to identify features associated with a median overall survival of <or= 12 months. These putative AP features were then validated by following the course of chronic-phase patients (no AP features at baseline) until the development of one or more AP features and determining their subsequent survival.

RESULTS

The following three characteristics were associated with poor survival at baseline and were selected as putative AP features: blasts in blood or bone marrow >or= 10%, platelets less than 50 x 10(9)/L, and chromosome 17 aberrations (median overall survival, 10, 12, and 5 months, respectively). In the validation phase, chronic-phase patients who developed AP features during follow-up were found to have short subsequent survival times (median overall survival, 12, 15, and 6 months, respectively). AP was a necessary step in the progression to blast phase, with leukemic transformation being exceedingly rare (3% risk at 10 years) in patients who remained persistently in chronic phase.

CONCLUSION

Blood or bone marrow blasts >or= 10%, platelets less than 50 x 10(9)/L, and chromosome 17 aberrations defined AP in patients with MF. Patients in AP should be candidates for intensive therapeutic interventions.

Array CGH analysis of chronic lymphocytic leukemia reveals frequent cryptic monoallelic and biallelic deletions of chromosome 22q11 that include the PRAME gene

We used BAC array-based CGH to detect genomic imbalances in 187 CLL cases. Submicroscopic deletions of chromosome 22q11 were observed in 28 cases (15%), and the frequency of these deletions was second only to loss of the 13q14 region, the most common genomic aberration in CLL. Oligonucleotide-based array CGH analysis showed that the 22q11 deletions ranged in size from 0.34 Mb up to approximately 1 Mb. The minimally deleted region included the ZNF280A, ZNF280B, GGTLC2, and PRAME genes. Quantitative real-time PCR revealed that ZNF280A, ZNF280B, and PRAME mRNA expression was significantly lower in the 22q11 deletion cases compared to non-deleted cases.

B-cell antigen receptor signaling enhances chronic lymphocytic leukemia cell migration and survival: specific targeting with a novel spleen tyrosine kinase inhibitor, R406

Antigenic stimulation through the B-cell antigen receptor (BCR) is considered to promote the expansion of chronic lymphocytic leukemia (CLL) B cells. The spleen tyrosine kinase (Syk), a key component of BCR signaling, can be blocked by R406, a small-molecule Syk inhibitor, that displayed activity in CLL patients in a first clinical trial. In this study, we investigated the effects of BCR stimulation and R406 on CLL cell survival and migration. The prosurvival effects promoted by anti-IgM stimulation and nurselike cells were abrogated by R406. BCR triggering up-regulated adhesion molecules, and increased CLL cell migration toward the chemokines CXCL12 and CXCL13. BCR activation also enhanced CLL cell migration beneath marrow stromal cells. These responses were blocked by R406, which furthermore abrogated BCR-dependent secretion of T-cell chemokines (CCL3 and CCL4) by CLL cells. Finally, R406 inhibited constitutive and BCR-induced activation of Syk, extracellular signal-regulated kinases, and AKT, and blocked BCR-induced calcium mobilization. These findings suggest that BCR activation favors CLL cell homing, retention, and survival in tissue microenvironments. R406 effectively blocks these BCR-dependent responses in CLL cells, providing an explanation for the activity of R406 in patients with CLL.

Anti-B4 Blocked Ricin Post Chemotherapy in Patients with Chronic Lymphocytic Leukemia--Long-term Follow-up of a Monoclonal Antibody-based Approach to Residual Disease

Anti-B4-blocked ricin is an immunotoxin consisting of anti-B4 murine monoclonal antibody and "blocked ricin" toxin. The anti-B4 monoclonal antibody is directed against the CD19 antigen, which is expressed on B-lymphocytes. A phase II study of anti-B4 blocked ricin toxin in patients with B-cell chronic lymphocytic leukemia (CLL) with residual disease after chemotherapy was conducted. Eleven patients received anti-B4 blocked ricin at 30 microg/kg lean body mass (LBM) daily by continuous infusion for 7 days followed with repeat infusion administered at 14-day intervals. No patient achieved an objective response. The major reasons for failure to respond were the presence of adenopathy and residual marrow disease. Three patients achieved immunophenotypic response in marrow and peripheral blood. Three of 6 patients with rearranged IgH and/or Ig kappa were germline after anti-B4 blocked ricin. The median follow-up of surviving patients is 8.6 years. The median survival is 5.8 years (range, 0.0-8.8). All patients have progressed. The median time to progression was 0.8 years (range, 0.3-3.0). Infusion-related toxicities were all grade 1-2. The most common toxicity was transaminitis. Human antimouse antibody (HAMA) and/or human antiricin antibody (HARA) development was documented in 2 patients. Anti-B4 blocked ricin was well tolerated but had limited activity in patients with residual CLL after chemotherapy.

Treatment of fludarabine-refractory chronic lymphocytic leukemia

The development of resistance to purine analogs defines a poor-risk subset of patients with chronic lymphocytic leukemia (CLL). Although in recent years chemoimmunotherapeutic combinations such as fludarabine, cyclophosphamide, and rituximab have induced response rates of 95% in previously untreated patients and increased the rates of failure-free survival, CLL remains incurable for many patients because of a lack of disease response or the development of refractoriness to fludarabine. Fludarabine-refractory disease is defined as CLL that does not respond to fludarabine or that recurs within 6 months of treatment with a fludarabine-containing regimen. The natural course of the disease is associated with poor survival. Salvage therapeutic strategies include alemtuzumab-containing regimens, targeted agents, and allogeneic stem cell transplantation. Single-agent alemtuzumab induces response in up to 40% of patients with fludarabine-refractory CLL, but responses are not durable, and the median survival is approximately 1 to 2 years. Alemtuzumab is also combined with fludarabine, cyclophosphamide, and/or rituximab, and other agents such as lenalidomide and flavopiridol, as well as targeted agents, and used in fludarabine-refractory CLL. Cumulative evidence suggests that allogeneic stem cell transplantation is an efficacious therapeutic strategy for patients who do not respond to fludarabine or who develop disease recurrence within 12 months after purine analog treatment. In conclusion, chemoimmunotherapy regimens that include alemtuzumab and/or rituximab and allogeneic stem cell transplantation improve the prognosis of this disease, but there is a continued need for novel, more effective therapies.

Mechanism of action of SNS-032, a novel cyclin-dependent kinase inhibitor, in chronic lymphocytic leukemia

Inhibitors of cyclin-dependent kinases (Cdks) have been reported to have activities in chronic lymphocytic leukemia cells by inhibiting Cdk7 and Cdk9, which control transcription. Here we studied the novel Cdk inhibitor SNS-032, which exhibits potent and selective inhibitory activity against Cdk2, Cdk7, and Cdk9. We hypothesized that transient inhibition of transcription by SNS-032 would decrease antiapoptotic proteins, resulting in cell death. SNS-032 effectively killed chronic lymphocytic leukemia cells in vitro regardless of prognostic indicators and treatment history. This was associated with inhibition of phosphorylation of RNA polymerase II and inhibition of RNA synthesis. Consistent with the intrinsic turnover rates of their transcripts and proteins, antiapoptotic proteins, such as Mcl-1 and X-linked inhibitor of apoptosis protein (XIAP), were rapidly reduced on exposure to SNS-032, whereas Bcl-2 protein was not affected. The initial decrease of Mcl-1 protein was the result of transcriptional inhibition rather than cleavage by caspase. Compared with flavopiridol and roscovitine, SNS-032 was more potent, both in inhibition of RNA synthesis and at induction of apoptosis. SNS-032 activity was readily reversible; removal of SNS-032 reactivated RNA polymerase II, which led to resynthesis of Mcl-1 and cell survival. Thus, these data support the clinical development of SNS-032 in diseases that require short-lived oncoproteins for survival.

Chronic lymphocytic leukemia With t(2;14)(p16;q32) involves the BCL11A and IgH genes and is associated with atypical morphologic features and unmutated IgVH genes

The t(2;14)(p16;q32) has been reported previously in only 12 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The clinicopathologic features have been incompletely described. We describe 6 new cases of CLL/SLL with t(2;14)(p16;q32). All had marrow involvement, 4 had absolute lymphocytosis, 4 had lymphadenopathy, and 3 had hepatosplenomegaly. All showed atypical lymphocyte morphologic features with plasmacytoid differentiation and irregular nuclei; 3 had increased prolymphocytes. Flow cytometry demonstrated typical immunophenotypes in 5 and an atypical immunophenotype in 1. All expressed ZAP70; 5 assessed showed unmutated IgV(H) genes. Karyotyping identified t(2;14)(p16;q32) as the sole abnormality in 1, primary abnormality in 2, and part of a complex karyotype in 3. Fluorescence in situ hybridization analysis revealed BCL11A/IgH rearrangement in all. After chemotherapy, 3 patients died of disease and 3 were alive with disease (median follow-up, 80 months). We conclude that CLL/SLL with t(2;14) (p16;q32) and BCL11A/IgH rearrangement is characterized by atypical morphologic features and unmutated IgV(H) genes.

Chemoimmunotherapy may overcome the adverse prognostic significance of 11q deletion in previously untreated patients with chronic lymphocytic leukemia

BACKGROUND

An 11q22 deletion is considered an independent factor predicting poor survival in chronic lymphocytic leukemia (CLL).

METHODS

We searched the electronic CLL database for consecutive patients who presented to the M. D. Anderson Cancer Center Department of Leukemia from October 2003 to April 2007 with untreated CLL and who had an 11q22 deletion, detected by fluorescence in situ hybridization (FISH) analysis of bone marrow samples. FISH analysis was performed using the following probes: trisomy 12 (12p11.1-q11), TP53 (17p13.1), ATM (11q22.3), LAMP1 (13q34), and D13S319 loci (13q14.3).

RESULTS

Sixty-nine patients with untreated CLL with an 11q22 deletion were identified. The median patient age was 59 years (range, 26-81 years); 80% were men, 53% had Zubrod performance status>0, and 13% had Rai stage III to IV disease. Lymphadenopathy (massive), splenomegaly, anemia, and thrombocytopenia were present in 96% (12%), 19%, 9%, and 4%, respectively. In addition, 62% of patients had deletions in 13q, and 3% had trisomy 12. Forty patients required therapy for progressive disease. The overall response rates for FCR (fludarabine, cyclophosphamide, and rituximab), CFAR (FCR plus alemtuzumab), and rituximab plus granulocyte-macrophage colony-stimulating factor were 100%, 100%, and 33%, respectively. The 11q22 deletion was undetectable in 25 of 27 patients monitored after treatment using FISH analysis. The median follow-up was 17 months. At 1 and 3 years, the survival rates were 97% and 91%, respectively, and the relapse-free survival rates were 100% and 77%, respectively.

CONCLUSIONS

CLL with an 11q22 deletion was associated with high rates of response, survival, and relapse-free survival when treated with chemoimmunotherapy.

Other malignancies in chronic lymphocytic leukemia/small lymphocytic lymphoma

PURPOSE

Other malignancies have been reported to occur with increased frequency in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The aim of this study was to determine the frequency, outcomes, and factors associated with other cancers in patients with CLL/SLL.

PATIENTS AND METHODS

We reviewed the records of consecutive patients with previously untreated CLL/SLL seen at The University of Texas M. D. Anderson Cancer Center from 1985 to 2005. The number of second cancers observed was compared with the number expected from the Surveillance, Epidemiology, and End Results database.

RESULTS

Among 2,028 patients, 324 (16%) had a history of other cancers and 227 (11.2%) developed other malignancies during the follow-up period. Overall, 625 cancers were observed in 551 patients, including skin (30%), prostate (13%), breast (9%), melanoma (8%), lymphoma (8%), gastrointestinal (9%), lung (6%), and other cancers (17%). The risk of a second cancer was 2.2 times higher than the expected risk. The response rates in patients with and without a history of other cancers were 86% and 92%, respectively (P = .04), and the 5-year survival rates were 70% and 82%, respectively (P < .001). In Cox analysis, independent factors predicting development of new cancers were older age, male sex, and elevated levels of beta2-microglobulin, lactate dehydrogenase, and creatinine. In patients who were treated for CLL/SLL, the treatment regimen did not affect the risk of subsequent cancer (P = .49).

CONCLUSION

Patients with CLL/SLL have more than twice the risk of developing a second cancer and an increased frequency of certain cancer types. Awareness of risk factors could permit early detection.

Customized oligonucleotide array-based comparative genomic hybridization as a clinical assay for genomic profiling of chronic lymphocytic leukemia

Chromosome gains and losses used for risk stratification in chronic lymphocytic leukemia (CLL) are commonly assessed by multiprobe fluorescence in situ hybridization (FISH) studies. We designed and validated a customized array-comparative genomic hybridization (aCGH) platform as a clinical assay for CLL genomic profiling. A 60-mer, 44,000-probe oligonucleotide array with a 50-kb average spatial resolution was augmented with high-density probe tiling at loci that are frequently aberrant in CLL. Aberrations identified by aCGH were compared with those identified by a FISH panel, including locus-specific probes to ATM (11q22.3), the centromeric region of chromosome 12 (12p11.1-q11), D13S319 (13q14.3), LAMP1 (13q34), and TP53 (17p13.1). In 100 CLL samples, aCGH/FISH concordance was seen for 89% of FISH-called aberrations at the ATM (n=18), D13S319 (n=42), LAMP (n=12), and TP53 (n=22) loci and for chromosome 12 (n=14). Eighty-four percentage of FISH/aCGH discordant calls were in samples either at or below the limit of aCGH sensitivity (10% to 25% FISH aberration-containing cells). Therefore, aCGH profiling is a feasible routine clinical test with comparable results to multiprobe FISH studies; however, it may be less sensitive than FISH in cases with low-level aberrations. Further, a customized array design can provide comprehensive genomic profiling with additional accuracy in both identifying and defining the extent of small aberrations at target loci.

Chromosomal abnormalities detected by multicolor fluorescence in situ hybridization in fine-needle aspirates from patients with small lymphocytic lymphoma are useful for predicting survival

BACKGROUND

Fine-needle aspiration (FNA) of lymph nodes is commonly used to assess disease progression in patients with small lymphocytic lymphoma (SLL). Although cytologic features are helpful for diagnosing typical SLL and transformed large-cell lymphoma (tLCL), SLL in accelerated phase (SLLacc) is more difficult to diagnose. Additional tests are needed to identify those patients who are transforming to a higher-grade lymphoma. This study evaluated the use of a multicolor fluorescence in situ hybridization (FISH) probe panel specifically designed for chronic lymphocytic leukemia (CLL)/SLL and assessed the association between FISH findings and cytologic diagnosis, proliferation index, and risk of death.

METHODS

FNA specimens from 50 patients (32 men and 18 women; mean age, 57 years [range, 36-77 years]) with histologically confirmed CLL and/or SLL were evaluated in this study for chromosomal abnormalities of 11q22 (ATM), 12, 13q14.3, 13q34.3 (LAMP1), and 17p13.1 (p53) by using a multiprobe FISH kit. One of the 50 cases was excluded because of an insufficient number of cells for FISH analysis. The FISH findings were compared with the cytologic diagnoses (26 SLLs, 12 SLLaccs, and 11 tLCLs), Ki-67 immunostaining, and risk of death.

RESULTS

Abnormal signal patterns for 17p13.1 and 13q34.3 were associated with tLCL. Aberrations of 17p13.1 were found to be significantly associated with Ki-67 staining. Of the 49 patients with interpretable FISH results, 22 (45%) had died at the time of the study, with a mean overall survival time of 17 months after FNA. Patients with aberrations of 17p13.1 and 11q22 had 3.7 and 2.7 times the risk of death, respectively, compared with patients with normal patterns.

CONCLUSIONS

FISH can be performed on FNA specimens from patients with a history of SLL/CLL. Chromosomal aberrations of 17p13.1 and 11q22 are associated with an increased risk of death. Knowledge of genetic abnormalities from FNAs may be useful in deciding when and how to treat indolent or progressive SLL.

Myeloid sarcoma is associated with superior event-free survival and overall survival compared with acute myeloid leukemia

BACKGROUND

It is unknown whether patients with nonleukemic myeloid sarcoma (MS) and those with acute myeloid leukemia (AML) have similar responses to anti-AML treatment. In the current study, the authors addressed this question by matching MS patients with analogous AML patients and comparing their clinical outcomes.

METHODS

Twenty-three consecutive patients with MS and 1720 consecutive patients with AML were identified who presented at The University of Texas M. D. Anderson Cancer Center from 1990 to 2004. All AML patients and 16 MS patients received cytarabine plus idarubicin or fludarabine as induction remission therapy. Treated MS patients and AML patients were matched according to cytogenetics, age, Zubrod performance status, and time of treatment. Event-free survival (EFS) and overall survival (OS) were compared using Kaplan-Meier analyses.

RESULTS

Complete response rates were 69% in patients with MS and 57% in patients with AML (P = .45). The respective 2-year EFS and OS rates were 32% and 18% (P = .08) and 43% and 29% (P = .11). Matches were identified for 14 MS patients who were paired repeatedly with 91 AML patients to produce 94 matches (3 AML patients were matched twice). EFS was longer in 56 MS pair mates, shorter in 26 pair mates, and similar in 12 pair mates (P = .01; Fisher exact test). OS analyses yielded similar results.

CONCLUSIONS

Anti-AML therapy was highly effective in patients with nonleukemic MS. The results from this study emphasize the need to treat patients who have nonleukemic MS with AML-type therapy.

Multiple-dose granulocyte-macrophage-colony-stimulating factor plus 23-valent polysaccharide pneumococcal vaccine in patients with chronic lymphocytic leukemia: a prospective, randomized trial of safety and immunogenicity

BACKGROUND

For the current study, the authors sought to determine whether administration of multiple-dose granulocyte-macrophage-colony-stimulating factor (GM-CSF) could improve response to standard 23-valent polysaccharide pneumococcal vaccine (PPV) in patients with chronic lymphocytic leukemia (CLL).

METHODS

Patients were allocated randomly to receive PPV either alone or with 3 doses of GM-CSF (250 microg) given before or after vaccination. Serum was obtained before, 4 weeks after, and 12 weeks after vaccination for antibody determination. Thirty-two patients with CLL were given PPV. They were randomized to receive 3 doses of GM-CSF either before or after vaccination or to receive no GM-CSF.

RESULTS

A 4-fold rise in immunoglobulin G (IgG) to capsular polysaccharides from Streptococcus pneumoniae types 4, 6B, 9V, 14, 19F, and 23F occurred in <10% of patients in each of the 3 groups. There were no differences in geometric mean IgG levels in any of the 3 groups 4 weeks or 12 weeks after vaccination.

CONCLUSIONS

In patients with CLL, the response to pure polysaccharide pneumococcal vaccine was low despite immune enhancement with multiple doses of GM-CSF. In all patients, reactogenicity was minor.

Whole-genome scanning by array comparative genomic hybridization as a clinical tool for risk assessment in chronic lymphocytic leukemia

Array-based comparative genomic hybridization (array CGH) provides a powerful method for simultaneous genome-wide scanning and prognostic marker assessment in chronic lymphocytic leukemia (CLL). In the current study, commercially available bacterial artificial chromosome and oligonucleotide array CGH platforms were used to identify chromosomal alterations of prognostic significance in 174 CLL cases. Tumor genomes were initially analyzed by bacterial artificial chromosome array CGH followed by confirmation and breakpoint mapping using oligonucleotide arrays. Genomic changes involving loci currently interrogated by fluorescence in situ hybridization (FISH) panels were detected in 155 cases (89%) at expected frequencies: 13q14 loss (47%), trisomy 12 (13%), 11q loss (11%), 6q loss (7.5%), and 17p loss (4.6%). Genomic instability was the second most commonly identified alteration of prognostic significance with three or more alterations involving loci not interrogated by FISH panels identified in 37 CLL cases (21%). A subset of 48 CLL cases analyzed by six-probe FISH panels (288 total hybridizations) was concordant with array CGH results for 275 hybridizations (95.5%); 13 hybridizations (4.5%) were discordant because of clonal populations that comprised less than 30% of the sample. Array CGH is a powerful, cost-effective tool for genome-wide risk assessment in the clinical evaluation of CLL.

MYC translocation in chronic lymphocytic leukaemia is associated with increased prolymphocytes and a poor prognosis

Chromosomal translocations that involve MYC, characteristic of Burkitt lymphoma, are rare in chronic lymphocytic leukaemia (CLL). We report the clinical, morphological, immunophenotypic, cytogenetic and molecular genetic features of eight CLL cases with MYC rearrangement. The patients, five men and three women (median age, 71 years) had bone marrow involvement and an absolute peripheral blood lymphocytosis; five had lymphadenopathy; seven had splenomegaly. Prolymphocytes were increased (>/=10%) in all cases. Six cases were classified as CLL with increased prolymphocytes (CLL/PL; prolymphocytes 10-55%), and two were classified as CLL in prolymphocytic transformation (CLL/PT; prolymphocytes >55%). All cases co-expressed CD5, CD19, and CD23; five of eight expressed ZAP-70. Of seven cases tested, four had mutated and three had unmutated IGHV genes. Conventional cytogenetic studies demonstrated t(8;14)(q24.1;q32) in five cases, t(8;22)(q24.1;q11) in two cases, and t(2;8)(p12;q24.1) in one case. Seven cases contained additional chromosomal abnormalities. All patients received combination chemotherapy. Two developed Epstein-Barr virus (EBV)-associated diffuse large B-cell lymphomas (DLBCL) that were clonally unrelated to the CLL. At follow-up, two patients are alive, four died of underlying disease, one died of EBV-associated DLBCL, and one died of an unrelated cancer. In summary, MYC rearrangement, which occurs rarely in CLL patients, is associated with increased prolymphocytes, complex cytogenetic abnormalities, and a poor prognosis.

The prognostic significance of serum beta2 microglobulin levels in acute myeloid leukemia and prognostic scores predicting survival: analysis of 1,180 patients

PURPOSE

Serum beta(2) microglobulin (beta2M) is prognostic in other hematologic malignancies; therefore, we evaluated its prognostic significance in acute myeloid leukemia (AML).

EXPERIMENTAL DESIGN

Multivariate analyses were used to examine the effect of pretreatment serum beta2M levels on clinical outcomes in patients with AML. beta2M was associated with poorer survival in older but not younger patients. We thus fit separate Cox survival models in patients above and below age 60 years treated with remission induction therapy containing high-dose cytarabine (n = 1,280). In each age group, 50% of the patients were used to develop the model, which was tested in the other 50%. Resampling methods were also used to validate the independent prognostic significance of covariates.

RESULTS

In patients 60 years or older (n = 591), poorer risk cytogenetics; poorer performance status; and higher levels of beta2M, uric acid, and lactate dehydrogenase were each found to independently predict shorter survival and formed the basis of a scoring system. A similar approach was used in patients younger than 60 years (n = 589), with poorer risk cytogenetics, poorer performance status, older age, higher hemoglobin level, and higher leukocyte count predicting a shorter survival and forming the basis of the scoring system. Higher beta2M levels were an adverse independent factor for response, survival, relapse-free survival, and event-free survival in older but not in younger patients.

CONCLUSIONS

Serum beta2M levels can help predict outcome in patients > or =60 years with untreated AML, and their use is strongly encouraged.