RUNX1/ETO blocks selectin-mediated adhesion via epigenetic silencing of PSGL-1

RUNX1/ETO (RE), the t(8;21)-derived leukemic transcription factor associated with acute myeloid leukemia (AML) development, deregulates genes involved in differentiation, self-renewal and proliferation. In addition, these cells show differences in cellular adhesion behavior whose molecular basis is not well understood. Here, we demonstrate that RE epigenetically silences the gene encoding P-Selectin Glycoprotein Ligand-1 (PSGL-1) and downregulates PSGL-1 expression in human CD34+ and murine lin− hematopoietic progenitor cells. Levels of PSGL-1 inversely and dose-dependently correlate with RE oncogene levels. However, a DNA-binding defective mutant fails to downregulate PSGL-1. We show by ChIP experiments that the PSGL-1 promoter is a direct target of RE and binding is accompanied by high levels of the repressive chromatin mark histone H3K27me3. In t(8;21)+ Kasumi-1 cells, PSGL-1 expression is completely restored at both the mRNA and cell surface protein levels following RE downregulation with short hairpin RNA (shRNA) or RE inhibition with tetramerization-blocking peptides, and at the promoter H3K27me3 is replaced by the activating chromatin mark H3K9ac as well as by RNA polymerase II. Upregulation of PSGL-1 restores the binding of cells to P- and E-selectin and re-establishes myeloid-specific cellular adhesion while it fails to bind to lymphocyte-specific L-selectin. Overall, our data suggest that the RE oncoprotein epigenetically represses PSGL-1 via binding to its promoter region and thus affects the adhesive behavior of t(8;21)+ AML cells.

Sequential therapy combining clofarabine and T-cell-replete HLA-haploidentical haematopoietic SCT is feasible and shows efficacy in the treatment of refractory or relapsed aggressive lymphoma

Prognosis is poor for patients with biologically aggressive Non-Hodgkin lymphoma (NHL), refractory to chemotherapy or relapsed after autologous transplantation, especially when no disease control before allogeneic transplantation is achieved. In 16 patients (median age 53, median prior regimes 5) with relapsed or refractory non-remission NHL, we analysed retrospectively the efficacy of a sequential therapy comprising clofarabine re-induction followed by a reduced-intensity conditioning with fludarabine, CY and melphalan, and T-cell-replete HLA-haploidentical transplantation. High-dose CY was utilized post-transplantation. All patients engrafted. Early response (day +30) was achieved in 94%. Treatment-related grade III-IV toxicity occurred in 56%, most commonly transient elevation of transaminases (36%), while there was a low incidence of infections (19% CMV reactivation, 19% invasive fungal infection) and GVHD (GVHD: acute III-IV: 6%; mild chronic: 25%). One-year non-relapse mortality was 19%. After a median follow-up of 21 months, estimated 1- and 2-year PFS was 56 and 50%, respectively, with 11 patients (69%) still alive after 2 years. In summary, sequential therapy is feasible and effective and provides an acceptable toxicity profile in high-risk non-remission NHL. Presumably, cytotoxic reinduction with clofarabine provides enough remission time for the graft-versus lymphoma effect of HLA-haploidentical transplantation to kick in, even in lymphomas that are otherwise chemo-refractory.

[Chemotherapy of metastatic colorectal cancer]

Increasing numbers of therapeutic options are becoming available for the systemic treatment of metastasized colorectal cancer (mCRC) which emphasizes the need for strategic decision making and planning across multiple lines of treatment. The choice of first-line therapy is influenced by clinical and molecular characteristics of patients and tumors, such as (K-)RAS gene mutations with respect to therapy guidance of epidermal growth factor receptor (EGFR) antibodies. First-line therapy is the major determinant of subsequent treatment regimens and can therefore be considered as the key decision in patients with mCRC. The German standard for first-line therapy in the majority of patients includes chemotherapy in combination with biological agents, with antibodies targeting EGFR possibly being the preferable option in patients with (K-)RAS wild-type tumors. The development of effective therapeutic strategies in patients with (K-)RAS mutant mCRC tumors must be promoted in the future and requires intensive research because the therapy options for this group of patients are very limited.

[Metastatic colorectal cancer--analysis of treatment modalities and survival now and then]

BACKGROUND AND AIM

In metastatic colorectal cancer (mCRC) available systemic treatment options substantially increased in the last decades. Nowadays, overall survival in mCRC patients ranges from 25 to 35 months as recent studies report. We compared treatment modalities and survival in mCRC patients who were treated at our center in two different periods.

PATIENTS AND METHODS

Within two sequential monocentric analyses patients with mCRC treated at our Comprehensive Cancer Center (CCC) between 07/1994 and 10/2007 (cohort 1) and from 11/2007 to 05/2010 (cohort 2) were evaluated for applied treatment, for best response to treatment and for survival (OS). For statistical analysis the Kaplan-Meier estimator was used.

RESULTS

Both patient cohorts showed comparable characteristics regarding median age (63 vs. 64 yrs), localization of primary tumor (colon 60% vs. rectum 40%) and number and site of distant metastasis (1 site [75%] vs. ≥ 2 site [25%]; liver-only metastasis [55%]). About half of all patients in each cohort received at least three consecutive chemotherapy regimens. In cohort 1, treatment mainly consisted of chemotherapy alone (>80%), whereas in cohort 2 chemotherapy was combined with a monoclonal antibody in nearly 70%. Rate of surgical resection of metastasis increased over time (8% vs. 17%). Median OS was 27.3 months (cohort 1) vs. 39.4 months (cohort 2).

CONCLUSION

The increasing availability of effective substances including monoclonal antibodies and individual approaches including secondary surgery of distant metastasis might explain that survival in pts with mCRC has substantially improved over the last decades.

[Symptomatic therapy of SIADH in small cell lung cancer by tolvaptan]

HISTORY AND CLINICAL FINDINGS

A 69-year-old woman with small cell lung cancer presented in the emergency ward because of severe back pain. She had received tolvaptan treatment in hospital for paraneoplastic SIADH but had discontinued the drug after discharge from hospital 3 days ago. Restriction of fluid intake was not tolerated.

INVESTIGATIONS

Consistent with SIADH, there were profound hyponatraemia, elevated urine osmolality and urine sodium.

TREATMENT AND COURSE

After a generalized seizure triggered by hyponatraemia, tolvaptan was reintroduced in addition to radiochemotherapy. Serum sodium concentration increased and finally returned to normal.

CONCLUSION

If restriction of fluid intake is not tolerated by the patients the vasopressin antagonist tolvaptan provides an alternative symptomatic treatment of paraneoplastic SIADH.

Framework for timing of the discussion about forgoing cancer-specific treatment based on a qualitative study with oncologists

BACKGROUND

Many patients with advanced cancer receive aggressive chemotherapy close to death and are referred too late to palliative or hospice care.

AIM

The aim of this study was to investigate oncologists' and oncology nurses' perceptions of the optimal timing for discussions about forgoing cancer-specific therapy at the End-of-Life (EOL) and the reasons that might hinder them.

DESIGN

Qualitative in-depth interviews with oncologists and oncology nurses were carried out. The empirical data were evaluated from a normative perspective.

SETTING/PARTICIPANTS

Twenty-nine physicians and nurses working at the Department of Hematology and Oncology of a German university hospital were interviewed.

RESULTS

Health-care professionals differed considerably in their understanding of when to initiate discussions about forgoing cancer-specific therapy at the EOL. However, their views could be consolidated into three approaches: (1) preparing patients gradually throughout the course of disease (anticipatory approach) which is best suited to empower patient self-determination in decision-making, (2) waiting until the patient him/herself starts the discussion about forgoing cancer-specific treatment, and (3) waiting until all tumor-specific therapeutic options are exhausted.

CONCLUSION

The empirically informed ethical analysis clearly favors an approach that prepares patients for forgoing cancer-specific therapy throughout the course of disease. Since the last two approaches often preclude advance care planning, these approaches may be less ethically acceptable. The proposed framework could serve as a starting point for the development of concrete recommendations on the optimal timing for EOL discussions.

How we manage follicular lymphoma

Major changes have taken place within the last few years in the management of follicular lymphoma (FL) leading to substantial improvement in prognosis and overall survival. For some patients with limited disease stages I and II, radiotherapy may be associated with durable responses; however, it is unclear whether patients are cured and new approaches such as the combination of irradiation with rituximab or even single-agent rituximab need to be explored. Whereas watch and wait is the current standard for stage III and IV disease with low tumour burden, better indices are warranted to potentially select patients for whom early intervention is preferred. For advanced stages with a high tumour burden, immunochemotherapy followed by 2 years of rituximab maintenance is widely accepted as standard therapy, although re-treatment at recurrence may be an alternative option. Highly attractive new therapeutic options have recently arisen from new antibodies, and from new agents targeting oncogenic pathways such as B-cell receptor signalling pathways or inhibition of bcl 2. Furthermore, immunomodulatory drugs may add to the therapeutic armamentarium and may lead to 'chemotherapy-free' therapies in the near future. Hence, the management of FLs has become a moving target and the hope is justified that the long-term perspectives of patients suffering from the disease will be further improved in the near future.

[Hemato-oncological diseases]

Acquired inhibitors of coagulation cause a life-threatening disease. Clinically newly occurring hemorrhagic diathesis combined with prolonged activated partial thromboplastin time (aPTT) time is diagnostically indicative and can be confirmed by a positive plasma exchange test. For thrombotic thrombocytopenic purpura and hemolytic uremic syndrome (TTP-HUS) the diagnosis of Coombs negative hemolytic anemia together with thrombocytopenia should lead to the detection of fragmentocytes in peripheral blood smears. Hairy cell leukemia is a rare subgroup of chronic B-cell neoplasia with the clinical signs of pancytopenia and splenomegaly which characteristically stain positive for CD103. The gastrointestinal stromal tumor (GIST) has nothing in common with classical soft tissue sarcoma based on the activating mutation of the KIT or PDGFRA gene (positivity for CD117). In all of these disorders the correct diagnosis has a major influence on patient outcome. For the case of acquired inhibitors of coagulation immunosuppressive therapy and substitution of coagulation factors (e.g. recombinant factor VIIa) or for TTP-HUS the immediate start of plasma exchange are mandatory. For hairy cell leukemia a very effective treatment exists with purine analogs (e.g. cladribine) and for metastatic inoperable GIST with tyrosine kinase inhibitors (e.g. imatinib).

Treatment of older patients with mantle-cell lymphoma

BACKGROUND

The long-term prognosis for older patients with mantle-cell lymphoma is poor. Chemoimmunotherapy results in low rates of complete remission, and most patients have a relapse. We investigated whether a fludarabine-containing induction regimen improved the complete-remission rate and whether maintenance therapy with rituximab prolonged remission.

METHODS

We randomly assigned patients 60 years of age or older with mantle-cell lymphoma, stage II to IV, who were not eligible for high-dose therapy to six cycles of rituximab, fludarabine, and cyclophosphamide (R-FC) every 28 days or to eight cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) every 21 days. Patients who had a response underwent a second randomization to maintenance therapy with rituximab or interferon alfa, each given until progression.

RESULTS

Of the 560 patients enrolled, 532 were included in the intention-to-treat analysis for response, and 485 in the primary analysis for response. The median age was 70 years. Although complete-remission rates were similar with R-FC and R-CHOP (40% and 34%, respectively; P=0.10), progressive disease was more frequent with R-FC (14%, vs. 5% with R-CHOP). Overall survival was significantly shorter with R-FC than with R-CHOP (4-year survival rate, 47% vs. 62%; P=0.005), and more patients in the R-FC group died during the first remission (10% vs. 4%). Hematologic toxic effects occurred more frequently in the R-FC group than in the R-CHOP group, but the frequency of grade 3 or 4 infections was balanced (17% and 14%, respectively). In 274 of the 316 patients who were randomly assigned to maintenance therapy, rituximab reduced the risk of progression or death by 45% (in remission after 4 years, 58%, vs. 29% with interferon alfa; hazard ratio for progression or death, 0.55; 95% confidence interval, 0.36 to 0.87; P=0.01). Among patients who had a response to R-CHOP, maintenance therapy with rituximab significantly improved overall survival (4-year survival rate, 87%, vs. 63% with interferon alfa; P=0.005).

CONCLUSIONS

R-CHOP induction followed by maintenance therapy with rituximab is effective for older patients with mantle-cell lymphoma. (Funded by the European Commission and others; ClinicalTrials.gov number, NCT00209209.).

The clathrin-binding domain of CALM and the OM-LZ domain of AF10 are sufficient to induce acute myeloid leukemia in mice

The t(10;11)(p13-14;q14-21) translocation, giving rise to the CALM-AF10 fusion gene, is a recurrent chromosomal rearrangement observed in patients with poor prognosis acute myeloid leukemia (AML). Although splicing of the CALM-AF10 fusion transcripts has been described in AML patients, the contribution of different CALM and AF10 domains to in vivo leukemogenesis remains to be defined. We therefore performed detailed structure-function studies of the CALM-AF10 fusion protein. We demonstrate that fusion of the C-terminal 248 amino acids of CALM, which include the clathrin-binding domain, to the octapeptide motif-leucine-zipper (OM-LZ) domain of AF10 generated a fusion protein (termed CALM-AF10 minimal fusion (MF)), with strikingly enhanced transformation capabilities in colony assays, providing an efficient system for the expeditious assessment of CALM-AF10-mediated transformation. Leukemias induced by the CALM-AF10 (MF) mutant recapitulated multiple aspects of full-length CALM-AF10-induced leukemia, including aberrant Hoxa cluster upregulation, a characteristic molecular lesion of CALM-AF10 leukemias. In summary, this study indicates that collaboration of the clathrin-binding and the OM-LZ domains of CALM-AF10 is sufficient to induce AML. These findings further suggest that future approaches to antagonize CALM-AF10-induced transformation should incorporate strategies, which aim at blocking these key domains.