Christian W. Scholz

Costimulation by CD137/4–1BB inhibits T cell apoptosis and induces Bcl‐xL and c‐FLIPshort via phosphatidylinositol 3‐kinase and AKT/protein kinase B

Costimulation is essential for induction of T lymphocyte proliferation and inhibition of activation‐induced cell death. While signaling pathways activated following the ligation of the costimulatory molecule CD28 are well defined, less is known about the molecular events induced by alternative costimulators. CD137/4–1BB, a costimulatory member of the tumor necrosis factor receptor family, plays an important role during late primary T cell stimulation. Here, we demonstrate for the first time that inhibition of activation‐induced cell death by exposure to the CD137/4–1BB ligand involves up‐regulation of the anti‐apoptotic protein c‐FLIPshort. Inhibition of T cell death by 4–1BB ligation and up‐regulation of c‐FLIPshort and Bcl‐xL were abolished by blocking the phosphatidylinositol 3‐kinase or the AKT/protein kinase B, which also mediate CD28‐induced inhibition of activation‐induced cell death. Our findings, therefore, demonstrate that costimulatory molecules, although belonging to different protein families and participating in distinct upstream signaling pathways, employ common downstream signaling pathways.

90Yttrium-Ibritumomab-Tiuxetan as First-Line Treatment for Follicular Lymphoma: 30 Months of Follow-Up Data From an International Multicenter Phase II Clinical Trial

PURPOSE We report on a multicenter phase II trial of (90)yttrium-ibritumomab-tiuxetan ((90)YIT) as first-line stand-alone therapy for patients with follicular lymphoma (FL). PATIENTS AND METHODS Fifty-nine patients with CD20(+) FL grade 1 to 3a in stages II, III, or IV, age 50 years old or older requiring therapy were enrolled. They received (90)YIT according to standard procedure. If complete response (CR) or unconfirmed complete response (CRu) without evidence for minimal residual disease (MRD) 6 months after application of (90)YIT was achieved, patients were observed without further intervention. The same applied to patients with partial response (PR) or with stable disease (SD). Patients with CR but with persisting MRD were to receive a consolidation treatment with rituximab. Primary end point was the clinical and molecular response rate. Secondary end points were time to progression, safety, and tolerability. RESULTS Six months after treatment with (90)YIT, 56% of the patients showed a CR or CRu and 31% achieved a PR. After a median follow-up of 30.6 months, the progression-free survival (PFS) was 26 months. There was a trend for shorter PFS in patients with increased lactate dehydrogenase (LDH). Of the 26 patients who had CR 12 months after (90)YIT, only three had relapsed. Median time to next treatment has not been reached. The most common toxicities were transient thrombocytopenia and leukocytopenia. Nonhematologic toxicities never exceeded grade 2 according to Common Terminology Criteria for Adverse Events (CTCAE v2.0). CONCLUSION (90)YIT is well tolerated and achieves high response rates. Patients with increased LDH tend to relapse earlier, and individuals in remission 1 year after (90)YIT appear to have long- lasting responses.

Phase II study of central nervous system (CNS)-directed chemotherapy including high-dose chemotherapy with autologous stem cell transplantation for CNS relapse of aggressive lymphomas

The prognosis of patients with central nervous system relapse of aggressive lymphoma is very poor with no therapy established so far. In a prospective multicenter phase II study, we evaluated a potentially curative chemotherapy-only regimen in these patients. Adult immunocompetent patients 65 years of age or under received induction chemotherapy with MTX/IFO/DEP (methotrexate 4 g/m2 intravenously (i.v.) Day 1, ifosfamide 2 g/m2 i.v. Days 3– 5 and liposomal cytarabine 50 mg intrathecally (i.th) Day 6) and AraC/TT/DEP (cytarabine 3g/m2 i.v. Days 1–2, thiotepa 40 mg/m2 i.v. Day 2 and i.th. liposomal cytarabine 50 mg i.th. Day 3) followed by high-dose chemotherapy with carmustine 400 mg/m2 i.v. Day −5, thiotepa 2×5 mg/kg i.v. Days −4 to −3 and etoposide 150 mg/m2 i.v. Days −5 to −3, and autologous stem cell transplantation Day 0 (HD-ASCT). Thirty eligible patients (median age 58 years) were enrolled. After HD-ASCT (n=24), there was a complete remission in 15 (63%), partial remission in 2 (8%) and progressive disease in 7 (29%) patients. Myelotoxicity was the most adverse event with CTC grade 3/4 infections in 12% of MTX/IFO/DEP courses, 21% of AraC/TT/DEP courses and 46% of HD-ASCT courses. The 2-year time to treatment failure was 49%±19 for all patients and 58%±22 for patients completing HD-ASCT. The protocol assessed proved feasible and highly active with long-lasting remissions in a large proportion of patients. (ClinicalTrials.govIdentifier NCT01148173)

Distinction of acute lymphoblastic leukemia from acute myeloid leukemia through microarray-based DNA methylation analysis.

Patterns of DNA methylation are substantially altered in malignancies compared to normal tissue, with both genome-wide hypomethylation and regional increase of cytosine methylation at dinucleotides of cytosine and guanine, i.e., CpG dinucleotides. While genome-wide hypomethylation renders chromosomes instable, hypermethylation of CpGs in promoter regions is generally associated with transcriptional silencing, e.g., of tumor suppressor genes. To investigate whether disease-specific methylation profiles exist for different entities of acute leukemia, a microarray-based DNA methylation analysis simultaneously assessing 249 CpG dinucleotides originating from 57 genes was employed. Hereby, samples from precursor B-cell acute lymphoblastic leukemia (ALL) could be distinguished from cases of acute myeloid leukemia by virtue of N33, EGR4, CDC2, CCND2, or MOS hypermethylation in ALL.

Inhibition of pan-class I phosphatidyl-inositol-3-kinase by NVP-BKM120 effectively blocks proliferation and induces cell death in diffuse large B-cell lymphoma.

Abstract Diffuse large B-cell lymphoma (DLBCL) is the most frequent aggressive lymphoma, with a great demand for novel treatments for relapsing and refractory disease. Constitutive activation of the phosphatidyl-inositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway is often detected in this lymphoma. Inhibition of this signaling cascade with the pan-class I PI3K inhibitor NVP-BKM120 decreased cell proliferation and increased apoptotic cell death. DLBCL proliferation was further decreased if NVP-BKM120-induced autophagy was blocked. Treatment with NVP-BKM120 was associated with an increase of the pro-apoptotic BH3-only proteins Puma and Bim and down-regulation of the anti-apoptotic Bcl-xL and Mcl-1. Translation of Bcl-xL and Mcl-1 is facilitated by cap-dependent mRNA translation, a process that was partially inhibited by NVP-BKM120. Overall, we demonstrated here the potential of NVP-BKM120 for the treatment of DLBCL.

Concurrent inhibition of PI3-Kinase and mTOR induces cell death in diffuse large B cell lymphomas, a mechanism involving down regulation of Mcl-1

Phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling is frequently dysregulated in diffuse large B cell lymphoma (DLBCL) including the favorable germinal centre B-cell (GCB) and the unfavorable activated B-cell (ABC) subtypes. mTOR promotes cap-dependent translation of proteins, like Mcl-1, through inhibitory phosphorylation of the eukaryotic translation initiation factor 4E binding protein 1 (4EBP1). Inhibition of mTOR by RAD001 reduces proliferation but fails to dephosphorylate 4EBP1 and to induce cell death in either DLBCL subtype. In contrast, concurrent inhibition of PI3K and mTOR with NVP-BEZ235 inhibits proliferation, dephosphorylates 4EBP1, and induces cells death, notably more pronounced in CGB cells. Small RNA interference identifies Mcl-1 as a crucial cell death mediator of both DLBCL subtypes. Inhibition of the PI3K/mTOR/4EBP1 by NVP-BEZ235 results in suppression of the cap-dependent translation initiation complex and concomitant downregulation of Mcl-1 in GCB cell lines. In ABC cell lines, this suppression is possibly compensated by NF-κB- or Pim kinase-mediated signaling.

Primary tumor excision in stage IV breast cancer at diagnosis without influence on survival: a retrospective analysis and review of the literature.

Background: Patients with synchronous metastastic breast cancer and intact primary tumor traditionally undergo systemic treatment. Surgical intervention at the primary site is typically reserved for palliation and often replaceable by radiation. Nevertheless, local surgery in metastatic breast cancer has become an issue of great controversy since retrospective studies published during the recent years suggested a slight benefit from an operative procedure. We evaluated the effect of surgery on long-term survival and progression-free survival in synchronous stage IV breast cancer. Methods: We retrospectively reviewed the records of all breast cancer patients treated at our institution between 1986 and 2007. Information recorded for each patient included age, tumor characteristics, metastasis characteristics, therapy, progression-free survival, and overall survival. Survival data were compared between surgical and nonsurgical patients. Results: 61 patients with synchronous metastastic breast cancer and intact primary tumor were analyzed. 26 patients (43%) received no primary site surgery and 35 (57%) patients had surgery. Overall survival and progression-free survival determined via the Kaplan-Meier method showed no significant difference between the surgery and the non-surgery group. Conclusion: In patients with metastatic breast cancer, the operation of the primary tumor did not influence overall survival or progression-free survival.

Breast Cancer-Associated Thrombotic Microangiopathy

Background: Thrombotic microangiopathy (TMA) is defined as thrombocytopenia and microangiopathic hemolytic anemia. Cancer-associated TMA, a rare but fatal condition, seems an entity distinct from classical thrombotic thrombocytopenic purpura (TTP)/hemolytic uremic syndrome (HUS). Patients and Methods: All patients with breast cancer-associated TMA treated at our institution between 2003 and 2008 were analyzed retrospectively. To elucidate pathophysiological mechanisms, we measured the serum activity of the metalloprotease ADAMTS13. Results: 8 patients were identified. All showed bone marrow infiltration of breast cancer as well as thrombocytopenia, schistocytes, and hemolytic anemia. ADAMTS13 activity was mildly decreased in 4/6 patients (20–108%, normal range 30–120%), but none showed severely low levels as is characteristic of classical TTP. 6 patients were treated with anthracycline-containing fractionated chemotherapy, 5/6 patients experienced partial response. Overall survival was 13 months. Fractionated chemotherapy was well tolerated. Conclusions: Cancer-associated TMA has an underlying mechanism different from classical TTP. While bone marrow infiltration might be of major relevance, ADAMTS13 deficiency seems to be an epiphenomenon. Fractionated chemotherapy resulted in higher remission rates and comparatively long survival.

Assessment of free light chains in the cerebrospinal fluid of patients with lymphomatous meningitis – a pilot study

BackgroundLymphomatous meningitis (LM) represents a severe complication of malignant lymphomas. While clinical suspicion is raised by symptoms ranging from mild disturbances of sensation to severe pain or impaired consciousness, the definite diagnosis of LM is often difficult to obtain. Since B-cell lymphomas are clonally restricted to express either kappa or lambda immunoglobulin light chain, we hypothesised that analysis of free light chain (FLC) ratios might facilitate the diagnosis of LM.MethodsKappa and lambda FLC were measured using a novel nephelometric assay in cerebrospinal fluid (CSF) and serum from 17 patients. 5/17 suffered from LM as demonstrated by cytology, immunocytology, and/or imaging procedures.ResultsMeasurement of FLC concentrations in CSF was achieved for all 17 patients. FLC levels in CSF were lower than serum FLC levels in samples for the same patient obtained at the same time (p < 0.01). CSF and serum FLC concentrations correlated weakly in all patients irrespective of LM status. Significantly more patients with cytopathologically and immunohistochemically proven LM displayed abnormal kappa/lambda FLC ratios in CSF compared to individuals with no LM (p < 0.01).ConclusionThis is the first report demonstrating that a significant proportion of LM patients display an abnormal kappa/lambda FLC ratio in the CSF.

Radioimmunotherapy in relapsed/refractory mantle cell lymphoma patients: final results of a European MCL Network Phase II Trial

Radioimmunotherapy in relapsed/refractory mantle cell lymphoma patients: final results of a European MCL Network Phase II Trial