Search

Diffuse large B-cell lymphoma (DLBCL) can be subdivided into activated B-cell like (ABC) and germinal center B-cell-like (GCB) DLCBL. Self-antigen engagement of B-cell receptors (BCRs) in ABC tumors induces their clustering, thereby initiating chronic active signaling and activation of NF-kB and PI3 kinase. Constitutive BCR signaling is essential in some GCB tumors but primarily activates PI3 kinase. We devised genome-wide CRISPR-Cas9 screens to identify regulators of IRF4, a direct transcriptional target of NF-kB and an indicator of proximal BCR signaling in ABC DLBCL. Unexpectedly, inactivation of N-linked protein glycosylation by the oligosaccharyltransferase-B (OST-B) complex reduced IRF4 expression. OST-B inhibition of BCR glycosylation reduced BCR clustering and internalization while promoting its association with CD22, which attenuated PI3 kinase and NF-kB activation. By directly interfering with proximal BCR signaling, OST-B inactivation killed models of ABC and GCB DLBCL, supporting the development of selective OST-B inhibitors for the treatment of these aggressive cancers.

Somatic mutations can lead to the transformation of healthy cells into malignant cells and allow their evasion from immune surveillance. To uncover genes that play a role in the detection and lysis of tumor cells by natural killer (NK) cells, a B lymphoblastoid cell line was subjected to a genome-wide CRISPR screen. Among the top hits that facilitated NK evasion wasSPPL3, which encodes an intramembrane protease that cleaves transmembrane glycosyltransferases in the Golgi apparatus.SPPL3-deficient cells accumulated glycosyltransferases, such as acetylglucosaminyltransferase 5 (MGAT5), and displayed increased N-glycosylation. Binding of NK receptors NKG2D and CD2 to their corresponding ligands MICB and CD58, and binding of rituximab to CD20, was disrupted bySPPL3-deletion. Inhibition of N-glycan maturation restored receptor binding and sensitivity to NK cells. To elucidate the mechanism of this resistant phenotype, a secondary CRISPR screen was performed inSPPL3-deficient cells. This screen identified glycosyltransferases that catalyze the formation of highly branched N-glycans and N-acetyl-lactosamine (LacNAc) extensions as key regulators that prevent killing. A significant enrichment of poly-LacNAc-containing tetra-antennary species was confirmed by glycoproteomic analysis. These findings provide mechanistic insight into howSPPL3deletions have been linked to cancer.

Burkitt lymphoma (BL) is an aggressive lymphoma type that is currently treated by intensive chemoimmunotherapy. Despite the favorable clinical outcome for most patients with BL, chemotherapy-related toxicity and disease relapse remain major clinical challenges, emphasizing the need for innovative therapies. Using genome-scale CRISPR-Cas9 screens, we identified B-cell receptor (BCR) signaling, specific transcriptional regulators, and one-carbon metabolism as vulnerabilities in BL. We focused on serine hydroxymethyltransferase 2 (SHMT2), a key enzyme in one-carbon metabolism. Inhibition of SHMT2 by either knockdown or pharmacological compounds induced anti-BL effects in vitro and in vivo. Mechanistically, SHMT2 inhibition led to a significant reduction of intracellular glycine and formate levels, which inhibited the mTOR pathway and thereby triggered autophagic degradation of the oncogenic transcription factor TCF3. Consequently, this led to a collapse of tonic BCR signaling, which is controlled by TCF3 and is essential for BL cell survival. In terms of clinical translation, we also identified drugs such as methotrexate that synergized with SHMT inhibitors. Overall, our study has uncovered the dependency landscape in BL, identified and validated SHMT2 as a drug target, and revealed a mechanistic link between SHMT2 and the transcriptional master regulator TCF3, opening up new perspectives for innovative therapies.

Multiple myeloma (MM) is a malignant hematological disease with the clonal proliferation of plasma cells and accounts for approximately 10% of all malignant hematologic entities [1]. In eligible pa...

Epstein-Barr virus (EBV) infects human B cells and reprograms them to allow virus replication and persistence. One key viral factor in this process is latent membrane protein 2A (LMP2A), which has been described as a B cell receptor (BCR) mimic promoting malignant transformation. However, how LMP2A signaling contributes to tumorigenesis remains elusive. By comparing LMP2A and BCR signaling in primary human B cells using phosphoproteomics and transcriptome profiling, we identified molecular mechanisms through which LMP2A affects B cell biology. Consistent with the literature, we found that LMP2A mimics a subset of BCR signaling events, including tyrosine phosphorylation of the kinase SYK, the calcium initiation complex consisting of BLNK, BTK, and PLCγ2, and its downstream transcription factor NFAT. However, the majority of LMP2A-induced signaling events markedly differed from those induced by BCR stimulation. These included differential phosphorylation of kinases, phosphatases, adaptor proteins, transcription factors such as nuclear factor κB (NF-κB) and TCF3, as well as widespread changes in the transcriptional output of LMP2A-expressing B cells. LMP2A affected apoptosis and cell-cycle checkpoints by dysregulating the expression of apoptosis regulators such as BCl-xL and the tumor suppressor retinoblastoma-associated protein 1 (RB1). LMP2A cooperated with MYC and mutant cyclin D3, two oncogenic drivers of Burkitt lymphoma, to promote proliferation and survival of primary human B cells by counteracting MYC-induced apoptosis and by inhibiting RB1 function, thereby promoting cell-cycle progression. Our results indicate that LMP2A is not a pure BCR mimic but rather rewires intracellular signaling in EBV-infected B cells that optimizes cell survival and proliferation, setting the stage for oncogenic transformation.

Objectives Clostridioides difficile infections (CDI) are common in autologous (auto-HSCT) or allogenic hematopoietic stem cell transplant (allo-HSCT) recipients. However, the impact of CDI on patient outcomes is controversial. We conducted this study to examine the impact of CDI on patient outcomes. Methods We performed a retrospective single-center study, including 191 lymphoma patients receiving an auto-HSCT and 276 acute myeloid leukemia (AML) patients receiving an allo-HSCT. The primary endpoint was overall survival (OS). Secondary endpoints were causes of death and, for the allo-HSCT cohort, GvHD- and relapse-free survival (GRFS). Results The prevalence of CDI was 17.6% in the AML allo-HSCT and 7.3% in the lymphoma auto-HSCT cohort. A higher prevalence of bloodstream infections, but no differences concerning OS or cause of death were found for patients with CDI in the auto-HSCT cohort. [AU] In the allo-HSCT cohort, OS and GRFS were similar between CDI and non-CDI patients. However, the leading cause of death was relapse among non-CDI patients, but it was infectious diseases in the CDI group with fewer deaths due to relapse. Conclusions CDI was not associated with worse survival in patients receiving a hematopoietic stem cell transplantation, and there were even fewer relapse-related deaths in the AML allo-HSCT cohort.

Hypomethylating agents decitabine and azacytidine are regarded as interchangeable in the treatment of acute myeloid leukemia (AML). However, their mechanisms of action remain incompletely understood, and predictive biomarkers for HMA efficacy are lacking. Here, we show that the bioactive metabolite decitabine triphosphate, but not azacytidine triphosphate, functions as activator and substrate of the triphosphohydrolase SAMHD1 and is subject to SAMHD1-mediated inactivation. Retrospective immunohistochemical analysis of bone marrow specimens from AML patients at diagnosis revealed that SAMHD1 expression in leukemic cells inversely correlates with clinical response to decitabine, but not to azacytidine. SAMHD1 ablation increases the antileukemic activity of decitabine in AML cell lines, primary leukemic blasts, and xenograft models. AML cells acquire resistance to decitabine partly by SAMHD1 up-regulation. Together, our data suggest that SAMHD1 is a biomarker for the stratified use of hypomethylating agents in AML patients and a potential target for the treatment of decitabine-resistant leukemia., In acute myeloid leukemia, hypomethylating agents decitabine and azacytidine are used interchangeably. Here, the authors show that the major metabolite of decitabine, but not azacytidine, is subject to SAMHD1 inactivation, highlighting SAMHD1 as a potential biomarker and therapeutic target

Enterococcus species are commensals of the human gastrointestinal tract with the ability to cause invasive infections. For patients with hematological diseases, enterococcal bloodstream infections (BSI) constitute a serious clinical complication which may even be aggravated if the pathogen is vancomycin-resistant. Therefore, we analyzed the course of BSI due to vancomycin-susceptible enterococci (VSE) in comparison to vancomycin-resistant enterococci (VRE) on patient survival. In this retrospective single-center study, BSI were caused by VRE in 47 patients and by VSE in 43 patients. Baseline patient characteristics were similar in both groups. Concerning infection-related characteristics, an increased CRP value and an increased rate of prior colonization with multidrug-resistant organisms were detected in the VRE BSI group. More enterococcal invasive infections were found in the VSE group. The primary endpoint, overall survival (OS) at 30 days after BSI, was significantly lower in patients with VRE BSI compared to patients with VSE BSI (74.5% vs. 90.7%, p = 0.039). In a multivariate regression analysis, VRE BSI and a Charlson comorbidity index higher than 4 were independent factors associated with 30-day mortality. Moreover, we found that VRE with an additional teicoplanin resistance showed a trend towards an even lower OS.

Acute myeloid leukemia (AML) is a hematologic malignancy that is treated in medically fit patients with intensive induction chemotherapy (IT) and postremission therapy to achieve a complete and long-term remission. The incidence of obesity in the general population is steadily increasing and has been identified as a major risk factor for all-cause mortality. Despite previous studies assessing the role of obesity in AML patients undergoing IT, there is an ongoing debate on the impact of obesity on patient outcome as well as the optimal dosing strategy in obese AML patients. We conducted a retrospective registry study assessing 1677 AML patients who were treated with IT for newly diagnosed AML. The primary endpoint was overall survival (OS) while event-free survival (EFS), the rate of first complete remission (CR1), relapse/refractory disease and non-relapse/refractory-related mortality (NRRrM), treatment-related toxicities, patient comorbidities and chemotherapy dosing strategies were analyzed as secondary endpoints. Obese patients (body mass index, BMI ≥ 30) displayed a significant inferior median OS (29.44 vs. 47.94 months, p = 0.015) without a significant difference in median EFS (7.8 vs. 9.89 months, p = 0.3) compared to non-obese patients (BMI < 30). The cumulative incidence (CI) of NRRrM was significantly increased in obese patients compared to non-obese patients while no differences could be observed regarding the CI of relapsed or refractory disease. Obesity was identified as an independent risk factor for death (HR 1.27, [95% CI 1.07-1.51], p = 0.005) in a multivariable Cox regression analysis. When the cohort was stratified by age (≥/< 60 years), the difference in OS as well as the significantly increased CI of NRRrM was only observed in patients ≥ 60 years. Notably, obese patients demonstrated higher rates of cardiovascular and metabolic comorbidities regardless of their age. No disparities for OS, EFS, CR1 rate or treatment-related toxicities were observed when the entire study population was stratified for the used dosing strategy (dose calculation using total body weight, idealized body weight, adjusted idealized body weight or capped at body surface area of 2 m 2). In conclusion, the present study identifies obesity as a major independent risk factor for worse overall survival and increased CI of non-relapse/refractory-related mortality in older (≥60 years) AML patients undergoing curative IT. These findings may be most likely attributed to obesity related comorbidities and not to dose adaption of chemotherapy in obese AML patients. Disclosures Schliemann: Boehringer-Ingelheim: Research Funding; Abbvie: Consultancy, Other: travel grants; Philogen S.p.A.: Consultancy, Honoraria, Research Funding; Astellas: Consultancy; AstraZeneca: Consultancy; BMS: Consultancy, Other: travel grants; Jazz Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy; Roche: Consultancy; Pfizer: Consultancy. Krause: Siemens: Research Funding; Takeda: Honoraria; Pfizer: Honoraria; art-tempi: Honoraria; Kosmas: Honoraria; Gilead: Other: travel support; Abbvie: Other: travel support. Haenel: Jazz: Consultancy, Honoraria; GSK: Consultancy; Bayer Vital: Honoraria; Takeda: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Amgen: Consultancy; Celgene: Consultancy, Honoraria. Fransecky: Amgen: Honoraria; Abbvie: Honoraria, Research Funding; Novartis: Honoraria; Medac: Honoraria; Takeda: Honoraria. Burchert: Novartis: Honoraria, Research Funding; AOP Orphan: Honoraria, Research Funding; Pfizer: Honoraria; Incyte: Honoraria; Gilead: Honoraria; BMS: Honoraria. Crysandt: Incyte: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees. Müller-Tidow: Janssen: Consultancy, Research Funding; Bioline: Research Funding; Pfizer: Research Funding. Platzbecker: Celgene/BMS: Honoraria; AbbVie: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Takeda: Honoraria; Geron: Honoraria. Baldus: Jazz: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Celgene/BMS: Honoraria.

BACKGROUND Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment option for patients with acute myeloid leukemia (AML). During transplantation, patients undergo a period of severe neutropenia, which puts them at high risk for infectious complications. However, the impact of patient colonization with multidrug-resistant organisms (MDRO) on overall survival remains unclear. METHODS In this retrospective, single-center study, the authors analyzed data from 264 patients with AML who underwent a first allo-HSCT between January 2006 and March 2016 at their institution. Primary endpoints were overall survival and nonrelapse-related mortality. RESULTS One hundred forty-two of 264 patients (53.8%) were colonized by at least 1 MDRO, mainly with vancomycin-resistant Enterococcus faecalis/faecium (n = 122). The characteristics of colonized patients did not differ from those of MDRO-negative patients with respect to median age (53.5 vs 53 years), cytogenetic risk according to European LeukemiaNet criteria, remission status before allo-HSCT (first or second complete remission: 55.7% vs 60.7%, respectively; active disease: 44.4% vs 39.3%, respectively), donor type, or hematopoietic cell transplantation-comorbidity index (HCT-CI). Compared with noncolonized patients, MDRO-positive patients had an inferior probability of survival at 5 years (43.3% vs 65.5%; P = .002), primarily because of a higher cumulative incidence of nonrelapse-related mortality (33.9% vs 9.4%; P < .001). Death caused by infections occurred in 15.5% of colonized patients versus 4.9% of noncolonized patients. There was no difference in the cumulative incidence of relapse in MDRO-positive versus MDRO-negative patients (33.8% vs 42.1%, respectively; P = .798). CONCLUSIONS The current data emphasize the importance of regular MDRO screenings and prompt further investigations into the impact of colonization with MDRO on the immune system after allo-HSCT. Cancer 2018;124:286-96. © 2017 American Cancer Society.

Summary: Clonal hematopoiesis of indeterminate potential (CHIP) is caused by recurrent somatic mutations leading to clonal blood cell expansion. However, direct evidence of the fitness of CHIP-mutated human hematopoietic stem cells (HSCs) in blood reconstitution is lacking. Because myeloablative treatment and transplantation enforce stress on HSCs, we followed 81 patients with solid tumors or lymphoid diseases undergoing autologous stem cell transplantation (ASCT) for the development of CHIP. We found a high incidence of CHIP (22%) after ASCT with a high mean variant allele frequency (VAF) of 10.7%. Most mutations were already present in the graft, albeit at lower VAFs, demonstrating a selective reconstitution advantage of mutated HSCs after ASCT. However, patients with CHIP mutations in DNA-damage response genes showed delayed neutrophil reconstitution. Thus, CHIP-mutated stem and progenitor cells largely gain on clone size upon ASCT-related blood reconstitution, leading to an increased future risk of CHIP-associated complications. : With age, human hematopoiesis becomes affected by blood cell clones with recurrent acquired mutations, resulting in clonal hematopoiesis (CHIP). Ortmann et al. show that hematopoietic stress caused by autologous stem cell transplantation and cytotoxic therapy promotes both size and number of mutant clones in 81 myeloma and lymphoma patients. Keywords: clonal hematopoiesis, CHIP, autologous stem cell transplantation, ASCT, hematopoietic stress, hematopoietic stem cells, clonal dominance, chemotherapy, somatic mutations, leukemia

Non-clear cell renal cell carcinomas (nccRCC) are rare diseases with heterogeneous histopathologically and genetically defined entities. The clinical data on optimal systemic treatments of nccRCC is rather limited. In this review, the current World Health Organization (WHO) classification of nccRCC based on histopathologic and genetic findings is reported. Regarding systemic treatment options, the most commonly used agents are mTOR inhibitors like everolimus or temsirolimus, or tyrosine kinase inhibitors like sunitinib. 2 small randomized clinical trials with nccRCC comparing sunitinib with everolimus revealed a trend towards a better progression-free survival (PFS) and overall survival (OS) in favor of sunitinib. In RCC with predominant sarcomatoid features, both chemotherapy and targeted agents are reported without any preference for outcome. For subsequent lines of therapy, some case reports describe promising effects of PD-1 or PD-L1 inhibitors in nccRCC including sarcomatoid subtype and Bellini duct carcinoma. Currently, nccRCCs are treated similarly to clear cell RCC or, whenever possible, within clinical trials. Clinical trials with immune checkpoint inhibitors are ongoing.

BACKGROUND In hematology and oncology, in particular in the setting of allogeneic hematopoietic stem cell transplantation (allo-HSCT), vancomycin-resistant Enterococcus spp. (VRE) colonization rates are high due to previous hospital stays and preceding antibiotic treatment and colonized patients have a lower overall survival (OS). OBJECTIVE We reanalyzed our previously published cohort, to unravel which colonization timepoints before and during allo-HSCT might be predictive for the subsequent outcome. PATIENTS AND METHODS We report about 268 patients with acute myeloid leukemia receiving an allo-HSCT between 2006 and 2016. RESULTS We identified 129 never-colonized patients, 15 previously colonized patients (positive only before admission for allo-HSCT), 41 persistently colonized patients (positive before and at admission for allo-HSCT), and 83 newly colonized patients (positive only during allo-HSCT). Persistently and newly colonized patients had a worse 60 months OS due to increased incidence of non-relapse-related mortality (NRM) than never-colonized patients (OS: never-colonized: 61.0% vs persistently colonized: 43.5%; P = 0.023 vs newly colonized: 45.6%; P = 0.046). In contrast, OS and NRM of never-colonized and previously colonized patients as well as between persistently and newly colonized patients were similar. CONCLUSION Patients can lose their VRE colonization status and acquisition of VRE during inpatient stay for allo-HSCT decreases survival to a similar extend as persistent colonization.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment option for patients with acute myeloid leukemia (AML). During transplantation, patients undergo a period of severe neutropenia, which puts them at high risk for infectious complications. However, the impact of patient colonization with multidrug-resistant organisms (MDRO) on overall survival remains unclear.In this retrospective, single-center study, the authors analyzed data from 264 patients with AML who underwent a first allo-HSCT between January 2006 and March 2016 at their institution. Primary endpoints were overall survival and nonrelapse-related mortality.One hundred forty-two of 264 patients (53.8%) were colonized by at least 1 MDRO, mainly with vancomycin-resistant Enterococcus faecalis/faecium (n = 122). The characteristics of colonized patients did not differ from those of MDRO-negative patients with respect to median age (53.5 vs 53 years), cytogenetic risk according to European LeukemiaNet criteria, remission status before allo-HSCT (first or second complete remission: 55.7% vs 60.7%, respectively; active disease: 44.4% vs 39.3%, respectively), donor type, or hematopoietic cell transplantation-comorbidity index (HCT-CI). Compared with noncolonized patients, MDRO-positive patients had an inferior probability of survival at 5 years (43.3% vs 65.5%; P = .002), primarily because of a higher cumulative incidence of nonrelapse-related mortality (33.9% vs 9.4%; P.001). Death caused by infections occurred in 15.5% of colonized patients versus 4.9% of noncolonized patients. There was no difference in the cumulative incidence of relapse in MDRO-positive versus MDRO-negative patients (33.8% vs 42.1%, respectively; P = .798).The current data emphasize the importance of regular MDRO screenings and prompt further investigations into the impact of colonization with MDRO on the immune system after allo-HSCT. Cancer 2018;124:286-96. © 2017 American Cancer Society.

A significant increase in infections caused by multidrug-resistant organisms (MDRO) has been observed in recent years, resulting in an increase of mortality in all fields of health care. Hematological patients are particularly affected by MDRO infections because of disease- and therapy-related immunosuppression. To determine the impact of colonization with MDRO on overall survival, we retrospectively analyzed data from patients undergoing autologous hematopoietic stem cell transplantation at our institution. In total, 184 patients were identified, mainly patients with lymphomas (n = 98, 53.3%), multiple myelomas (n = 80, 43.5%), germ cell cancers (n = 5, 2.7%), or acute myeloid leukemia (n = 1, .5%). Forty patients (21.7%) tested positive for MDRO colonization. At a median follow-up time of 21.5 months, the main causes of death were infection in colonized and disease progression in noncolonized patients. Nonrelapse mortality (NRM) was higher in patients who tested positive for MDRO than in the noncolonized group (25.4% versus 3%, P .001). Interestingly, NRM in neutropenia after autologous transplantation did not differ between colonized and noncolonized patients. Colonized patients, however, had inferior overall survival after autologous transplantation in univariate (61.7% versus 73.3%, P = .005) as well as in multivariate analysis (hazard ratio, 2.463; 95% confidence interval, 1.311 to 4.626; P = .005). We conclude that the period after discharge from hospital after autologous transplantation seems critical and patients with MDRO colonization should be observed closely for infections in the post-transplantation period in outpatient care.

Autologous hematopoietic stem cell transplantation (auto-HSCT) provides a potentially curative treatment option for relapsed and refractory lymphomas. Obesity displays an emerging epidemic risk factor for global mortality and is associated with an increased mortality in cancer patients. To date, the impact of obesity on the outcome of lymphoma patients undergoing auto-HSCT is understudied. We conducted a retrospective single-center study assessing 119 lymphoma patients who underwent auto-HSCT. Overall survival (OS) served as the primary endpoint whereas progression free survival (PFS), cumulative incidence of non-relapse related mortality (NRM) and cumulative incidence of relapse were analyzed as secondary endpoints. Obese patients (Body mass index, BMI≥30) had significantly lower OS (45.3% vs. 77.9%; p = 0.005) and PFS (29.8% vs. 67.2%; p

Integrated analysis of genomes, transcriptomes, proteomes and drug responses of cancer cell lines (CCLs) is an emerging approach to uncover molecular mechanisms of drug action. We extend this paradigm to measuring proteome activity landscapes by acquiring and integrating quantitative data for 10,000 proteins and 55,000 phosphorylation sites (p-sites) from 125 CCLs. These data are used to contextualize proteins and p-sites and predict drug sensitivity. For example, we find that Progesterone Receptor (PGR) phosphorylation is associated with sensitivity to drugs modulating estrogen signaling such as Raloxifene. We also demonstrate that Adenylate kinase isoenzyme 1 (AK1) inactivates antimetabolites like Cytarabine. Consequently, high AK1 levels correlate with poor survival of Cytarabine-treated acute myeloid leukemia patients, qualifying AK1 as a patient stratification marker and possibly as a drug target. We provide an interactive web application termed ATLANTiC (http://atlantic.proteomics.wzw.tum.de), which enables the community to explore the thousands of novel functional associations generated by this work., Proteome activity has a major role in cancer progression and response to drugs. Here, the authors use comprehensive proteomic and phosphoproteomic data, in conjunction with drug-sensitivity screens, to generate a community resource consisting of landscapes of pathway and kinase activity across different cell lines