Safety of AFM11 in the treatment of patients with B-cell malignancies: findings from two phase 1 studies.

BACKGROUND: The prognosis for patients with relapsed and/or refractory (R/R) non-Hodgkin's lymphoma (NHL) or acute lymphoblastic leukaemia (ALL) remains poor, with existing treatments having significant side effects. Developed for the treatment of these cancers, AFM11 is a tetravalent, bispecific humanised recombinant antibody construct (TandAb®) designed to bind to human CD19 and CD3 and lead to the activation of T cells inducing apoptosis and killing of malignant B cells. METHODS: Two open-label, multicentre, dose-escalation phase 1 studies evaluated the safety, pharmacokinetics and activity of AFM11 in patients with R/R CD19-positive B cell NHL (AFM11-101) and in patients with CD19 + B-precursor Philadelphia-chromosome negative ALL (AFM11-102). Adverse events (AEs) were assessed and recorded; imaging (NHL) or bone marrow assessment (ALL) were used to evaluate response. Additional pharmacodynamic assays undertaken included cytokine release analysis and B-cell and T-cell depletion. RESULTS: In AFM11-101, 16 patients with R/R NHL received AFM11 in five different dose cohorts. Of which, 14 experienced drug-related treatment-emergent AEs (TEAEs) [including five serious AEs (SAEs)], five patients experienced dose-limiting toxicity (DLT) and ten patients discontinued the study. The high number of neurological events led to a decrease in infusion frequency during the study. No objective response to treatment was observed. In AFM11-102, 17 patients with R/R ALL received AFM11 in six different dose cohorts. Thirteen patients experienced drug-related TEAEs (including four SAEs), DLTs occurred in two patients and five patients discontinued the study. An objective response was recorded in three patients. The maximum tolerated dose could not be determined in either study due to early termination. CONCLUSIONS: AFM11 treatment was associated with frequent neurological adverse reactions that were severe in some patients. In ALL, some signs of activity, albeit short-lived, were observed whereas no activity was observed in patients with NHL; therefore, further clinical development was terminated. TRIAL REGISTRATION: NCT02106091 . Safety Study to Assess AFM11 in Patients With Relapsed and/or Refractory CD19 Positive B-cell NHL. Registered April 2014. NCT02848911 . Safety Study to Assess AFM11 in Patients With Relapsed or Refractory Adult B-precursor ALL. Registered July 2016.

Loss of SUV420H2-Dependent Chromatin Compaction Drives Right-Sided Colon Cancer Progression.

BACKGROUND & AIMS: Epigenetic processes regulating gene expression contribute markedly to epithelial cell plasticity in colorectal carcinogenesis. The lysine methyltransferase SUV420H2 comprises an important regulator of epithelial plasticity and is primarily responsible for trimethylation of H4K20 (H4K20me3). Loss of H4K20me3 has been suggested as a hallmark of human cancer due to its interaction with DNMT1. However, the role of Suv4-20h2 in colorectal cancer is unknown. METHODS: We examined the alterations in histone modifications in patient-derived colorectal cancer organoids. Patient-derived colorectal cancer organoids and mouse intestinal organoids were genetically manipulated for functional studies in patient-derived xenograft and orthotopic transplantation. Gene expression profiling, micrococcal nuclease assay, and chromatin immunoprecipitation were performed to understand epigenetic regulation of chromatin states and gene expression in patient-derived and mouse intestinal organoids. RESULTS: We found that reduced H4K20me3 levels occurred predominantly in right-sided patient-derived colorectal cancer organoids, which were associated with increased chromatin accessibility. Re-compaction of chromatin by methylstat, a histone demethylase inhibitor, resulted in reduced growth selectively in subcutaneously grown tumors derived from right-sided cancers. Using mouse intestinal organoids, we confirmed that Suv4-20h2-mediated H4K20me3 is required for maintaining heterochromatin compaction and to prevent R-loop formation. Cross-species comparison of Suv4-20h2-depleted murine organoids with right-sided colorectal cancer organoids revealed a large overlap of gene signatures involved in chromatin silencing, DNA methylation, and stemness/Wnt signaling. CONCLUSIONS: Loss of Suv4-20h2-mediated H4K20me3 drives right-sided colorectal tumorigenesis through an epigenetically controlled mechanism of chromatin compaction. Our findings unravel a conceptually novel approach for subtype-specific therapy of this aggressive form of colorectal cancer.

Prognostic factors and outcome of adult allogeneic hematopoietic stem cell transplantation patients admitted to intensive care unit during transplant hospitalization.

Patients undergoing allogeneic hematopoietic stem cell transplantation have a high morbidity and mortality, especially after admission to intensive care unit (ICU) during peri-transplant period. The objective of this study was to identify new clinical and biological parameters and validate prognostic scores associated with ICU, short-and long-term survival. Significant differences between ICU survivors and ICU non-survivors for the clinical parameters invasive mechanical ventilation, urine output, heart rate, mean arterial pressure, and amount of vasopressors have been measured. Among prognostic scores (SOFA, SAPSII, PICAT, APACHE II, APACHE IV) assessing severity of disease and predicting outcome of critically ill patients on ICU, the APACHE II score has shown most significant difference (p = 0.002) and the highest discriminative power (area under the ROC curve (AUC) 0.74). An elevated level of lactate at day of admission was associated with poor survival on ICU and the most significant independent parameter (p < 0.001). In our cohort kidney damage with low urine output has a highly relevant impact on ICU, short- and long-term overall survival. The APACHE II score was superior predicting ICU mortality compared to all other tested prognostic scores for patients on ICU during peri-transplant period.

Granulocyte functions are independent of arginine availability.

Arginine depletion via myeloid cell arginase is critically involved in suppression of the adaptive immune system during cancer or chronic inflammation. On the other hand, arginine depletion is being developed as a novel anti-tumor metabolic strategy to deprive arginine-auxotrophic cancer cells of this amino acid. In human immune cells, arginase is mainly expressed constitutively in PMNs. We therefore purified human primary PMNs from healthy donors and analyzed PMN function as the main innate effector cell and arginase producer in the context of arginine deficiency. We demonstrate that human PMN viability, activation-induced IL-8 synthesis, chemotaxis, phagocytosis, generation of ROS, and fungicidal activity are not impaired by the absence of arginine in vitro. Also, profound pharmacological arginine depletion in vivo via ADI-PEG20 did not inhibit PMN functions in a mouse model of pulmonary invasive aspergillosis; PMN invasion into the lung, activation, and successful PMN-dependent clearance of Aspergillus fumigatus and survival of mice were not impaired. These novel findings add to a better understanding of immunity during inflammation-associated arginine depletion and are also important for the development of therapeutic arginine depletion as anti-metabolic tumor therapy.

A microarray analysis of gene expression patterns during early phases of newt lens regeneration.

PURPOSE: Notophthalmus viridescens, the red-spotted newt, possesses tremendous regenerative capabilities. Among the tissues and organs newts can regenerate, the lens is regenerated via transdifferentiation of the pigment epithelial cells of the dorsal iris, following complete removal (lentectomy). Under normal conditions, the same cells from the ventral iris are not capable of regenerating. This study aims to further understand the initial signals of lens regeneration. METHODS: We performed microarray analysis using RNA from a dorsal or ventral iris isolated 1, 3, and 5 days after lentectomy and compared to RNA isolated from an intact iris. This analysis was supported with quantitative real-time polymerase chain reaction (qRT-PCR) of selected genes. RESULTS: Microarrays showed 804 spots were differentially regulated 1, 3, and 5 days post-lentectomy in the dorsal and ventral iris. Functional annotation using Gene Ontology revealed interesting terms. Among them, factors related to cell cycle and DNA repair were mostly upregulated, in the microarray, 3 and 5 days post-lentectomy. qRT-PCR for rad1 and vascular endothelial growth factor receptor 1 showed upregulation for the dorsal iris 3 and 5 days post- lentectomy and for the ventral iris 5 days post-lentectomy. Rad1 was also upregulated twofold more in the dorsal iris than in the ventral iris 5 days post-lentectomy (p<0.001). Factors related to redox homeostasis were mostly upregulated in the microarray in all time points and samples. qRT-PCR for glutathione peroxidase 1 also showed upregulation in all time points for the ventral and dorsal iris. For the most part, mitochondrial enzymes were downregulated with the notable exception of cytochrome c-related oxidases that were mostly upregulated at all time points. qRT-PCR for cytochrome c oxidase subunit 2 showed upregulation especially 3 days post-lentectomy for the dorsal and ventral iris (p<0.001). Factors related to extracellular matrix and tissue remodeling showed mostly upregulation (except collagen I) for all time points and samples. qRT-PCR for stromelysin 1/2 alpha and avidin showed upregulation in all the time points for the dorsal and ventral iris. CONCLUSIONS: The results show that the dorsal iris and the ventral iris follow the same general pattern with some distinct differences especially 5 days after lentectomy. In addition, while the expression of genes involved in DNA repair, redox homeostasis, and tissue remodeling in preparation for proliferation and transdifferentiation is altered in the entire iris, the response is more prominent in the dorsal iris following lentectomy.

A de novo assembly of the newt transcriptome combined with proteomic validation identifies new protein families expressed during tissue regeneration.

BACKGROUND: Notophthalmus viridescens, an urodelian amphibian, represents an excellent model organism to study regenerative processes, but mechanistic insights into molecular processes driving regeneration have been hindered by a paucity and poor annotation of coding nucleotide sequences. The enormous genome size and the lack of a closely related reference genome have so far prevented assembly of the urodelian genome. RESULTS: We describe the de novo assembly of the transcriptome of the newt Notophthalmus viridescens and its experimental validation. RNA pools covering embryonic and larval development, different stages of heart, appendage and lens regeneration, as well as a collection of different undamaged tissues were used to generate sequencing datasets on Sanger, Illumina and 454 platforms. Through a sequential de novo assembly strategy, hybrid datasets were converged into one comprehensive transcriptome comprising 120,922 non-redundant transcripts with a N50 of 975. From this, 38,384 putative transcripts were annotated and around 15,000 transcripts were experimentally validated as protein coding by mass spectrometry-based proteomics. Bioinformatical analysis of coding transcripts identified 826 proteins specific for urodeles. Several newly identified proteins establish novel protein families based on the presence of new sequence motifs without counterparts in public databases, while others containing known protein domains extend already existing families and also constitute new ones. CONCLUSIONS: We demonstrate that our multistep assembly approach allows de novo assembly of the newt transcriptome with an annotation grade comparable to well characterized organisms. Our data provide the groundwork for mechanistic experiments to answer the question whether urodeles utilize proprietary sets of genes for tissue regeneration.

Spiked-in pulsed in vivo labeling identifies a new member of the CCN family in regenerating newt hearts.

The newt Notophthalmus viridescens , which belongs to the family of salamanders (Urodela), owns remarkable regenerative capacities allowing efficient scar-free repair of various organs including the heart. Salamanders can regrow large parts of the myocardium unlike mammals, which cannot replace lost cardiomyocytes efficiently. Unfortunately, very little is known about the molecules and the regulatory circuits facilitating efficient heart regeneration in newts or salamanders. To identify proteins that are involved in heart regeneration, we have developed a pulsed SILAC-based mass spectrometry method based on the detection of paired peptide peaks after ¹³C6-lysine incorporation into proteins in vivo. Proteins were identified by matching mass spectrometry derived peptide sequences to a recently established normalized newt EST library. Our approach enabled us to identify more than 2200 nonredundant proteins in the regenerating newt heart. Because of the pulsed in vivo labeling approach, accurate quantification was achieved for 1353 proteins, of which 72 were up- and 31 down-regulated with a (|log 2 ratio| > 1) during heart regeneration. One deregulated member was identified as a new member of the CCN protein family, showing a wound specific activation. We reason that the detection of such deregulated newt-specific proteins in regenerating hearts supports the idea of a local evolution of tissue regeneration in salamanders. Our results significantly improve understanding of dynamic changes in the complex protein network that underlies heart regeneration and provides a basis for further mechanistic studies.