Safety and tolerability of AMG 330 in adults with relapsed/refractory AML: a phase 1a dose-escalation study.

AMG 330, a bispecific T-cell engager (BiTE®) that binds CD33 and CD3 on T cells facilitates T-cell-mediated cytotoxicity against CD33+ cells. This first-in-human, open-label, dose-escalation study evaluated the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of AMG 330 in adults with relapsed/refractory acute myeloid leukemia (R/R AML). Amongst 77 patients treated with AMG 330 (0.

Clinical Significance of Transient Asymptomatic Elevations in Aminotransferase (TAEAT) in Oncology.

Monitoring for liver injury remains an important aspect of drug safety assessment, including for oncotherapeutics. When present, drug-induced liver injury may limit the use or result in the discontinuation of these agents. Drug-induced liver injury can exhibit with a wide spectrum of clinical and biochemical manifestations, ranging from transient asymptomatic elevations in aminotransferases (TAEAT) to acute liver failure.

Leukemic stem cells as a target for eliminating acute myeloid leukemia: Gaps in translational research.

Relapse is common in acute myeloid leukemia (AML) and thought to be due to resistance of underlying leukemic stem cells (LSCs) to current standard therapies, although a lack of tools to measure the quantity and quality of these cells in patients precludes the clinical testing of this concept. This review discusses the current knowledge of LSC properties and appraises strategies aimed to bring the therapeutic targeting of LSCs to the bedside to improve patient outcomes. We highlight pathways and targets of interest and summarize available information on drugs that might eradicate LSCs.

Complement activation in the context of stem cells and tissue repair.

The complement pathway is best known for its role in immune surveillance and inflammation. However, its ability of opsonizing and removing not only pathogens, but also necrotic and apoptotic cells, is a phylogenetically ancient means of initiating tissue repair. The means and mechanisms of complement-mediated tissue repair are discussed in this review.

Hyaluronan in the healthy and malignant hematopoietic microenvironment.

The fate of both endogenous and transplanted stem cells is dependent on the functional status of the regulatory local microenvironment, which is compromised by disease and therapeutic intervention. The glycosaminoglycan hyaluronan (HA) is a critical component of the hematopoietic microenvironment. We summarize recent advances in our understanding of the role of HA in regulating mesenchymal stem cells, osteoblasts, fibroblasts, macrophages, and endothelium in bone marrow (BM) and their crosstalk within the hematopoietic microenvironment.

Homing of neural stem cells from the venous compartment into a brain infarct does not involve conventional interactions with vascular endothelium.

Human neural stem cells (hNSCs) hold great potential for treatment of a wide variety of neurodegenerative and neurotraumatic conditions. Heretofore, administration has been through intracranial injection or implantation of cells. Because neural stem cells are capable of migrating to the injured brain from the intravascular space, it seemed feasible to administer them intravenously if their ability to circumvent the blood-brain barrier was enhanced.

A novel three-dimensional flow chamber device to study chemokine-directed extravasation of cells circulating under physiological flow conditions.

Extravasation of circulating cells from the bloodstream plays a central role in many physiological and pathophysiological processes, including stem cell homing and tumor metastasis. The three-dimensional flow chamber device (hereafter the 3D device) is a novel in vitro technology that recreates physiological shear stress and allows each step of the cell extravasation cascade to be quantified. The 3D device consists of an upper compartment in which the cells of interest circulate under shear stress, and a lower compartment of static wells that contain the chemoattractants of interest.

The chemokine CCL18 causes maturation of cultured monocytes to macrophages in the M2 spectrum.

The observation that human monocytes cultured in the presence of the chemokine CCL18 showed increased survival, led us to profile cytokine expression in CCL18-stimulated versus control cultures. CCL18 caused significantly increased expression of chemokines (CXCL8, CCL2, CCL3 and CCL22), interleukin-10 (IL-10) and platelet-derived growth factor, but no up-regulation of M1 cytokines IL-1β or IL-12. CCL18-stimulated monocytes matured into cells with morphological resemblance to IL-4-stimulated macrophages, and expressed the monocyte marker CD14 as well the M2 macrophage markers CD206 and 15-lipoxygenase, but no mature dendritic cell markers (CD80, CD83 or CD86).

Expression of soluble proteins in Escherichia coli by linkage with the acidic propiece of eosinophil major basic protein.

An expression method has been developed to produce soluble cationic polypeptides in Escherichia coli while avoiding inclusion body deposition. For this technique the recombinant product is linked through a thrombin or factor Xa susceptible bond to the amino-terminal domain of the precursor of eosinophil major basic protein (MBP). This N-terminal domain is strongly acidic and is apparently able to shield eosinophils from the potentially injurious activities of MBP.

Hyaluronan is required for generation of hematopoietic cells during differentiation of human embryonic stem cells.

Hyaluronan (HA) is an important component of the microenvironment in bone marrow, but its role in regulation of the development of hematopoietic cells is not well understood. To address the role of HA in regulation of human embryonic stem cell (hESC) differentiation into the hematopoietic lineage, we screened for genes encoding components of the HA pathway. Using gene arrays, we found that HA synthases and HA receptors are expressed in both undifferentiated and differentiating hESCs.

Hyaluronan inhibits postchemotherapy tumor regrowth in a colon carcinoma xenograft model.

Bone marrow hypoplasia and pancytopenia are among the most undesirable sequelae of chemotherapy for the treatment of cancer. We recently showed that hyaluronan (HA) facilitates hematopoietic recovery in tumor-free animals receiving chemotherapeutic agents. However, following a chemotherapeutic regimen in tumor-bearing animals, it is possible that residual tumor cells might respond to systemic injections of HA.

Alpha 7 subunit of nAChR regulates migration of human mesenchymal stem cells.

The efficient migration of mesenchymal stem cells (MSCs) to diseased tissues is required for the fulfillment of their regenerative potential. Recruitment of circulating cells into the damaged tissues is regulated by a complex network, which includes the non-neural cholinergic system. We found that human MSCs (hMSCs) express nicotinic acetylcholine receptor subunits alpha 7, beta 2 and beta 4.

Hyaluronan stimulates mobilization of mature hematopoietic cells but not hematopoietic progenitors.

Hyaluronan (HA) is expressed by cells in bone marrow where it contributes to the regulation of hematopoietic homeostasis. In this study, we have demonstrated that exogenous low molecular weight HA (LMW HA) polymers mobilize leukocytes, but not hematopoietic progenitor cells, to peripheral blood within a 3 hour time period following HA administration. Mobilization of leukocytes correlated with increased extracellular MMP-9 concentrations induced by LMW HA, but not high molecular weight (HMW) HA.

C3a and C5a are chemotactic factors for human mesenchymal stem cells, which cause prolonged ERK1/2 phosphorylation.

Mesenchymal stem cells (MSCs) have a great potential for tissue repair, especially if they can be delivered efficiently to sites of tissue injury. Since complement activation occurs whenever there is tissue damage, the effects of the complement activation products C3a and C5a on MSCs were examined. Both C3a and C5a were chemoattractants for human bone marrow-derived MSCs, which expressed both the C3a receptor (C3aR) and the C5a receptor (C5aR; CD88) on the cell surface.

Key players in the gene networks guiding ESCs toward mesoderm.

Embryonic stem cells (ESCs) offer a powerful in vitro model to study mechanisms implicated in cell fate decision. Developmental pathways by which pluripotent ESCs become committed to specific lineages are reflected in dynamic changes of signaling and transcriptional programs. However, the mechanisms that govern the regulatory intracellular networks underlying lineage fate decisions and differentiation programs remain poorly understood and differ significantly in different species.

Adhesive interactions between human neural stem cells and inflamed human vascular endothelium are mediated by integrins.

Understanding the mechanisms by which stem cells home precisely to regions of injury or degeneration is of importance to both basic and applied regenerative medicine. Optimizing regenerative processes may depend on identifying the range of molecules that subserve stem cell trafficking. The "rolling" of extravasating cells on endothelium under conditions of physiological flow is the first essential step in the homing cascade and determines cell adhesion and transmigration.

CCL18/PARC stimulates hematopoiesis in long-term bone marrow cultures indirectly through its effect on monocytes.

Chemokines play a role in regulating hematopoietic stem cell function, including migration, proliferation, and retention. We investigated the involvement of CCL18 in the regulation of bone marrow hematopoiesis. Treatment of human long-term bone marrow cultures (LTBMCs) with CCL18 resulted in significant stimulation of hematopoiesis, as measured by the total number of hematopoietic cells and their committed progenitors produced in culture.

Nicotinic acetylcholine receptor-mediated stimulation of endothelial cells results in the arrest of haematopoietic progenitor cells on endothelium.

The function of endothelial cells that contribute to the regulation of haematopoietic stem/progenitor cells (HSPC) migration from peripheral blood into bone marrow can be influenced by extrinsic factors including nicotine. Therefore, the effect of nicotine on HSPC extravasation was studied. Using a parallel laminar flow chamber, we demonstrated an increase in the number of HSPC adhering to the nicotine-exposed endothelium under conditions of physiological shear stress in vitro.

Exposure to nicotine during gestation interferes with the colonization of fetal bone marrow by hematopoietic stem/progenitor cells.

Environmental factors, including cigarette smoke components, can cross the placental barrier and accumulate in amniotic fluid and fetal tissue, and, therefore, interfere with the normal course of ontogenesis. Although cigarette smoke contains numerous compounds, the most adverse effects on mammalian tissues have been associated with nicotine. The aim of this study was to investigate the effect of intrauterine exposure to nicotine on hematopoiesis during fetal development and postpartum.

Hyaluronic acid facilitates the recovery of hematopoiesis following 5-fluorouracil administration.

The fate of hematopoietic stem cells (HSCs) is determined by microenvironmental niches, but the molecular structure of these local networks is not yet completely characterized. Our recent observation that glycosaminoglycan hyaluronic acid (HA), a major component of the bone marrow extracellular matrix, is required for in vitro hematopoiesis led us to suggest a role for HA in structuring the hematopoietic niche. Accordingly, HA deprivation induced by various treatments might lead to an imbalance of normal HSC homeostasis.

A Role of Endogenous Retroviral MCF env Gene in Proliferation of Pluripotent Hemopoietic Progenitors in Mice.

We have investigated the role of endogenous retroviral mink cell focus-forming (MCF) genes in the regulation of mouse bone marrow hemopoietic progenitor cell proliferation. The p15E protein coded by the MCF env gene is expressed by early hemopoietic progenitors, mostly on spleen colony forming units (CFUs-12) and on erythropoietin-independent erythroid progenitors. Stimulation of cell proliferation in hemopoietic precursors by steroid hormone (testosterone propionate) treatment resulted in upregulation of the expression of the endogenous p15E protein on bone marrow cells.

MDA-MB-435 human breast carcinoma cell homo- and heterotypic adhesion under flow conditions is mediated in part by Thomsen-Friedenreich antigen-galectin-3 interactions.

The importance of Thomsen-Friedenreich antigen (T antigen)-galectin-3 interactions in adhesion of human breast carcinoma cells to the endothelium under conditions of flow was studied. Highly metastatic cells (MDA-MB-435) expressing high levels of both galectin-3 and T antigen demonstrated significantly increased adhesion to monolayers of endothelial cells compared with their non-metastatic counterpart (MDA-MB-468) in vitro. Within minutes of adhesion, the highly metastatic cells acquire the ability of enhanced homotypic adhesion, leading to the formation of multicellular aggregates at sites of attachment to endothelial cells in vitro.