Real-Time Characterization of Clonal Fate Decisions in Complex Leukemia Samples by Fluorescent Genetic Barcoding.

Clonal heterogeneity in acute myeloid leukemia (AML) forms the basis for treatment failure and relapse. Attempts to decipher clonal evolution and clonal competition primarily depend on deep sequencing approaches. However, this prevents the experimental confirmation of the identified disease-relevant traits on the same cell material.

A pro B cell population forms the apex of the leukemic hierarchy in Hoxa9/Meis1-dependent AML.

Relapse is a major challenge to therapeutic success in acute myeloid leukemia (AML) and can be partly associated with heterogeneous leukemic stem cell (LSC) properties. In the murine Hoxa9/Meis1-dependent (H9M) AML model, LSC potential lies in three defined immunophenotypes, including LincKit progenitor cells (Lin), Gr1CD11bcKit myeloid cells, and lymphoid cells (Lym). Previous reports demonstrated their interconversion and distinct drug sensitivities.

A Multiplex CRISPR-Screen Identifies PLA2G4A as Prognostic Marker and Druggable Target for HOXA9 and MEIS1 Dependent AML.

and are frequently upregulated in acute myeloid leukemia (AML), including those with MLL-rearrangement. Because of their pivotal role in hemostasis, HOXA9 and MEIS1 appear non-druggable. We, thus, interrogated gene expression data of pre-leukemic (overexpressing ) and leukemogenic (overexpressing and ; H9M) murine cell lines to identify cancer vulnerabilities.

An Improved Lentiviral Fluorescent Genetic Barcoding Approach Distinguishes Hematopoietic Stem Cell Properties in Multiplexed Experiments.

Hematopoietic stem cells (HSCs) represent a rare cell population of particular interest for biomedical research and regenerative medicine. Various marker combinations enable the isolation of HSCs, but fail to reach purity in transplantation assays. To reduce animal consumption, we developed a multiplexing system based on lentiviral fluorescent genetic barcoding (FGB) to enable the parallel characterization of multiple HSC samples within single animals.

Competitive sgRNA Screen Identifies p38 MAPK as a Druggable Target to Improve HSPC Engraftment.

Previous gene therapy trials for X-linked chronic granulomatous disease (X-CGD) lacked long-term engraftment of corrected hematopoietic stem and progenitor cells (HSPCs). Chronic inflammation and high levels of interleukin-1 beta (IL1B) might have caused aberrant cell cycling in X-CGD HSPCs with a concurrent loss of their long-term repopulating potential. Thus, we performed a targeted CRISPR-Cas9-based sgRNA screen to identify candidate genes that counteract the decreased repopulating capacity of HSPCs during gene therapy.

An endothelial cell line infected by Kaposi's sarcoma-associated herpes virus (KSHV) allows the investigation of Kaposi's sarcoma and the validation of novel viral inhibitors in vitro and in vivo.

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), a tumor of endothelial origin predominantly affecting immunosuppressed individuals. Up to date, vaccines and targeted therapies are not available. Screening and identification of anti-viral compounds are compromised by the lack of scalable cell culture systems reflecting properties of virus-transformed cells in patients.

Tuning of thermo-responsive self-assembly monolayers on gold for cell-type-specific control of adhesion.

Self-assembled monolayers (SAMs) on gold containing a thermo-responsive poly( N-isopropylacrylamide)-poly(ethylene glycol)-thiol copolymer were formed. These layers show considerable potential for inducing enzyme-free and gentle detachment of cultivated cells. In an effort to optimize detachment of cells, including strongly adhering ones, two approaches are presented.

Control of cell detachment in a microfluidic device using a thermo-responsive copolymer on a gold substrate.

The control of cell adhesion is crucial in many procedures in cellular biotechnology. A thermo-responsive poly(N-isopropylacrylamide)-poly(ethylene glycol)-thiol (PNIPAAm-PEG-thiol) copolymer was synthesized for the formation of self-assembled monolayers (SAM) that allow the control of adhesion of cells on gold substrates. The contact angle of water on these layers varies between 65 degrees at a temperature of 45 degrees C and 54 degrees at 25 degrees C.

99mTc labelled model drug carriers - labeling, stability and organ distribution in rats.

The surface characteristics of intravenously administered particulate drug carriers decisively influence the protein adsorption that is regarded as a key factor for the in vivo fate of the carriers. We labeled surface-modified polymer particles with the gamma-emitting radioisotope 99mTc in order to test their properties in blood and follow their in vivo fate. The biodistribution was different in various types of polymer particles.

Functional groups on polystyrene model nanoparticles: influence on protein adsorption.

The surface characteristics of intravenously administered particulate drug carriers decisively influence the protein adsorption that is regarded as a key factor for the in vivo fate of the carriers. Latex nanoparticles were synthesized to study the influence of different basic and acidic functional groups on particulate surfaces on the protein adsorption from human serum. The protein mass adsorbed to the particles was assessed by BCA protein assay, the protein adsorption patterns were analyzed by two-dimensional electrophoresis.

Influence of surface charge density on protein adsorption on polymeric nanoparticles: analysis by two-dimensional electrophoresis.

Plasma protein adsorption is regarded as a key factor for the in vivo organ distribution of intravenously administered colloidal drug carriers, and strongly depends on their surface characteristics, e.g. surface hydrophobicity or charge.

Nanoparticles with decreasing surface hydrophobicities: influence on plasma protein adsorption.

The rapid uptake of i.v. injected nanoparticles by cells of the mononuclear phagocytic system (MPS) is a major obstacle for a long blood circulation time and a drug targeting to sites other than the MPS.