Thrombopoietin-independent Megakaryocyte Differentiation of Hematopoietic Progenitor Cells from Patients with Myeloproliferative Neoplasms
Primary hematopoietic stem and progenitor cell (HSPC)-derived megakaryocytes are a valuable tool for translational research interrogating disease pathogenesis and developing new therapeutic avenues for patients with hematologic disorders including myeloproliferative neoplasms (MPNs). Thrombopoietin (TPO)-independent proliferation and megakaryocyte differentiation play a central role in the pathogenesis of essential thrombocythemia and myelofibrosis, two MPN subtypes that are characterized by increased numbers of bone marrow megakaryocytes and somatic mutations in either JAK2, CALR, or MPL. However, current culture strategies generally use healthy HSPCs for megakaryocyte production and are not optimized for the investigation of TPO-independent or TPO-hypersensitive growth and megakaryocyte-directed differentiation of primary patient–derived HSPCs. Here, we describe a detailed protocol covering all necessary steps for the isolation of CD34+ HSPCs from the peripheral blood of MPN patients and the subsequent TPO-independent differentiation into CD41+ megakaryocytes using both a collagen-based colony assay and a liquid culture assay. This protocol provides a novel, reproducible, and cost-effective approach for investigating megakaryocyte growth and differentiation properties from primary MPN patient cells that can be easily adapted for research on other megakaryocyte-related disorders.
Graphical abstract
Schematic representation of the isolation of CD34+ progenitor cells and subsequent TPO-independent megakaryocyte differentiation
Low-viscosity Matrix Suspension Culture for Human Colorectal Epithelial Organoids and Tumoroids
Three-dimensional culture of human normal colorectal epithelium and cancer tissue as organoids and tumoroids has transformed the study of diseases of the large intestine. A widely used strategy for generating patient-derived colorectal organoids and tumoroids involves embedding cells in domes of extracellular matrix (ECM). Despite its success, dome culture is not ideal for scalable expansion, experimentation, and high-throughput screening applications. Our group has developed a protocol for growing patient-derived colorectal organoids and tumoroids in low-viscosity matrix (LVM) suspension culture. Instead of embedding colonic crypts or tumor fragments in solid ECM, these are grown suspended in medium containing only a low percentage of ECM. Compared with dome cultures, LVM suspension culture reduces the labor and cost of establishing and passaging organoids and tumoroids, enables rapid expansion, and is readily adaptable for high-throughput screening.
Graphical abstract:
Generation of organoids and tumoroids from human large intestine using LVM suspension culture (Created with BioRender.com).
Strategy of Isolating ‘Primed’ Tumor Initiating Cells Based on Mitochondrial Transmembrane Potential
Various stem cells have been found to be dependent on mitochondrial energetics. The role of mitochondria in regulating the self-renewal of normal stem cells and stem-like tumor initiating cells (TICs) is increasingly being appreciated. We proposed that TIC populations have a sub population of cells that are “primed” by mitochondria for self-renewal. Using ovarian cancer model, we have developed a protocol to identify and isolate these “primed” cells using Fluorescence-Assisted Cell Sorting (FACS). We combined live cell stains for a functional marker of TICs and for mitochondrial transmembrane potential to enrich TICs with higher mitochondrial potential that form in vitro spheroids 10-fold more than the other TICs with lower mitochondrial potential. This protocol can be directly used or modified to be used in various cell types. Thus, this protocol is anticipated to be invaluable for the basic understanding of mitochondrial and energetic heterogeneity within stem cell population, and may also prove valuable in translational studies in regenerative medicine and cancer biology.
Isolation of Stem Cells, Endothelial Cells and Pericytes from Human Infantile Hemangioma
Investigating Neural Stem Cell and Glioma Stem Cell Self-renewal Potential Using Extreme Limiting Dilution Analysis (ELDA)
3D Culture Protocol for Testing Gene Knockdown Efficiency and Cell Line Derivation
Primary Cultures from Human GH-secreting or Clinically Non-functioning Pituitary Adenomas
FACS-based Isolation of Neural and Glioma Stem Cell Populations from Fresh Human Tissues Utilizing EGF Ligand
Isolation and Separation of Epithelial CD34+ Cancer Stem Cells from Tgfbr2-deficient Squamous Cell Carcinoma
Melanoma Stem Cell Sphere Formation Assay