Characterization of miRNomes in Acute and Chronic Myeloid Leukemia Cell Lines

AbstractMyeloid leukemias are highly diverse diseases and have been shown to be associated with microRNA (miRNA) expression aberrations. The present study involved an in-depth miRNome analysis of two human acute myeloid leukemia (AML) cell lines, HL-60 and THP-1, and one human chronic myeloid leukemia (CML) cell line, K562, via massively parallel signature sequencing. mRNA expression profiles of these cell lines that were established previously in our lab facilitated an integrative analysis of miRNA and mRNA expression patterns. miRNA expression profiling followed by differential expression analysis and target prediction suggested numerous miRNA signatures in AML and CML cell lines. Some miRNAs may act as either tumor suppressors or oncomiRs in AML and CML by targeting key genes in AML and CML pathways. Expression patterns of cell type-specific miRNAs could partially reflect the characteristics of K562, HL-60 and THP-1 cell lines, such as actin filament-based processes, responsiveness to stimulus and phagocytic activity. miRNAs may also regulate myeloid differentiation, since they usually suppress differentiation regulators. Our study provides a resource to further investigate the employment of miRNAs in human leukemia subtyping, leukemogenesis and myeloid development. In addition, the distinctive miRNA signatures may be potential candidates for the clinical diagnosis, prognosis and treatment of myeloid leukemias

Evaluation of Cytotoxicity, Cell Cycle, and Apoptosis Induction of Methyl Thiosemicarbazone Complex with Copper on K562 Cell Line

Background & Aims:  Chronic human myeloid leukemia (CML) is caused by mutations and changes in stem cells. This study aimed to investigate the toxicity, apoptosis, and cell cycle of thiosemicarbazone complex with copper on the human chronic myelogenous K562 leukemia cell line. Materials & Methods:  After culturing the human K562 cell line, it was exposed to the combination of methyl thiosemicarbazone complex with copper in different concentrations and durations. Trypan blue dye exclusion test and MTT were used to determine cell viability and cell growth inhibition. The occurrence of apoptosis was examined by dual acridine orange/ethidium bromide (AO/EB) fluorescent staining and fluorescence microscopy, cell cycle analysis, and dual PI/AnnexinV staining using flow cytometry. Results:  The data obtained from the present study showed morphological changes resulting from apoptosis and cell cycle arrest in Sub G1 in the presence of phosphatidylserine in the outer leaflet of the cell membrane due to treatment with thiosemicarbazone compound. It also decreased the biological growth of the K562 cell line in a concentration-/ and time-dependent manner. Conclusion:  effective at low concentrations and short duration of action, this compound can be a suitable candidate for future pharmacological studies on treating CML

Epigenetic dysregulation in chronic myeloid leukaemia: A myriad of mechanisms and therapeutic options

The onset of global epigenetic changes in chromatin that drive tumor proliferation and heterogeneity is a hallmark of many forms cancer. Identifying the epigenetic mechanisms that govern these changes and developing therapeutic approaches to modulate them, is a well-established avenue pursued in translational cancer medicine. Chronic myeloid leukemia (CML) arises clonally when a hematopoietic stem cell (HSC) acquires the capacity to produce the constitutively active tyrosine kinase BCR-ABL1 fusion protein which drives tumor development. Treatment with tyrosine kinase inhibitors (TKI) that target BCR-ABL1 has been transformative in CML management but it does not lead to cure in the vast majority of patients. Thus novel therapeutic approaches are required and these must target changes to biological pathways that are aberrant in CML − including those that occur when epigenetic mechanisms are altered. These changes may be due to alterations in DNA or histones, their biochemical modifications and requisite ‘writer’ proteins, or to dysregulation of various types of non-coding RNAs that collectively function as modulators of transcriptional control and DNA integrity. Here, we review the evidence for subverted epigenetic mechanisms in CML and how these impact on a diverse set of biological pathways, on disease progression, prognosis and drug resistance. We will also discuss recent progress towards developing epigenetic therapies that show promise to improve CML patient care and may lead to improved cure rates

Dysregulated Expression of MiR-19b, MiR-25, MiR-17, WT1, and CEBPA in Patients with Acute Myeloid Leukemia and Association with Graft versus Host Disease after Hematopoietic Stem Cell Transplantation

Objectives Acute myeloid leukemia (AML) is a blood malignancy characterized by the proliferation of aberrant cells in the bone marrow and blood that interfere with normal blood cells. We have investigated whether changes in the level of micro-ribonucleic acid (miR)-19b, miR-17, and miR-25, Wilms' tumor (WT1), and CCAAT enhancer-binding protein α (CEBPA) genes expression affect disease prognosis and clinical outcome in AML patients. Materials and Methods The expression level of miR-19-b, miR-17, and miR-25, as well as WT1 and CEBPA genes in a group of patients and controls as well as different risk groups (high, intermediate, and favorite risk), M3 versus non-M3, and graft-versus-host disease (GvHD) versus non-GvHD patients were assessed using a quantitative SYBR Green real-time polymerase chain reaction method. Results When compared with the baseline level at the period of diagnosis before chemotherapy, the expression of miR-19b and miR-17 in AML patients increased significantly after chemotherapy. The level of miR-19b and miR-25 expression in AML patients with M3 and non-M3 French–American–British subgroups differ significantly. MiR-19b and miR-25 expression was elevated in GvHD patients, while miR-19b and miR-25 expression was somewhat decreased in GvHD patients compared with non-GvHD patients, albeit the difference was not statistically significant. Also, patients with different cytogenetic aberrations had similar levels of miR-19-b and miR-25 expression. Conclusion MiR-19b, miR-17, and miR-25 are aberrantly expressed in AML patients' peripheral blood leukocytes, which may play a role in the development of acute GvHD following hematopoietic stem cell transplantation

miRNAs link metabolic reprogramming to oncogenesis

The most profound biochemical phenotype of cancer cells is their ability to metabolize glucose to lactate, even under aerobic conditions. This alternative metabolic circuitry is sufficient to support the biosynthetic and energy requirements for cancer cell proliferation and metastasis. Alterations in oncogenes and tumor suppressor genes are involved in the metabolic switch of cancer cells to aerobic glycolysis, increased glutaminolysis and fatty acid biosynthesis. MiRNAs mediate fine-tuning of genes involved directly or indirectly in cancer metabolism. In this review, we discuss the regulatory role of miRNAs on enzymes, signaling pathways and transcription factors involved in glucose and lipid metabolism. We further consider the therapeutic potential of metabolism-related miRNAs in cancer

Extracellular vesicles in hematological malignancies: EV-dence for reshaping the tumoral microenvironment

Following their discovery at the end of the 20th century, extracellular vesicles (EVs) ranging from 50-1,000 nm have proven to be paramount in the progression of many cancers, including hematological malignancies. EVs are a heterogeneous group of cell-derived membranous structures that include small EVs (commonly called exosomes) and large EVs (microparticles). They have been demonstrated to participate in multiple physiological and pathological processes by allowing exchange of biological material (including among others proteins, DNA and RNA) between cells. They are therefore a crucial way of intercellular communication. In this context, malignant cells can release these extracellular vesicles that can influence their microenvironment, induce the formation of a tumorigenic niche, and prepare and establish distant niches facilitating metastasis by significantly impacting the phenotypes of surrounding cells and turning them toward supportive roles. In addition, EVs are also able to manipulate the immune response and to establish an immunosuppressive microenvironment. This in turn allows for ideal conditions for heightened chemoresistance and increased disease burden. Here, we review the latest findings and reports studying the effects and therapeutic potential of extracellular vesicles in various hematological malignancies. The study of extracellular vesicles remains in its infancy; however, rapid advances in the analysis of these vesicles in the context of disease allow us to envision prospects to improve the detection and treatment of hematological malignancies

Interactions between platelets and hematopoietic cells

In addition to their primary role in hemostasis, platelets are increasingly recognized as important participants in numerous biological processes. Their ability to adhere to and communicate with different immune cells, endothelial cells, and cancer cells makes them a natural nexus that participates in development of different diseases, including cancer. Thus, one could also surmise interactions between platelets and hematopoietic stem and progenitor cells. Previous studies have shown that bone marrow function recovers more quickly after transplantation with mobilized peripheral blood stem cells than with bone marrow-derived hematopoietic stem cells. A major difference between the two techniques is that mobilized peripheral blood stem cells are exposed to activated platelets during harvesting. As platelets communicate with a myriad of blood cells and carry cargoes of hundreds of proteins and other biologically active compounds, I wanted to investigate potential interactions between platelets and hematopoietic progenitor cells, including leukemic cells from acute myelogenous leukemia (AML). Using flow cytometric analysis and colony forming unit (CFU) assessment, our group show that platelet releasate inhibits proliferation, conserves erythroid phenotype, and increases levels of erythroid progenitors in cultivated mobilized peripheral blood stem and progenitor cells. Expression of CD14 antigen and monocyte-associated mRNAs also increased, suggesting that platelet releasate induced monocytopoiesis. Upon activation, platelets degranulate and release the content of their alpha granules, dense granules, and lysosomes. Activated platelets also shed platelet microparticles (PMP), membranous vesicles that contain platelet cargo. These microparticles are internalized by many different cells, including cancer cells, and are known to alter their biological behavior. Using flow cytometry and fluorescence microscopy, we show that these microparticles are internalized by AML cells, with a subsequent transfer of miR-125a and miR-125b and a downregulation of the pro-apoptotic protein PUMA. This microRNA transfer could explain the anti-apoptotic properties of PMPs that we also observed following treatment with several apoptosis inductors, where daunorubicin is of particular interest, as it is a mainstay in the treatment of AML. Thus, multiple potential interactions between platelets and hematopoietic progenitor cells and leukemic cells are identified. The results must be confirmed by more advanced in vitro and translational models before their clinical relevance can be fully appreciated, but the findings may benefit ex vivo production of monocytes and erythrocytes and support the use of therapeutic platelet inhibition in AML patients

Precision Medicine

This colligated Special Issue of Pharmaceutics on Precision Medicine: Applied Concepts of Pharmacogenomics in Patients with Various Diseases and Polypharmacy offers to the reader a series of articles that describe the concept of Precision Medicine, discuss its implementation process and limitations, demonstrate its value by illustrating some clinical cases, and open the door to new and more sophisticated techniques and applications