Relevance of renin expression by real-time PCR in acute myeloid leukemia

Identification of a Seven-lncRNA-mRNA Signature for Recurrence and Prognostic Prediction in Relapsed Acute Lymphoblastic Leukemia Based on WGCNA and LASSO Analyses

Abnormal expressions of long noncoding RNAs (lncRNAs) and protein-encoding messenger RNAs (mRNAs) are important for the development of childhood acute lymphoblastic leukemia (ALL). This study developed an lncRNA-mRNA integrated classifier for the prediction of recurrence and prognosis in relapsed childhood ALL by using several transcriptome data. Weighted gene coexpression network analysis revealed that green, turquoise, yellow, and brown modules were preserved across the TARGET, GSE60926, GSE28460, and GSE17703 datasets, and they were associated with clinical relapse and death status. A total of 184 genes in these four modules were differentially expressed between recurrence and nonrecurrence samples. Least absolute shrinkage and selection operator analysis showed that seven genes constructed a prognostic signature (including one lncRNA: LINC00652 and six mRNAs: INSL3, NIPAL2, REN, RIMS2, RPRM, and SNAP91). Kaplan-Meier curve analysis observed that patients in the high-risk group had a significantly shorter overall survival than those of the low-risk group. Receiver operating characteristic curve analysis demonstrated that this signature had high accuracy in predicting the 5-year overall survival and recurrence outcomes, respectively. LINC00652 may function by coexpressing with the above prognostic genes (INSL3, SNAP91, and REN) and lipid metabolism-related genes (MIA2, APOA1). Accordingly, this lncRNA-mRNA-based classifier may be clinically useful to predict the recurrence and prognosis for childhood ALL. These genes represent new targets to explain the mechanisms for ALL.

Local Renin-Angiotensin system in normal hematopoietic and multiple myeloma-related progenitor cells

Objective: The prominent functions of the local renin-angiotensin system (RAS) in primitive hematopoiesis further support the hypothesis that local autocrine bone marrow RAS could also be active in neoplastic hematopoiesis. The aim of this study is to examine critical RAS elements in normal CD34+ hematopoietic stem cells and multiple myeloma (MM)-related progenitor cells.

Materials and Methods: The study group comprised the total bone marrow cells (CBM) of 10 hematologically normal people, the CD34+ stem cell samples (CD34+CBM) of 9 healthy donors for allogeneic peripheral stem cell transplantation, and the CD34+ stem cell samples (CD34+MM) of 9 MM patients undergoing autologous peripheral stem cell transplantation. We searched for the gene expression of the major RAS components in healthy hematopoietic cells and myeloma cells by quantitative real-time polymerase chain reaction analysis.

Results: RENIN, angiotensinogen (ANGTS), and angiotensin converting enzyme-I (ACE I) mRNA expression levels of CBM were significantly higher than those in myeloma patients (p=0.03, p=0.002, and p=0.0008, respectively). Moreover, RENIN and ANGTS mRNA expression levels were significantly higher in CD34+ stem cell samples of healthy allogeneic donors compared to those in myeloma patients (p=0.001 and p=0.01). However, ACE I expression levels were similar in CD34+CBM and CD34+MM hematopoietic cells (p=0.89).

Conclusion: Although found to be lower than in the CBM and CD34+CBM hematopoietic cells, the local RAS components were also expressed in CD34+MM hematopoietic cells. This point should be kept in mind while focusing on the immunobiology of MM and the processing of autologous cells during the formation of transplantation treatment protocols.

Local bone marrow renin-angiotensin system in primitive, definitive and neoplastic haematopoiesis

The locally active ligand peptides, mediators, receptors and signalling pathways of the haematopoietic BM (bone marrow) autocrine/paracrine RAS (renin-angiotensin system) affect the essential steps of definitive blood cell production. Haematopoiesis, erythropoiesis, myelopoiesis, formation of monocytic and lymphocytic lineages, thrombopoiesis and other stromal cellular elements are regulated by the local BM RAS. The local BM RAS is present and active even in primitive embryonic haematopoiesis. ACE (angiotensin-converting enzyme) is expressed on the surface of the first endothelial and haematopoietic cells, forming the marrow cavity in the embryo. ACE marks early haematopoietic precursor cells and long-term blood-forming CD34(+) BM cells. The local autocrine tissue BM RAS may also be active in neoplastic haematopoiesis. Critical RAS mediators such as renin, ACE, AngII (angiotensin II) and angiotensinogen have been identified in leukaemic blast cells. The local tissue RAS influences tumour growth and metastases in an autocrine and paracrine fashion via the modulation of numerous carcinogenic events, such as angiogenesis, apoptosis, cellular proliferation, immune responses, cell signalling and extracellular matrix formation. The aim of the present review is to outline the known functions of the local BM RAS within the context of primitive, definitive and neoplastic haematopoiesis. Targeting the actions of local RAS molecules could represent a valuable therapeutic option for the management of neoplastic disorders.

Review: Pathobiological aspects of the local bone marrow renin-angiotensin system: a review

The local haematopoietic bone marrow (BM) renin—angiotensin system (RAS) mediates pathobiological alterations of haematopoiesis in an autocrine/paracrine/intracrine fashion. Recent data further indicated the existence of angiotensin-converting enzyme (ACE) in human primitive lympho-haematopoietic cells, embryonic, foetal and adult haematopoietic tissues. Human umbilical cord blood cells also express renin, angiotensinogen, and ACE mRNAs. As ACE and other angiotensin peptides function in human haematopoietic stem cells (HSCs) throughout haematopoietic ontogeny and adulthood, local RAS could also have a function in HSC plasticity, and the development of haematological neoplastic disorders. The presence of ACE on leukaemic blast cells within leukaemic BM, on erythroleukaemic cells, ACE-expressing macrophages in lymph nodes of Hodgkin disease, renin activity in leukaemic blasts, angiotensin II as an autocrine growth factor for AML, increased renin gene activity during NUP98-HOXA9 enhanced blast formation, higher levels of BB9/ACE (+) AML isoforms, and altered JAK-STAT pathway as a link between RAS and leukaemia indicated the wide pathobiological aspects of local BM RAS. The comparable biological actions of local RASs throughout the human body (including myocardium, pancreas, pituitary gland, ovary and kidney) represent the true basis for the search of their prominence in tissue functions. Recent data and perspectives of the local BM RAS in health and disease are reviewed in this paper.

Effects of the NUP98-DDX10 oncogene on primary human CD34+ cells: role of a conserved helicase motif

NUP98 gene rearrangements occur in acute myeloid leukemia and result in the expression of fusion proteins. One of the most frequent is NUP98-DDX10 that fuses a portion of NUP98 to a portion of DDX10, a putative DEAD-box RNA helicase. Here we show that NUP98-DDX10 dramatically increases proliferation and self-renewal of primary human CD34+ cells, and disrupts their erythroid and myeloid differentiation. It localizes to their nuclei and extensively deregulates gene expression. Comparison to another leukemogenic NUP98 fusion, NUP98-HOXA9, reveals a number of genes deregulated by both oncoproteins, including HOX genes, COX-2, MYCN, ANGPT1, REN, HEY1, SOX4, and others. These genes may account for the similar leukemogenic properties of NUP98 fusion oncogenes. The YIHRAGRTAR sequence in the DDX10 portion of NUP98-DDX10 represents a major motif shared by DEAD-box RNA helicases that is required for ATP binding, RNA-binding, and helicase functions. Mutating this motif diminished the in vitro transforming ability of NUP98-DDX10, indicating that it plays a role in leukemogenesis. These data demonstrate for the first time the in vitro transforming ability of NUP98-DDX10 and show that it is partially dependent on one of the consensus helicase motifs of DDX10. They also point to common pathways that may underlie leukemogenesis by different NUP98 fusions.