Pinch-1 was up-regulated in leukemia BMSC and its possible effect.

Department of Hematology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, China.
Clinical and Experimental Medicine (Impact Factor: 2.83). 02/2012; DOI: 10.1007/s10238-012-0176-7
Source: PubMed

ABSTRACT Pinch-1, a widely expressed focal adhesion protein, has been demonstrated to be up-regulated in multiple solid tumor-associated stromal cells, particularly at invasive edges. It was supposed that Pinch-1 was intimately associated with development and progression of tumors. The expression of Pinch-1 in hematopoietic microenvironment in patients with leukemia remains unclear. This study focused on the expression of Pinch-1 in bone marrow stromal cells (BMSCs) from leukemia patients and its possible effect. BMSC was isolated and cultured from bone marrow in leukemia patients and normal healthy donors. RT-PCR and Western blot analysis were performed to determine Pinch-1 mRNA and protein level in BMSC, respectively. Lentiviral vector containing Pinch-1 siRNA was constructed, and the recombinant lentivirus particle was packaged in 293 cells. Effectiveness of Pinch-1 siRNA was determined by Western blot. The proliferation, apoptosis and motility of leukemia BMSC subjected to Pinch-1 knockdown using siRNA were tested by flow cytometry, TUNEL assay and Transwell system, respectively. Pinch-1 mRNA and protein were significantly up-regulated in ALL and AML BMSC compared to normal BMSC (p < 0.01). Although there was no difference in Pinch-1 mRNA between ALL and AML BMSC, cellular levels of Pinch-1 protein in ALL BMSC were significantly higher than that in AML BMSC (p < 0.01). Overexpressed Pinch-1 was significantly reduced in leukemia BMSC transfected with Pinch-1 siRNA evidenced by Western blot. Flow cytometry analysis showed that the percentage of cells in S + G2 phases in leukemia BMSC transfected with Pinch-1 siRNA was significantly lower than control (p < 0.01). The percentage of apoptotic cells in leukemia BMSC transfected with Pinch-1 siRNA was 19.8 ± 1.0%, significantly higher than controls (p < 0.01). The number of leukemia BMSC transfected with Pinch-1 siRNA that migrated to the lower chamber after culturing for 24 h was 8.4 ± 1.1 per field, significantly lower than controls (p < 0.01). Pinch-1 mRNA and protein in leukemia BMSC were up-regulated drastically compared with BMSC from healthy donors. Leukemia BMSC displayed hypoproliferation, decreased migration and increased apoptosis after transfecting Pinch-1 siRNA.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Hematopoiesis takes place preferentially within bone cavities, suggesting that bone-derived factors contribute to blood formation. Hematopoietic stem and progenitor cells (HSPCs) can be mobilized from the bone marrow parenchyma to the circulation by various agonists whose common downstream action leads to alteration in the expression or function of the chemokine CXCL12 and adhesion molecules mediating migration. Granulocyte colony-stimulating factor (G-CSF), the most prevalent drug used to mobilize HSPCs, dramatically suppresses osteoblast function. Recent studies suggest that G-CSF-mediated suppression requires signals from the sympathetic nervous system (SNS). This review summarizes emerging concepts thought to contribute to stem cell migration.
    Annals of the New York Academy of Sciences 12/2007; 1116:392-413. · 4.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Stromal cells generated in long-term cultures appear to follow a vascular smooth muscle differentiation pathway. Such a pathway, comprising several steps hallmarked by the expression of cytoskeletal and extracellular matrix markers, is found not only for bone marrow stromal cells, but also for stromal cells generated from the different developmental sites of hematopoiesis (yolk sac, aorta-gonad-mesonephros region, fetal liver, and spleen). Factors responsible for this differentiation pathway and its functional significance are discussed. The mesenchymal founder cell might be, at least for bone marrow, a mesenchymal stem cell (MSC), giving rise to stromal cells, endothelial cells, adipocytes, osteoblasts, and chondrocytes. A feature that distinguishes the MSC lineage from that of the hematopoietic stem cell lineage is that differentiation pathways are not strictly delineated, since even apparently fully differentiated cells from a given lineage have the potential to convert into another lineage (phenotype "plasticity") and intermediate cell phenotypes are observed. A stochastic Repression/Induction model that would account for this plasticity is proposed.
    Stem Cells 02/2002; 20(3):205-14. · 7.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: PINCH-1 is a widely expressed focal adhesion protein that forms a ternary complex with integrin-linked kinase (ILK) and CH-ILKBP/actopaxin/alpha-parvin (abbreviated as alpha-parvin herein). We have used RNA interference, a powerful approach of reverse genetics, to investigate the functions of PINCH-1 and ILK in human cells. We report here the following. First, PINCH-1 and ILK, but not alpha-parvin, are essential for prompt cell spreading and motility. Second, PINCH-1 and ILK, like alpha-parvin, are crucial for cell survival. Third, PINCH-1 and ILK are required for optimal activating phosphorylation of PKB/Akt, an important signaling intermediate of the survival pathway. Whereas depletion of ILK reduced Ser473 phosphorylation but not Thr308 phosphorylation of PKB/Akt, depletion of PINCH-1 reduced both the Ser473 and Thr308 phosphorylation of PKB/Akt. Fourth, PINCH-1 and ILK function in the survival pathway not only upstream but also downstream (or in parallel) of protein kinase B (PKB)/Akt. Fifth, PINCH-1, ILK and to a less extent alpha-parvin are mutually dependent in maintenance of their protein, but not mRNA, levels. The coordinated down-regulation of PINCH-1, ILK, and alpha-parvin proteins is mediated at least in part by proteasomes. Finally, increased expression of PINCH-2, an ILK-binding protein that is structurally related to PINCH-1, prevented the down-regulation of ILK and alpha-parvin induced by the loss of PINCH-1 but failed to restore the survival signaling or cell shape modulation. These results provide new insights into the functions of PINCH proteins in regulation of ILK and alpha-parvin and control of cell behavior.
    Journal of Biological Chemistry 01/2004; 278(51):51324-33. · 4.65 Impact Factor