scholarly journals Nucleophosmin Regulates Cell Cycle Progression and Stress Response in Hematopoietic Stem/Progenitor Cells

2006 ◽  
Vol 281 (24) ◽  
pp. 16536-16545 ◽  
Author(s):  
June Li ◽  
Daniel P. Sejas ◽  
Reena Rani ◽  
Tara Koretsky ◽  
Grover C. Bagby ◽  
...  
Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 312-312
Author(s):  
June Li ◽  
Daniel P. Sejas ◽  
Qishen Pang

Abstract Nucleophosmin (NPM) is a multifunctional protein frequently overexpressed in actively proliferating cells including tumor and hematopoietic stem cells. Strong evidence indicates that NPM is involved in hematopoiesis and leukemic development. Here we report that NPM enhances the proliferative potential of hematopoietic stem/progenitor cells and increases cell survival upon stress challenge. Specifically, lin-Sca1+c-kit+ bone marrow cells transduced with retroviral vector expressing NPM exhibited higher proliferative rates in both short-term liquid culture and clonogenic progenitor cell assays, compared to the cells transduced with empty vector. Interestingly, NPM overexpression appears to inhibit differentiation of myeloid progenitors. Hematopoietic stem/progenitor cells infected with the NPM retrovirus expressed significantly lower levels of mature cell markers Gr-1 and Mac-1 compared to empty vector transduced cells, and majority of the NPM-overexpressing cells remained Sca1+C-Kit+ during the 5-day culture. Bone marrow transplantation experiments demonstrated that NPM overexpression increases long-term multi-lineage repopulating capacity of hematopoietic progenitors. We have not observed any evidence of proliferative disorders or leukemia in recipients transplanted with NPM-expressing progenitors thus far (4 months posttransplantation). Through cell-cycle profile analysis and single-cell division experiments, we showed that NPM overexpression induces rapid entry of hematopoietic progenitors into the cell cycle, probably via promoting G0/G1 to S transition. Furthermore, immunocytochemical and Western-blot analyses demonstrated that NPM-transduced cells expressed higher level of cyclin A compared to vector-transduced cells. Finally, overexpression of NPM significantly increased the survival of hematopoietic progenitors exposed to mitomycin C or hydrogen peroxide, suggesting that NPM can protect cells from DNA damage and oxidative stress. Together, these results indicate that NPM plays an important role in hematopoiesis via mechanisms involving modulation of progenitor differentiation, cell cycle progression, and stress response.


Blood ◽  
2002 ◽  
Vol 99 (5) ◽  
pp. 1585-1593 ◽  
Author(s):  
Anna Jetmore ◽  
P. Artur Plett ◽  
Xia Tong ◽  
Frances M. Wolber ◽  
Robert Breese ◽  
...  

Differences in engraftment potential of hematopoietic stem cells (HSCs) in distinct phases of cell cycle may result from the inability of cycling cells to home to the bone marrow (BM) and may be influenced by the rate of entry of BM-homed HSCs into cell cycle. Alternatively, preferential apoptosis of cycling cells may contribute to their low engraftment potential. This study examined homing, cell cycle progression, and survival of human hematopoietic cells transplanted into nonobese diabetic severe combined immunodeficient (NOD/SCID) recipients. At 40 hours after transplantation (AT), only 1% of CD34+ cells, or their G0(G0CD34+) or G1(G1CD34+) subfractions, was detected in the BM of recipient mice, suggesting that homing of engrafting cells to the BM was not specific. BM of NOD/SCID mice receiving grafts containing approximately 50% CD34+ cells harbored similar numbers of CD34+ and CD34− cells, indicating that CD34+ cells did not preferentially traffic to the BM. Although more than 64% of human hematopoietic cells cycled in culture at 40 hours, more than 92% of cells recovered from NOD/SCID marrow were quiescent. Interestingly, more apoptotic human cells were detected at 40 hours AT in the BM of mice that received xenografts of expanded cells in S/G2+M than in recipients of G0/G1 cells (34.6% ± 5.9% and 17.1% ± 6.3%, respectively; P < .01). These results suggest that active proliferation inhibition in the BM of irradiated recipients maintains mitotic quiescence of transplanted HSCs early AT and may trigger apoptosis of cycling cells. These data also illustrate that trafficking of transplanted cells to the BM is not selective, but lodgment of BM-homed cells may be specific.


2010 ◽  
Vol 19 (4) ◽  
pp. 453-460 ◽  
Author(s):  
Peter J. Quesenberry ◽  
Gerri J. Dooner ◽  
Michael Del Tatto ◽  
Gerald A. Colvin ◽  
Kevin Johnson ◽  
...  

2020 ◽  
Vol 21 (6) ◽  
pp. 2073
Author(s):  
Tomas Zikmund ◽  
Helena Paszekova ◽  
Juraj Kokavec ◽  
Paul Kerbs ◽  
Shefali Thakur ◽  
...  

ISWI chromatin remodeling ATPase SMARCA5 (SNF2H) is a well-known factor for its role in regulation of DNA access via nucleosome sliding and assembly. SMARCA5 transcriptionally inhibits the myeloid master regulator PU.1. Upregulation of SMARCA5 was previously observed in CD34+ hematopoietic progenitors of acute myeloid leukemia (AML) patients. Since high levels of SMARCA5 are necessary for intensive cell proliferation and cell cycle progression of developing hematopoietic stem and progenitor cells in mice, we reasoned that removal of SMARCA5 enzymatic activity could affect the cycling or undifferentiated state of leukemic progenitor-like clones. Indeed, we observed that CRISPR/cas9-mediated SMARCA5 knockout in AML cell lines (S5KO) inhibited the cell cycle progression. We also observed that the SMARCA5 deletion induced karyorrhexis and nuclear budding as well as increased the ploidy, indicating its role in mitotic division of AML cells. The cytogenetic analysis of S5KO cells revealed the premature chromatid separation. We conclude that deleting SMARCA5 in AML blocks leukemic proliferation and chromatid cohesion.


2018 ◽  
Vol 69 (4) ◽  
pp. 622-635.e6 ◽  
Author(s):  
Cindy Meyer ◽  
Aitor Garzia ◽  
Michael Mazzola ◽  
Stefanie Gerstberger ◽  
Henrik Molina ◽  
...  

2015 ◽  
Vol 210 (2) ◽  
pp. 2102OIA144
Author(s):  
Nicole Mende ◽  
Erika E Kuchen ◽  
Mathias Lesche ◽  
Tatyana Grinenko ◽  
Konstantinos D Kokkaliaris ◽  
...  

Leukemia ◽  
2012 ◽  
Vol 27 (5) ◽  
pp. 1127-1138 ◽  
Author(s):  
O S Kustikova ◽  
A Schwarzer ◽  
M Stahlhut ◽  
M H Brugman ◽  
T Neumann ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1708-1708
Author(s):  
Gesine Bug ◽  
Hilal Gul ◽  
Kerstin Schwarz ◽  
Manuela Kampfmann ◽  
Xiaomin Zheng ◽  
...  

Abstract Histone deacetylase inhibitors (HDI) have attracted considerable attention because of their ability to overcome the differentiation block in leukemic blasts either alone, or in combination with differentiating agents such as all-trans retinoic acid (ATRA). We have previously reported favorable effects of the potent HDI valproic acid (VPA) in combination with ATRA in a small subset of patients with advanced acute myeloid leukemia (AML) leading to blast cell reduction and improvement of hemoglobin. This effect was accompanied by hypergranulocytosis most likely due to an enhancement of non-leukemic myelopoiesis and suppression of malignant hematopoiesis rather than enforced differentiation of leukemic cells. These data prompted us to investigate the impact of VPA on normal hematopoietic stem cells (HSC). Differentiation of cord blood-derived, purified CD34+ cells was assessed by FACS analysis after a 7-days suspension culture in presence of early acting cytokines and 30–150μg/mL VPA. VPA prevented differentation of CD34+ cells in a dose-dependent manner: concomitant with an increase of CD34+ cells from 17 to 47%, the proportion of monocytic CD14+ cells decreased from 27 to 3% (n=3). In addition, VPA induced a 30-fold amplification of CD34+ bone marrow (BM) cells within 10 days as determined by colony assays (n=3). To evaluate the functional capacity of VPA-treated HSC, murine Sca1+/lin−s cells were harvested from colony assays and replated. VPA treatment allowed up to four cycles of replating in contrast to VPA-naïve control cells. Further analysis demonstrated that the stimulatory effect of VPA on the in vitro growth and colony formation capacity of HSC was mainly due to accelerated cell cycle progression. VPA strongly increased the proportion of cells in S phase compared to untreated controls (38 vs. 17%, resp.), as detected by propidium iodid staining and BRDU incorporation as well as reduced expression of the CDK-inhibitor p21cip-1/waf using murine HSC after 7 days of culture. Downregulation of p21cip-1/waf was confirmed in CD34+ BM cells showing maximum inhibition after 48 hours of VPA treatment and no recovery thereafter. Recent results indicate that VPA exerts inhibitory activity on GSK3beta by phosphorylation on Ser-9 and stimulates Akt in human neuroblastoma cells. GSK3beta is an effector of the Wnt-signaling pathway located upstream of beta-catenin. Wnt-signaling can directly stimulate the proliferation of HSC, expand the HSC pool and lead to upregulation of HoxB4. Here we show that VPA increased the inhibition-associated phosphorylation of GSK3beta on Ser-9 in human CD34+ BM cells after 48 hours as well as in murine Sca1+/lin− cells after 7 days. Exposure to VPA enhanced beta-catenin and Akt activity not only in CD34+ HSC but also in KG-1 and TF-1 cells with maximum activation after 48 hours of VPA stimulation. Moreover, VPA lead to an 8-fold increase of the HoxB4 level in CD34+ BM cells as determined by real time PCR at 48 hours. In conclusion, we show that VPA i.) expands HSC as assesed by phenotype and function; ii.) accelerates cell cycle progression of HSC accompanied by the down-regulation of p21cip-1waf; iii.) activates the GSK3beta depending beta-catenin pathway and Akt and iv.) up-regulates HoxB4. Our data strongly suggest that VPA is able to influence some of the signaling pathway considered relevant for proliferation and self-renewal which might request reconsideration of their employment for the treatment of AML.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1322-1322
Author(s):  
Wei Du ◽  
Yun Zhou ◽  
Suzette Pike ◽  
Qishen Pang

Abstract An elevated level of nucleophosmin (NPM) is often found in actively proliferative cells including human tumors. To identify the regulatory role for NPM phosphorylation in proliferation and cell cycle control, a series of mutants targeting the consensus cyclin-dependent kinase (CKD) phosphorylation sites was created to mimic or abrogate either single-site or multi-site phosphorylation. Cells expressing the phosphomimetic NPM mutants showed enhanced proliferation and G2/M cell-cycle transition; whereas nonphosphorylatable mutants induced G2/M cell-cycle arrest. Simultaneous inactivation of two CKD phosphorylation sites at Ser10 and Ser70 (S10A/S70A, NPM-AA) induced phosphorylation of Cdk1 at Tyr15 (Cdc2Tyr15) and increased cytoplasmic accumulation of Cdc25C. Strikingly, stress-induced Cdk1Tyr15 and Cdc25C sequestration were completely suppressed by expression of a double phosphomimetic NPM mutant (S10E/S70E, NPM-EE). Further analysis revealed that phosphorylation of NPM at both Ser10 and Ser70 sites were required for proper interaction between Cdk1 and Cdc25C in mitotic cells. Moreover, the NPM-EE mutant directly bound to Cdc25C and prevented phosphorylation of Cdc25C at Ser216 during mitosis. Finally, NPM-EE overrided stress-induced G2/M arrest, increased peripheral-blood blasts and splenomegaly in a NOD/SCID xenograft model, and promoted leukemia development in Fanconi mouse hematopoietic stem/progenitor cells. Thus, these findings reveal a novel function of NPM on regulation of cell-cycle progression, in which Cdk1-dependent phosphorylation of NPM controls cell-cycle progression at G2/M transition through modulation of Cdc25C activity.


2006 ◽  
Vol 1088 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Masaki Ueno ◽  
Kei-ichi Katayama ◽  
Hirofumi Yamauchi ◽  
Hiroyuki Nakayama ◽  
Kunio Doi

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