Increased separase activity and occurrence of centrosome aberrations concur with transformation of MDS

Ruppenthal, Sabrina; Kleiner, Helga; Nolte, Florian; Fabarius, Alice; Hofmann, Wolf‐Karsten; Nowak, Daniel; Seifarth, Wolfgang

doi:10.1371/journal.pone.0191734

Cited by 7 publications

(5 citation statements)

References 50 publications

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“…The cyclin B-CDK1 complex is important for progression from G 2 to mitosis, and in the Load LV we found upregulated CDK1 and a tendency for increased cyclin B1 expression. Further investigation found upregulation in Load hearts of the spindle checkpoint gene MAD2, important for chromosomal segregation (49), and ESLP1, important for proteolytic cleavage to allow separation of sister chromatids (37). These changes are in concordance with the tendency for increased cell cycle activity in the LV of Load neonates, despite evidence that there was neither increased cardiomyocyte number nor increased nucleation (in which karyokinesis without cytokinesis occurs).…”

Section: Discussionmentioning

confidence: 75%

Systemic arterial hypertension but not IGF-I treatment stimulates cardiomyocyte enlargement in neonatal lambs

Wilburn

Giraud

Louey

et al. 2018

American Journal of Physiology-Regulatory, Integrative and Comp

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Although cardiomyocyte terminal differentiation is nearly complete at birth in sheep, very limited postnatal expansion of myocyte number may occur. The capacity of newborn cardiomyocytes to respond to growth stimulation by proliferation is poorly understood. Our objective was to test this growth response in newborn lambs using two different stimuli shown to induce strong responses in fetuses and adults: increased systolic load (Load) and insulin-like growth factor I (IGF-1). METHODS Vascular catheters and an inflatable aortic occluder were implanted in lambs. Hearts were collected for analysis at 18 days of age after a 7-day experiment, and compared to Control hearts. RESULTS Load hearts, but not IGF-1 hearts, were heavier (P=0.001) due to increased mass of the LV, septum and left atrium (40-50%, P=0.004). Terminal differentiation and cell cycle activity were not different between groups. Myocyte length was 7% greater in Load lamb hearts (P<0.05), and binucleated myocytes, which comprise ~90% of LV cells, were 25% larger in volume (P=0.03). Myocyte number per gram of myocardium was decreased in all ventricles of Load lambs (P=0.01). Cells from the IGF-1 group were not found to be different by any comparison. CONCLUSIONS These results suggest that the newborn sheep LV responds to systolic stress with cardiomyocyte hypertrophy, not proliferation. Further, IGF-1 is ineffective at stimulating cardiomyocyte proliferation at this age (despite effectiveness prior to birth). Thus to expand cardiomyocyte number in the newborn heart, therapies other than systolic pressure load and IGF-1 treatment need to be developed.

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Section: Discussionmentioning

confidence: 75%

Systemic arterial hypertension but not IGF-I treatment stimulates cardiomyocyte enlargement in neonatal lambs

Wilburn

Giraud

Louey

et al. 2018

American Journal of Physiology-Regulatory, Integrative and Comp

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“…2d). In other words, the SAD value is a calculative value for the occurrence of cells with prominent separase activity even though the number of these cells may be low as demonstrated previously [35,43]. Thus, analysis of the healthy donor, CML patient in MR 4 , and CML patient without MMR revealed SAD values of 12.2, 15.6, and 19.2, respectively ( Fig.…”

Section: Elevated Sad Values Are Found In Pbmnc Fractions Of CML Patimentioning

confidence: 53%

“…Since separase overactivity has been repeatedly reported to be associated with the occurrence of numeric centrosome aberrations and aneuploidy, the increased separase activity levels observed in CD34 + cells (H-fractions) may represent a novel cardinal feature of LSCs [43,49]. This mechanism of genomic destabilization may pave the way for residual tumor cells to clonal evolution and a more efficient therapy for survival.…”

Section: Discussionmentioning

confidence: 99%

Separase activity distribution can be a marker of major molecular response and proliferation of CD34+ cells in TKI-treated chronic myeloid leukemia patients

et al. 2020

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Separase, a cysteine endopeptidase, is a key player in mitotic sister chromatid separation, replication fork dynamics, and DNA repair. Aberrant expression and/or altered separase proteolytic activity are associated with aneuploidy, tumorigenesis, and disease progression. Since genomic instability and clonal evolution are hallmarks of progressing chronic myeloid leukemia (CML), we have comparatively examined separase proteolytic activity in TKI-treated chronic phase CML. Separase proteolytic activity was analyzed on single cell level in 88 clinical samples and in 14 healthy controls by a flow cytometric assay. In parallel, BCR-ABL1 gene expression and replication fork velocity were measured by qRT-PCR and DNA fiber assays, respectively. The separase activity distribution (SAD) value indicating the occurrence of MNCs with elevated separase proteolytic activity within samples was found to positively correlate with BCR-ABL1 gene expression levels and loss of MMR (relapse) throughout routine BCR-ABL1 monitoring. Analyses of CD34 + cells and MNCs fractionized by flow cytometric cell sorting according to their separase activity levels (H-and L-fractions) revealed that CD34 + cells with elevated separase activity levels (H-fractions) displayed enhanced proliferation/viability when compared with cells with regular (L-fraction) separase activity (mean 3.3-fold, p = 0.0011). BCR-ABL1 gene expression positivity prevailed in MNC H-fractions over L-fractions (42% vs. 8%, respectively). Moreover, expanding CD34 + cells of H-fractions showed decreased replication fork velocity compared with cells of Lfractions (p < 0.0001). Our data suggests an association between high separase activity, residual BCR-ABL1 gene expression, and enhanced proliferative capacity in hematopoietic cells within the leukemic niche of TKI-treated chronic phase CML.

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“…γH2AX foci, aberrant centrosomes and aberrant metaphases were increased in CD34+ cells exposed to recombinant GRP78, CALR, PDIA3 and GPI. These characteristics do not only mark genetic instability in CD34+ cells but may indicate malignant transformation: (i) γH2AX foci increase across the spectrum from myelodysplastic syndromes (MDS) to AML [ 50 ], (ii) centrosome aberrations occur during transformation of MDS [ 51 ] and correlate with the cytogenetic risk profile of AML [ 52 ] and (iii) complex aberrant karyotypes are an adverse prognostic factor in AML [ 53 ].…”

Section: Discussionmentioning

confidence: 99%

Evidence for Recombinant GRP78, CALR, PDIA3 and GPI as Mediators of Genetic Instability in Human CD34+ Cells

Fabarius

Samra

Drews

et al. 2022

Cancers

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Soluble factors released from irradiated human mesenchymal stromal cells (MSC) may induce genetic instability in human CD34+ cells, potentially mediating hematologic disorders. Recently, we identified four key proteins in the secretome of X-ray-irradiated MSC, among them three endoplasmic reticulum proteins, the 78 kDa glucose-related protein (GRP78), calreticulin (CALR), and protein disulfide-isomerase A3 (PDIA3), as well as the glycolytic enzyme glucose-6-phosphate isomerase (GPI). Here, we demonstrate that exposition of CD34+ cells to recombinant GRP78, CALR, PDIA3 and GPI induces substantial genetic instability. Increased numbers of γH2AX foci (p < 0.0001), centrosome anomalies (p = 0.1000) and aberrant metaphases (p = 0.0022) were detected in CD34+ cells upon incubation with these factors. Specifically, γH2AX foci were found to be induced 4–5-fold in response to any individual of the four factors, and centrosome anomalies by 3–4 fold compared to control medium, which contained none of the recombinant proteins. Aberrant metaphases, not seen in the context of control medium, were detected to a similar extent than centrosome anomalies across the four factors. Notably, the strongest effects were observed when all four factors were collectively provided. In summary, our data suggest that specific components of the secretome from irradiated MSC act as mediators of genetic instability in CD34+ cells, thereby possibly contributing to the pathogenesis of radiation-induced hematologic disorders beyond direct radiation-evoked DNA strand breaks.

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Increased separase activity and occurrence of centrosome aberrations concur with transformation of MDS

Cited by 7 publications

References 50 publications

Systemic arterial hypertension but not IGF-I treatment stimulates cardiomyocyte enlargement in neonatal lambs

Systemic arterial hypertension but not IGF-I treatment stimulates cardiomyocyte enlargement in neonatal lambs

Separase activity distribution can be a marker of major molecular response and proliferation of CD34+ cells in TKI-treated chronic myeloid leukemia patients

Evidence for Recombinant GRP78, CALR, PDIA3 and GPI as Mediators of Genetic Instability in Human CD34+ Cells

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