scholarly journals Silencing Lysine-Specific Histone Demethylase 1 (LSD1) Causes Increased HP1-Positive Chromatin, Stimulation of DNA Repair Processes, and Dysregulation of Proliferation by Chk1 Phosphorylation in Human Endothelial Cells

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1212 ◽  
Author(s):  
Wojtala ◽  
Dąbek ◽  
Rybaczek ◽  
Śliwińska ◽  
Świderska ◽  
...  

: The methylation of histone lysine residues modifies chromatin conformation and regulates the expression of genes implicated in cell metabolism. Lysine-specific demethylase 1 (LSD1) is a flavin-dependent monoamine oxidase that can demethylate mono- and dimethylated histone lysines 4 and 9 (H3K4 and H3K9). The removal of methyl groups from the lysine residues of histone and non-histone proteins was found to be an important regulatory factor of cell proliferation. However, its role has not been fully elucidated. In this study, we assessed LSD1-mediated cell cycle progression using a human endothelial cell model. The short hairpin RNA knockdown of LSD1 inhibits the G2/M phase of cell cycle progression by checkpoint kinase 1 (Chk1) phosphorylation (S137). We observed elevated DNA damage, which was consistent with the increased detection of double-strand breaks as well as purines and pyrimidines oxidation, which accompanied the activation of ATR/ATRIP signaling by H2AXS139 phosphorylation. The irreversible pharmacological inhibition of LSD1 by 2-phenylcyclopropylamine (2-PCPA) inactivated its enzymatic activity, causing significant changes in heterochromatin and euchromatin conformation assessed by chromatin assembly factor 1 subunit A (CAF1A) and heterochromatin protein 1 isoform α and γ (HP1α/γ) immunofluorescence analysis. We conclude that the knockdown of LSD1 in endothelial cells leads to increased HP1-positive chromatin, the stimulation of DNA repair processes, and the dysregulation of proliferation machinery.

2012 ◽  
Vol 417 (2) ◽  
pp. 771-776 ◽  
Author(s):  
Runting Yin ◽  
Weiwei Bao ◽  
Yingying Xing ◽  
Tao Xi ◽  
Shaohua Gou

2012 ◽  
Vol 72 (4 Supplement) ◽  
pp. C46-C46
Author(s):  
Kamini Singh ◽  
Sayer R. Al-Harbi ◽  
Akwasi Agyeman ◽  
Janet A. Houghton ◽  
Warren D. Heston ◽  
...  

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1674-1674
Author(s):  
Francesco Albano ◽  
Luisa Anelli ◽  
Antonella Zagaria ◽  
Nicoletta Coccaro ◽  
Luciana Impera ◽  
...  

Abstract Abstract 1674 The t(9;22)(q34;q11) generating the Philadelphia chromosome and the BCR/ABL1 fusion gene represents the cytogenetic hallmark of chronic myeloid leukemia (CML). About 5–10% of CML cases show variant translocations with the involvement of other chromosomes in addition to chromosomes 9 and 22. The greater frequency of occurrence of genomic microdeletions proximally to ABL1 or distally to BCR has been reported in CML cases with variant translocations (30–40%) than in cases with a classic t(9;22) (10–18%). The prognostic significance of variant t(9;22) was unclear and debated in the pre-imatinib era, whereas recent studies of large CML series showed that the presence of variant translocations has no impact on the cytogenetic and molecular response or on prognosis (Marzocchi et al. Blood 2011,117:6793-800). However, the molecular bases of differences between CML patients with classic and variant t(9;22) have never been elucidated. Here we report a gene expression profile analysis of 8 CML cases with variant t(9;22) and 12 patients with a classic t(9;22). RNA samples were extracted from bone marrow cells and hybridized on the Agilent SurePrint G3 Human GE 8×60K Microarray slide (Agilent Technologies). Ingenuity Pathways Analysis (IPA, www.ingenuity.com) software was used to provide an accurate biological and statistical analysis of microarray experimental data revealing functional relationships among the identified genes. Gene expression analysis identified a 59 gene set able to distinguish the two CML subsets. These genes are mostly involved in the development of the hematological system and in the occurrence of hematological diseases. Forty-five out of 59 (76%) genes were up-regulated, causing the probable activation of different molecular mechanisms such as cellular responses to stimuli, protein degradation, DNA repair, cell cycle progression. IPA analysis revealed that most of the dysregulated genes are included in a network where they are functionally linked to MAPK p38, AKT, and NFKB. Moreover, several genes play a role in cytoskeleton organization (WIPF1), in signal transduction and cell cycle progression (TRIB1, PDE4B, PTK2B, PLK3), in regulation of apoptosis (ZFAND5, STK17B), and in protein degradation (ZFAND5, SNRPG). On the contrary, among the downregulated genes, 5 (BCDIN3D, TMEM68, HILPDA, TMEM68, and C17orf61) establish direct interactions with ubiquitin C (UBC), a crucial gene involved in different intracellular mechanisms such as protein degradation, DNA repair, cell cycle regulation, and the regulation of other signaling pathways. In conclusion, gene expression profiling in cases with variant t(9;22) revealed biological differences in this CML subset. Our data show an overall deregulation of genes involved in hematological system development and in cell proliferation signaling pathway. Disclosures: No relevant conflicts of interest to declare.


2006 ◽  
Vol 5 (4) ◽  
pp. 885-892 ◽  
Author(s):  
Christopher M. Sturgeon ◽  
Zachary A. Knight ◽  
Kevan M. Shokat ◽  
Michel Roberge

1997 ◽  
Vol 17 (2) ◽  
pp. 742-750 ◽  
Author(s):  
T Matsumoto

Successful recovery from DNA damage requires coordination of several biological processes. Eukaryotic cell cycle progression is delayed when the cells encounter DNA-damaging agents. This cell cycle delay allows the cells to cope with DNA damage by utilizing DNA repair enzymes. Thus, at least two processes, induction of the cell cycle delay and repair of damaged DNA, are coordinately required for recovery. In this study, a fission yeast rad mutant (slp1-362) was genetically investigated. In response to radiation, slp1 stops cell division; however, it does not restart it. This defect is suppressed when slp1-362 is combined with wee1-50 or cdc2-3w; in these mutants, the onset of mitosis is advanced due to the premature activation of p34cdc2. In contrast, slp1 is synthetically lethal with cdc25, nim1/cdr1, or cdr2, all of which are unable to activate the p34cdc2 kinase correctly. These genetic interactions of slp1 with cdc2 and its modulators imply that slp1 is not defective in either "induction of cell cycle delay" or "DNA repair." slp1+ may be involved in a critical process which restarts cell cycle progression after the completion of DNA repair. Molecular cloning of slp1+ revealed that slp1+ encodes a putative 488-amino-acid polypeptide exhibiting significant homology to WD-domain proteins, namely, CDC20 (budding yeast), p55CDC (human), and Fizzy (fly). A possible role of slp1+ is proposed.


1991 ◽  
Vol 11 (9) ◽  
pp. 4466-4472 ◽  
Author(s):  
K Kovary ◽  
R Bravo

The expression of different members of the Jun and Fos families of transcription factors is rapidly induced following serum stimulation of quiescent fibroblasts. To determine whether these proteins are required for cell cycle progression, we microinjected affinity-purified antibodies directed against c-Fos, FosB, Fra-1, c-Jun, JunB, and JunD, and antibodies that recognize either the Fos or the Jun family of proteins, into Swiss 3T3 cells and determined their effects in cell cycle progression by monitoring DNA synthesis. We found that microinjection of anti-Fos and anti-Jun family antibodies efficiently blocked the entrance to the S phase of serum-stimulated or asynchronously growing cells. However, the antibodies against single members of the Fos family only partially inhibited DNA synthesis. In contrast, all three Jun antibodies prevented DNA synthesis more effectively than did any of the anti-Fos antibodies.


Sign in / Sign up

Export Citation Format

Share Document