Apoptosis Susceptibility and Cell-Cycle Distribution in Cells from Myelodysplastic Syndrome Patients: Modulatory In-Vitro Effects of G-CSF and Interferon-α

2004 ◽  
Vol 45 (7) ◽  
pp. 1437-1443 ◽  
Author(s):  
Maria R Ricciardi ◽  
Maria T Petrucci ◽  
Chiara Gregorj ◽  
Vincenza Martini ◽  
Anna Levi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Myelodysplastic Syndrome ◽  
Interferon Α ◽  
Cell Cycle Distribution ◽  
In Vitro Effects ◽  
In Cells

A novel PLK1 inhibitor onvansertib effectively sensitizes MYC-driven medulloblastoma to radiotherapy

2021 ◽  
Author(s):  
Dong Wang ◽  
Bethany Veo ◽  
Angela Pierce ◽  
Susan Fosmire ◽  
Krishna Madhavan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Tumor Growth ◽  
Radiation Treatment ◽  
Tumor Regression ◽  
Tumor Growth Inhibition ◽  
Cell Cycle Distribution ◽  
Cell Renewal ◽  
Group 3

Abstract Background Group 3 medulloblastoma (MB) is often accompanied by MYC amplification. PLK1 is an oncogenic kinase that controls cell cycle and proliferation and has been preclinically validated as a cancer therapeutic target. Onvansertib (PCM-075) is a novel, orally available PLK1 inhibitor, which shows tumor growth inhibition in various types of cancer. We aim to explore the effect of onvansertib on MYC-driven medulloblastoma as a monotherapy or in combination with radiation. Methods Crisper-Cas9 screen was used to discover essential genes for MB tumor growth. Microarray and immunohistochemistry on pediatric patient samples were performed to examine the expression of PLK1. The effect of onvansertib in vitro was measure by cell viability, colony-forming assays, extreme limiting dilution assay and RNA-Seq. ALDH activity, cell-cycle distribution and apoptosis were analyzed by flow cytometry. DNA damage was assessed by immunofluorescence staining. Medulloblastoma xenografts were generated to explore the monotherapy or radio-sensitizing effect. Results PLK1 is overexpressed in Group 3 MB. The IC50 concentrations of onvansertib in Group 3 MB cell lines were in a low nanomolar range. Onvansertib reduced colony formation, cell proliferation, stem cell renewal and induced G2/M arrest in vitro. Moreover, onvansertib in combination with radiation increased DNA damage and apoptosis compare with radiation treatment alone. The combination radiotherapy resulted in marked tumor regression in xenografts. Conclusions These findings demonstrate the efficacy of a novel PLK1 inhibitor onvansertib in vitro and in xenografts of Group 3 MB, which suggests onvansertib is an effective strategy as monotherapy or in combination with radiotherapy in MB.

scholarly journals TRB3 is elevated in psoriasis vulgaris lesions and mediates HaCaT cells proliferation in vitro

2017 ◽  
Vol 65 (7) ◽  
pp. 1084-1088 ◽  
Author(s):  
Xiao-Jing Yu ◽  
Tie-Jun Song ◽  
Lu-Wei Zhang ◽  
Ying Su ◽  
Ke-Yu Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Messenger Rna ◽  
Psoriasis Vulgaris ◽  
Metabolic Diseases ◽  
Brdu Incorporation ◽  
Cell Cycle Distribution ◽  
Hacat Cells ◽  
Keratinocyte Proliferation

Psoriasis is a chronic skin disease characterized by abnormal keratinocyte proliferation and differentiation, inflammation, and angiogenesis. Overexpression of tribbles homolog3 (TRB3), which belongs to the tribbles family of pseudokinases, has been found in several human tumors and metabolic diseases, but its role in psoriasis has not been fully clarified. The aim of this study is to investigate the expression of TRB3 in psoriasis and explore its roles in the proliferation of keratinocytes. Twenty-four patients with psoriasis vulgaris were recruited for the study. Diagnosis of psoriasis was based on clinical and histologic examinations. Immunohistochemistry and real-time reverse transcription PCR (RT-PCR) were performed to determine protein and messenger RNA (mRNA) expression of TRB3 in psoriasis lesions. 5-Bromo-2-deoxyUridine (BrdU) incorporation assay were performed for cell proliferation. Cell cycle distribution was assessed by flow cytometry analysis. The levels of TRB3 is elevated in psoriatic lesions compared with psoriatic non-lesions. The HaCat cells expressed the TRB3 gene. We found TRB3 silencing to significantly inhibit HaCat cell proliferation. Furthermore, the specific knockdown of TRB3 slowed down the cell cycle at the gap 0/first gap phase. In conclusion, our data suggest that TRB3 is overexpressed in lesions of patients with psoriasis and may be involved in the abnormal proliferation of keratinocytes. Therefore, TRB3 may be a potential therapeutic target for psoriasis.

SU-F-T-665: Confocal Microscopy Imaging of Cell Cycle Distribution in Cells Treated with Pegylated Gold Nanoshells

2016 ◽  
Vol 43 (6Part23) ◽  
pp. 3617-3617
Author(s):  
D Sadetaporn ◽  
D Flint ◽  
C McFadden ◽  
A Asaithamby ◽  
G Sawakuchi
Keyword(s):  
Cell Cycle ◽  
Confocal Microscopy ◽  
Gold Nanoshells ◽  
Cell Cycle Distribution ◽  
Microscopy Imaging ◽  
Confocal Microscopy Imaging ◽  
In Cells

Type II pneumocyte hypertrophy without activation of surfactant biosynthesis after partial pneumonectomy

1993 ◽  
Vol 264 (2) ◽  
pp. L153-L159 ◽  
Author(s):  
B. D. Uhal ◽  
M. D. Etter
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Tritiated Thymidine ◽  
Cell Cycle Distribution ◽  
Type Ii ◽  
Adult Rats ◽  
Type Ii Pneumocyte ◽  
Significant Difference

Hypertrophic and normotrophic type II pneumocytes were isolated from pneumonectomized adult rats by unit gravity (1 g) sedimentation or by fluorescence-activated cell sorting (FACS). In vivo or in vitro, hypertrophic cells incorporated significantly more 5-bromo-2'-deoxyuridine or tritiated thymidine into acid-insoluble material than did normotrophic cells. By FACS analysis of cell subpopulations isolated by 1 g, > 97% of normotrophic cells had G0-phase DNA content. In contrast, the cell cycle distribution of hypertrophic cells was 75% G1, 5% S, and 20% G2/M phases. Rates of incorporation of tritiated choline into total cellular phosphatidylcholine (PC) were identical in type II cells isolated from normal or pneumonectomized rats. The intracellular contents of disaturated phosphatidylcholine (DSPC) and total PC, as well as the ratio of these two lipids, were the same in hypertrophic and normotrophic cells from pneumonectomized rats and in cells isolated from normal rats. No significant difference was observed in the rate at which hypertrophic or normotrophic cells incorporated choline into DSPC. These results demonstrate that type II pneumocyte hypertrophy after pneumonectomy reflects balanced cell growth secondary to cell cycle progression in vivo. The data also indicate that epithelial cell hypertrophy after pneumonectomy, in contrast to that which develops after more acute lung injury, occurs without activation of surfactant biosynthesis or storage.

scholarly journals Suppression of long noncoding RNA MALAT1 inhibits the development of uveal melanoma via microRNA-608-mediated inhibition of HOXC4

2020 ◽  
Vol 318 (5) ◽  
pp. C903-C912 ◽  
Author(s):  
Shuai Wu ◽  
Han Chen ◽  
Ling Zuo ◽  
Hai Jiang ◽  
Hongtao Yan
Keyword(s):  
Cell Cycle ◽  
Uveal Melanoma ◽  
Noncoding Rna ◽  
Cell Cycle Progression ◽  
Melanoma Cells ◽  
Cell Cycle Distribution ◽  
Invasion And Migration ◽  
And Migration

This study explored the effects of the metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on the development of uveal melanoma. Moreover, the role of the MALAT1/microRNA-608 (miR-608)/homeobox C4 (HOXC4) axis was assessed by evaluating the proliferation, invasion, and migration, as well as the cell cycle distribution of uveal melanoma in vitro after knocking down MALAT1 or HOXC4 and/or overexpression of miR-608 in uveal melanoma cells (MUM-2B and C918). Moreover, the effects of the MALAT1/miR-608/HOXC4 axis in uveal melanoma in vivo were further evaluated by injecting the C918 cells into the NOD/SCID mice. HOXC4 was found to be a gene upregulated in uveal melanoma, while knockdown of its expression resulted in suppression of uveal melanoma cell migration, proliferation, and invasion, as well as cell cycle progression. In addition, the upregulation of miR-608 reduced the expression of HOXC4 in the uveal melanoma cells, which was rescued by overexpression of MALAT1. Hence, MALAT1 could upregulate the HOXC4 by binding to miR-608. The suppressed progression of uveal melanoma in vitro by miR-608 was rescued by overexpression of MALAT1. Additionally, in vivo assays demonstrated that downregulation of MALAT1 could suppress tumor growth through downregulation of HOXC4 expression via increasing miR-608 in uveal melanoma. In summary, MALAT1 downregulation functions to restrain the development of uveal melanoma via miR-608-mediated inhibition of HOXC4.

Plk3 phosphorylates topoisomerase IIα at Thr1342, a site that is not recognized by Plk1

2008 ◽  
Vol 411 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Masato Iida ◽  
Masao Matsuda ◽  
Hideya Komatani
Keyword(s):  
Cell Cycle ◽  
Kinase Assay ◽  
Cell Cycle Distribution ◽  
Physical Interaction ◽  
Topoisomerase Iiα ◽  
In Vitro Kinase Assay ◽  
A Site ◽  
Cycle Regulation

The Plk (polo-like kinase) family is involved in cell-cycle machinery. Despite the possible overlapping involvement of Plk1 and Plk3 in cell-cycle distribution, the precise role of each Plk might be different. To investigate mechanisms that may differentiate their physiological roles, we compared the substrate specificities of Plk1 and Plk3 using synthetic peptides. Among these substrate peptides, topoisomerase IIα EKT1342DDE-containing synthetic peptide was strongly phosphorylated by Plk3 but not by Plk1. By modulating the topoisomerase IIα peptide, we identified residues at positions +1, +2 and +4 as determinants of differential substrate recognition between Plk1 and Plk3. Acidic residues at positions +2 and +4 appear to be a positive determinant for Plk3 but not Plk1. Variation at position +1 appears to be tolerated by Plk3, while a hydrophobic residue at +1 is critical for Plk1 activity. The direct phosphorylation of Thr1342 of topoisomerase IIα by Plk3 was demonstrated with an in vitro kinase assay, and overexpression of Plk3 induced the phosphorylation of Thr1342 in cellular topoisomerase IIα. Furthermore, the physical interaction between Plk3 and topoisomerase IIα was also demonstrated in cells in addition to phosphorylation. These data suggest that topoisomerase IIα is a novel physiological substrate for Plk3 and that Plk1 and Plk3 play different roles in cell-cycle regulation.

scholarly journals Identification of an Arginine-Rich Motif in Human Papillomavirus Type 1 E1^E4 Protein Necessary for E4-Mediated Inhibition of Cellular DNA Synthesis In Vitro and in Cells

2008 ◽  
Vol 82 (18) ◽  
pp. 9056-9064 ◽  
Author(s):  
Sally Roberts ◽  
Sarah R. Kingsbury ◽  
Kai Stoeber ◽  
Gillian L. Knight ◽  
Phillip H. Gallimore ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Host Cell ◽  
S Phase ◽  
Human Papillomaviruses ◽  
Soluble Form ◽  
Cellular Dna ◽  
In Cells

ABSTRACT Productive infections by human papillomaviruses (HPVs) are restricted to nondividing, differentiated keratinocytes. HPV early proteins E6 and E7 deregulate cell cycle progression and activate the host cell DNA replication machinery in these cells, changes essential for virus synthesis. Productive virus replication is accompanied by abundant expression of the HPV E4 protein. Expression of HPV1 E4 in cells is known to activate cell cycle checkpoints, inhibiting G2-to-M transition of the cell cycle and also suppressing entry of cells into S phase. We report here that the HPV1 E4 protein, in the presence of a soluble form of the replication-licensing factor (RLF) Cdc6, inhibits initiation of cellular DNA replication in a mammalian cell-free DNA replication system. Chromatin-binding studies show that E4 blocks replication initiation in vitro by preventing loading of the RLFs Mcm2 and Mcm7 onto chromatin. HPV1 E4-mediated replication inhibition in vitro and suppression of entry of HPV1 E4-expressing cells into S phase are both abrogated upon alanine replacement of arginine 45 in the full-length E4 protein (E1^E4), implying that these two HPV1 E4 functions are linked. We hypothesize that HPV1 E4 inhibits competing host cell DNA synthesis in replication-activated suprabasal keratinocytes by suppressing licensing of cellular replication origins, thus modifying the phenotype of the infected cell in favor of viral genome amplification.

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