Arrest of cell cycle progression of HeLa cells in the early G1 phase in K+-depleted conditions and its recovery upon addition of insulin and LDL

1993 ◽  
Vol 53 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Hisao Yamaguchi ◽  
Keiko Hosokawa ◽  
Zheng-Lin Jiang ◽  
Akira Takahashi ◽  
Toshitaka Ikehara ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Hela Cells ◽  
Cell Cycle Progression ◽  
G1 Phase ◽  
Cycle Progression

scholarly journals The in vitro effects of compound-X on growth, morphology, the induction of autophagy and apoptosis, as well as cell cycle progression in a cervical adenocarcinoma cell line

2012 ◽  
Vol 31 (1) ◽  
Author(s):  
S. Marais ◽  
T.V. Mqoco ◽  
B.A. Stander ◽  
R. Prudent ◽  
L. Lafanechère ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Hela Cells ◽  
Cell Cycle Progression ◽  
Cervical Adenocarcinoma ◽  
Growth Morphology ◽  
Adenocarcinoma Cell Line ◽  
Cycle Progression ◽  
Adenocarcinoma Cell

It can be concluded that compound-X induced both autophagy and apoptosis as a means of celldeath in HeLa cells.

scholarly journals Growth factor, steroid, and steroid antagonist regulation of cyclin gene expression associated with changes in T-47D human breast cancer cell cycle progression.

1993 ◽  
Vol 13 (6) ◽  
pp. 3577-3587 ◽  
Author(s):  
E A Musgrove ◽  
J A Hamilton ◽  
C S Lee ◽  
K J Sweeney ◽  
C K Watts ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cell Cycle ◽  
Cyclin D1 ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Cell Cycle Progression ◽  
S Phase ◽  
G1 Phase ◽  
Cycle Progression

Cyclins and proto-oncogenes including c-myc have been implicated in eukaryotic cell cycle control. The role of cyclins in steroidal regulation of cell proliferation is unknown, but a role for c-myc has been suggested. This study investigated the relationship between regulation of T-47D breast cancer cell cycle progression, particularly by steroids and their antagonists, and changes in the levels of expression of these genes. Sequential induction of cyclins D1 (early G1 phase), D3, E, A (late G1-early S phase), and B1 (G2 phase) was observed following insulin stimulation of cell cycle progression in serum-free medium. Transient acceleration of G1-phase cells by progestin was also accompanied by rapid induction of cyclin D1, apparent within 2 h. This early induction of cyclin D1 and the ability of delayed administration of antiprogestin to antagonize progestin-induced increases in both cyclin D1 mRNA and the proportion of cells in S phase support a central role for cyclin D1 in mediating the mitogenic response in T-47D cells. Compatible with this hypothesis, antiestrogen treatment reduced the expression of cyclin D1 approximately 8 h before changes in cell cycle phase distribution accompanying growth inhibition. In the absence of progestin, antiprogestin treatment inhibited T-47D cell cycle progression but in contrast did not decrease cyclin D1 expression. Thus, changes in cyclin D1 gene expression are often, but not invariably, associated with changes in the rate of T-47D breast cancer cell cycle progression. However, both antiestrogen and antiprogestin depleted c-myc mRNA by > 80% within 2 h. These data suggest the involvement of both cyclin D1 and c-myc in the steroidal control of breast cancer cell cycle progression.

The Fluctuation of Telomere Repeat Binding Factor 1 during Cell Cycle and Its Localization in Telomerase-Positive and Negative Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4326-4326
Author(s):  
Jianping Lan ◽  
He Huang ◽  
Yuanyuan Zhu ◽  
Jie Sun
Keyword(s):  
Cell Cycle ◽  
Telomere Length ◽  
Hela Cells ◽  
Cell Cycle Progression ◽  
Promyelocytic Leukemia ◽  
Final Concentration ◽  
Cycle Progression ◽  
Telomere Repeat ◽  
Binding Factor ◽  
M Phase

Abstract Telomere is a nucleoprotein complex which caps the extreme ends of eukaryotic chromosomes. In human, telomere is composed of a tandem repeat array of TTAGGG hexanucleotide and bound to a set of specific proteins. These proteins function to maintain the integrity of chromosomes and genomic stability. Among these proteins, telomere repeat binding factor 1(TRF1) is the first telomere binding protein which was isolated by DNA affinity chromatography in 1995. TRF1 serves as a negative regulator of telomere length since TRF1 overexpression would elicit the shortening of telomere length in telomerase-positive cells. Meanwhile, overexpression of TRF1 would also induce the entry into mitosis and increase mitotic cells. These observation indicated TRF1 might participate in cell cycle regulation. However, the underlying mechanism in which TRF1 regulates the cell cycle and the endogenous level of TRF1 were not well-documented during cell cycle progression. To address these questions, we arrested HeLa cells at different phases by a combination of thymidine(5mM at final concentration) and nocodazole(20mM at final concentration) and detected the TRF1 levels by semi-quantitive Western Blotting assay. Cell cycle was verified by flow cytometry. Our results showed TRF1 level fluctuated coincided with cell cycle progression which reached the zenith at the M phase and went down to the nadir at G1/S point. Densitometry analysis demonstrated that the level of TRF1 at M phase was 3.9 times more than that at G1/S point(n=3, p<0.01). These results suggested that TRF1 might be essential for proper cell cycle progression and it was likely to take part in regulation of cell cycle chechpoint. TRF1 is also expressed in telomerase-negative cells. To further discriminate the different functions of TRF1 and decipher its protein-protein interaction network in telomerase-positive and negative cells, full-length TRF1 cDNA was amplified by PCR and subsequently subcloned into pEGFP-C2 vector to express TRF1 tagged by enhanced green fluorescent protein. This construct was then transiently transfected into telomerase-negative cells(WI38-2RA) and telomerase-positive cells(HeLa). Immunoflourescent staining was employed to check the localization of TRF1 in these two kinds of cells. Although in both cells, TRF1 was distributed in a speckled pattern in the nuclei, TRF1 did exclusively colocalize with promyelocytic leukemia(PML) nuclear body in WI38-2RA cells but not in HeLa cells. PML fused with RARα due to chromosome15,17 translocation which led to disassembly of PML nucleur body in acute promyelocytic leukemia. These preliminary results suggested that TRF1 might have the different regulating mechanism and interacting network.

The Underlying Mechanism of Telomere Maintenance in Human Bone Marrow-Derived Mesenchymal Stem Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4252-4252
Author(s):  
He Huang ◽  
Jingyuan Li ◽  
Jianping Lan ◽  
Yanmin Zhao ◽  
Xiaoyu Lai
Keyword(s):  
Cell Cycle ◽  
Bone Marrow ◽  
Telomere Length ◽  
Hela Cells ◽  
Cell Cycle Progression ◽  
Telomerase Activity ◽  
Telomeric Repeat ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Cycle Progression

Abstract Objective: Human bone marrow-derived mesenchymal stem cells(MSCs) are thought to be promising tools in cell and gene therapy. Unfortunately, the low frequency of MSCs in bone marrow and rapid aging in in vitro expansion, which profoundly compromise their proliferative capacity, give rise to a huge hindrance for their clinical use. Previous study indicated that MSCs would undergo quick telomere shortening as well as reduced replicative capacity during in vitro expansion. These findings suggested that MSCs’ telomere loss might be associated with their decreased proliferative and differentiative potentials. However, the mechanisms by which MSCs maintain their telomere homeostasis have not yet been fully addressed to date. In the present study, we compared the telomere length, the distribution pattern of telomeric repeat binding factor 1(TRF1) between MSCs and other telomerase-positive cells or telomerase-negative cells, detected extrachromosomal telomeric repeat DNA (ECTR DNA) in MSCs and the variation of telomerase activity during cell cycle progression in order to unveil the mystery of telomere regulation in MSCs. METHODS: MSCs were isolated from healthy human bone marrow (n=34) by the plastic adherence protocols and identified by flow cytometry with markers of CD14, CD45, CD44, HLA-DR, CD34, CD29 and CD166. Telomere length and ECTR DNA were detected with Southern hybridization. The TRF1 distribution were probed with immunofluorescence staining. Telomeric repeat amplification protocol (TRAP ) and/or semi-quantitive Western blot assay were performed to determine the telomerase activity in MSCs, MSCs-derived adipocytes and telomerase levels during cell cycle progression. MSCs were synchronized by serum starvation and Aphidicolin treatment for the aforementioned assay. RESULTS: The mean telomere restriction fragment (mTRF) in MSCs was 8.0 kbp( range, 2.7 kbp-18.0 kbp), similar to telomerase-positive HeLa cells 6.0 kbp (range, 2.7 kbp-8.6 kbp) and 293T cells 5.0 kbp(range, 2.7 kbp-8.6 kbp); while the mTRF in telomerase-negative cells WI-38–2RA was 21.2 kb (range 2.0 kbp->21.2 kbp). The results indicated that telomere length in MSCs and HeLa cells were shorter and relatively more homogeneous than WI-38–2RA cells. TRF1 did not coincide with promyelocytic leukemia (PML) nuclear body in MSCs and HeLa cells while it exclusively did in WI-38–2RA cells. ECTR DNA was negative in MSCs and HeLa cells but positive in WI-38–2RA cells. Detected by TRAP, telomerase activity in MSCs(n=34) was negative with relative telomerase activity (RTA) of 1.44%±0.77%, but it was positive in MSCs-derived adipocytes (n=3) with RTA of 11.80±2.52%(P<0.001). Moreover, a cell cycle-dependent expression profile of telomerase was found in MSCs when they were synchronized by serum starvation and Aphidicolin treatment. Untreated MSCs expressed extremely low level of telomerase probed by Western blot with the 2C4 mAb, but the telomerase level had significantly increased when these cells were trapped in S phase. CONCLUSION: Since MSCs possessed similar features to telomerase-positive cells in telomere length, TRF1 localization pattern and ECTR DNA which were distinct from telomerase-negative ALT cells, and they had increased telomerase activity following differentiation into adipocytes and entrance into S phase, We postulated that the telomere in MSCs was maintained by telomerase pathway other than ALT pathway. The telomerase expression level of MSCs was tightly regulated with cell cycle progression.

scholarly journals Id3 is a novel regulator of p27kip1 mRNA in early G1 phase and is required for cell-cycle progression

Oncogene ◽  
2007 ◽  
Vol 26 (39) ◽  
pp. 5772-5783 ◽  
Author(s):  
A-A Chassot ◽  
L Turchi ◽  
T Virolle ◽  
G Fitsialos ◽  
M Batoz ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
G1 Phase ◽  
Cycle Progression

Functional and molecular identification of intermediate-conductance Ca2+-activated K+ channels in breast cancer cells: association with cell cycle progression

2004 ◽  
Vol 287 (1) ◽  
pp. C125-C134 ◽  
Author(s):  
Halima Ouadid-Ahidouch ◽  
Morad Roudbaraki ◽  
Philippe Delcourt ◽  
Ahmed Ahidouch ◽  
Nathalie Joury ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Membrane Potential ◽  
Current Density ◽  
Cell Cycle Progression ◽  
G1 Phase ◽  
Cycle Progression ◽  
Mcf 7 ◽  
In Cells

We have previously reported that the hEAG K+ channels are responsible for the potential membrane hyperpolarization that induces human breast cancer cell progression into the G1 phase of the cell cycle. In the present study, we evaluate the role and functional expression of the intermediate-conductance Ca2+-activated K+ channel, hIK1-like, in controlling cell cycle progression. Our results demonstrate that hIK1 current density increased in cells synchronized at the end of the G1 or S phase compared with those in the early G1 phase. This increased current density paralleled the enhancement in hIK1 mRNA levels and the highly negative membrane potential. Furthermore, in cells synchronized at the end of G1 or S phases, basal cytosolic Ca2+ concentration ([Ca2+]i) was also higher than in cells arrested in early G1. Blocking hIK1 channels with a specific blocker, clotrimazole, induced both membrane potential depolarization and a decrease in the [Ca2+]i in cells arrested at the end of G1 and S phases but not in cells arrested early in the G1 phase. Blocking hIK1 with clotrimazole also induced cell proliferation inhibition but to a lesser degree than blocking hEAG with astemizole. The two drugs were essentially additive, inhibiting MCF-7 cell proliferation by 82% and arresting >90% of cells in the G1 phase. Thus, although the progression of MCF-7 cells through the early G1 phase is dependent on the activation of hEAG K+ channels, when it comes to G1 and checkpoint G1/S transition, the membrane potential appears to be primarily dependent on the hIK1-activity level.

scholarly journals The long non-coding RNA LINC00152 is essential for cell cycle progression through mitosis in HeLa cells

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Linda Nötzold ◽  
Lukas Frank ◽  
Minakshi Gandhi ◽  
Maria Polycarpou-Schwarz ◽  
Matthias Groß ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Hela Cells ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Non Coding Rna ◽  
Long Non Coding Rna

scholarly journals Involvement of Rho proteins in G1 phase cell cycle progression

2013 ◽  
Vol 67 ◽  
pp. 15-25 ◽  
Author(s):  
Anna Klimaszewska-Wiśniewska ◽  
Jakub Marcin Nowak ◽  
Agnieszka Żuryń ◽  
Alina Grzanka
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Phase Cell ◽  
G1 Phase ◽  
Rho Proteins ◽  
Cycle Progression
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