scholarly journals Association of cellular thiol redox status with mitogen-induced calcium mobilization and cell cycle progression in human fibroblasts

1991 ◽  
Vol 45 (1) ◽  
pp. 82-92 ◽  
Author(s):  
S. R. Mallery ◽  
H. B. Laufman ◽  
C. W. Solt ◽  
R. E. Stephens
2002 ◽  
Vol 76 (24) ◽  
pp. 12543-12552 ◽  
Author(s):  
Amy Mauser ◽  
Elizabeth Holley-Guthrie ◽  
Adam Zanation ◽  
Wendall Yarborough ◽  
William Kaufmann ◽  
...  

ABSTRACT The Epstein-Barr virus (EBV) immediate-early protein BZLF1 mediates the switch between the latent and lytic forms of EBV infection and has been previously shown to induce a G1/S block in cell cycle progression in some cell types. To examine the effect of BZLF1 on cellular gene expression, we performed microarray analysis on telomerase-immortalized human keratinocytes that were mock infected or infected with a control adenovirus vector (AdLacZ) or a vector expressing the EBV BZLF1 protein (AdBZLF1). Cellular genes activated by BZLF1 expression included E2F-1, cyclin E, Cdc25A, and a number of other genes involved in cell cycle progression. Immunoblot analysis confirmed that BZLF1 induced expression of E2F-1, cyclin E, Cdc25A, and stem loop binding protein (a protein known to be primarily expressed during S phase) in telomerase-immortalized keratinocytes. Similarly, BZLF1 increased expression of E2F-1, cyclin E, and stem loop binding protein (SLBP) in primary tonsil keratinocytes. In contrast, BZLF1 did not induce E2F-1 expression in normal human fibroblasts. Cell cycle analysis revealed that while BZLF1 dramatically blocked G1/S progression in normal human fibroblasts, it did not significantly affect cell cycle progression in primary human tonsil keratinocytes. Furthermore, in EBV-infected gastric carcinoma cells, the BZLF1-positive cells had an increased number of cells in S phase compared to the BZLF1-negative cells. Thus, in certain cell types (but not others), BZLF1 enhances expression of cellular proteins associated with cell cycle progression, which suggests that an S-phase-like environment may be advantageous for efficient lytic EBV replication in some cell types.


2004 ◽  
Vol 165 (5) ◽  
pp. 609-615 ◽  
Author(s):  
Yumi Uetake ◽  
Greenfield Sluder

Failure of cells to cleave at the end of mitosis is dangerous to the organism because it immediately produces tetraploidy and centrosome amplification, which is thought to produce genetic imbalances. Using normal human and rat cells, we reexamined the basis for the attractive and increasingly accepted proposal that normal mammalian cells have a “tetraploidy checkpoint” that arrests binucleate cells in G1, thereby preventing their propagation. Using 10 μM cytochalasin to block cleavage, we confirm that most binucleate cells arrest in G1. However, when we use lower concentrations of cytochalasin, we find that binucleate cells undergo DNA synthesis and later proceed through mitosis in >80% of the cases for the hTERT-RPE1 human cell line, primary human fibroblasts, and the REF52 cell line. These observations provide a functional demonstration that the tetraploidy checkpoint does not exist in normal mammalian somatic cells.


1999 ◽  
Vol 73 (1) ◽  
pp. 676-683 ◽  
Author(s):  
Mansuo Lu ◽  
Thomas Shenk

ABSTRACT Earlier studies have revealed that human cytomegalovirus rapidly inhibits the growth of fibroblasts, blocking cell cycle progression at multiple points, including the G1-to-S-phase transition. The present study demonstrates that the UL69 protein, a virus-encoded constituent of the virion, is able to arrest cell cycle progression when introduced into uninfected cells. Expression of the UL69 protein causes U2 OS cells and primary human fibroblasts to accumulate within the G1 compartment of the cell cycle, and serum fails to induce the progression of quiescent human fibroblasts into the S phase when the protein is present. Therefore, the UL69 protein is at least partially responsible for the cell cycle block that is instituted after infection of permissive cells with human cytomegalovirus.


2019 ◽  
Vol 47 (21) ◽  
pp. 11197-11208 ◽  
Author(s):  
Amy E Schade ◽  
Martin Fischer ◽  
James A DeCaprio

Abstract Cell cycle gene expression occurs in two waves. The G1/S genes encode factors required for DNA synthesis and the G2/M genes contribute to mitosis. The Retinoblastoma protein (RB) and DREAM complex (DP, RB-like, E2F4 and MuvB) cooperate to repress all cell cycle genes during G1 and inhibit entry into the cell cycle. DNA damage activates p53 leading to increased levels of p21 and inhibition of cell cycle progression. Whether the G1/S and G2/M genes are differentially repressed by RB and the RB-like proteins p130 and p107 in response to DNA damage is not known. We performed gene expression profiling of primary human fibroblasts upon DNA damage and assessed the effects on G1/S and G2/M genes. Upon p53 activation, p130 and RB cooperated to repress the G1/S genes. In addition, in the absence of RB and p130, p107 contributed to repression of G1/S genes. In contrast, G2/M genes were repressed by p130 and p107 after p53 activation. Furthermore, repression of G2/M genes by p107 and p130 led to reduced entry into mitosis. Our data demonstrates specific roles for RB, p130-DREAM, and p107-DREAM in p53 and p21 mediated repression of cell cycle genes.


1996 ◽  
Vol 17 (11) ◽  
pp. 2395-2401 ◽  
Author(s):  
Lucia Anna Stivala ◽  
Monica Savio ◽  
Ornella Cazzalini ◽  
Roberto Pizzala ◽  
Laura Rehak ◽  
...  

2001 ◽  
Vol 281 (1) ◽  
pp. C188-C194 ◽  
Author(s):  
Derek W. Gilroy ◽  
Michael A. Saunders ◽  
Kenneth K. Wu

Cyclooxygenase-2 (COX-2) is continuously expressed in most cancerous cells where it appears to modulate cellular proliferation and apoptosis. However, little is known about the contribution of transient COX-2 induction to cell cycle progression or programmed cell death in primary cells. In this study we determined whether COX-2 regulates proliferation or apoptosis in human fibroblasts. COX-2 mRNA, protein, and prostaglandin E2(PGE2) were not detected in quiescent cells but were expressed during the G0/G1 phase of the cell cycle induced by serum. Inhibition of COX-2 did not alter G0/G1 to S phase transition or induce apoptosis at concentrations that diminished PGE2. Addition of interleukin-1β to serum enhanced COX-2 expression and PGE2 synthesis over that by serum alone but had no effect on the progression of these cells into S phase. Furthermore, platelet-derived growth factor drove the G0 fibroblasts into the cell cycle without inducing detectable levels of COX-2 or PGE2. Collectively, these data show that transient COX-2 expression in primary human fibroblasts does not influence cell cycle progression.


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