Apoptosis or senescence-like growth arrest: Influence of cell-cycle position, p53, p21 and bax in H2O2 response of normal human fibroblasts

Qin Chen, Juping Liu, Jessica B. Merrett

Research output: Contribution to journalArticle

190 Citations (Scopus)

Abstract

Early-passage human diploid fibroblasts (HDFs) undergo senescence-like growth arrest in response to sublethal concentrations of H2O2. We determine here whether H2O2 can cause apoptosis in HDFs and the molecular changes that differ between apoptosis and senescence-like growth arrest. When exponentially growing early-passage IMR-90 cells were treated for 2 h with 50-200 μM (or 0.25-1 pmol/cell) H2O2, a fraction of cells detached at 16-32 h after the treatment. The cells remaining attached were growth-arrested and developed features of senescence in 1 week. The detached cells showed caspase-3 activation and typical morphological changes associated with apoptosis. Caspase-3 activation was H2O2 dose-dependent and preceded nuclear condensation or plasma membrane leakage. Apoptotic cells were mainly distributed in the S-phase of the cell cycle, while growth-arrested cells exhibited predominantly G1- and G2/M-phase distributions. H2O2 pretreatment induced G1 arrest and prohibited induction of apoptosis by a subsequent H2O2 challenge. The p53 protein showed an average 6.1-fold elevation in apoptotic cells and a 3.5-fold elevation in growth-arrested cells. Reduction of p53 levels with human papillomavirus E6 protein prohibited the activation of caspase-3 and decreased the proportion of apoptotic cells. Growth-arrested cells had elevated p21, while p21 was absent in apoptotic cells. Bcl-2 was elevated in both growth-arrested and apoptotic cells. Finally, although the overall level of bax did not change in growth-arrested or apoptotic cells, the solubility of bax protein increased in apoptotic cells. Our data suggest that in contrast with growth arrested cells, apoptotic cells show an S-phase cell cycle distribution, a higher degree of p53 elevation, an absence of p21 protein and increased solubility of bax protein.

Original languageEnglish (US)
Pages (from-to)543-551
Number of pages9
JournalBiochemical Journal
Volume347
Issue number2
DOIs
StatePublished - Apr 15 2000

Fingerprint

Fibroblasts
Cell Cycle Checkpoints
Cells
Apoptosis
Growth
Cell growth
Caspase 3
bcl-2-Associated X Protein
Chemical activation
Solubility
Proteins
Diploidy
S Phase
Cell membranes
Cell Cycle
Condensation
G2 Phase
Nuclear Envelope
Cell Division

Keywords

  • Caspases
  • G1 arrest
  • Oxidants
  • S-phase

ASJC Scopus subject areas

  • Biochemistry

Cite this

Apoptosis or senescence-like growth arrest : Influence of cell-cycle position, p53, p21 and bax in H2O2 response of normal human fibroblasts. / Chen, Qin; Liu, Juping; Merrett, Jessica B.

In: Biochemical Journal, Vol. 347, No. 2, 15.04.2000, p. 543-551.

Research output: Contribution to journalArticle

@article{89be279d050448aabefd223f77bb11bc,
title = "Apoptosis or senescence-like growth arrest: Influence of cell-cycle position, p53, p21 and bax in H2O2 response of normal human fibroblasts",
abstract = "Early-passage human diploid fibroblasts (HDFs) undergo senescence-like growth arrest in response to sublethal concentrations of H2O2. We determine here whether H2O2 can cause apoptosis in HDFs and the molecular changes that differ between apoptosis and senescence-like growth arrest. When exponentially growing early-passage IMR-90 cells were treated for 2 h with 50-200 μM (or 0.25-1 pmol/cell) H2O2, a fraction of cells detached at 16-32 h after the treatment. The cells remaining attached were growth-arrested and developed features of senescence in 1 week. The detached cells showed caspase-3 activation and typical morphological changes associated with apoptosis. Caspase-3 activation was H2O2 dose-dependent and preceded nuclear condensation or plasma membrane leakage. Apoptotic cells were mainly distributed in the S-phase of the cell cycle, while growth-arrested cells exhibited predominantly G1- and G2/M-phase distributions. H2O2 pretreatment induced G1 arrest and prohibited induction of apoptosis by a subsequent H2O2 challenge. The p53 protein showed an average 6.1-fold elevation in apoptotic cells and a 3.5-fold elevation in growth-arrested cells. Reduction of p53 levels with human papillomavirus E6 protein prohibited the activation of caspase-3 and decreased the proportion of apoptotic cells. Growth-arrested cells had elevated p21, while p21 was absent in apoptotic cells. Bcl-2 was elevated in both growth-arrested and apoptotic cells. Finally, although the overall level of bax did not change in growth-arrested or apoptotic cells, the solubility of bax protein increased in apoptotic cells. Our data suggest that in contrast with growth arrested cells, apoptotic cells show an S-phase cell cycle distribution, a higher degree of p53 elevation, an absence of p21 protein and increased solubility of bax protein.",
keywords = "Caspases, G1 arrest, Oxidants, S-phase",
author = "Qin Chen and Juping Liu and Merrett, {Jessica B.}",
year = "2000",
month = "4",
day = "15",
doi = "10.1042/0264-6021:3470543",
language = "English (US)",
volume = "347",
pages = "543--551",
journal = "Biochemical Journal",
issn = "0264-6021",
publisher = "Portland Press Ltd.",
number = "2",

}

TY - JOUR

T1 - Apoptosis or senescence-like growth arrest

T2 - Influence of cell-cycle position, p53, p21 and bax in H2O2 response of normal human fibroblasts

AU - Chen, Qin

AU - Liu, Juping

AU - Merrett, Jessica B.

PY - 2000/4/15

Y1 - 2000/4/15

N2 - Early-passage human diploid fibroblasts (HDFs) undergo senescence-like growth arrest in response to sublethal concentrations of H2O2. We determine here whether H2O2 can cause apoptosis in HDFs and the molecular changes that differ between apoptosis and senescence-like growth arrest. When exponentially growing early-passage IMR-90 cells were treated for 2 h with 50-200 μM (or 0.25-1 pmol/cell) H2O2, a fraction of cells detached at 16-32 h after the treatment. The cells remaining attached were growth-arrested and developed features of senescence in 1 week. The detached cells showed caspase-3 activation and typical morphological changes associated with apoptosis. Caspase-3 activation was H2O2 dose-dependent and preceded nuclear condensation or plasma membrane leakage. Apoptotic cells were mainly distributed in the S-phase of the cell cycle, while growth-arrested cells exhibited predominantly G1- and G2/M-phase distributions. H2O2 pretreatment induced G1 arrest and prohibited induction of apoptosis by a subsequent H2O2 challenge. The p53 protein showed an average 6.1-fold elevation in apoptotic cells and a 3.5-fold elevation in growth-arrested cells. Reduction of p53 levels with human papillomavirus E6 protein prohibited the activation of caspase-3 and decreased the proportion of apoptotic cells. Growth-arrested cells had elevated p21, while p21 was absent in apoptotic cells. Bcl-2 was elevated in both growth-arrested and apoptotic cells. Finally, although the overall level of bax did not change in growth-arrested or apoptotic cells, the solubility of bax protein increased in apoptotic cells. Our data suggest that in contrast with growth arrested cells, apoptotic cells show an S-phase cell cycle distribution, a higher degree of p53 elevation, an absence of p21 protein and increased solubility of bax protein.

AB - Early-passage human diploid fibroblasts (HDFs) undergo senescence-like growth arrest in response to sublethal concentrations of H2O2. We determine here whether H2O2 can cause apoptosis in HDFs and the molecular changes that differ between apoptosis and senescence-like growth arrest. When exponentially growing early-passage IMR-90 cells were treated for 2 h with 50-200 μM (or 0.25-1 pmol/cell) H2O2, a fraction of cells detached at 16-32 h after the treatment. The cells remaining attached were growth-arrested and developed features of senescence in 1 week. The detached cells showed caspase-3 activation and typical morphological changes associated with apoptosis. Caspase-3 activation was H2O2 dose-dependent and preceded nuclear condensation or plasma membrane leakage. Apoptotic cells were mainly distributed in the S-phase of the cell cycle, while growth-arrested cells exhibited predominantly G1- and G2/M-phase distributions. H2O2 pretreatment induced G1 arrest and prohibited induction of apoptosis by a subsequent H2O2 challenge. The p53 protein showed an average 6.1-fold elevation in apoptotic cells and a 3.5-fold elevation in growth-arrested cells. Reduction of p53 levels with human papillomavirus E6 protein prohibited the activation of caspase-3 and decreased the proportion of apoptotic cells. Growth-arrested cells had elevated p21, while p21 was absent in apoptotic cells. Bcl-2 was elevated in both growth-arrested and apoptotic cells. Finally, although the overall level of bax did not change in growth-arrested or apoptotic cells, the solubility of bax protein increased in apoptotic cells. Our data suggest that in contrast with growth arrested cells, apoptotic cells show an S-phase cell cycle distribution, a higher degree of p53 elevation, an absence of p21 protein and increased solubility of bax protein.

KW - Caspases

KW - G1 arrest

KW - Oxidants

KW - S-phase

UR - http://www.scopus.com/inward/record.url?scp=0034655373&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034655373&partnerID=8YFLogxK

U2 - 10.1042/0264-6021:3470543

DO - 10.1042/0264-6021:3470543

M3 - Article

C2 - 10749685

AN - SCOPUS:0034655373

VL - 347

SP - 543

EP - 551

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

IS - 2

ER -