The rodent nongenotoxic hepatocarcinogen and peroxisome proliferator nafenopin inhibits intercellular communication in rat but not guinea-pig hepatocytes, perturbing S-phase but not apoptosis

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@article{6ad2b7e2200e481886ed6f87319a2f0e,
title = "The rodent nongenotoxic hepatocarcinogen and peroxisome proliferator nafenopin inhibits intercellular communication in rat but not guinea-pig hepatocytes, perturbing S-phase but not apoptosis",
abstract = "Previously, we have shown that the peroxisome proliferator (PP), nafenopin, induces S-phase in rat hepatocytes and suppresses apoptosis in hepatocytes from both rat and guinea-pig. Here, we confirm and extend these findings by defining the time course of growth perturbation and by correlating this with species differences in loss of gap junctional intercellular communication (GJIC). GJIC is associated with nongenotoxic carcinogenesis, possibly reflecting a tumour suppresser role of the connexins. Fluorescence microscopy of Hoechst 33258-stained rat or guinea- pig hepatocyte monolayers showed 1% apoptosis during the first 8 h of culture, peaking to 2-2.5% at 20-24 h. Nafenopin suppressed apoptosis compared with controls in both rat and guinea-pig, measured at 20 h and 24 h onwards, respectively. The induction of S-phase in rat hepatocytes by nafenopin could be detected as early as 4 h after compound addition whereas S-phase was not altered by nafenopin in guinea-pig hepatocytes. Intercellular communication as measured by intercellular transfer of microinjected Lucifer Yellow CH was observed during the first 14 h of primary rat hepatocyte culture peaking at a maximum value of 88 ± 3.0% after 7 h. In hepatocyte cultures from guinea-pig, dye-coupling levels were maintained between 88 ± 3.0 and 93 ± 3.0% within 2-10 h of culture and by 12 h showed only a slight decrease to 72 ± 3.0%. In the rat, significant inhibition was observed at 4 h after administration of nafenopin since GJIC was reduced by 20 ± 5% compared with vehicle control. By contrast, in the presence of nafenopin, the level of dye-coupling between guinea-pig hepatocytes did not decrease but remained between 85 ± 5 and 93 ± 3.0%, similar to that observed in control guinea-pig cultures. The data obtained contribute to our understanding of the role of GJIC inhibition in the perturbation of cell survival and proliferation caused by nongenotoxic hepatocarcinogens.",
keywords = "Apoptosis, Gap junctional intercellular communication, Nongenotoxic carcinogenesis, Peroxisome proliferators, S-phase",
author = "Elcock, {Fiona J.} and Chipman, {J. Kevin} and Roberts, {Ruth A.}",
year = "1998",
month = jul
day = "18",
doi = "10.1007/s002040050524",
language = "English",
volume = "72",
pages = "439--444",
journal = "Archives of toxicology",
issn = "0340-5761",
publisher = "Springer",
number = "7",

}

RIS

TY - JOUR

T1 - The rodent nongenotoxic hepatocarcinogen and peroxisome proliferator nafenopin inhibits intercellular communication in rat but not guinea-pig hepatocytes, perturbing S-phase but not apoptosis

AU - Elcock, Fiona J.

AU - Chipman, J. Kevin

AU - Roberts, Ruth A.

PY - 1998/7/18

Y1 - 1998/7/18

N2 - Previously, we have shown that the peroxisome proliferator (PP), nafenopin, induces S-phase in rat hepatocytes and suppresses apoptosis in hepatocytes from both rat and guinea-pig. Here, we confirm and extend these findings by defining the time course of growth perturbation and by correlating this with species differences in loss of gap junctional intercellular communication (GJIC). GJIC is associated with nongenotoxic carcinogenesis, possibly reflecting a tumour suppresser role of the connexins. Fluorescence microscopy of Hoechst 33258-stained rat or guinea- pig hepatocyte monolayers showed 1% apoptosis during the first 8 h of culture, peaking to 2-2.5% at 20-24 h. Nafenopin suppressed apoptosis compared with controls in both rat and guinea-pig, measured at 20 h and 24 h onwards, respectively. The induction of S-phase in rat hepatocytes by nafenopin could be detected as early as 4 h after compound addition whereas S-phase was not altered by nafenopin in guinea-pig hepatocytes. Intercellular communication as measured by intercellular transfer of microinjected Lucifer Yellow CH was observed during the first 14 h of primary rat hepatocyte culture peaking at a maximum value of 88 ± 3.0% after 7 h. In hepatocyte cultures from guinea-pig, dye-coupling levels were maintained between 88 ± 3.0 and 93 ± 3.0% within 2-10 h of culture and by 12 h showed only a slight decrease to 72 ± 3.0%. In the rat, significant inhibition was observed at 4 h after administration of nafenopin since GJIC was reduced by 20 ± 5% compared with vehicle control. By contrast, in the presence of nafenopin, the level of dye-coupling between guinea-pig hepatocytes did not decrease but remained between 85 ± 5 and 93 ± 3.0%, similar to that observed in control guinea-pig cultures. The data obtained contribute to our understanding of the role of GJIC inhibition in the perturbation of cell survival and proliferation caused by nongenotoxic hepatocarcinogens.

AB - Previously, we have shown that the peroxisome proliferator (PP), nafenopin, induces S-phase in rat hepatocytes and suppresses apoptosis in hepatocytes from both rat and guinea-pig. Here, we confirm and extend these findings by defining the time course of growth perturbation and by correlating this with species differences in loss of gap junctional intercellular communication (GJIC). GJIC is associated with nongenotoxic carcinogenesis, possibly reflecting a tumour suppresser role of the connexins. Fluorescence microscopy of Hoechst 33258-stained rat or guinea- pig hepatocyte monolayers showed 1% apoptosis during the first 8 h of culture, peaking to 2-2.5% at 20-24 h. Nafenopin suppressed apoptosis compared with controls in both rat and guinea-pig, measured at 20 h and 24 h onwards, respectively. The induction of S-phase in rat hepatocytes by nafenopin could be detected as early as 4 h after compound addition whereas S-phase was not altered by nafenopin in guinea-pig hepatocytes. Intercellular communication as measured by intercellular transfer of microinjected Lucifer Yellow CH was observed during the first 14 h of primary rat hepatocyte culture peaking at a maximum value of 88 ± 3.0% after 7 h. In hepatocyte cultures from guinea-pig, dye-coupling levels were maintained between 88 ± 3.0 and 93 ± 3.0% within 2-10 h of culture and by 12 h showed only a slight decrease to 72 ± 3.0%. In the rat, significant inhibition was observed at 4 h after administration of nafenopin since GJIC was reduced by 20 ± 5% compared with vehicle control. By contrast, in the presence of nafenopin, the level of dye-coupling between guinea-pig hepatocytes did not decrease but remained between 85 ± 5 and 93 ± 3.0%, similar to that observed in control guinea-pig cultures. The data obtained contribute to our understanding of the role of GJIC inhibition in the perturbation of cell survival and proliferation caused by nongenotoxic hepatocarcinogens.

KW - Apoptosis

KW - Gap junctional intercellular communication

KW - Nongenotoxic carcinogenesis

KW - Peroxisome proliferators

KW - S-phase

UR - http://www.scopus.com/inward/record.url?scp=0031837090&partnerID=8YFLogxK

U2 - 10.1007/s002040050524

DO - 10.1007/s002040050524

M3 - Article

C2 - 9708883

AN - SCOPUS:0031837090

VL - 72

SP - 439

EP - 444

JO - Archives of toxicology

JF - Archives of toxicology

SN - 0340-5761

IS - 7

ER -