Inhibition of gap junctional intercellular communication by tumor promoters in connexin43 and connexin32-expressing liver cells: Cell specificity and role of protein kinase C

Ping Ren, Parmender P. Mehta, Randall J. Ruch

Research output: Contribution to journalArticle

62 Citations (Scopus)

Abstract

In this study, we investigated whether the tumor promoters, 12-O-tetradecanoylphorbol-13-acetate (TPA), phenobarbital (PB), and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), inhibited gap junctional intercellular communication (GJIC) in a cell-specific or connexin-specific manner and whether protein kinase C was involved. To do this, we used highly communicating WB-F344 rat liver epithelial cells, which express connexin43 as their predominant gap junction protein, WB-aB1 cells, which are a GJIC-incompetent mutant line of WB-F344 cells and that express connexin43, WB-a/32-10 cells, which are a highly communicating derivative of WB-aB1 cells generated by stable transduction with a connexin32 retroviral expression vector, and primary cultured rat hepatocytes, which express conexin32 predominantly. Treatment of WB-F344 and WB-a/32-10 cells, but not hepatocytes, with TPA inhibited GJIC (assayed by Lucifer Yellow dye microinjection). This inhibition involved protein kinase C because (i) inhibition was prevented by co-treatment of the cells with a specific protein kinase C inhibitor, bis-indolylmaleimide, and (ii) treatment with TPA for 24 h had no effect on dye-coupling in agreement with the downregulation of protein kinase C. TPA also caused the internalization of Cx43-containing gap junctions and the formation of a hyperphosphorylated form of Cx43, Cx43-P3, in WB-F344 cells only, but TPA had no effect on Cx32-containing gap junctions or protein mobility. In contrast, PB inhibited GJIC only in hepatocytes and DDT inhibited GJIC in all three types of cells; bis-indolylmaleimide did not block the effects of either agent. These results indicate that the inhibitory actions of TPA and PB on GJIC are cell-specific rather than connexin-specific and that TPA inhibits connexin43 and connexin32-mediated GJIC through a protein kinase C-dependent mechanism.

Original languageEnglish (US)
Pages (from-to)169-175
Number of pages7
JournalCarcinogenesis
Volume19
Issue number1
DOIs
StatePublished - Jan 1 1998

Fingerprint

Connexin 43
Carcinogens
Protein Kinase C
Tetradecanoylphorbol Acetate
Liver
Connexins
Phenobarbital
Hepatocytes
DDT
Coloring Agents
Inhibition (Psychology)
Protein C Inhibitor
Gap Junctions
Inbred F344 Rats
Microinjections
Protein Kinase Inhibitors
Cell Communication
Therapeutics
Down-Regulation
Epithelial Cells

ASJC Scopus subject areas

  • Cancer Research

Cite this

Inhibition of gap junctional intercellular communication by tumor promoters in connexin43 and connexin32-expressing liver cells : Cell specificity and role of protein kinase C. / Ren, Ping; Mehta, Parmender P.; Ruch, Randall J.

In: Carcinogenesis, Vol. 19, No. 1, 01.01.1998, p. 169-175.

Research output: Contribution to journalArticle

@article{1c1844e15a374023b8a04a862d8497a6,
title = "Inhibition of gap junctional intercellular communication by tumor promoters in connexin43 and connexin32-expressing liver cells: Cell specificity and role of protein kinase C",
abstract = "In this study, we investigated whether the tumor promoters, 12-O-tetradecanoylphorbol-13-acetate (TPA), phenobarbital (PB), and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), inhibited gap junctional intercellular communication (GJIC) in a cell-specific or connexin-specific manner and whether protein kinase C was involved. To do this, we used highly communicating WB-F344 rat liver epithelial cells, which express connexin43 as their predominant gap junction protein, WB-aB1 cells, which are a GJIC-incompetent mutant line of WB-F344 cells and that express connexin43, WB-a/32-10 cells, which are a highly communicating derivative of WB-aB1 cells generated by stable transduction with a connexin32 retroviral expression vector, and primary cultured rat hepatocytes, which express conexin32 predominantly. Treatment of WB-F344 and WB-a/32-10 cells, but not hepatocytes, with TPA inhibited GJIC (assayed by Lucifer Yellow dye microinjection). This inhibition involved protein kinase C because (i) inhibition was prevented by co-treatment of the cells with a specific protein kinase C inhibitor, bis-indolylmaleimide, and (ii) treatment with TPA for 24 h had no effect on dye-coupling in agreement with the downregulation of protein kinase C. TPA also caused the internalization of Cx43-containing gap junctions and the formation of a hyperphosphorylated form of Cx43, Cx43-P3, in WB-F344 cells only, but TPA had no effect on Cx32-containing gap junctions or protein mobility. In contrast, PB inhibited GJIC only in hepatocytes and DDT inhibited GJIC in all three types of cells; bis-indolylmaleimide did not block the effects of either agent. These results indicate that the inhibitory actions of TPA and PB on GJIC are cell-specific rather than connexin-specific and that TPA inhibits connexin43 and connexin32-mediated GJIC through a protein kinase C-dependent mechanism.",
author = "Ping Ren and Mehta, {Parmender P.} and Ruch, {Randall J.}",
year = "1998",
month = "1",
day = "1",
doi = "10.1093/carcin/19.1.169",
language = "English (US)",
volume = "19",
pages = "169--175",
journal = "Carcinogenesis",
issn = "0143-3334",
publisher = "Oxford University Press",
number = "1",

}

TY - JOUR

T1 - Inhibition of gap junctional intercellular communication by tumor promoters in connexin43 and connexin32-expressing liver cells

T2 - Cell specificity and role of protein kinase C

AU - Ren, Ping

AU - Mehta, Parmender P.

AU - Ruch, Randall J.

PY - 1998/1/1

Y1 - 1998/1/1

N2 - In this study, we investigated whether the tumor promoters, 12-O-tetradecanoylphorbol-13-acetate (TPA), phenobarbital (PB), and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), inhibited gap junctional intercellular communication (GJIC) in a cell-specific or connexin-specific manner and whether protein kinase C was involved. To do this, we used highly communicating WB-F344 rat liver epithelial cells, which express connexin43 as their predominant gap junction protein, WB-aB1 cells, which are a GJIC-incompetent mutant line of WB-F344 cells and that express connexin43, WB-a/32-10 cells, which are a highly communicating derivative of WB-aB1 cells generated by stable transduction with a connexin32 retroviral expression vector, and primary cultured rat hepatocytes, which express conexin32 predominantly. Treatment of WB-F344 and WB-a/32-10 cells, but not hepatocytes, with TPA inhibited GJIC (assayed by Lucifer Yellow dye microinjection). This inhibition involved protein kinase C because (i) inhibition was prevented by co-treatment of the cells with a specific protein kinase C inhibitor, bis-indolylmaleimide, and (ii) treatment with TPA for 24 h had no effect on dye-coupling in agreement with the downregulation of protein kinase C. TPA also caused the internalization of Cx43-containing gap junctions and the formation of a hyperphosphorylated form of Cx43, Cx43-P3, in WB-F344 cells only, but TPA had no effect on Cx32-containing gap junctions or protein mobility. In contrast, PB inhibited GJIC only in hepatocytes and DDT inhibited GJIC in all three types of cells; bis-indolylmaleimide did not block the effects of either agent. These results indicate that the inhibitory actions of TPA and PB on GJIC are cell-specific rather than connexin-specific and that TPA inhibits connexin43 and connexin32-mediated GJIC through a protein kinase C-dependent mechanism.

AB - In this study, we investigated whether the tumor promoters, 12-O-tetradecanoylphorbol-13-acetate (TPA), phenobarbital (PB), and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), inhibited gap junctional intercellular communication (GJIC) in a cell-specific or connexin-specific manner and whether protein kinase C was involved. To do this, we used highly communicating WB-F344 rat liver epithelial cells, which express connexin43 as their predominant gap junction protein, WB-aB1 cells, which are a GJIC-incompetent mutant line of WB-F344 cells and that express connexin43, WB-a/32-10 cells, which are a highly communicating derivative of WB-aB1 cells generated by stable transduction with a connexin32 retroviral expression vector, and primary cultured rat hepatocytes, which express conexin32 predominantly. Treatment of WB-F344 and WB-a/32-10 cells, but not hepatocytes, with TPA inhibited GJIC (assayed by Lucifer Yellow dye microinjection). This inhibition involved protein kinase C because (i) inhibition was prevented by co-treatment of the cells with a specific protein kinase C inhibitor, bis-indolylmaleimide, and (ii) treatment with TPA for 24 h had no effect on dye-coupling in agreement with the downregulation of protein kinase C. TPA also caused the internalization of Cx43-containing gap junctions and the formation of a hyperphosphorylated form of Cx43, Cx43-P3, in WB-F344 cells only, but TPA had no effect on Cx32-containing gap junctions or protein mobility. In contrast, PB inhibited GJIC only in hepatocytes and DDT inhibited GJIC in all three types of cells; bis-indolylmaleimide did not block the effects of either agent. These results indicate that the inhibitory actions of TPA and PB on GJIC are cell-specific rather than connexin-specific and that TPA inhibits connexin43 and connexin32-mediated GJIC through a protein kinase C-dependent mechanism.

UR - http://www.scopus.com/inward/record.url?scp=0031819436&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031819436&partnerID=8YFLogxK

U2 - 10.1093/carcin/19.1.169

DO - 10.1093/carcin/19.1.169

M3 - Article

C2 - 9472709

AN - SCOPUS:0031819436

VL - 19

SP - 169

EP - 175

JO - Carcinogenesis

JF - Carcinogenesis

SN - 0143-3334

IS - 1

ER -