Intercellular communication in primary cultures of putative preneoplastic and 'normal' hepatocytes.
Gap junctional intercellular communication (IC) was studied in gamma-glutamyltranspeptidase (gamma-GT)-positive and -negative hepatocytes isolated from carcinogen-treated rats. Putative preneoplastic gamma-GT-positive hepatocytes were visualized in monolayer cultures by indirect immunofluorescence using anti-gamma-GT-antibodies. IC was evaluated by studying dye coupling of the cells. gamma-GT-positive hepatocytes showed a significantly lower dye coupling than did gamma-GT-negative liver cells. Spread of the dye Lucifer Yellow CH to neighboring cells was decreased further by the tumor-promoting chemical phenobarbital in both cell types in vitro. Also treatment in vivo with the barbiturate significantly reduced dye coupling of hepatocytes. The findings suggest that as a result of their decreased ability to communicate, preneoplastic hepatocytes may escape from growth control and differentiation signals given out by surrounding 'normal' cells.
Leibold
E
E
GSF-Institut für Toxikologie, Oberschleissheim, Germany.
Schwarz
L R
LR
D015073:2-Acetylaminofluorene; D000818:Animals; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004052:Diethylnitrosamine; D006498:Hepatectomy; D008099:Liver / Q000166:cytology / Q000201:enzymology / Q000503:physiopathology*; D008114:Liver Neoplasms, Experimental / Q000201:enzymology / Q000503:physiopathology*; D008297:Male; D010634:Phenobarbital / Q000633:toxicity*; D011230:Precancerous Conditions / Q000201:enzymology / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D005723:gamma-Glutamyltransferase / Q000032:analysis*
D004052:Diethylnitrosamine; D015073:2-Acetylaminofluorene; D005723:gamma-Glutamyltransferase; D010634:Phenobarbital