12-O-TETRADECANOYLPHORBOL-13-ACETATE-INDUCED INHIBITION OF GAP JUNCTIONAL COMMUNICATION IS DIFFERENTIALLY REGULATED IN A TRANSFORMATION-SENSITIVE SYRIAN-HAMSTER EMBRYO CELL-LINE COMPARED TO EARLY-PASSAGE SHE CELLS
Le. Roseng et al., 12-O-TETRADECANOYLPHORBOL-13-ACETATE-INDUCED INHIBITION OF GAP JUNCTIONAL COMMUNICATION IS DIFFERENTIALLY REGULATED IN A TRANSFORMATION-SENSITIVE SYRIAN-HAMSTER EMBRYO CELL-LINE COMPARED TO EARLY-PASSAGE SHE CELLS, Carcinogenesis, 14(9), 1993, pp. 1851-1855
The transformation-sensitive cell-line BPNi was more susceptible to 12
-O-tetradecanoylphorbol-13-acetate (TPA)-induced inhibition of gap jun
ctional intercellular communication (GJIC) than early passage Syrian h
amster embryo (SHE) cells, while the potency of TPA to down-regulate E
GF-binding was similar in the two cell types. The kinetics of TPA-indu
ced inhibition of GJIC suggested that different mechanisms may operate
at high and low TPA concentrations. The initial inhibition after expo
sure to high TPA concentrations was followed by a recovery of GJIC. Th
e recovery was much more pronounced in SHE than in BPNi cells. This ef
fect could not be explained by differences in down-regulation of prote
in kinase C. Removal of high TPA concentrations also resulted in a fas
ter recovery of GJIC in SHE than in BPNi cells. In addition, although
forskolin induced a similar protection against the inhibitory effect o
f TPA on GJIC, forskolin restored GJIC blocked by TPA much faster in S
HE than in BPNi cells. Thus, BPNi cells are more sensitive to TPA indu
ced inhibition of GJIC than SHE cells, and have reduced capability to
recover from down-regulated GJIC as compared to SHE cells.