RT Journal Article
SR Electronic
T1 Antisense Oligonucleotides Targeting Human Protein Kinase C-α Inhibit Phorbol Ester-Induced Reduction of Bradykinin-Evoked Calcium Mobilization in A549 Cells
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 209
OP 216
DO 10.1124/mol.51.2.209
VO 51
IS 2
A1 Luc Levesque
A1 Nicholas M. Dean
A1 Henri Sasmor
A1 Stanley T. Crooke
YR 1997
UL http://molpharm.aspetjournals.org/content/51/2/209.abstract
AB Regulation of the bradykinin-evoked increase in intracellular Ca2+ concentration by protein kinase C (PKC)-α was investigated in A549 human lung carcinoma cells. Bradykinin, a potent and selective kinin B2 receptor agonist, induces calcium mobilization in a concentration-dependent fashion in this cell line. 12-O-Tetradecanoylphorbol-13-acetate (TPA), a potent activator of PKC, is known to reduce the amplitude of agonist-induced calcium mobilization in various cell lines. Because PKC-α is a major PKC isozyme in A549 cells, we investigated whether this isozyme plays a role in this process. A 20-mer phosphorothioate oligonucleotide targeting the 3′-untranslated region of the human PKC-α mRNA, which contains 2′-methoxyethyl modifications incorporated into the 5′ and 3′ segments of the oligonucleotide, was used to assess the putative role of PKC-α in the receptor regulation. ISIS 9606 reduced PKC-α mRNA for ≥72 hr after the initial treatment and the reduction was concentration dependent, whereas the mismatch control, ISIS 13009, had no effect. Concentrations of ISIS 9606 of 150 nmspecifically reduced the level of immunoreactive PKC-α protein by 66.3 ± 2.5% at 72 hr after treatment, without an effect on immunoreactive PKC-δ protein. This reduction in PKC-α was sufficient to inhibit the reduction of bradykinin-induced calcium mobilization by TPA. This finding is corroborated by the use of staurosporine, a nonselective PKC inhibitor, that prevented the effect of TPA. These results suggest that PKC-α is involved in kinin B2 receptor regulation by phorbol esters in A549 cells.