TY - JOUR
T1 - Deregulation of PKB influences antiapoptotic signaling by PKC in breast cancer cells.
AU - Lu, Dongmei
AU - Huang, Jie
AU - Basu, Alakananda
PY - 2004/9
Y1 - 2004/9
N2 - We have previously shown that novel protein kinase C (nPKC) isozymes, such as nPKCepsilon, negatively regulate TNF-induced apoptosis in breast cancer cells although the level on nPKCs did not correlate with cellular sensitivity to TNF. In the present study, we examined if the level/activation status of Akt/PKB influences antiapoptotic signaling by nPKCepsilon. While MCF-7 cells overexpressed PKB, BT-20 and SKBR-3 cells expressed constitutively phosphorylated PKB, and MDA-MB-231 cells expressed unphosphorylated PKB. Ly294002, an inhibitor of PI-3 kinase, induced cell death in SKBR-3 cells, which contained little nPKCs. Although Ly294002 by itself had only a modest effect on cell death in BT-20 and MCF-7 cells, it potentiated sensitivity of these cells to TNF. In contrast, Ly294002 either alone or in combination with TNF had little effect on cell death in MDA-MB-231 cells. These results suggest that the status of PKB in breast cancer cells influences antiapoptotic signaling by PKC.
AB - We have previously shown that novel protein kinase C (nPKC) isozymes, such as nPKCepsilon, negatively regulate TNF-induced apoptosis in breast cancer cells although the level on nPKCs did not correlate with cellular sensitivity to TNF. In the present study, we examined if the level/activation status of Akt/PKB influences antiapoptotic signaling by nPKCepsilon. While MCF-7 cells overexpressed PKB, BT-20 and SKBR-3 cells expressed constitutively phosphorylated PKB, and MDA-MB-231 cells expressed unphosphorylated PKB. Ly294002, an inhibitor of PI-3 kinase, induced cell death in SKBR-3 cells, which contained little nPKCs. Although Ly294002 by itself had only a modest effect on cell death in BT-20 and MCF-7 cells, it potentiated sensitivity of these cells to TNF. In contrast, Ly294002 either alone or in combination with TNF had little effect on cell death in MDA-MB-231 cells. These results suggest that the status of PKB in breast cancer cells influences antiapoptotic signaling by PKC.
UR - http://www.scopus.com/inward/record.url?scp=16644363036&partnerID=8YFLogxK
U2 - 10.3892/ijo.25.3.671
DO - 10.3892/ijo.25.3.671
M3 - Article
C2 - 15289868
AN - SCOPUS:16644363036
SN - 1019-6439
VL - 25
SP - 671
EP - 676
JO - International Journal of Oncology
JF - International Journal of Oncology
IS - 3
ER -