Dominant Negative α-Subunit of FTase Inhibits Effects of Insulin and IGF-I in MCF-7 Cells
We recently designed a dominant negative (DN) farnesyltransferase (FTase)/geranyl-gerahyltransferase I (GGTase I) α-subunit that when expressed in vascular smooth muscle cells decreased insulin-stimulated phosphorylation of FTase, FTase activity, amounts of farnesylated p21Ras, DNA synthesis, and ce...
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Published in | Biochemical and biophysical research communications Vol. 291; no. 3; pp. 458 - 465 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.03.2002
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Subjects | |
Online Access | Get full text |
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Summary: | We recently designed a dominant negative (DN) farnesyltransferase (FTase)/geranyl-gerahyltransferase I (GGTase I) α-subunit that when expressed in vascular smooth muscle cells decreased insulin-stimulated phosphorylation of FTase, FTase activity, amounts of farnesylated p21Ras, DNA synthesis, and cell migration. Currently, we explored the inhibitory effects of DN FTase/GGTase I α-subunit in MCF-7 cells on IGF-1- and insulin-stimulated DNA synthesis and cell proliferation. Expression of the DN FTase/GGTase I α-subunit completely blocked IGF-1- and insulin-stimulated BrdU incorporation and cell count. DN FTase/GGTase I α-subunit inhibited insulin-stimulated phosphorylation of FTase/GGTase I α-subunit, FTase and GGTase I activity, and prenylation of p21Ras and RhoA. Expression of DN FTase/GGTase I α-subunit diminished IGF-1- and insulin-stimulated phosphorylation of ERK (extracellular signal-regulated kinase), but had no effect on IGF-1- and insulin-stimulated phosphorylation of Akt. Taken together, these data suggest that DN FTase/GGTase I α-subunit can assuage the mitogenic effects of IGF-1 and insulin on MCF-7 breast cancer cells. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0006-291X 1090-2104 |
DOI: | 10.1006/bbrc.2002.6471 |