Regulation of bradykinin B2 receptors by the ras oncogene : Evidence for multiple mechanisms
(1996) In Journal of Cellular Physiology 169(2). p.248-255- Abstract
The objective of this study was to probe the molecular mechanisms underlying the increase in sensitivity of cells to bradykinin (BK) following expression of a transforming Ha-ras oncogene. We used native NIH3T3 fibroblast (3T3) cells and 3T3 cells transfected with a glucocorticoid-sensitive oncogenic Ha-ras construct (DT cells). DT cells incubated in the presence of 1 μM dexamethasone (DEX) for 24 hr expressed a relatively high level of membrane-bound Ha-Ras protein, BK B2 receptor mRNA, and B2 receptor binding as determined by Western blotting with anti-Ha-Ras antibodies, reverse transcriptase polymerase chain reaction using B2 receptor-specific primers, and specific [3H]BK binding, respectively. BK also stimulated a... (More)
The objective of this study was to probe the molecular mechanisms underlying the increase in sensitivity of cells to bradykinin (BK) following expression of a transforming Ha-ras oncogene. We used native NIH3T3 fibroblast (3T3) cells and 3T3 cells transfected with a glucocorticoid-sensitive oncogenic Ha-ras construct (DT cells). DT cells incubated in the presence of 1 μM dexamethasone (DEX) for 24 hr expressed a relatively high level of membrane-bound Ha-Ras protein, BK B2 receptor mRNA, and B2 receptor binding as determined by Western blotting with anti-Ha-Ras antibodies, reverse transcriptase polymerase chain reaction using B2 receptor-specific primers, and specific [3H]BK binding, respectively. BK also stimulated a significant B2 receptor-mediated increase in [3H]thymidine incorporation in the cells both alone and in synergy with epidermal growth factor. In the absence of DEX, the DT cells expressed a considerably lower but yet clearly significant level of Ha-Ras. Under this condition, receptor mRNA and receptor binding remained maximally expressed. On the other hand, BK was unable to stimulate any increase in [3H]thymidine incorporation. In contrast to DT cells, no Ha-Ras, receptor mRNA, receptor binding, or BK-stimulated, B2 receptor-mediated [3H]thymidine incorporation was detected in 3T3 cells (+/- DEX). However, BK stimulated a transient increase in the level of intracellular free Ca2+ in the 3T3 cells indicating that these cells express a small number of functional B2 receptors. In all, these results show that oncogenic Ha-Ras regulates the sensitivity of 3T3 cells to BK through at least two different mechanisms. One mechanism occurs at a relatively low level of Ha-Ras and involves an increase in B2 receptor mRNA and expressed B2 receptor levels, and another mechanism occurs at a relatively high level of Ha-Ras and involves an increase in B2 receptor-mediated mitogenic signaling.
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- author
- Hembree, Timothy N. and Leeb-Lundberg, L. M Fredrik LU
- publishing date
- 1996-11-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Cellular Physiology
- volume
- 169
- issue
- 2
- pages
- 248 - 255
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:0029912747
- pmid:8908192
- ISSN
- 0021-9541
- DOI
- 10.1002/(SICI)1097-4652(199611)169:2<248::AID-JCP4>3.0.CO;2-O
- language
- English
- LU publication?
- no
- id
- 92ea9114-acda-46a4-84e3-84cfb1e36241
- date added to LUP
- 2019-06-10 11:13:06
- date last changed
- 2025-04-04 14:22:48
@article{92ea9114-acda-46a4-84e3-84cfb1e36241,
abstract = {{<p>The objective of this study was to probe the molecular mechanisms underlying the increase in sensitivity of cells to bradykinin (BK) following expression of a transforming Ha-ras oncogene. We used native NIH3T3 fibroblast (3T3) cells and 3T3 cells transfected with a glucocorticoid-sensitive oncogenic Ha-ras construct (DT cells). DT cells incubated in the presence of 1 μM dexamethasone (DEX) for 24 hr expressed a relatively high level of membrane-bound Ha-Ras protein, BK B2 receptor mRNA, and B2 receptor binding as determined by Western blotting with anti-Ha-Ras antibodies, reverse transcriptase polymerase chain reaction using B2 receptor-specific primers, and specific [<sup>3</sup>H]BK binding, respectively. BK also stimulated a significant B2 receptor-mediated increase in [<sup>3</sup>H]thymidine incorporation in the cells both alone and in synergy with epidermal growth factor. In the absence of DEX, the DT cells expressed a considerably lower but yet clearly significant level of Ha-Ras. Under this condition, receptor mRNA and receptor binding remained maximally expressed. On the other hand, BK was unable to stimulate any increase in [<sup>3</sup>H]thymidine incorporation. In contrast to DT cells, no Ha-Ras, receptor mRNA, receptor binding, or BK-stimulated, B2 receptor-mediated [<sup>3</sup>H]thymidine incorporation was detected in 3T3 cells (+/- DEX). However, BK stimulated a transient increase in the level of intracellular free Ca<sup>2+</sup> in the 3T3 cells indicating that these cells express a small number of functional B2 receptors. In all, these results show that oncogenic Ha-Ras regulates the sensitivity of 3T3 cells to BK through at least two different mechanisms. One mechanism occurs at a relatively low level of Ha-Ras and involves an increase in B2 receptor mRNA and expressed B2 receptor levels, and another mechanism occurs at a relatively high level of Ha-Ras and involves an increase in B2 receptor-mediated mitogenic signaling.</p>}},
author = {{Hembree, Timothy N. and Leeb-Lundberg, L. M Fredrik}},
issn = {{0021-9541}},
language = {{eng}},
month = {{11}},
number = {{2}},
pages = {{248--255}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Journal of Cellular Physiology}},
title = {{Regulation of bradykinin B2 receptors by the ras oncogene : Evidence for multiple mechanisms}},
url = {{http://dx.doi.org/10.1002/(SICI)1097-4652(199611)169:2<248::AID-JCP4>3.0.CO;2-O}},
doi = {{10.1002/(SICI)1097-4652(199611)169:2<248::AID-JCP4>3.0.CO;2-O}},
volume = {{169}},
year = {{1996}},
}