edoc

Nuclear PIM1 confers resistance to rapamycin-impaired endothelial proliferation

Walpen, Thomas and Kalus, Ina and Schwaller, Jürg and Peier, Martin A. and Battegay, Edouard J. and Humar, Rok. (2012) Nuclear PIM1 confers resistance to rapamycin-impaired endothelial proliferation. Biochemical and Biophysical Research Communications, 429 (1-2). pp. 24-30.

Full text not available from this repository.

Official URL: https://edoc.unibas.ch/62076/

Downloads: Statistics Overview

Abstract

The PIM serine/threonine kinases and the mTOR/AKT pathway integrate growth factor signaling and promote cell proliferation and survival. They both share phosphorylation targets and have overlapping functions, which can partially substitute for each other. In cancer cells PIM kinases have been reported to produce resistance to mTOR inhibition by rapamycin. Tumor growth depends highly on blood vessel infiltration into the malignant tissue and therefore on endothelial cell proliferation. We therefore investigated how the PIM1 kinase modulates growth inhibitory effects of rapamycin in mouse aortic endothelial cells (MAEC). We found that proliferation of MAEC lacking Pim1 was significantly more sensitive to rapamycin inhibition, compared to wildtype cells. Inhibition of mTOR and AKT in normal MAEC resulted in significantly elevated PIM1 protein levels in the cytosol and in the nucleus. We observed that truncation of the C-terminal part of Pim1 beyond Ser 276 resulted in almost exclusive nuclear localization of the protein. Re-expression of this Pim1 deletion mutant significantly increased the proliferation of Pim1(-/-) cells when compared to expression of the wildtype Pim1 cDNA. Finally, overexpression of the nuclear localization mutant and the wildtype Pim1 resulted in complete resistance to growth inhibition by rapamycin. Thus, mTOR inhibition-induced nuclear accumulation of PIM1 or expression of a nuclear C-terminal PIM1 truncation mutant is sufficient to increase endothelial cell proliferation, suggesting that nuclear localization of PIM1 is important for resistance of MAEC to rapamycin-mediated inhibition of proliferation.
Faculties and Departments:03 Faculty of Medicine > Bereich Kinder- und Jugendheilkunde (Klinik) > Kinder- und Jugendheilkunde (UKBB) > Kindliche Leukämie (Schwaller)
03 Faculty of Medicine > Departement Klinische Forschung > Bereich Kinder- und Jugendheilkunde (Klinik) > Kinder- und Jugendheilkunde (UKBB) > Kindliche Leukämie (Schwaller)
03 Faculty of Medicine > Departement Biomedizin > Department of Biomedicine, University Children's Hospital > Childhood Leukemia (Schwaller)
UniBasel Contributors:Schwaller, Jürg
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:Elsevier
ISSN:0006-291X
e-ISSN:1090-2104
Note:Publication type according to Uni Basel Research Database: Journal article
Identification Number:
Last Modified:28 Jul 2020 12:06
Deposited On:28 Jul 2020 12:06

Repository Staff Only: item control page