PI3K-like kinases restrain Pim gene expression in endothelial cells.

Abstract

Pim kinases contribute to tumor formation and development of lymphoma, which shows enhanced DNA replication, DNA recombination and repair. Endothelial cells^(ECs) express all the three members of Pim kinase gene family. We hypothesized that DNA repair gene would regulate Pim expression in ECs. Human umbilical vein endothelial cells (HUVECs) were isolated and maintained in M199 culture medium. The cellular distribution of Pim-3 in ECs was determined by immunofluorescent staining. The siRNA fragments were synthesized and transfected by using Lipofectamine LTX. The total cellular RNA was extracted from the cells by using Trizol reagent. cDNAs were quantified by semi-quantity PCR. The effects of LY294002 and wortmannin on RNA stability in ECs were also examined. Our data showed that LY294002 and wortmannin, phosphatidylinositol 3-kinase (PI3K) and PI3K-like kinase inhibitors, increased Pim mRNA expression in ECs without altering the mRNA stability. RNA interference (RNAi) targeting DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and ataxia telangiectasia mutated (ATM) increased mRNA expression of Pim-3 and Pim-1, respectively. Silencing of Akt decreased Pim-1 instead of Pm-2 and Pim-3 gene expression in ECs. But etoposide, a nucleoside analogue, which could activate DNA-PKcs and ATM, increased Pim expression in ECs. Our study indicates that the expression of Pim kinases is physiologically related to DNA-PKcs and ATM in ECs.

• Authors: Xinwen Min, Jie Tang, Yinfang Wang, Minghua Yu, Libing Zhao, Handong Yang, Peng Zhang, Yexin Ma
• Journal: Journal of Huazhong University of Science and Technology. Medical sciences = Hua zhong ke ji da xue xue bao. Yi xue Ying De wen ban = Huazhong keji daxue xuebao. Yixue Yingdewen ban (J Huazhong Univ Sci Technolog Med Sci) Vol. 32 Issue 1 Pg. 17-23 (Feb 2012) ISSN: 1672-0733 [Print] China
• PMID: 22282239 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Phosphatidylinositol 3-Kinases
• ATM protein, human
• Ataxia Telangiectasia Mutated Proteins
• Proto-Oncogene Proteins c-pim-1
• proto-oncogene proteins pim

Topics

• Ataxia Telangiectasia Mutated Proteins (metabolism)
• Cells, Cultured
• Down-Regulation (physiology)
• Endothelial Cells (metabolism)
• Gene Expression Regulation, Enzymologic (physiology)
• Humans
• Phosphatidylinositol 3-Kinases (metabolism)
• Proto-Oncogene Proteins c-pim-1 (metabolism)
• Subcellular Fractions (metabolism)