Ras is known to active three mitogen-activated protein kinase (MAPK) pathways, including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. While the essential roles of the ERK and the JNK pathways in Ras mitogenic signaling have been demonstrated, the contribution of the p38 pathway remains unclear. It is proposed here that activation of the p38 by Ras constitutes a negative feedback to restrain its mitogenic signaling. This hypothesis is based on our preliminary results that Ras activates several molecules of the p38 pathway, and each of these in turn inhibits Ras-dependent gene expression and proliferation. Published evidence of anti-mitogenic activity of the p38 pathway also supports this model. This hypothesis will be tested by the following specific aims: 1) To examine whether the p38 pathway functions downstream of MEK/ERK in Ras signaling; 2) To characterize the anti-mitogenic property of the p38 pathway in Ras proliferative signaling; 3) To determine whether the p38 pathway inhibits Ras activity by antagonizing JNK activation. Experiments will be carried out to dissect three MAPK pathways by focusing on analyses of the signaling mechanism as well as the consequence of the p38 activation by Ras in our NIH3T3 cell model. Knowledge obtained will be then applied to tumor cells where the proliferative signaling is constitutively active. Taken together, these studies will establish a negative feedback mechanism by which Ras signaling is regulated at the level of MAPK cascades. The information gained will advance our understanding of oncogene signaling networks and provide a new angle to develop signaling transduction pathway-oriented strategies against proliferative diseases.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA091576-05
Application #
6798214
Study Section
Pathology B Study Section (PTHB)
Program Officer
Blair, Donald G
Project Start
2000-09-13
Project End
2005-12-31
Budget Start
2004-09-01
Budget End
2005-12-31
Support Year
5
Fiscal Year
2004
Total Cost
$216,600
Indirect Cost
Name
Loyola University Chicago
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
791277940
City
Maywood
State
IL
Country
United States
Zip Code
60153
Qi, Xiao-Mei; Wang, Fang; Mortensen, Matthew et al. (2018) Targeting an oncogenic kinase/phosphatase signaling network for cancer therapy. Acta Pharm Sin B 8:511-517
Hou, Songwang; Suresh, Padmanaban S; Qi, Xiaomei et al. (2012) p38? Mitogen-activated protein kinase signals through phosphorylating its phosphatase PTPH1 in regulating ras protein oncogenesis and stress response. J Biol Chem 287:27895-905
Zhi, H-Y; Hou, S-W; Li, R-S et al. (2011) PTPH1 cooperates with vitamin D receptor to stimulate breast cancer growth through their mutual stabilization. Oncogene 30:1706-15
Hou, Song-Wang; Zhi, Hui-Ying; Pohl, Nicole et al. (2010) PTPH1 dephosphorylates and cooperates with p38gamma MAPK to increase ras oncogenesis through PDZ-mediated interaction. Cancer Res 70:2901-10
Loesch, Mathew; Zhi, Hui-Ying; Hou, Song-Wang et al. (2010) p38gamma MAPK cooperates with c-Jun in trans-activating matrix metalloproteinase 9. J Biol Chem 285:15149-58
Loesch, Mathew; Chen, Guan (2008) The p38 MAPK stress pathway as a tumor suppressor or more? Front Biosci 13:3581-93
Qi, Xiaomei; Pohl, Nicole M; Loesch, Mathew et al. (2007) p38alpha antagonizes p38gamma activity through c-Jun-dependent ubiquitin-proteasome pathways in regulating Ras transformation and stress response. J Biol Chem 282:31398-408
Li, Qing-Ping; Qi, Xiaomei; Pramanik, Rocky et al. (2007) Stress-induced c-Jun-dependent Vitamin D receptor (VDR) activation dissects the non-classical VDR pathway from the classical VDR activity. J Biol Chem 282:1544-51
Qi, Xiaomei; Tang, Jun; Loesch, Mathew et al. (2006) p38gamma mitogen-activated protein kinase integrates signaling crosstalk between Ras and estrogen receptor to increase breast cancer invasion. Cancer Res 66:7540-7
Qi, Xiaomei; Borowicz, Stanley; Pramanik, Rocky et al. (2004) Estrogen receptor inhibits c-Jun-dependent stress-induced cell death by binding and modifying c-Jun activity in human breast cancer cells. J Biol Chem 279:6769-77

Showing the most recent 10 out of 14 publications