Pin1 is overexpressed in breast cancer and cooperates with Ras signaling in increasing the transcriptional activity of c-Jun towards cyclin D1.
Phosphorylation on serines or threonines preceding proline (Ser/Thr-Pro) is a major signaling mechanism. The conformation of a subset of phosphorylated Ser/Thr-Pro motifs is regulated by the prolyl isomerase Pin1. Inhibition of Pin1 induces apoptosis and may also contribute to neuronal death in Alzheimer's disease. However, little is known about the ... role of Pin1 in cancer or in modulating transcription factor activity. Here we report that Pin1 is strikingly overexpressed in human breast cancers, and that its levels correlate with cyclin D1 levels in tumors. Overexpression of Pin1 increases cellular cyclin D1 protein and activates its promoter. Furthermore, Pin1 binds c-Jun that is phosphorylated on Ser63/73-Pro motifs by activated JNK or oncogenic Ras. Moreover, Pin1 cooperates with either activated Ras or JNK to increase transcriptional activity of c-Jun towards the cyclin D1 promoter. Thus, Pin1 is up-regulated in human tumors and cooperates with Ras signaling in increasing c-Jun transcriptional activity towards cyclin D1. Given the crucial roles of Ras signaling and cyclin D1 overexpression in oncogenesis, our results suggest that overexpression of Pin1 may promote tumor growth.
Mesh Terms:
Adult, Aged, Aged, 80 and over, Breast, Breast Neoplasms, Carcinoma in Situ, Cells, Cultured, Cyclin D1, Female, Gene Expression Regulation, Gene Expression Regulation, Neoplastic, Humans, JNK Mitogen-Activated Protein Kinases, Middle Aged, Mitogen-Activated Protein Kinases, Peptidylprolyl Isomerase, Phosphorylation, Promoter Regions, Genetic, Proto-Oncogene Proteins c-jun, Receptor, erbB-2, Receptors, Estrogen, Signal Transduction, Transcription, Genetic, Tumor Cells, Cultured, Tumor Markers, Biological, ras Proteins
Adult, Aged, Aged, 80 and over, Breast, Breast Neoplasms, Carcinoma in Situ, Cells, Cultured, Cyclin D1, Female, Gene Expression Regulation, Gene Expression Regulation, Neoplastic, Humans, JNK Mitogen-Activated Protein Kinases, Middle Aged, Mitogen-Activated Protein Kinases, Peptidylprolyl Isomerase, Phosphorylation, Promoter Regions, Genetic, Proto-Oncogene Proteins c-jun, Receptor, erbB-2, Receptors, Estrogen, Signal Transduction, Transcription, Genetic, Tumor Cells, Cultured, Tumor Markers, Biological, ras Proteins
EMBO J.
Date: Jul. 02, 2001
PubMed ID: 11432833
View in: Pubmed Google Scholar
Download Curated Data For This Publication
6008
Switch View:
- Interactions 2