Oncotarget

Priority Research Papers:

c-Myb and C/EBPβ regulate OPN and other senescence-associated secretory phenotype factors

Kevin C. Flanagan, Elise Alspach, Ermira Pazolli, Shankar Parajuli, Qihao Ren, Laura L. Arthur, Roberto Tapia and Sheila A. Stewart _

PDF  |  HTML  |  Supplementary Files  |  How to cite

Oncotarget. 2018; 9:21-36. https://doi.org/10.18632/oncotarget.22940

Metrics: PDF 1931 views  |   HTML 3454 views  |   ?  


Abstract

Kevin C. Flanagan1,2, Elise Alspach1, Ermira Pazolli1, Shankar Parajuli1, Qihao Ren1, Laura L. Arthur1, Roberto Tapia1 and Sheila A. Stewart1,2,3,4

1 Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA

2 ICCE Institute, Washington University School of Medicine, St. Louis, MO, USA

3 Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA

4 Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, USA

Correspondence to:

Sheila A. Stewart, email:

Keywords: senescence; SASP; osteopontin; c-Myb; C/EBPβ

Received: July 15, 2017 Accepted: November 09, 2017 Published: December 05, 2017

Abstract

Tumorigenesis results from the convergence of cell autonomous mutations and corresponding stromal changes that promote tumor cell growth. Senescent cells, which secrete a plethora of pro-tumorigenic factors termed the senescence-associated secretory phenotype (SASP), play an important role in tumor formation. Investigation into SASP regulation revealed that many but not all SASP factors are subject to NF-kB and p38MAPK regulation. However, many pro-tumorigenic SASP factors, including osteopontin (OPN), are not responsive to these canonical pathways leaving the regulation of these factors an open question. We report that the transcription factor c-Myb regulates OPN, IL-6, and IL-8 in addition to 57 other SASP factors. The regulation of OPN is direct as c-Myb binds to the OPN promoter in response to senescence. Further, OPN is also regulated by the known SASP regulator C/EBPβ. In response to senescence, the full-length activating C/EBPβ isoform LAP2 increases binding to the OPN, IL-6, and IL-8 promoters. The importance of both c-Myb and C/EBPβ is underscored by our finding that the depletion of either factor reduces the ability of senescent fibroblasts to promote the growth of preneoplastic epithelial cells.


Creative Commons License All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 4.0 License.
PII: 22940