The prometastatic ribosomal S6 kinase 2-cAMP response element-binding protein (RSK2-CREB) signaling pathway up-regulates the actin-binding protein fascin-1 to promote tumor metastasis.

Abstract

Metastasis is the leading cause of death in patients with breast, lung, and head and neck cancers. However, the molecular mechanisms underlying metastases in these cancers remain unclear. We found that the p90 ribosomal S6 kinase 2 (RSK2)-cAMP response element-binding protein (CREB) pathway is commonly activated in diverse metastatic human cancer cells, leading to up-regulation of a CREB transcription target Fascin-1. We also observed that the protein expression patterns of RSK2 and Fascin-1 correlate in primary human tumor tissue samples from head and neck squamous cell carcinoma patients. Moreover, knockdown of RSK2 disrupts filopodia formation and bundling in highly invasive cancer cells, leading to attenuated cancer cell invasion in vitro and tumor metastasis in vivo, whereas expression of Fascin-1 significantly rescues these phenotypes. Furthermore, targeting RSK2 with the small molecule RSK inhibitor FMK-MEA effectively attenuated the invasive and metastatic potential of cancer cells in vitro and in vivo, respectively. Taken together, our findings for the first time link RSK2-CREB signaling to filopodia formation and bundling through the up-regulation of Fascin-1, providing a proinvasive and prometastatic advantage to human cancers. Therefore, protein effectors of the RSK2-CREB-Fascin-1 pathway represent promising biomarkers and therapeutic targets in the clinical prognosis and treatment of metastatic human cancers.

• Authors: Dan Li, Lingtao Jin, Gina N Alesi, Young-Mee Kim, Jun Fan, Jae Ho Seo, Dongsheng Wang, Meghan Tucker, Ting-Lei Gu, Benjamin H Lee, Jack Taunton, Kelly R Magliocca, Zhuo G Chen, Dong M Shin, Fadlo R Khuri, Sumin Kang
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 288 Issue 45 Pg. 32528-32538 (Nov 08 2013) ISSN: 1083-351X [Electronic] United States
• PMID: 24085294 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers, Tumor
• Carrier Proteins
• FSCN1 protein, human
• Microfilament Proteins
• Neoplasm Proteins
• CREB-Binding Protein
• CREBBP protein, human
• Ribosomal Protein S6 Kinases, 90-kDa
• ribosomal protein S6 kinase, 90kDa, polypeptide 3

Topics

• Animals
• Biomarkers, Tumor (genetics, metabolism)
• CREB-Binding Protein (genetics, metabolism)
• Carrier Proteins (biosynthesis, genetics)
• Cell Line, Tumor
• Gene Expression Regulation, Neoplastic
• Gene Knockdown Techniques
• Humans
• Mice
• Mice, Nude
• Microfilament Proteins (biosynthesis, genetics)
• Neoplasm Metastasis
• Neoplasm Proteins (genetics, metabolism)
• Neoplasms (genetics, metabolism, pathology)
• Pseudopodia (genetics, metabolism, pathology)
• Ribosomal Protein S6 Kinases, 90-kDa (genetics, metabolism)
• Signal Transduction
• Up-Regulation (genetics)