The p90 ribosomal S6 kinase (RSK) is a family of MAPK-activated serine/threonine kinases (RSK1-4) whose expression and/or activity are deregulated in several cancers, including breast cancer.
Our results suggest that the FGFR2-RSK2 signalling pathway is involved in pathophysiology of BCa and evaluation of FGFR2/RSK-P expression may be useful in disease prognostication.
Use of the ICSNPathway to analyze breast cancer GWAS data identified 16 candidate SNPs, 13 genes (including MBIP, RPS6KA1, and ITGB1), and 7 pathways that might contribute to the susceptibility of patients to breast cancer.
Notably, the addition of MEK- or RSK-specific inhibitors can overcome these resistance phenotypes, both in breast cancer cell lines and patient-derived xenograft models with elevated levels of RSK activity.
The expression of phosphorylated p90RSK (phospho-p90RSK) and chemotherapy response was measured in 11 breast cancer cell lines and 21 breast cancer tissues.
There was, however, no association between HER2 positivity and Ser(167) phosphorylation nor were the activities of MAPK or p90RSK associated with HER2 status, suggesting that other cell surface receptors may be important in regulating these activities in breast cancer.