β-adrenergic signaling modulates multiple cellular processes in tumor progression and metastasis. The ligation of β-ARs by epinephrine or norepinephrine triggers a G-protein coupled signaling cascade that stimulates cAMP synthesis. cAMP activates the PKA protein, which can mediate multiple signal pathways via the phosphorylation of various downstream signal proteins. In another major pathway, the cAMP activation of EPAC leads to the Rap1A-mediated activation of Raf/MAPK signaling pathways and downstream effects on diverse cellular processes.
Ji et al. Journal of Hematology & Oncology 2014 7:13 doi:10.1186/1756-8722-7-13