Inhibition of protein kinase II (CK2) prevents induced signal transducer and activator of transcription (STAT) 1/3 and constitutive STAT3 activation

• Published in: Oncotarget Vol. 5; no. 8; pp. 2131 - 2148
• Main Authors: Aparicio-Siegmund, Samadhi, Sommer, Jan, Monhasery, Niloufar, Schwanbeck, Ralf, Keil, Eric, Finkenstädt, David, Pfeffer, Klaus, Rose-John, Stefan, Scheller, Jürgen, Garbers, Christoph
• Format: Journal Article
• Language: English
• Published: United States Impact Journals LLC 30.04.2014
• Subjects: Animals; Blotting, Western; Casein Kinase II - metabolism; Cell Line, Tumor; Enzyme Activation - physiology; Humans; Janus Kinases - metabolism; Mice; Research Paper; Signal Transduction - physiology; STAT1 Transcription Factor - metabolism; STAT3 Transcription Factor - metabolism; Transfection
• ISSN: 1949-2553; 1949-2553
• DOI: 10.18632/oncotarget.1852

The Janus kinase / signal transducer and activator of transcription (Jak/STAT) pathway can be activated by many different cytokines, among them all members of the Interleukin (IL-)6 family. Dysregulation of this pathway, resulting in its constitutive activation, is associated with chronic inflammation and cancer development. In the present study, we show that activity of protein kinase II (CK2), a ubiquitously expressed serine/threonine kinase, is needed for induced activation of STAT1 and STAT3 by IL-6 classic and trans-signaling, IL-11, IL-27, oncostatin M (OSM), leukemia inhibitory factor (LIF) and cardiotrophin-1 (CT-1). Inhibition of CK2 efficiently prevented STAT phosphorylation and inhibited cytokine-dependent cell proliferation in a Jak1-dependent manner. Conversely, forced activation of CK2 alone was not sufficient to induce activation of the Jak/STAT signaling pathway. Inhibition of CK2 in turn inhibited Jak1-dependent STAT activation by oncogenic gp130 mutations. Furthermore, CK2 inhibition diminished the Jak1- and Src kinase-dependent phosphorylation of a constitutively active STAT3 mutant recently described in human large granular lymphocytic leukemia. In conclusion, we characterize CK2 as an essential component of the Jak/STAT pathway. Pharmacologic inhibition of this kinase is therefore a promising strategy to treat human inflammatory diseases and malignancies associated with constitutive activation of the Jak/STAT pathway.