Regulation of CXC chemokine gene expression by keratin 17 and hnRNP K in skin tumor keratinocytes

BM Chung, A Arutyunov, E Ilagan, N Yao… - Journal of Cell …, 2015 - rupress.org
BM Chung, A Arutyunov, E Ilagan, N Yao, M Wills-Karp, PA Coulombe
Journal of Cell Biology, 2015rupress.org
High levels of the intermediate filament keratin 17 (K17) correlate with a poor prognosis for
several types of epithelial tumors. However, the causal relationship and underlying
mechanisms remain undefined. A recent study suggested that K17 promotes skin
tumorigenesis by fostering a specific type of inflammation. We report here that K17 interacts
with the RNA-binding protein hnRNP K, which has also been implicated in cancer. K17 is
required for the cytoplasmic localization of hnRNP K and for its role in regulating the …
High levels of the intermediate filament keratin 17 (K17) correlate with a poor prognosis for several types of epithelial tumors. However, the causal relationship and underlying mechanisms remain undefined. A recent study suggested that K17 promotes skin tumorigenesis by fostering a specific type of inflammation. We report here that K17 interacts with the RNA-binding protein hnRNP K, which has also been implicated in cancer. K17 is required for the cytoplasmic localization of hnRNP K and for its role in regulating the expression of multiple pro-inflammatory mRNAs. Among these are the CXCR3 ligands CXCL9, CXCL10, and CXCL11, which together form a signaling axis with an established role in tumorigenesis. The K17–hnRNP K partnership is regulated by the ser/thr kinase RSK and required for CXCR3-dependent tumor cell growth and invasion. These findings functionally integrate K17, hnRNP K, and gene expression along with RSK and CXCR3 signaling in a keratinocyte-autonomous axis and provide a potential basis for their implication in tumorigenesis.
rupress.org