IKKε coordinates invasion and metastasis of ovarian cancer
Menée sur 120 échantillons tumoraux prélevés sur des patientes atteintes d'un cancer de l'ovaire, cette étude met en évidence le rôle joué par la kinase IKKε dans les processus invasif et métastatique
I-κB kinases (IKKs) are key regulators of NF-κB signaling. Three IKK isoforms - α, β and ε - have been linked to oncogenesis, yet the precise components of NF-κB signaling in ovarian cancer have not yet been dissected. We surveyed 120 ovarian cancer specimens for IKKε expression. Notably, cytoplasmic expression was elevated in metastatic lesions relative to primary tumors (p=0.03). Therefore, we hypothesized that IKKε drives ovarian cancer metastasis. IKKε was identified previously as a breast cancer oncogene and was associated with poor clinical outcome in ovarian cancer. We now define an ovarian cancer-specific IKKε-regulated gene expression signature using stably expressed shRNA targeting IKKε. Pathway analysis of the signature indicated that IKKε regulates expression of genes involved in cell motility and inflammation. We further showed that IKKε depletion in metastatic ovarian cancer cell lines decreased growth, adhesion, and invasion. Consistently, human xenografts depleted of IKKε in mice demonstrated decreased aggressiveness, while overexpression of IKKε in a less invasive ovarian cancer cell line increased metastasis in vivo. Taken together, these data provide evidence that IKKε is a key coordinator of invasion and metastasis programs in ovarian cancer. Inhibition of IKKε signaling thus emerges as a viable therapeutic strategy in women whose ovarian cancer demonstrates aberrant activation of this pathway.