Overexpressed Nup88 stabilized through interaction with Nup62 promotes NFκB dependent pathways in cancer

Abstract

Nuclear pores control nucleo-cytoplasmic trafficking and directly or indirectly regulate vital cellular processes. Nup88, important for Crm1 mediated nuclear export process, is overexpressed in many cancers. A positive correlation exists between progressive stages of cancer and Nup88 expression. However, links between Nup88 overexpression and head and neck cancer are insignificant, and mechanistic details are non-existent. Here, we report that Nup88 exhibits positive correlation in head and neck cancer in addition to elevated Nup62 levels. We demonstrate that Nup88 interacts with Nup62 in a cell-cycle and glycosylation independent manner. The overexpression of Nup88 or Nup62 imparts proliferation and migration advantages to cells. We further report that the interaction with Nup62 stabilizes Nup88 by inhibiting proteasome-mediated degradation of overexpressed Nup88. Overexpressed Nup88 is stabile and partly inside the nucleus and can interact with NF{kappa}B (p65). Nup88 overexpression induces proliferative and inflammatory responses downstream of p65. Altogether, we suggest that simultaneous overexpression of Nup62 and Nup88 in head and neck cancer stabilizes overexpressed Nup88. Stable Nup88 interacts with p65 and induces inflammatory, proliferative, and migratory advantages to cells, which perhaps is the underlying mechanism driving tumorigenic transformations.