Importin subunit beta-1 mediates ERK5 nuclear translocation, and its inhibition synergizes with ERK5 kinase inhibitors in reducing cancer cell proliferation

Year: 2024

Authors: Lombardi Z., Gardini L., Kashchuk AV., Menconi A., Lulli M., Tusa I., Tubita A., Maresca L., Stecca B., Capitanio M., Rovida E.

Autors Affiliation: Univ Florence, Dept Clin & Expt Biomed Sci, I-50134 Florence, Italy; CNR, Natl Inst Opt, Florence, Italy; European Lab Nonlinear Spect LENS, Florence, Italy; Univ Florence, Dept Phys & Astron, Florence, Italy; Inst Canc Res & Prevent ISPRO, Core Res Lab, Florence, Italy.

Abstract: The mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase 5 (ERK5) is emerging as a promising target in cancer. Indeed, alterations of the MEK5/ERK5 pathway are present in many types of cancer, including melanoma. One of the key events in MAPK signalling is MAPK nuclear translocation and its subsequent regulation of gene expression. Likewise, the effects of ERK5 in supporting cancer cell proliferation have been linked to its nuclear localization. Despite many processes regulating ERK5 nuclear translocation having been determined, the nuclear transporters involved have not yet been identified. Here, we investigated the role of importin subunit alpha (alpha importin) and importin subunit beta-1 (importin beta 1) in ERK5 nuclear shuttling to identify additional targets for cancer treatment. Either importin beta 1 knockdown or the alpha/beta 1 importin inhibitor ivermectin reduced the nuclear amount of overexpressed and endogenous ERK5 in HEK293T and A375 melanoma cells, respectively. These results were confirmed in single-molecule microscopy in HeLa cells. Moreover, immunofluorescence analysis showed that ivermectin impairs epidermal growth factor (EGF)-induced ERK5 nuclear shuttling in HeLa cells. Both co-immunoprecipitation experiments and proximity ligation assay provided evidence that ERK5 and importin beta 1 interact and that this interaction is further induced by EGF administration and prevented by ivermectin treatment. The combination of ivermectin and the ERK5 inhibitor AX15836 synergistically reduced cell viability and colony formation ability in A375 and HeLa cells and was more effective than single treatments in preventing the growth of A375 and HeLa spheroids. The increased reduction of cell viability upon the same combination was also observed in patient-derived metastatic melanoma cells. The combination of ivermectin and ERK5 inhibitors other than AX15836 provided similar effects on cell viability. The identification of importin beta 1 as the nuclear transporter of ERK5 may be exploited for additional ERK5-inhibiting strategies for cancer therapy.

Journal/Review: MOLECULAR ONCOLOGY

More Information: The research leading to these results has received funding from AIRC and Fondazione CR Firenze under IG 2018 – ID 21349 project (P.I. Rovida Elisabetta), European Union-NextGenerationEU-National Recovery and Resilience Plan, Mission 4 Component 2-Investment 1.5-THE-Tuscany Health Ecosystem-ECS00000017-CUP B83C22003920001 to ER. We took advantage of the Molecular Medicine Facility of our Department, supported in part by the Italian Ministry of Education, University and Research (MIUR). AT was supported by a Carlo Zanotti Fondazione Italiana per la Ricerca sul Cancro (FIRC)-AIRC fellowship (ID-23847). MC and LG were supported by the European Union Horizon 2020 research and innovation programme under grant agreement no. 871124 Laserlab-Europe.
KeyWords: combined therapy; ivermectin; KPNB1; MAPK7; nuclear import
DOI: 10.1002/1878-0261.13674

Citations: 3
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-10
References taken from IsiWeb of Knowledge: (subscribers only)

Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here