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bioRxiv · 10.1101/2024.11.26.625308

Inhibition of microtubule polymerization and dynein impairs the nuclear localization of the ependymoma-associated ZFTA-RELA fusion protein and NF-κB activation

Ishii, M.·Suto, N.·Katakawa, K.·Makino, K.·TOMA-FUKAI, S.·Sueki, S.·Anada, M.·Kojima, H.·Ohata, S.
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Abstract

Ependymomas are rare and chemotherapy-resistant gliomas. One subclass of supratentorial ependymomas, ST-EPN-ZFTA, expresses a fusion protein consisting of a nuclear protein, zinc finger translocation associated (ZFTA), and v-rel reticuloendotheliosis viral oncogene homolog A (RELA), an effector transcription factor of the nuclear factor-{kappa}B (NF-{kappa}B) pathway (ZFTA-RELA). Constitutive localization of ZFTA-RELA to the nucleus hyperactivates the oncogenic NF-{kappa}B signaling pathway, thereby contributing to the pathogenesis of ST-EPN-ZFTA. To identify compounds that inhibit NF-{kappa}B activity induced by ZFTA-RELA, we established a high-throughput screening system using the NF-{kappa}B-responsive luciferase reporter cell line 6E8, which expresses ZFTA-RELA in a doxycycline-dependent manner. A chemical library of 9600 compounds selected for their structural diversity was screened, and a colchicine derivative was identified. Among colchicine and six of its derivatives, the IC50 on ZFTA-RELA-dependent NF-{kappa}B-responsive luciferase activity in 6E8 cells was found to be the lowest for colchicine at 90 nM. Interestingly, microtubule polymerization inhibitors (colchicine and vinblastine) and dynein inhibitors (ciliobrevin D and dynarrestin) impaired ZFTA-RELAs nuclear localization and NF-{kappa}B activity in 6E8 cells. These findings indicate that microtubule polymerization and dynein play pivotal roles in activating the NF-{kappa}B pathway in ST-EPN-ZFTA by promoting the nuclear localization of ZFTA-RELA. Consequently, inhibition of microtubule polymerization may be a therapeutic strategy for ST-EPN-ZFTA.

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Ishii, M., Suto, N., Katakawa, K., Makino, K., TOMA-FUKAI, S., Sueki, S., Anada, M., Kojima, H., Ohata, S.. 2024-11-28. Inhibition of microtubule polymerization and dynein impairs the nuclear localization of the ependymoma-associated ZFTA-RELA fusion protein and NF-κB activation. https://doi.org/10.1101/2024.11.26.625308

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