[Results] We found that chemotherapy compounds induced genotoxic stress and cellular senescence in HEI-193 VS cells, as characterized by increased SA-β-GAL activity, growth arrest, increased levels of the cyclin-dependent kinase inhibitor p21 and the accumulation of DNA damage. These cellular senescence markers were also accompanied by an increase of senescence-associated secretory phenotype (SASP): IL6, IL8, IL1B and MMP1. Induction of senescence by chemotherapy rendered HEI-193 VS cells as druggable targets for senolytic compounds, as navitoclax. Thus, treatment with navitoclax selectively eliminated bleomycin-induced senescent HEI193 VS cells by activating the extrinsic and intrinsic apoptosis pathways. Our data also show the presence of senescent cells, SA-β-GAL-positive stain, in human VS tumors, which are not present in healthy great auricular nerve sections.

[Background] Vestibular schwannomas (VS) are complex and heterogeneous human tumors arising from the Schwann cell compartment of the vestibulocochlear nerve. VS cause significant neurological deficit such as hearing loss and vestibular impairment, and in some cases death due to brainstem compression. There is an urgent need to find pharmacotherapies for VS since surgical removal and stereotactic radiosurgery are the only effective treatments. Cancer therapy based in the combination of drug-induced senescence and senolytics may provide an innovative pharmacological alternative for VS management.

[Description of methods used for collection/generation of data] HEI-193 vestibular schwannoma cell lines, healthy human Great Auricular Nerve and vestibular schwannoma tumor samples, drug treatments, cell viability assay, In vitro senescence associated B-galactosidase activity assay, cell cycle analysis, western blotting, RNA extraction and expression analysis, annexin V-FITC and propidium iodide dual staining, immunofluorescence assays.

This research was funded by Spanish MCIN/ AEI/ 10.13039/ 501100011033THEARPY-PID2020-115274RB-I00,MINA-CM Madrid Innovative Neurotech Alliance P2022/BMD-7236, CA20113 COST Action EU-ProteoCure, CA23119 COST Action EU-SENESCENCE2030: Targeting Cell Senescence to Prevent Age-Related Diseases and the Spanish Senescence Network, Senestherapy (RED2018-102698-T) FEDER/MICIN grants to Isabel Varela Nieto.

[Methods] Senescence-associated β-galactosidase (SA-β-GAL) activity detection assay, real-time polymerase chain reaction (RT-PCR), western blotting and immunofluorescence, together with viability assays were used to analyze the response to different chemotherapy drugs of the human VS HEI-193 cell line. Human VS tumor paraffin sections were also studied for SA-β-GAL-stained cells.

[Conclusions] These findings suggest that a one-two punch strategy of pro-senescence therapy induced by chemotherapy treatment followed by senolytic therapy represents a new paradigm for the pharmacological treatment of VS.

Figure_1_ Figure_2, Figure_3, Figure_4, Figure_5, Figure_6.

Peer reviewed