Intranasal Administration of Temozolomide Delayed the Development ofBrain Tumors Initiated by Human Glioma Stem-Like Cell in Nude Mice

Objective: Intranasal route is an emerging option for brain cancer treatment to infuse directly telomerase inhibitors and/or viruses into the brain. Paradoxically, the standard chemotherapeutic Temozolomide (TMZ) widely used to treat glioma tumors is orally given. Here, we tested for the first time the intranasal administration of TMZ in nude mice xenograft models carrying human glioblastoma tumors generated from the human glioma stem-like cells TG16, TG1N and TG20.Methods: The resistance to TMZ of the different glioma stem-like cells was determined by WST-1 cell proliferation and cell viability assay. Tumour cells were stereotaxically injected intrastriatally and one month after graft, mice were anesthetized using Isofluorane and TMZ was infused into the nostrils three times a week during two weeks with a nano-injector using Hamilton syringe coupled to a cannula. Buried food pellet test was carried out to check the sense of smell. Animals were weighted and surveilled once a week and separated into two cohorts, one for histopathological analysis and the other for Kaplan-Meier survival analysis.Results: Intranasal administration of TMZ did not induce major adverse effects on the sense of smell of the animals. TMZ administred intranasally delayed tumour growth and significantly extended the lifespan of mice engrafted with TG16 and TG1N cells, which are sensitive in vitro to TMZ. By contrast, TMZ at the dose tested had no effects on the tumors generated by TG20 cells that are resistant to TMZ in vitro.Conclusion: Our results demonstrate that the intranasal route should be further considered as an option for TMZ delivery into the brain to treat intrastriatal brain tumours. Moreover, it consists of an easy, fast, and cost-less method to gain direct access to the brain.