MiR-3116 sensitizes glioma cells to temozolomide by targeting FGFR1 and regulating the FGFR1/PI3K/AKT pathway.

Glioma is a brain tumour that is often diagnosed, and temozolomide (TMZ) is a common chemotherapeutic drug used in glioma. Yet, resistance to TMZ is a chief hurdle towards curing the malignancy. The current work explores the pathways and involvement of miR-3116 in the TMZ resistance. miR-3116 and FGFR1 mRNA were quantified by real-time PCR in malignant samples and cell lines. Appropriate assays were designed for apoptosis, viability, the ability to form colonies and reporter assays to study the effects of the miR-3116 or FGFR1. The involvement of PI3K/AKT signalling was assessed using Western blotting. Tumorigenesis was evaluated in an appropriate xenograft mouse model in vivo. This work revealed that the levels of miR-3116 dipped in samples resistant to TMZ, while increased miR-3116 caused an inhibition of the tumour features mentioned above to hence augment TMZ sensitivity. miR-3116 was found to target FGFR1. When FGFR1 was overexpressed, resistance to TMZ was augmented and reversed the sensitivity caused by miR-3116. Our findings further confirmed PI3K/AKT signalling pathway is involved in this action. In conclusion, miR-3116 sensitizes glioma cells to TMZ through FGFR1 downregulation and the PI3K/AKT pathway inactivation. Our results provide a strategy to overcome TMZ resistance in glioma treatment.