Mitochondrial fission protein 1 determines mitochondrial fission and cisplatin sensitivity in tongue squamous cell carcinoma

To investigate the effect of mitochondrial fission protein 1 (FIS1) on apoptosis and cisplatin resistance in tongue squamous cell carcinoma (TSCC) cells.

The squamous cell carcinoma cell lines SCC9 and CAL27 were used to detect the mRNA and protein levels of FIS1 after cisplatin treatment, the knockdown and over-expression of FIS1 of SCC9 and CAL27 with or without cisplatin treatment were accomplished through small interfering RNA (siRNA) and plasmid, respectively. The mitochondrial division state in cells was detected by mitochondrial staining, and the apoptosis state of cells was detected by TUNEL, flow cytometry and Caspase 3/7.

FIS1 protein expression in tongue squamous carcinoma cells treated with cisplatin was increased, but the mRNA level did not change. Silencing of FIS1 expression reduced mitochondrial division and apoptosis in squamous cell carcinoma cells treated with cisplatin, whereas overexpression of FIS1 exhibited the opposite effects. The percentage of dividing mitochondria, the number of apoptotic cells and the activity of Caspase 3/7 in SCC9 and CAL27 cells were significantly different before and after modulation of FIS1 expression (P < 0.05).

FIS1 is involved in the regulation of cisplatin chemotherapy sensitivity in tongue squamous cell carcinoma and can be used as a new target for improving the sensitivity of cisplatin chemotherapy in oral squamous cell carcinoma.