Protective effect of klotho protein against cisplatin ototoxicity in an auditory cell line.
OBJECTIVE
Klotho protein is involved in insulin-signalling and ageing. Klotho mutation causes premature ageing and significantly shortens the lifespan. The anti-neoplastic drug cisplatin promotes ototoxicity at higher doses by inducing apoptosis. This study aimed to clarify the effect of klotho expression on cisplatin ototoxicity, using an auditory cell line.


METHODS
Expressions of klotho messenger RNA and protein were analysed by reverse-transcription polymerase chain reaction and western blotting. Auditory cells (HEI-OC1 line) were pretreated with 2 nM klotho protein for 2 hours; 15 µM cisplatin was then applied. After 48 hours incubation, assessment of cell viability (via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay), apoptosis (via Hoechst 33258 staining) and reactive oxygen species was performed.


RESULTS
Klotho protein expression increased in cisplatin-treated auditory cells. Cells treated with both klotho protein and cisplatin showed a viability of 67.7 per cent, versus 59.4 per cent in cisplatin-treated cells. Klotho significantly attenuated the cisplatin-induced increase in reactive oxygen species, and increased the viability of cells with cisplatin-induced cytotoxicity.


CONCLUSIONS
Klotho protein is protective against cisplatin-induced auditory cell cytotoxicity; inhibition of reactive oxygen species may be the main mechanism.
Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Seoul, South Korea.
Se Jin
SJ
Park
So Hyun
SH
Park
Ji Won
JW
Chang
June
J
Choi
Hak Hyun
HH
Jung
Gi Jung
GJ
Im
D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity*; D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002945:Cisplatin / Q000633:toxicity*; D005966:Glucuronidase / Q000378:metabolism / Q000494:pharmacology*; D006198:Hair Cells, Auditory / Q000187:drug effects* / Q000378:metabolism; D000090265:Klotho Proteins; D051379:Mice; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000970:Antineoplastic Agents; D017382:Reactive Oxygen Species; D005966:Glucuronidase; D000090265:Klotho Proteins; D002945:Cisplatin