口腔がん細胞（KB）およびそのシスプラチン耐性株（KB-R）に対するネダプラチンおよびカルボプラチンの作用

oral carcinoma cell

北海道歯学会

北海道歯学雑誌

Purpose : We examined the change of sensitivity for nedaplatin and carboplatin of oral carcinoma cell line, KB, and its cisplatin-resistant cell line, KB-R. Materials and methods : We used oral carcinoma cells (parent cell line: KB) and cisplatin-resistant line of KB (resistant cell line: KB-R). The cells were disseminated at a 96-well plate and incubated with 0, 7.8, 15.6, 31.2, 62.5, 125, 250 and 500μM nedaplatin or carboplatin for 12, 24 or 48 and 72 hours. Then the intracellular ATP content was measured by use of ViaLight? plus kit (LONZA) for the measurement of the survival rate of the cells. Results and discussion : The survival rate of KB and KB-R decreased depending on the concentration of nedaplatin or carboplatin after 72 hours incubation. The 50% inhibitory concentrations of survival rate for KB and KB-R were 11 and 69 μM for nedaplatin and 86 and 334 μM for carboplatin. This suggests that the cisplatin resistant cell line showed resistance to nedaplatin or carboplatin. A higher concentration was required for carboplatin to decrease the survival rate compared to nedaplatin. The survival rate of KB was the lowest at 62.5 μM nedaplatin and 125 μM carboplatin, but the survival rate increased at higher concentrations of nedaplatin or carboplatin. This suggests there are two concentration ranges for nedaplatin or carboplatin, and one is for cell death and the other is for recovery from cell death. KB-R showed resistance to lower concentration of nedaplatin or carboplatin compared to KB, but KB-R did not show an increase of survival rate, which KB showed, at higher concentration of nedaplatin or carboplatin. These results suggest that cisplatin resistant KB-R show resistance to nedaplatin or carboplatin and that KB and KB-R possess different sensitivity to nedaplatin or carboplatin. Conclusion : Cisplatin resistant KB-R showed cross resistance to nedaplatin and carboplatin. Also, the effect of nedaplatin and carboplatin on KB and KB-R changed due to becoming cisplatin resistant.