Figure 8. Chemosensitivity of MDR KB-V1 cancer cells to doxorubicin in the presence of various RNA nanoparticles.

(A) Inhibition of cell growth of drug-resistant KB-V1 cancer cells treated in the RNPs-24h-Dox-24h method or RNPs/Dox-48h method. Various RNA nanoparticles (20 μg/mL) were treated, either alone or together with doxorubicin, in the two-step RNPs-24h-Dox-24h sequential or RNPs/Dox-48h simultaneous method, while doxorubicin was administered over a wide range of concentrations. 24 h after doxorubicin treatment, Cytotoxicities of doxorubicin were measured by using XTT assay. IC₅₀ values of doxorubicin were calculated by Origin 8 using nonlinear regression analysis. Data were collected from 5 independent experiments and represented as mean ± s.d. (B) Inhibition of cell growth of KB cancer cells treated in the RNPs-24h-Dox-24h method or RNPs/Dox-48h method. Dsi RNPs-treated KB cells do not reveal any marked enhancement to the chemosensitivity in either two-step sequential or simultaneous method. (C) TUNEL assay of MDR KB-V1 cancer cells after RNPs-24h-Dox-24h treatment. DNA breaks and total cellular DNA content were visualized by Alexa Fluor 488-labeled anti-BrdU antibodies (green) and Propidium Iodide (red), respectively.