Fig. 2: OSMR overexpression promotes chemoresistance.

a, b Cell viability was determined using CCK8 reagent in both control and OSMR overexpressing OVCAR8 and A2780 cells were treated with different concentrations of cisplatin for 48 h. The IC₅₀ of cisplatin in both control and OSMR overexpressing cell lines were quantitated and presented below in the respective boxes. c, d OVCAR8 and A2780 cells stably overexpressing OSMR, and the control cells were lysed and immunoblotted using indicated antibodies. e, f mRNA expression of cancer stemness markers and EMT markers were evaluated using qPCR in OVCAR8 and A2780 cells stably overexpressing OSMR and the control cells. g OVCAR8 and A2780 cells stably overexpressing OSMR and the control cells were grown in the presence and absence of cisplatin 5 μM for 15 days and imaged (left panel). Colonies formed were lysed using 10% acetic acid and absorbance were quantitated at 560 nm (right panel). h Control and OSMR overexpressing OVCAR8 and A2780 cells were treated with and without cisplatin for 16 h and the level of cellular apoptosis was quantitated using Annexin V-APC/7-AAD staining followed by flow cytometry (left). Bar graph shows percentage of viable cells, cells undergoing early, or late apoptosis quantitated from flow cytometry. Individual data points are represented as mean ± SEM. Student’s t test (two tailed, unpaired) was performed to determine significance between groups. ****P ≤ 0.0001, ***P ≤ 0.001, **P ≤ 0.01, *P ≤ 0.05, ns non-significant.