Fig. 5

KRAS promotes platinum resistance in ovarian cancer cells

A, B. qRT-PCR was performed to determine KRAS mRNA levels in KURAMOCHI-i-NC (negative control sgRNA for the inhibition system), KURAMOCHI-i-KRAS (KRAS inhibition sgRNA), CAOV3-a-NC (negative control sgRNA for the activation system), CAOV3-a-KRAS-1 (KRAS activation sgRNA #1) and CAOV3-a-KRAS-2 (KRAS activation sgRNA #2). RPS13 was used as a housekeeping gene. C, D. Flow cytometry assay was used to detect apoptotic cells in KURAMOCHI (C) after 72 h treatment with carboplsatin (12 μM) and cisplatin (3 μM) or CAOV3 (D) with carboplatin (9 μM) and cisplatin (1.5 μM). E, F. Quantification of percentage of apoptotic cells from (C) and (D). G, H. Colony formation assay was performed to verify the colony formation ability of KURAMOCHI (G) and CAOV3 (H) after 7 days of presence of the indicated concentration of platinum plus another 7 days after removing platinum. I, J Quantification of the colony intensity from (G) and (H) after normalization by untreated condition. (Student’s t test were used; NS p > 0.05, * p < 0.05, ** p < 0.01, *** p < 0.001; replicates: n = 3)