Selective and potent KRAS silencing in MM cells exposed to AZD4785. (A) Human KRAS, HRAS, and NRAS mRNA levels were evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) using the 2^−ΔΔCt method, with normalization to glyceraldehyde-3-phosphate dehydrogenase (GAPDH), in MM.1S, U266, MM.1R, RPMI.8226, OPM2, and KMS12 cells after 48 hours of treatment with AZD4785 at the indicated concentrations. ASO control (ctrl)–treated cells were used as control. (B) MM.1S, U266, MM.1R, KMS20, OPM2, and KMS12 cells were cultured in the presence or absence of AZD4785 or ASO ctrl at the indicated concentrations for 48 hours. MM cells were then harvested, and cell lysates were subjected to western blot using anti-KRAS, -HRAS, -NRAS, and -GAPDH antibodies. (C) Human DUSP6 and ETV4 mRNA levels were evaluated by qRT-PCR using the 2^−ΔΔCt method, with normalization to GAPDH, in MM.1S, U266, MM.1R, RPMI.8226, OPM2, and KMS12 cells after 48 hours of treatment with AZD4785 at the indicated concentrations. ASO ctrl–treated cells were used as ctrl. (D) MM.1S, KMS20, OPM2, and U266 cells were exposed to AZD4785 (0-3 μM) for 48 hours and subjected to wide transcriptome profiling. Significant inhibition of DUPS- and ETV-related gene sets was found in KRAS-mutated cells, as assessed by gene set enrichment analysis. Normalized enrichment score (NES) was generated by comparing AZD4785-treated vs untreated cells. NES, nominal P value, and false discovery rate (FDR) q value are reported for each plot. n.s., not significant.