Inhibition of RAB protein function mediates the anti-AML activity of statins. (A) Heatmap illustrating sensitivity of 20 primary human AML specimens to 2.5 μM of indicated statins. (B) Viability of primary human AML cells after 6-day incubation in the presence of 2.5 μM of atorvastatin or pravastatin. Horizontal lines represent median inhibition achieved by pravastatin (14%) and atorvastatin (74%). (C) Expression levels of genes implicated in transmembrane transport of pravastatin in primary human AML specimens from the Leucegene cohort. Dotted line, 1 TPM. (D) Schematic representation of the mevalonate pathway. Red bars indicate targets of statins and TH-Z145 compound. (E) Knockdown efficiency achieved by short hairpin RNAs (shRNAs) targeting HMGCR, FDFT1, and GGPS1 (top) and corresponding fold change (FC) in atorvastatin 50% inhibitory concentration (IC₅₀; bottom) in OCI-AML5 cells. Average of 3 shRNAs achieving similar knockdown levels is shown with standard error of the mean. (F) Heatmaps showing excess bliss scores for treatment of OCI-AML3 and OCI-AML5 cells with atorvastatin, cytarabine, and TH-Z145 at indicated concentrations. Numbers in white refer to the sum of all scores >0 (indicative of synergy) for each surface. Representative of 2 independent experiments. Results were analyzed using the R (v3.6.1) SynergyFinder (v2.0.12) package. (G) Results of CRISPR/Cas9 whole-genome screening performed in NALM6 cells treated with 150 nM of cerivastatin. Robust analytics and normalization for knockout screens (RANKS) scores are presented (average of 10 sgRNAs per gene), and statistical assessment was performed by RANKS with false discovery rate (FDR) correction. Genes with FDR values <0.001 were assigned a FDR value of 0.001. ***P < .0001. PP, pyrophosphate; TPM, transcripts per million.