RNAi profiling of primary human AML cells identifies ROCK1 as a therapeutic target and nominates fasudil as an antileukemic drug

Abstract

Key Points• Large-scale loss-of-function RNAi screens in patientderived AML cells are feasible and able to pinpoint therapeutic targets.• ROCK1 inhibition exerts antileukemic effects in primary human AML cells in vitro and in vivo.Acute myeloid leukemia (AML) is characterized by a marked genetic heterogeneity, which complicates the development of novel therapeutics. The delineation of pathways essential within an individual patient's mutational background might overcome this limitation and facilitate personalized treatment. We report the results of a large-scale lentiviral lossof-function RNA interference (RNAi) screen in primary leukemic cells. Stringent validation identified 6 genes (BNIPL1, ROCK1, RPS13, STK3, SNX27, WDHD1) whose knockdown impaired growth and viability of the cells. Dependence on these genes was not caused by mutation or overexpression, and although some of the candidates seemed to be rather patient specific, others were essential in cells isolated from other AML patients. In addition to the phenotype observed after ROCK1 knockdown, treatment with the approved ROCK inhibitor fasudil resulted in increased apoptosis and decreased viability of primary AML cells. In contrast to observations in some other malignancies, ROCK1 inhibition did not foster growth of immature malignant progenitors but was toxic to this cell fraction in feeder coculture and xenotransplant experiments, indicating a distinct effect of ROCK1 inhibition on leukemic progenitors. We conclude that large-scale RNAi screens in primary patient-derived cells are feasible and can complement other methods for personalized cancer therapies, such as expression and mutation profiling. (Blood. 2015;125(24):3760-3768)

Novel Significant Stage-Specific Differentially Expressed Genes in Liver Hepatocellular Carcinoma

“…A similar knock out experiment of PRR11 in hilar cholangiocarcinoma cell lines resulted in decreased cellular proliferation, migration, and tumor growth . WDHD1 is a key post-transcriptional regulator of centromeric, and consequently genomic, integrity (Hsieh et al, 2011) and its overexpression has been identified as biomarker of acute myeloid leukemia (Wermke et al, 2015), and lung and esophageal carcinomas (Sato et al, 2010). C15orf42 has been implicated in nasopharyngeal carcinoma .…”

A novel therapeutic strategy for cartilage diseases based on lipid nanoparticle-RNAi delivery system

“…Currently, RNAi is widely used in the treatment of many diseases including amyloid disease, infectious diseases, myeloid leukemia, bone metabolic disorders, and so on. 21,[33][34][35] However, there is no available cartilage-specific targeting delivery system for siRNA delivery in the treatment of cartilage metabolic disorders, because cartilage is a relatively solid and compact tissue that is not easily penetrated by small molecules. In this study, we modified LNP, a positively charged siRNA delivery system, to specifically target articular cartilage, a negatively charged tissue, and to facilitate the delivery of therapeutic cargos to the chondrocytes.…”

Continuous high-resolutionin vivoimaging reveals tumor-specific dissemination in an embryonic zebrafish xenograft model

“…To evaluate the utility of the eZXM for drug screening, we studied the effects of the ROCK1 (Rho-associated coiled-coil protein kinase 1) inhibitor Fasudil in our model using leukemic tumor cells. As our colleagues have demonstrated that ROCK1 inhibition suppresses leukemic growth in-vitro and engraftment in a long-term murine xenotransplantation model 33 , we set out to study its effects in our in vivo set-up. We found that, compared to the untreated control embryos at 24 hpi (82.67 ± 11.02), Fasudil-treated embryos showed a significant reduction in tumor cell…”

“…Functional validation of the model was carried out using the Rock-inhibitor, Fasudil 33 . A working concentration of 50 µM Fasudil in water, prepared from 1 mM stock, also in water, was added to E3 medium containing injected embryos.…”