{"database":"ENA","file_versions":[],"scores":null,"additional":{"omics_type":["Genomics"],"center_name":["Eric Lai Lab, Department of Developmental Biology, Sloan-Kettering Institute"],"full_dataset_link":["https://www.ebi.ac.uk/ena/browser/view/PRJNA1148192"],"scientific_name":["Homo sapiens"],"long_description":["The core miRNA biogenesis enzyme Dicer sustains recurrent mutations in cancer, which specifically compromise catalysis by its RNase IIIb domain. These are proposed to act as selective hypomorphs, since Dicer-RNase IIIb cleaves the 5p arms of pre-miRNA hairpins. However, the lack of knockin models has hindered a full understanding of the consequences of Dicer hotspot mutations for miRNA biogenesis. Here, we generated Dicer-KO and Dicer-S1344L (homozygous and hemizygous) hESCs the latter is a non-catalytic mutation in RNase IIIa that impairs RNase IIIb activity. Consistent with our previous work, Dicer-KO is cell lethal in hESCs. However, in contrast to the expectation that Dicer hotspot mutations confer cell advantages, Dicer-S1344L knockin hESCs were subviable and also required a conditional genetic strategy for isolation. Small RNA sequencing using spike-in normalization reveals two broad trends: ablation of miRNA-5p species, and selective changes in miRNA-3p species. Curiously, we recognized a directional upregulation of miRNA-3p passenger strands, indicating a broad strand switch. Activity assays and Argonaute profiling of the transcriptome confirm that these confer increased repression capacity. Finally, we used in vitro assays to show 3p arm-nicked pre-miRNAs preferentially load miRNA-3p species into Argonaute, compared to corresponding miRNA/passenger duplexes. Overall, Dicer hotspot mutations have unexpected neomorphic consequences on miRNAs, including both loss- and gain-of-function. Overall design: To investigate the consequences of the Dicer cancer hotspot mutation, we generated CRISPR-Cas9 engineered Dicer-S1344L homozygous and hemizygous hESCs cells."],"repository":["ENA"],"additional_accession":[]},"is_claimable":false,"name":"Human Dicer hotspot mutation induces both loss and gain of miRNA function [RNA-seq]","description":"Human Dicer hotspot mutation induces both loss and gain of miRNA function [RNA-seq]","dates":{"last_updated":"2025-09-24","first_public":"2025-08-14"},"accession":"PRJNA1148192","cross_references":{"GEO":["GSE274849"],"taxon":["9606"]}}