A role of Dicer, which converts precursor miRNAs to mature miRNAs, in the tumor-promoting effect of hypoxia is currently emerging in some tumor entities. Its role in hepatocellular carcinoma (HCC) is unknown. HepG2 and Huh-7 cells were stably transfected with an inducible Dicer expression vector and were exposed to hypoxia/normoxia. HepG2-Dicer xenografts were established in nude mice; hypoxic areas and Dicer were detected in HCC xenografts and HCCs from mice with endogenous hepatocarcinogenesis; and epithelial-mesenchymal transition (EMT) markers were analyzed by immunohistochemistry or by immunoblotting. The correlation between Dicer and carbonic anhydrase 9 (CA9), a marker of hypoxia, was investigated in resected human HCCs. Hypoxia increased EMT markers and and led to a downregulation of Dicer in HCC cells. The levels of Dicer were downregulated in hypoxic tumor regions in mice with endogenous hepatocarcinogenesis and in HepG2 xenografts. In human HCCs, the levels of Dicer correlated inversely with those of CA9, indicating that the negative regulation of Dicer by hypoxia also applies to HCC patients. Forced expression of Dicer prevented the hypoxia-induced increase in hypoxia-inducible factor 1α (HIF1α), HIF2α, hypoxia-inducible genes (CA9, glucose transporter 1), EMT markers, and cell migration. We here identify downmodulation of Dicer as novel essential process in hypoxia-induced EMT in HCC and demonstrate that induced expression of Dicer counteracted hypoxia-induced EMT. Thus, targeting hypoxia-induced downmodulation of Dicer is a promising novel strategy to reduce HCC progression. .
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http://dx.doi.org/10.1158/1078-0432.CCR-16-1762 | DOI Listing |
STAR Protoc
January 2025
CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China. Electronic address:
Mammalian Dicer has been proved to be functional on double-stranded RNAs (dsRNAs) and involved in antiviral immunity or immune regulation. Here, we present a protocol for identifying Dicer as a dsRNA binding and cleaving factor to transfected dsRNA in cell lines, based on small RNA sequencing (RNA-seq) and dsRNA-immunoprecipitation (dsRNA-IP). We detail both experimental processes and analysis on small RNA-seq data.
View Article and Find Full Text PDFPlants (Basel)
January 2025
Corteva Agriscience, 7000 NW 62nd Ave, Johnston, IA 50131, USA.
Maize lethal necrosis (MLN) is a significant threat to food security in Sub-Saharan Africa (SSA), with limited commercial inbred lines displaying tolerance. This study analyzed the transcriptomes of four commercially used maize inbred lines and a non-adapted inbred line, all with varying response levels to MLN. RNA-Seq revealed differentially expressed genes in response to infection by maize chlorotic mottle virus (MCMV) and sugarcane mosaic virus (SCMV), the causative agents of MLN.
View Article and Find Full Text PDFBiology (Basel)
January 2025
Division of Thoracic Surgery, Cantonal Hospital Lucerne, 6000 Lucerne, Switzerland.
In 2001, two enzyme-encoding genes were recognized in the fruit fly . The genetic material, labeled and , encodes ribonuclease-type enzymes with slightly diverse target substrates. The human orthologue is .
View Article and Find Full Text PDFJ Pathol
January 2025
Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
DICER1-associated sarcoma is an emerging entity, defined by either somatic or germline dicer 1, ribonuclease III (DICER1) mutations and sharing characteristic morphologic features irrespective of the site of origin. In addition to the DICER1 driver mutation, concurrent genomic alterations, including tumor protein 53 (TP53) inactivation and RAS pathway activation, are frequently detected. Tumors that morphologically resemble malignant peripheral nerve sheath tumor (MPNST) have rarely been reported among DICER1 sarcomas and often pose diagnostic challenges.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, P. R. China.
MicroRNAs (miRNAs) are associated with amyloid-β (Aβ) dysmetabolism, a pivotal factor in the pathogenesis of Alzheimer's disease (AD). This study unveiled a novel miRNA, microRNA-32533 (miR-32533), featuring a distinctive base sequence identified through RNA sequencing of the APPswe/PSEN1dE9 (APP/PS1) mouse brain. Its role and underlying mechanisms were subsequently explored.
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