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Thu, C.

Publications and source records attributed to Thu, C..

2 recordsLinked to original sources

microRNAs bidirectionally regulate FUT1 to modulate α-1,2-fucosylation and cancer-associated biology

The -1,2-fucosyltransferase, FUT1, plays a central role in blood type determination, the establishment of the gut microbiota, and cancer progression. Using high-throughput analysis, we mapped the miRNA regulatory landscape of FUT1 and found that miRNAs bidirectionally regulate this enzyme. Validation of miRFluR assay results across multiple cell lines confirmed that both upregulatory and downregulatory miRNA interactions affect endogenous FUT1 and its enzymatic product, -1,2-fucosylation. Inhibitors of endogenous miRNA impacted both enzyme and glycan levels, underscoring the biological impact of bidirectional miRNA regulation. Upregulatory binding sites (miR-200c-5p and miR-361-3p) and the downregulatory binding site (miR-29c-5p) identified in this work both displayed non-canonical binding. Notably, miRNAs upregulating FUT1 are depleted in various cancers, aligning with observations that loss of -1,2-fucosylation is a hallmark of esophageal cancer, melanoma biogenesis, and metastasis. Furthermore, integration of our previous work with the current results indicates that the loss of miR-200c family has a strong correlation with the loss of -1,2-fucosylation during epithelial-to-mesenchymal transition. Together, these results identify miRNAs as key regulators of FUT1 and demonstrate that bidirectional miRNA control of glycosyltransferases can reshape cell-surface glycosylation with important implications for cancer biology.

molecular biology↗

Analyzing the miRNA regulatory landscape of OGT identifies evolutionarily conserved upregulation.

O-GlcNAc transferase (OGT) is the key enzyme involved in post-translationally modifying cytoplasmic and nuclear proteins with O-GlcNAc. Maintenance of cellular O-GlcNAcylation levels is critical to cell health and requires precise transcriptional and post-transcriptional control. Herein we examine the miRNA regulation of OGT by the human miRNAome using our high-throughput miRFluR assay. We found >200 miRNA regulators of OGT, including 17 down- and 15 upregulatory miRNAs previously identified in CLIP datasets. We validated the impact of select miRNA on OGT and O-GlcNAc levels using both miRNA mimics and inhibitors that reduce endogenous miRNA levels. We focused our studies on two miRNA families, the downregulatory let-7 family and the upregulatory miR-148/152 family. For the let-7 family, we found that only let-7a-3p and let-7g-3p strongly downregulated OGT. Downregulation required two seed-dependent binding sites. Evolutionary analysis found that the more recent of the two sites emerged in placental mammals. A similar conservation pattern was observed for the site of regulation by the miR-148/152 family, which was previously identified in CLIP datasets. All three miRNA in this family upregulated OGT. Phylogenetic analysis revealed that this upregulatory site has been conserved for the past 98.7 million years. The emergence of these regulatory sites correlates with that of disease states that both OGT and the miRNA are known to impact. Overall, our results provide important insights into OGT, miRNA regulation and conservation through evolution.

molecular biology↗