In vivo NCL-targeting affects breast cancer aggressiveness through miRNA regulation [Affymetrix]

Numerous studies have described the altered expression and the causal role of miRNAs in human cancer. However, to date efforts to modulate miRNA levels for therapeutic purposes have been challenging to implement. Here, we find that Nucleolin (NCL), a major nucleolar protein, post-transcriptionally regulates the expression of a specific subset of miRNAs, including miR-21, miR-221, miR-222, and miR-103, causally involved in breast cancer initiation, progression and drug-resistance. We also show that NCL is commonly overexpressed in human breast tumors, and its expression correlates with that of NCL-dependent miRNAs. Finally, this study indicates that NCL-binding guanosine-rich aptamers affect the levels of NCL-dependent miRNAs and their target genes, reducing breast cancer cell aggressiveness, both in vitro and in vivo. These findings illuminate a path to novel therapeutic approaches based on NCL-targeting aptamers for the modulation of miRNA expression in the treatment of breast cancer.

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Pichiorri F, Palmieri D, De Luca L, Consiglio J, You J, Rocci A, Talabere T, Piovan C, Lagana A, Cascione L, Guan J, Gasparini P, Balatti V, Nuovo G, Coppola V, Hofmeister CC, Marcucci G, Byrd JC, Volinia S, Shapiro CL, Freitas MA, Croce CM